Vector boson+jets as background to top-quark physics at Tevatron and LHC

I review here the latest measurements related to vector boson production in association with light or heavy flavor jets at the Tevatron and at the LHC. The methods to estimate the W+jets and Z+jets background in top-quark analyses are also presented.Comment: 6 pages, 8 figures, proceedings for the 5th International Workshop on Top Quark Physics (Top2012), Winchester, U

Alternative methods for top-quark mass determination at the Tevatron and LHC

I am summarizing here the determination of the top-quark mass from the CDF and D0 Collaborations at the Tevatron and the ATLAS and CMS Collaborations at the LHC using non-conventional methods. I am concentrating on the extraction of the top-quark mass from the top-antitop cross-section, on the mass measurement using the so-called endpoint method and on the top-quark mass determination from the b-lifetime. Other alternative methods are described in another articleComment: proceedings for the 6th international workshop on top quark physics (Top2013, Durbach, Germany), 10 pages, 7 figure

tt cross section measurements at the Tevatron

We review recent measurements of the tt cross section measurements in proton anti-proton scattering performed by the CDF and DØCollaborations at a center-of-mass energy of √s = 1.96TeV at the Tevatron. The measurements in several top decay channels are described with the corresponding background estimations. Several top quark properties extracted from these measurements are also discussed, namely the top quark mass extraction from cross section measurement, ratios of tt cross sections, the measurement of the tt+jets cross section and some differential cross section measurements

Top Quark Asymmetries

The production of top quark pairs (t$\overline{t}$) via the quark-antiquark initial state is not symmetric under the exchange of top quark and antiquark. Calculations of this next-to-leading order effect predict asymmetries of about one to a few percent, depending on the centre-of-mass energy and the selected phase space. Experimentally, this charge asymmetry of t$\overline{t}$ production manifests itself in differences in angular distributions between top quarks and antiquarks. Sensitive observables are the rapidities of the produced top quarks and antiquarks as well as their energies. In dileptonic t$\overline{t}$ events, the asymmetry of the t$\overline{t}$ system is reflected in a similar asymmetry in the system of the produced lepton pair, with the crucial advantage of a simpler reconstruction procedure. In this article we review the measurements of this effect in different final states and using different observables by the ATLAS and CMS Collaborations in LHC collisions at three different centre-of-mass energies

Resonant sneutrino production at Tevatron Run II

We consider the single chargino production at Tevatron $p \bar p \to \tilde \nu_i \to \tilde \chi^{\pm}_1 l_i^{\mp}$ as induced by the resonant sneutrino production via a dominant \RPV coupling of type \l'_{ijk} L_i Q_j D_k^c. Within a supergravity model, we study the three leptons final state. The comparison with the expected background demonstrate that this signature allows to extend the sensitivity on the \susyq mass spectrum beyond the present LEP limits and to probe the relevant \RPV coupling down to values one order of magnitude smaller than the most stringent low energy indirect bounds. The trilepton signal offers also the opportunity to reconstruct the neutralino mass in a model independent way with good accuracy.Comment: 4 page

Top Quark Physics at the Tevatron

We review the field of top-quark physics with an emphasis on experimental techniques. The role of the top quark in the Standard Model of particle physics is summarized and the basic phenomenology of top-quark production and decay is introduced. We discuss how contributions from physics beyond the Standard Model could affect top-quark properties or event samples. The many measurements made at the Fermilab Tevatron, which test the Standard Model predictions or probe for direct evidence of new physics using the top-quark event samples, are reviewed here.Comment: 50 pages, 17 figures, 2 tables; version accepted by Review of Modern Physic

NaPi-IIa interacting proteins and regulation of renal reabsorption of phosphate

Control of phosphate (Pi) homeostasis is essential for many biologic functions and inappropriate low levels of Pi in plasma have been suggested to associate with several pathological states, including renal stone formation and stone recurrence. Pi homeostasis is achieved mainly by adjusting the renal reabsorption of Pi to the body's requirements. This task is performed to a major extent by the Na/Pi cotransporter NaPi-IIa that is specifically expressed in the brush border membrane of renal proximal tubules. While the presence of tight junctions in epithelial cells prevents the diffusion and mixing of the apical and basolateral components, the location of a protein within a particular membrane subdomain (i.e., the presence of NaPi-IIa at the tip of the apical microvilli) often requires its association with scaffolding elements which directly or indirectly connect the protein with the underlying cellular cytoskeleton. NaPi-IIa interacts with the four members of the Na+/H+ exchanger regulatory factor family as well as with the GABAA-receptor associated protein . Here we will discuss the most relevant findings regarding the role of these proteins on the expression and regulation of the cotransporter, as well as the impact that their absence has in Pi homeostasi