Pionic Hydrogen at PSI

The measurement of the pion-nucleon scattering lengths constitutes a high-precision test of the methods of Chiral Pertubation Theory, which is the low-energy approach of QCD. The pion-nucleon s-wave scattering lengths are related to the strong-interaction shift and width of the s-states of the pionic hydrogen atom. Shift and width are determined from the measured energies and line widths of X-ray transitions to the 1s ground state when compared to the calculated electromagnetic values. A new experiment, set up at the Paul-Scherrer-Institut, has completed a first series of measurements.Comment: 4 pages, 2figures, conference Moriond XXXVIII, 2003(QCD and Hadronic Interactions

Application Protocols enabling Internet of Remote Things via Random Access Satellite Channels

Nowadays, Machine-to-Machine (M2M) and Internet of Things (IoT) traffic rate is increasing at a fast pace. The use of satellites is expected to play a large role in delivering such a traffic. In this work, we investigate the use of two of the most common M2M/IoT protocols stacks on a satellite Random Access (RA) channel, based on DVB-RCS2 standard. The metric under consideration is the completion time, in order to identify the protocol stack that can provide the best performance level

The Archaeological Sites: from excavation to “open-air” museum Cultural uses, preservation, environments

“History” has allowed that ruins from past epochs characterized the contemporary landscape over the following centuries. But when did they begin setting up an “archaeological site” within this environments? This contribute provides, through the analysis of some emblematic cases, an historical reading of the main events that have contributed to the modern concepts of “archaeological park” and “archaeological site”, summarized below, and to the difficult relationship among their surroundings. Starting from 1700 the monuments of antiquity became a "material witness" and not only a model of inspiration: this was the end of the practice of re-using ancient architecture as building materials. Meanwhile, scientific archaeological research replaced the clandestine excavations, providing finds to be exhibited in new museums. The exceptional discovery of Herculaneum and Pompeii gave a new role to the architectural remains: they became materials to be restored, preserved and exhibited, also towards a non-specialist audience, in a kind of “open-air” museum with didactic purposes. Since 1800 archaeological excavations were focused on urban areas, at first in sparsely built-up areas, later in central zones. In Rome with this cultural climate, it began to feel the need of designing a route among ruins and, at the same time, reconnecting the “big central archaeological area” with the historical city. However, during the same years, the practice of “isolating monuments” also began, denying the relationship with the surrounding environment. This practice remains in use during the first half of ‘900: it determined a deep fracture (still unresolved) between the modern town and new and old excavated area. Lately, a new cultural use of the ruins and the protection of them together with their context determined the birth of the legal instrument of the archaeological park, a new concept of protection that allows you to combine all the modern instances of restoration and museology

On the characterisation of a Bragg spectrometer with X-rays from an ECR source

Narrow X-ray lines from helium-like argon emitted from a dedicated ECR source have been used to determine the response function of a Bragg crystal spectrometer equipped with large area spherically bent silicon (111) or quartz (10$\bar{1}$) crystals. The measured spectra are compared with simulated ones created by a ray-tracing code based on the expected theoretical crystal's rocking curve and the geometry of the experimental set-up.Comment: Version acceptee (NIM

Design on Archaeological Sites between Enhancement and Conservation. The Museographic Project of the Acropolis of Mount Filerimos (Rhodes)

The current appearance of the archaeological area of Mount Filerimos, in the island of Rhodes, is the result of design by Rodolfo Petracco, made during the Italian occupation of Dodecanese. The site, formerly the acropolis of the ancient Ialysos, has many stratifications: a pre-hellenic cult is attested since IX cent. B.C., while the remains of architectural structures are dated between the VI cent. B.C. and 1930s, when the re-built church of "Our Lady" was enlarged with the monastery. Purpose of the project illustrated in this paper is to improve the physical and cultural use of the site and facilitate its conservation, through a more appropriate use of the architectural structures. The project, based mainly on historical knowledge and on the critical reading of the archaeological site, includes two different forms of museography. An "open-air" museum, designed to ensure accessibility to different categories of users, allows to visit the main archaeological remains with safety for users protecting the structures. The new access walkway to the church replaces the current and precarious path on the east foundation of the late-classic temple of Athena. Part of the design is the lapidarium set up with Early Christian and Byzantine architectural fragments. It is located close to the structures of the multilayered Church, to emphasize the connection between exposure and environmental context. The typological exhibition promotes understanding by the visitor and, at same time, the conservation of the blocks. A "traditional" archaeological museum is set up with the votive offerings to the ancient deity of the acropolis, which are preserved at the moment in the city of Rhodes. The exhibition is located in the monastic structures, strongly degraded after almost a century of abandonment. The new use of the monastery doesn’t alter its original image, respects the architectural character of the building and preserves, where is possible, its furnishings

Unification of the physics of nucleons and nuclei

I outline an ambitious program which aims to achieve a unified description of nucleon and nuclear properties based on one chiral effective field theory.Comment: 9 pp, 6 figs, plenary talk at 17th International IUPAP Conference on Few-body Problems in Physics, June 5-10, 2003, Durham, North Carolina, US

Determination of pulsation periods and other parameters of 2875 stars classified as MIRA in the All Sky Automated Survey (ASAS)

We have developed an interactive PYTHON code and derived crucial ephemeris data of 99.4% of all stars classified as 'Mira' in the ASAS data base, referring to pulsation periods, mean maximum magnitudes and, whenever possible, the amplitudes among others. We present a statistical comparison between our results and those given by the AAVSO International Variable Star Index (VSX), as well as those determined with the machine learning automatic procedure of Richards et al. 2012. Our periods are in good agreement with those of the VSX in more than 95% of the stars. However, when comparing our periods with those of Richards et al, the coincidence rate is only 76% and most of the remaining cases refer to aliases. We conclude that automatic codes require still more refinements in order to provide reliable period values. Period distributions of the target stars show three local maxima around 215, 275 and 330 d, apparently of universal validity, their relative strength seems to depend on galactic longitude. Our visual amplitude distribution turns out to be bimodal, however 1/3 of the targets have rather small amplitudes (A $<$ 2.5$^{m}$) and could refer to semi-regular variables (SR). We estimate that about 20% of our targets belong to the SR class. We also provide a list of 63 candidates for period variations and a sample of 35 multiperiodic stars which seem to confirm the universal validity of typical sequences in the double period and in the Petersen diagramsComment: 14 pages, 14 figures, and 8 tables. Accepted to The Astrophysical Journal Supplement Series, September 201

Isospin-breaking corrections in the pion-deuteron scattering length

It is shown that isospin-breaking corrections to the pion-deuteron scattering length can be very large, because of the vanishing of the isospin-symmetric contribution to this scattering length at leading order in chiral perturbation theory. We further demonstrate that these corrections can explain the bulk of the discrepancy between the recent experimental data on pionic hydrogen and pionic deuterium. We also give the first determination of the electromagnetic low-energy constant f1.Comment: 4 pages, 1 postscript figure, uses REVTEX styl

Characterization of a CCD array for Bragg spectroscopy

The average pixel distance as well as the relative orientation of an array of 6 CCD detectors have been measured with accuracies of about 0.5 nm and 50 $\mu$rad, respectively. Such a precision satisfies the needs of modern crystal spectroscopy experiments in the field of exotic atoms and highly charged ions. Two different measurements have been performed by illuminating masks in front of the detector array by remote sources of radiation. In one case, an aluminum mask was irradiated with X-rays and in a second attempt, a nanometric quartz wafer was illuminated by a light bulb. Both methods gave consistent results with a smaller error for the optical method. In addition, the thermal expansion of the CCD detectors was characterized between -105 C and -40 C.Comment: Submitted to Review of Scientific Instrument