An update on Lattice QCD and Flavour Physics

In this paper I give a short update on recent advances in Lattice QCD calculations of quantities relevant for flavour physics. The aim is to give an overview of the state of the art of lattice calculations and to point out the main related issues. I summarize the present status of Lattice QCD machinery and then I focus on a couple of selected results, fK/fπ and fD(s) , using them as examples for discussion

Vector and scalar form factors for K- and D-meson semileptonic decays from twisted mass fermions with Nf = 2

We present lattice results for the form factors relevant in the K -> pion and D -> pion semileptonic decays, obtained from simulations with two flavors of dynamical twisted-mass fermions and pion masses as light as 260 MeV. For K -> pion decays we discuss the estimates of the main sources of systematic uncertainties, including the quenching of the strange quark, leading to our final result f+(0) = 0.9560 (57) (62). Combined with the latest experimental data, our value of f+(0) implies for the CKM matrix element |Vus| the value 0.2267 (5) (20) consistent with the first-row CKM unitarity. For D -> pion decays the application of Heavy Meson Chiral Perturbation Theory allows to extrapolate our results for both the scalar and the vector form factors at the physical point with quite good accuracy, obtaining a nice agreement with the experimental data. In particular at zero-momentum transfer we obtain f+(0) = 0.64 (5).Comment: 8 pages, 4 figures, 1 table, proceedings of the XXVII Int'l Symposium on Lattice Field Theory (LAT2009), July 26-31 2009, Peking University, Beijing (China

Two-loop QCD corrections to the MSSM Higgs masses beyond the effective-potential approximation

We compute the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM, including the effect of non-vanishing external momenta in the self-energies. We obtain corrections of O(alpha_t*alpha_s) and O(alpha*alpha_s), i.e., all two-loop corrections that involve the strong gauge coupling when the only non-vanishing Yukawa coupling is the top one. We adopt either the DRbar renormalization scheme or a mixed OS-DRbar scheme where the top/stop parameters are renormalized on-shell. We compare our results with those of earlier calculations, pointing out an inconsistency in a recent result obtained in the mixed OS-DRbar scheme. The numerical impact of the new corrections on the prediction for the lightest-scalar mass is moderate, but already comparable to the accuracy of the Higgs-mass measurement at the LHC.Comment: 22 pages, 5 pdf figures; v2: version to appear in EPJ

Changing mega-events’ spatial strategies and cultural policy: scaling down, spacing out, and assembling organizations in the cases of London and Milan

Despite the proposed ‘certainty’ in a city or region hosting a mega-event, there has long been issues of uncertainty surrounding the planning and implementation of what have until now essentially been mega-projects. Large events have found a variety of ways to adapt and respond to unforeseen circumstances due to political conflicts, planning of oversize venues, limited time of implementation, and legacies that are difficult to manage. Considering the further increased uncertainty surrounding the planning of mega-events as a result of the COVID-19 pandemic, this paper examines how an accompanying cultural component—e.g., the Cultural Olympiad—may help cities that plan for events like the Olympics transition toward diversified drivers and long-term legacy. In particular, the case of cultural offering in Milan between the two mega-events of Expo 2015 and the upcoming 2026 Milano-Cortina Olympic Games shows how host cities can address growing uncertainty through the expanded role of a cultural programme combined with the rescaling of traditional mega-event formats. With this purpose, 2012 London Cultural Olympiad has been selected as an antecedent example—with positive and negative outcomes—to critically review the relationships between the Olympics and the Cultural Olympiad, as well as their widespread spatial strategy and public engagement. In addition, the paper offers more general conclusions regarding learning potentials of jointly studying mega-events and cultural policy

Improved Semileptonic Form Factor Calculations in Lattice QCD

We investigate the computational efficiency of two stochastic based alternatives to the Sequential Propagator Method used in Lattice QCD calculations of heavy-light semileptonic form factors. In the first method, we replace the sequential propagator, which couples the calculation of two of the three propagators required for the calculation, with a stochastic propagator so that the calculations of all three propagators are independent. This method is more flexible than the Sequential Propagator Method but introduces stochastic noise. We study the noise to determine when this method becomes competitive with the Sequential Propagator Method, and find that for any practical calculation it is competitive with or superior to the Sequential Propagator Method. We also examine a second stochastic method, the so-called ``one-end trick", concluding it is relatively inefficient in this context. The investigation is carried out on two gauge field ensembles, using the non-perturbatively improved Wilson-Sheikholeslami-Wohlert action with N_f=2 mass-degenerate sea quarks. The two ensembles have similar lattice spacings but different sea quark masses. We use the first stochastic method to extract ${\mathcal O}(a)$-improved, matched lattice results for the semileptonic form factors on the ensemble with lighter sea quarks, extracting f_+(0)

Giuseppe Mercalli da Monza al Reale Osservatorio vesuviano: una vita tra insegnamento e ricerca. contributi presentati per l’inaugurazione dell’anno mercalliano

A cento anni dalla scomparsa di Giuseppe Mercalli, sismologo e vulcanologo, noto principalmente per aver legato il suo nome a quello della scala per la misura dell’intensità dei terremoti, l’Istituto Nazionale di Geofisica e Vulcanologia (INGV) ha promosso una serie di iniziative volte a rievocare la figura dell’illustre scienziato, in un itinerario lungo un anno che ripercorre i luoghi da lui vissuti da studioso e docente, dichiarando il duemilaquattordici “Anno Mercalliano”

Subsurface structure of the Solfatara volcano (Campi Flegreicaldera, Italy) as deduced from joint seismic-noise array,volcanological and morphostructural analysis

The joint application of different seismological techniques for seismic noise analysis, and the results of a volcanological and morphostructural survey, have allowed us to obtain a detailed and well constrained image of the shallow crustal structure of the Solfatara volcano (Campi Flegrei caldera, Italy). Horizontal-to-vertical spectral ratios, inversion of surface wave dispersion curves and polarization analysis provided resonance frequencies and peak amplitudes, shear wave velocity profiles and polarization pattern of coherent ambient noise. These results, combined in a unique framework, indicate that the volcanic edifice is characterized by lateral and vertical discontinuities and heterogeneities in terms of shear wave velocity, lithological contrasts and structural setting. The interpretation of the seismological results, with the volcanological and morphostructural constraints, supports the hypothesis that the volcano has been characterized by a complex and intense activity, with the alternation of constructive and destructive phases, during which magmatic and phreatomagmatic explosions built a complex tuff-cone, later reworked by atmospheric agents and altered by hydrothermal activity. The differences in the velocity structure between the central and eastern parts of the crater have been interpreted as resulting from a possible eastward migration of the eruptive vent along the deformational features affecting the area, and to the presence of viscous lava and lithified tuff bodies within the feeding conduits, which are buried under a covering of reworked materials of variable thickness. The observed fault and fracture systems, partially inherited from regional structural setting and exhumed during volcanism and ground deformation episodes also seems to strongly control wave propagation, affecting the noise polarization properties

A GIS-Based Hydrogeological Approach to the Assessment of the Groundwater Circulation in the Ischia Volcanic Island (Italy)

Assessing the variations in space and time of groundwater circulation in volcanic islands is of paramount importance to the description of the hydro-geo-thermal system and implementation of hydrogeological, geochemical, and volcanic monitoring systems. In fact, the reliable reconstruction of the groundwater potentiometric surface in such composite volcanic aquifer systems can enable the identification of the most advantageous strategies for both the sustainable use of groundwater resources and the management of volcanic risk. Geographical Information System (GIS) platforms can support the integration and analysis of many spatial and temporal variables derived from monitoring of active volcanoes and the elaboration of spatially continuous data. However, open issues still affect the reliability and general applicability of common spatial interpolation methods in the case of groundwater potentiometric surfaces. This is related to the assessment of the main stratigraphic and volcano-tectonic features affecting the hydraulic head changes. With regard to the dynamically very active Ischia Island (Italy), this study illustrates a GIS-based hydrogeological approach to identify the most accurate interpolation method for mapping the potentiometric surface in complex hydrogeological terrains. The proposed approach has been applied to the existing dataset (1977–2003) stored by Istituto Nazionale di Geofisica e Vulcanologia. Based on a careful geological and hydrogeological survey, a total of 267 wells, from 5 to 250 m in depth, were processed. The data pre-processing involved four meteorological time-series data (1922–1997) and six long records of piezometric water levels (1930–1994). As a result, knowledge of the delineation of rather homogeneous stratigraphic and volcano-tectonic structures at the basin-scale has improved. Thus, new, more reliable potentiometric surfaces of the four main geothermal areas closest to the coast were produced during both dry and wet seasons. The reliability of the processed potentiometric surface was then validated by comparing the spatially continuous data with complementary field data. These findings point toward an optimal interpolation approach for representing the seasonal and areal distribution of main hydrogeological parameters in complex aquifer systems. Finally, insights into variations of hydrological behavior at an active volcanic area will foster an understanding of possible involvement of fresh and thermal waters in triggering phreatic explosions

Thyroid dysfunctions induced by tyrosine kinase inhibitors

INTRODUCTION: Recently, tyrosine kinase inhibitors (TKIs) have emerged as a new class of anticancer therapy. Although generally considered less toxic than cytotoxic chemotherapy, TKIs do cause significant side effects including fatigue and hypertension. In addition, thyroid dysfunction is a well-known adverse effect of TKI. AREAS COVERED: This review provides a comprehensive assessment of TKI-induced thyroid dysfunctions by sunitinib, sorafenib, pazopanib, imatinib, dasatinib, nilotinib, vandetanib, axitinib, motesanib and tivozanib. Furthermore, the potential mechanisms that result in this toxicity, the clinical impact of thyroid dysfunction in these patients and the controversies regarding treatment with thyroid hormone (TH) therapy are evaluated. EXPERT OPINION: Detection of TKI-induced thyroid dysfunction requires routine monitoring of thyroid function and may necessitate treatment. Potential benefits in developing thyroid dysfunction and potential harm in treating it necessitate controlled studies. Finally, if treatment is pursued, appropriate dosing and timing of TH replacement will require prospective clinical evaluation