First Tests of Gaseous Detectors Made of a Resistive Mesh

We describe here various detectors designs: GEM type, MICROMEGAStype, PPACtype as well as cascaded detectors made of a resistive mesh manufactured from a resistive Kapton foil, (20 microns thick, resistivity a few MOhm per square) by a laser drilling technique. As in any other micropattern detectors the maximum achievable gas gain of these detectors is restricted by the Raether limit, however, the resistive mesh makes them and the front end electronics fully spark protected. This approach could be an alternative or complimentary to the ongoing efforts in developing MICROMEGAS and GEMs with resistive anode readout plates and can be especially beneficial in the case of micropattern detectors combined with a micropixel-type integrated front end electronic

An improved design of spark-protected microstrip gas counters (R-MSGC)

We have developed microstrip gas counters manufactured on standard printed circuit board and having the following features: resistive cathode strips, thin (10 micron) metallic anode strips and electrodes protected against surface discharges by a Coverlay layer at their edges. These features allow the detector to operate at gas gains as high as can be achieve with the best microstrip gas counters manufactured on glass substrates. We believe that after further developments this type of detectors can compete in some applications with other micropattern detectors, for example MICROMEGAS.Comment: Presented at the 7th RD51 Collaboration meeting, CERN, April 201

Nuclear shadowing in deep inelastic scattering on nuclei: a closer look

The measurement of the nuclear structure function $F_2^A (x,Q^2)$ at the future electron-ion collider (EIC) will be of great relevance to understand the origin of the nuclear shadowing and to probe gluon saturation effects. Currently there are several phenomenological models, based on very distinct approaches, which describe the scarce experimental data quite successfully. One of main uncertainties comes from the schemes used to include the effects associated to the multiple scatterings and to unitarize the cross section. In this paper we compare the predictions of three different unitarization schemes of the nuclear structure function which use the same theoretical input to describe the projectile-nucleon interaction. In particular, we consider as input the predictions of the Color Glass Condensate formalism, which reproduce the inclusive and diffractive $ep$ HERA data. Our results suggest that the experimental analysis of $F_2^A$ will be able to discriminate between the unitarization schemes.Comment: 16 pages, 4 figure

Running Gluon Mass from Landau Gauge Lattice QCD Propagator

The interpretation of the Landau gauge lattice gluon propagator as a massive type bosonic propagator is investigated. Three different scenarios are discussed: i) an infrared constant gluon mass; ii) an ultraviolet constant gluon mass; iii) a momentum dependent mass. We find that the infrared data can be associated with a massive propagator up to momenta $\sim 500$ MeV, with a constant gluon mass of 723(11) MeV, if one excludes the zero momentum gluon propagator from the analysis, or 648(7) MeV, if the zero momentum gluon propagator is included in the data sets. The ultraviolet lattice data is not compatible with a massive type propagator with a constant mass. The scenario of a momentum dependent gluon mass gives a decreasing mass with the momentum, which vanishes in the deep ultraviolet region. Furthermore, we show that the functional forms used to describe the decoupling like solution of the Dyson-Schwinger equations are compatible with the lattice data with similar mass scales.Comment: Version to appear in J. Phys. G. New version include some rewriting and new analysis. In particular, the section on the running mass is ne

Demonstration of new possibilities of multilayer technology on resistive microstrip/ microdot detectors

The first successful attempts to optimize the electric field in Resistive Microstrip Gas Chamber and resistive microdot detectors using additional field shaping strips located inside the detector substrate are describedComment: Presented at the RD-51 mmini week, CERN, June 201

The use of genes for performance enhancement: doping or therapy?

Recent biotechnological advances have permitted the manipulation of genetic sequences to treat several diseases in a process called gene therapy. However, the advance of gene therapy has opened the door to the possibility of using genetic manipulation (GM) to enhance athletic performance. In such ‘gene doping’, exogenous genetic sequences are inserted into a specific tissue, altering cellular gene activity or leading to the expression of a protein product. The exogenous genes most likely to be utilized for gene doping include erythropoietin (EPO), vascular endothelial growth factor (VEGF), insulin-like growth factor type 1 (IGF-1), myostatin antagonists, and endorphin. However, many other genes could also be used, such as those involved in glucose metabolic pathways. Because gene doping would be very difficult to detect, it is inherently very attractive for those involved in sports who are prepared to cheat. Moreover, the field of gene therapy is constantly and rapidly progressing, and this is likely to generate many new possibilities for gene doping. Thus, as part of the general fight against all forms of doping, it will be necessary to develop and continually improve means of detecting exogenous gene sequences (or their products) in athletes. Nevertheless, some bioethicists have argued for a liberal approach to gene doping

Controle de plantas daninhas em pomares de cajueiro.

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