Decoding (Pseudo)-Scalar Operators in Leptonic and Semileptonic BB Decays

We consider leptonic $B^-\to \ell^- \bar\nu_\ell$ and semileptonic $\bar B \to \pi \ell^- \bar\nu_\ell$, $\bar B \to \rho \ell^- \bar\nu_\ell$ decays and present a strategy to determine short-distance coefficients of New-Physics operators and the CKM element $|V_{ub}|$. As the leptonic channels play a central role, we illustrate this method for (pseudo)-scalar operators which may lift the helicity suppression of the corresponding transition amplitudes arising in the Standard Model. Utilising a new result by the Belle collaboration for the branching ratio of $B^-\to \mu^- \bar\nu_\mu$, we explore theoretically clean constraints and correlations between New Physics coefficients for leptonic final states with $\mu$ and $\tau$ leptons. In order to obtain stronger bounds and to extract $|V_{ub}|$, we employ semileptonic $\bar B \to \pi \ell^- \bar\nu_\ell$ and $\bar B \to \rho \ell^- \bar\nu_\ell$ decays as an additional ingredient, involving hadronic form factors which are determined through QCD sum rule and lattice calculations. In addition to a detailed analysis of the constraints on the New Physics contributions following from current data, we make predictions for yet unmeasured decay observables, compare them with experimental constraints and discuss the impact of CP-violating phases of the New-Physics coefficients.Comment: 35 pages, 19 figures, matches published versio

The Present and Future of Four Top Operators

We study the phenomenology of a strongly-interacting top quark at future hadron and lepton colliders, showing that the characteristic four-top contact operators give rise to the most significant effects. We demonstrate the extraordinary potential of a 100 TeV proton-proton collider to directly test such non-standard interactions in four-top production, a process that we thoroughly analyze in the same-sign dilepton and trilepton channels, and explore in the fully hadronic channel. Furthermore, high-energy electron-positron colliders, such as CLIC or the ILC, are shown to exhibit an indirect yet remarkable sensitivity to four-top operators, since these constitute, via renormalization group evolution, the leading new-physics deformations in top-quark pair production. We investigate the impact of our results on the parameter space of composite Higgs models with a strongly-coupled (right-handed) top quark, finding that four-top probes provide the best sensitivity on the compositeness scale at the future energy frontier. In addition, we investigate mild yet persisting LHC excesses in multilepton plus jets final states, showing that they can be consistently described in the effective field theory of such a new-physics scenario.Comment: 27 pages + references, 11 figures, 5 tables. v2: slight modification of title, minor additions to discussion (including HL-LHC projection), references added, results unchanged; version published in JHE

In situ assessment of quality-related compounds in fruits by using fluorescence sensors

Fruit quality compounds, such as antioxidant phenolics and chlorophyll, were assessed in situ by using a fluorescence method applied by a portable sensor. Indices of anthocyanins (ANTH) and flavonols (FLAV) localized on the fruit surface were obtained based on their screening of chlorophyll fluorescence excitation. The chlorophyll content was estimated by the far red to red chlorophyll fluorescence ratio (CHL index), due to the partial reabsorption of red fluorescence by chlorophyll itself. In kiwifruits, the CHL index was found to be well linearly correlated to the chlorophyll content determined by wet chemistry on the same fruit samples. Full sunlight exposed kiwifruits possessed a higher content of chlorophyll than shaded kiwifruits. This is an important parameter to know for assessing fruit quality and storability. Based on the estimation of the red-pigmented anthocyanins, we defined a new rapid method to determine the maturity level of olives after harvest, giving the proportion of red and green olives, important for the quality of the olive oil produced. In plums, ANTH and FLAV were found to be linearly correlated to the actual content of compounds measured by HPLC analysis of skin extracts. These indices can be, therefore, used to predict the phenolic antioxidant potential of plums and to define their maturity stage

Preoperative intensified radiochemotherapy for rectal cancer: experience of a single institution

The aim of our study was to evaluate the feasibility and the effectiveness of an intensified neoadjuvant protocol with the addition of weekly oxaliplatin in the preoperative strategy of rectal cancer treatment. Patients with locally advanced rectal cancer received continous infusion 5-Fluorouracil (5-FU) 200 mg/m(2)/day in combination with weekly oxaliplatin at a dose of 50 mg/m(2). Doses of radiotherapy were 45 Gy to the whole pelvis plus 5.4-9 Gy to the tumour mass. The primary end-points of the study were evaluation of toxicity, compliance with radiotherapy and chemotherapy, downstaging, pathological complete response (pCR) and the rate of sphincter preservation for distal cancers. Secondary end-points were relapse-free and overall survival. From November 2006 to June 2009, 51 patients were enrolled into the study. Compliance with chemotherapy was 80%. The incidence of G3 diarrhoea and proctitis were 17.6% and 21.5%, respectively. Surgery was performed in 48 patients with 100% R0 resection. 76.4% of low-lying tumours underwent conservative treatment. Seventy-nine percent of patients were downstaged: T and N downstaging were observed in 71% and 75% of patients, respectively. A pCR was obtained in 11 (22.9%) patients. Intensification of neoadjuvant treatment for rectal cancer with the addition of weekly oxaliplatin is feasible, with remarkable rates of downstaging and pathological complete response. Data on sphincter preservation for distal cancers were excellent. Phase III trials with a longer follow-up will establish whether this good outcome in terms of surrogate end-points will translate into better rates of disease-free and overall survival

Advances in Multi-Variate Analysis Methods for New Physics Searches at the Large Hadron Collider

International audienceBetween the years 2015 and 2019, members of the Horizon 2020-funded Innovative Training Network named “AMVA4NewPhysics” studied the customization and application of advanced multivariate analysis methods and statistical learning tools to high-energy physics problems, as well as developed entirely new ones. Many of those methods were successfully used to improve the sensitivity of data analyses performed by the ATLAS and CMS experiments at the CERN Large Hadron Collider; several others, still in the testing phase, promise to further improve the precision of measurements of fundamental physics parameters and the reach of searches for new phenomena. In this paper, the most relevant new tools, among those studied and developed, are presented along with the evaluation of their performances