Study of Resistive Micromegas in a Mixed Neutron and Photon Radiation Field

The Muon ATLAS Micromegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and gamma) high radiation field supplied by the Tandem accelerator, at the N.C.S.R. Demokritos in Athens. Monte-Carlo studies have been employed to study the effect of 5.5 MeV neutrons impinging on Micromegas detectors. The response of the Micromegas detectors on the photons originating from the inevitable neutron inelastic scattering on the surrounding materials of the experimental facility was also studied

Evidence for hadronic deconfinement in pˉ\bar{p}-p collisions at 1.8 TeV

We have measured deconfined hadronic volumes, $4.4 < V < 13.0$ fm$^{3}$, produced by a one dimensional (1D) expansion. These volumes are directly proportional to the charged particle pseudorapidity densities $6.75 < dN_{c}/d\eta < 20.2$. The hadronization temperature is $T = 179.5 \pm 5$ (syst) MeV. Using Bjorken's 1D model,the hadronization energy density is $\epsilon_{F} = 1.10 \pm 0.26$ (stat) GeV/fm$^{3}$ corresponding to an excitation of $24.8 \pm 6.2$ (stat) quark-gluon degrees of freedom.Comment: 15 pages, 3 figures, 2 table

Identification of circles from datapoints using Gaussian sums

We present a pattern recognition method which use datapoints on a plane and estimates the parameters of a circle. MC data are generated in order to test the method's efficiency over noise hits, uncertainty in the hits positions and number of datapoints. The scenario were the hits from a quadrant of the circle are missing is also considered. The method proposed is proven to be robust, accurate and very efficient.Comment: 4 pages, 5 figure

Examining the Geometric Mean Method for the Extraction of Spatial Resolution

The spatial resolution of a detector, using a reference detector telecscope, can be measured applying the geometric mean method, with tracks reconstructed from hits of all the detectors, including ($\sigma_\mathrm{in}$) and excluding ($\sigma_\mathrm{ex}$) the hit from the detector under study. The geometric mean of the two measured resolution values ($\sigma=\sqrt{\sigma_\mathrm{ex}\sigma_\mathrm{in}}$), is proposed to provide a more accurate estimate of the intrinsic detector resolution. This method has been tested using a Monte Carlo algorithm and is proven to give accurate results, independently of the distance between the detectors used for the track fitting. The method does not give meaningful results if all the detectors do not carry the same characteristics.Comment: 5 pages, 7 figures, JINST 201

On signals of new physics in global event properties in pp collisions in the TeV energy domain

In the framework of the weighted superposition mechanism of different classes of minimum bias events (or substructures), described by the negative binomial multiplicity distribution, in possible scenarios for pp collisions in the TeV energy domain, we explore global properties of an eventual new class of events, characterised by high hadron and clan densities, to be added to the soft (without minijets) and semihard (with minijets) ones. It turns out that the main signal of the mentioned new physical expectations at 14 TeV c.m. energy would be an ``elbow structure'' in the tail of the total charged particle multiplicity distribution in complete disagreement with the second shoulder structure predicted by Pythia Monte Carlo calculations: a challenging problem for new experimental work.Comment: 14 pages, 6 ps figures include

Co-creating sustainable food futures with botanical gardens and communities: reflections from the BigPicnic project

This article addresses the potential of participatory approaches and processes of co-creation in the context of botanical gardens. It examines how such approaches can not only help cultural heritage sector organisations to engage with different members of their public, but also how they can work with their communities to tackle globally significant societal and environmental goals. Drawing on research conducted for the EU-funded BigPicnic project, this article examines the methodological processes employed by a large consortium of botanical gardens and presents some examples of exhibitions and science cafés that attempted to both highlight issues of food security and sustainability and foster forms of knowledge that go beyond the dichotomy between experts and non-experts. A critical overview of the outcomes of this project serves to outline the potential of co-creation for promoting sustainable food futures

Percolation approach to quark gluon plasma in high energy pp collisions

We apply continuum percolation to proton-proton collisions and look for the possible threshold to phase transition from confined nuclear matter to quark gluon plasma. Making the assumption that J/Psi suppression is a good signal to the transition, we discuss this phenomenon for pp collisions, in the framework of a dual model with strings.Comment: 8 pages, 3 figure