Search results for "Pion"

Measurement of the partial cross sectionsσTT,σLT, and(σT+ɛσL)of the1H(e,e′π+)nreaction in theΔ(1232)resonance

2011

We report precision {sup 1}H(e, e{sup '{pi}+})n measurements in the {Delta}(1232) resonance at Q{sup 2}=0.127(GeV/c){sup 2} obtained at the MIT-Bates out-of-plane scattering facility. These are the lowest, but nonzero, Q{sup 2} measurements in the {pi}{sup +} channel. The data offer tests of the theoretical calculations, particularly of the background amplitude contributions. The chiral effective field theory and Sato-Lee model calculations are not in agreement with this experiment.

Unified Description of Pion Nuclear Reactions and Related Problems

2013

Forward-AngleH3e(e,e′π±)Coincident Electroproduction and the Search forΔ's in the Ground State ofH3e

1996

Forward-angle coincident electroproduction cross sections of charged pions from ${}^{3}\mathrm{He}$ have been measured at electron energies ${E}_{0}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}855$, 675, 600, and 555 MeV. The overall features of the data for energy transfers of $\ensuremath{\omega}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}370$ to 430 MeV with pions detected along the momentum transfer axis are reproduced in terms of a microscopic model, including pole terms, final state rescattering and produced and preformed $\ensuremath{\Delta}$ resonances. Separation of the cross section into its longitudinal and transverse parts was performed at ${Q}^{2}\phantom{\rule{0ex…

Measurement of the p(γ,π^{0}) cross section at threshold

1990

Differential and absolute cross sections for the reaction {ital p}({gamma},{pi}{sup 0}) have been measured with energy-defined photons in the threshold region ({ital E}{sub {gamma}}=131.4--157.2 MeV). The {ital E}{sub 0+} amplitude has been extracted out of the data. The values found are in disagreement with predictions of low-energy theorems.

Pion induced pion production on deuterium: A Quasifree process

1992

Abstract A detailed experimental analysis of the π+d → π+π−pp in-plane coincidence data first presented by Rui et al. is compared to an expanded version of the Oset and Vicente-Vacas model for pion-induced pion production on a free nucleon. This extended model averages over Fermi motion to describe the assumed quasifree nature of the process occurring on the deuteron and includes nine additional diagrams to account for the N ∗ → N (ππ) p-wave reaction channels. Experimental effects such as pion energy loss in the target and in the detectors, pion decay and muon detection are investigated and incorporated into the comparison of experimental data and theory. Inclusion of Fermi motion was foun…

The Pion Single-Event Effect Resonance and its Impact in an Accelerator Environment

2020

International audience; The pion resonance in the nuclear reaction cross section is seen to have a direct impact on the single-event effect (SEE) cross section of modern electronic devices. This was experimentally observed for single-event upsets and single-event latchup. Rectangular parallelepiped (RPP) models built to fit proton data confirm the existence of the pion SEE cross-section resonance. The impact on current radiation hardness assurance (RHA) soft error rate (SER) predictions is, however, minimal for the accelerator environment since this is dominated by high neutron fluxes. The resonance is not seen to have a major impact on the high-energy hadron equivalence approximation estab…

Graduate of Riga Polytechnic Institute, Athletics Statistician Andris Staģis

2020

The article summarizes the achievements of Andris Staģis, a graduate of the Faculty of Civil Engineering of Riga Polytechnic Institute (RPI; 1968), in the profession of an engineer, as well as reveals his contribution to the history and statistics of Latvian sports, achievements in athletics and their promotion. This is the first study on the activities and life of engineer, officer of the Order of the Three Stars, Latvian champion in athletics and the author of sports history books, and journalist A. Staģis. The aim of the research is to reveal the contribution of A. Staģis and the significance of his personality to Latvia using his and the authors’ personal archives, documents of the Stat…

Neonatal representation of odour objects: distinct memories of the whole and its parts

2014

Extraction of relevant information from highly complex environments is a prerequisite to survival. Within odour mixtures, such information is contained in the odours of specific elements or in the mixture configuration perceived as a whole unique odour. For instance, an AB mixture of the element A (ethyl isobutyrate) and the element B (ethyl maltol) generates a configural AB percept in humans and apparently in another species, the rabbit. Here, we examined whether the memory of such a configuration is distinct from the memory of the individual odorants. Taking advantage of the newborn rabbit's ability to learn odour mixtures, we combined behavioural and pharmacological tools to specifically…

Expansion cone for the 3-inch PMTs of the KM3NeT optical modules

2013

[EN] Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average…

STRATEGIE DI DIREZIONAMENTO ALL’EPATOCARCINOMA DI FARMACI ANTITUMORALI MEDIANTE SISTEMI NANOPARTICELLARI E DI VISUALIZZAZIONE IN CELLULE TUMORALI DEL…

Lo scopo di questo lavoro di tesi è stato quello di realizzare nuovi sistemi nanoparticellari per il direzionamento di farmaci o di agenti per l’imaging, potenzialmente utilizzabili per la terapia e/o per la diagnosi dell’epatocarcinoma (HCC), in particolare per quelle forme caratterizzate dall’overespressione del recettore di membrana degli epatociti ASGP-R o del recettore mitocondriale TSPO. In particolare, nel capitolo 2 sono state descritte la sintesi, la caratterizzazione chimico fisica, la capacità di internalizzazione cellulare e l’efficacia antitumorale di un nuovo sistema nanoparticellare, costituito da un dendrimero a struttura poli-amido-aminica (PAMAM) di quarta generazione, opp…