Theoretical view on Heavy Flavour schemes

Processes involving heavy quarks are crucial at the LHC, for flavour physics and Higgs physics and as backgrounds for new physics searches. In this brief contribution, I outline the main theoretical challenges involved in the theoretical description of this kind of processes, both at the inclusive and exclusive levels, and highlight a few examples that testify the enormous progress that has been made in the field over the past five years.M.U. is supported by the European Research Council under the European Union’s Horizon 2020 research and innovation Programme (grant agreement n.950246)

Constraining the gluon PDF at large x with LHC data

The NNPDF collaboration has recently presented NNPDF3.1, a new determination of the parton distribution functions (PDFs) of the proton including a number of new data, some of which are particularly sensitive to the gluon PDF at large x. In this contribution, we present the results of two new analyses based on NNPDF3.1. First, we study the impact of the ATLAS 2011 7 TeV inclusive jet data on the gluon PDF including different rapidity bins. Second, we quantitatively compare the constraints provided by all measurements sensitive to the large-x gluon PDF, namely inclusive jet cross sections, the transverse momentum distributions of the Z-boson and top-pair rapidity distributions

Spectrophotometric assessment of nuclear proteins: a preliminary study

Qualitative evaluation of protein content in formalin fixed, paraffin-embedded tissues is usually performed by means of cytofluorimetric analysis. On the other hand, several studies underline the opportunity to measure the concentration of nuclear proteins, which is often accomplished by using complex techniques and instrumentation. In the present work, we suggest a new application for the spectrophotometric evaluation of protein content on extracted and isolated nuclei, based on EDTA treatment of specimens and chemical extraction of proteins, followed by direct spectrophotometric measurement at UV wavelengths. We also demonstrate how this parameter correlates with other diagnostic factors, such as the proliferation index (MIB-1) and the DNA content (ploidy) of cells. This method is simple and effective, yet less expensive than other protein quantitation protocols

Radiative distortion of kinematic edges in cascade decays

Kinematic edges of cascade decays of new particles produced in high-energy collisions may provide important constraints on the involved particles' masses. For the exemplary case of gluino decay g˜→qq¯χ˜ into a pair of quarks and a neutralino through a squark resonance, we study the hadronic invariant mass distribution in the vicinity of the kinematic edge. We perform a next-to-leading order calculation in the strong coupling αs and the ratio of squark width and squark mass Γq˜/mq˜, based on a systematic expansion in Γq˜/mq˜. The separation into hard, collinear and soft contributions elucidates the process-dependent and universal features of distributions in the edge region, represented by on-shell decay matrix elements, universal jet functions and a soft function that depends on the resonance propagator and soft Wilson lines.The work of M.B. has been supported in part by the Bundesministerium für Bildung und Forschung (BMBF) under project no. 05H15W0CAA. L.J. was partially supported by the DFG contract STU 615/1-1, and M.U. is partially supported by the STFC grant ST/L000385/1 and her research is funded by a Royal Society Dorothy Hodgkin Research Fellowship

Precise predictions for charged Higgs boson production

We review some of the major progress in the accurate calculation of the cross section for the production of a charged Higgs boson in a generic two-Higgs double model, by focussing on the high-mass region, for which new calculations have been made available in the past few years, both at the level of total and of differential cross sections. Furthermore, we illustrate some recent progress in the calculation of the total cross section for a charged Higgs boson with mass in the intermediate range m_{H^\pm} \sim m_{t}, including top-resonant contributions

The impact of the LHC Z-boson transverse momentum data on PDF determinations

The LHC has recently released precise measurements of the transverse momentum distribution of the Z-boson that provide a unique constraint on the structure of the proton. Theoretical developments now allow the prediction of these observables through next-to-next-to-leading order (NNLO) in perturbative QCD. In this work we study the impact of incorporating these latest advances into a determination of parton distribution functions (PDFs) through NNLO including the recent ATLAS and CMS 7 TeV and 8 TeV pTZ data. We investigate the consistency of these measurements in a global fit to the available data and quantify the impact of including the pTZ distributions on the PDFs. The inclusion of these new data sets significantly reduces the uncertainties on select parton distributions and the corresponding parton-parton luminosities. In particular, we find that the pTZ data ultimately leads to a reduction of the PDF uncertainty on the gluon-fusion and vector-boson fusion Higgs production cross sections by about 30%, while keeping the central values nearly unchanged.This research was supported in part by the National Science Foundation under Grant No. NSF PHY11-25915 to the Kavli Institute of Theoretical Physics in Santa Barbara. R. B. is supported by the DOE contract DE-AC02-06CH11357. F. P. is supported by the DOE grants DE-FG02- 91ER40684 and DE-AC02-06CH11357. M. U. is supported by a Royal Society Dorothy Hodgkin Research Fellowship and partially supported by the STFC grant ST/L000385/1. A. G. is supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sk lodowska-Curie grant agreement No 659128 - NEXTGENPDF. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357

A multi-enzymatic cascade reaction for the synthesis of vidarabine 5'-monophosphate

We here described a three-step multi-enzymatic reaction for the one-pot synthesis of vidarabine 5'-monophosphate (araA-MP), an antiviral drug, using arabinosyluracil (araU), adenine (Ade), and adenosine triphosphate (ATP) as precursors. To this aim, three enzymes involved in the biosynthesis of nucleosides and nucleotides were used in a cascade mode after immobilization: uridine phosphorylase from Clostridium perfringens (CpUP), a purine nucleoside phosphorylase from Aeromonas hydrophila (AhPNP), and deoxyadenosine kinase from Dictyostelium discoideum (DddAK). Specifically, CpUP catalyzes the phosphorolysis of araU thus generating uracil and α-d-arabinose-1-phosphate. AhPNP catalyzes the coupling between this latter compound and Ade to form araA (vidarabine). This nucleoside becomes the substrate of DddAK, which produces the 5'-mononucleotide counterpart (araA-MP) using ATP as the phosphate donor. Reaction conditions (i.e., medium, temperature, immobilization carriers) and biocatalyst stability have been balanced to achieve the highest conversion of vidarabine 5'-monophosphate (≥95.5%). The combination of the nucleoside phosphorylases twosome with deoxyadenosine kinase in a one-pot cascade allowed (i) a complete shift in the equilibrium-controlled synthesis of the nucleoside towards the product formation; and (ii) to overcome the solubility constraints of araA in aqueous medium, thus providing a new route to the highly productive synthesis of araA-MP

The strangest proton?

We present an improved determination of the strange quark and antiquark parton distribution functions of the proton by means of a global QCD analysis that takes into account a comprehensive set of strangeness-sensitive measurements: charm-tagged cross sections for fixed-target neutrino–nucleus deep-inelastic scattering, and cross sections for inclusive gauge-boson production and W-boson production in association with light jets or charm quarks at hadron colliders. Our analysis is accurate to next-to-next-to-leading order in perturbative QCD where available, and specifically includes charm-quark mass corrections to neutrino–nucleus structure functions. We find that a good overall description of the input dataset can be achieved and that a strangeness moderately suppressed in comparison to the rest of the light sea quarks is strongly favored by the global analysis

The impact of heavy quark mass effects in the NNPDF global analysis

We discuss the implementation of the FONLL general-mass scheme for heavy quarks in deep-inelastic scattering in the FastKernel framework, used in the NNPDF series of global PDF analysis. We present the general features of FONLL and benchmark the accuracy of its implementation in FastKernel comparing with the Les Houches heavy quark benchmark tables. We then show preliminary results of the NNPDF2.1 analysis, in which heavy quark mass effects are included following the FONLL-A GM scheme.Comment: 5 pages, 3 figures; to appear in the proceedings of DIS 2010, Firenz

Recent progress on NNPDF for LHC

We present recent results of the NNPDF collaboration on a full DIS analysis of Parton Distribution Functions (PDFs). Our method is based on the idea of combining a Monte Carlo sampling of the probability measure in the space of PDFs with the use of neural networks as unbiased universal interpolating functions. The general structure of the project and the features of the fit are described and compared to those of the traditional approaches.Comment: 4 pages, 6 figures, contribution for the proceedings of the conference "Rencontres de Moriond, QCD and High Energy Interactions