On some notions of good reduction for endomorphisms of the projective line

Let $\Phi$ be an endomorphism of \SR(\bar{\Q}), the projective line over the algebraic closure of \Q, of degree $\geq2$ defined over a number field $K$. Let $v$ be a non-archimedean valuation of $K$. We say that $\Phi$ has critically good reduction at $v$ if any pair of distinct ramification points of $\Phi$ do not collide under reduction modulo $v$ and the same holds for any pair of branch points. We say that $\Phi$ has simple good reduction at $v$ if the map $\Phi_v$, the reduction of $\Phi$ modulo $v$, has the same degree of $\Phi$. We prove that if $\Phi$ has critically good reduction at $v$ and the reduction map $\Phi_v$ is separable, then $\Phi$ has simple good reduction at $v$.Comment: 15 page

Insights on the paleoepidemiology of ancient tuberculosis from the structural analysis of postcranial remains from the Ligurian Neolithic (northwestern Italy)

The aim of this research is to gain insights on the progression timeline of osteoarticular tuberculosis (TB) in people from the Neolithic period by using skeletal traits that are independent of the bony lesions. The body proportions and postcranial mechanical strength of bones from two individuals from Liguria in northwestern Italy (Arene Candide 5, adolescent, and Arma dell’Aquila 1, adult), were compared with the rest ofthe Ligurian Neolithic skeletal series (45 individuals). If TB led to wasting ofthe skeleton and lack of normal function that endured for years, as often happens today, a clear signature of postcranial gracility and disruption of development should be apparent. Conversely, rapid progress of the disease would leave little systemic macroscopic change in the skeleton, except for the bony lesions directly caused by the TB pathogen, suggesting a different level of bacterial virulence in the past. The extreme biomechanical gracility observed in the lower limb of Arene Candide 5 suggests a period of compromised diaphyseal periosteal apposition during ontogeny due to metabolic disturbances likely linked to TB. Results suggest that, in Neolithic Liguria, TB in humans saw a slow, chronic progression, which is characteristic of diseases with long histories of host-pathogen co-evolution

Capitate-trapezoid synostosis: analysis of an Early Bronze Age case and review of the literature

Background: Carpal synostoses are congenital defects characterised by complete or incomplete coalition of two or more carpal bones. Although most of these defects are discovered only incidentally, sometimes they become clinically manifest. Among the different types of carpal coalition, the synostosis between capitate and trapezoid bones is quite rare, with only sparse data available in the literature. The aim of this report was to describe a case of capitate-trapezoid synostosis (CTS) observed in an ancient human skeleton, as well as to scrutinise the pertinent literature in order to assess for the characteristics of this type of defect, including its potential relevance to clinical practice. Materials and methods: We studied the skeletal remains of an Early Bronze Age male warrior affected by incomplete CTS. Macroscopic and radiological examination of the defect was carried out. We also performed a comprehensive PubMed search in the Medline and other specialty literature databases to retrieve and analyse data relevant to the subject under consideration. Results and Conclusions: The present case is the most ancient CTS ever found. In those literature-reported cases accompanied by careful anatomical description, such as the present one, incomplete coalition invariably occurs between the dorsal surfaces of the two bones, this characteristic emerging as a distinctive morphological trait. Literature analysis further suggests that the true prevalence of CTS is likely to be higher than estimates based on data gathered from radiology series, and that this defect may be associated with pain and carpal bossing more frequently than generally though

VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photosensor's range of sensitivity is a key feature in detectors for Dark Matter search and neutrino physics based on liquid argon scintillation detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor optical window is the most common solution in current and planned experiments. Detector design and response can be evaluated and correctly simulated only when the properties of the optical system in use (TPB film + substrate) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission

Neutron to Gamma Pulse Shape Discrimination in Liquid Argon Detectors with High Quantum Effciency Photomultiplier Tubes

Abstract A high Light Yield Liquid Argon chamber has been radiated with an Am/Be source for signal-to-background separation level characterization in a Dark Matter Liquid Argon based detector. Apart from the standard nuclear recoil and electron events, from neutron elastic interactions and gamma conversions respectively, an intermediate population has been observed which is attributed to inelastic neutron scatters on Argon nuclei producing Argon recoil and simultaneous gammas from nuclear de-excitation. Taking account of these events results in a better determination of the recoil-like to electron-like separation based on the shape of the scintillation pulse. The results of this recent study as well as from a previous study with a chamber with a lower Light Yield are presented

A versatile cryogenic system for liquid argon detectors

Detectors for direct dark matter search using noble gases in liquid phase as detection medium need to be coupled to liquefaction, purification and recirculation systems. A dedicated cryogenic system has been assembled and operated at the INFN-Naples cryogenic laboratory with the aim to liquefy and purify the argon used as active target in liquid argon detectors to study the scintillation and ionization signals detected by large SiPMs arrays. The cryogenic system is mainly composed of a double wall cryostat hosting the detector, a purification stage to reduce the impurities below one part per billion level, a condenser to liquefy the argon, a recirculation gas panel connected to the cryostat equipped with a custom gas pump. The main features of the cryogenic system are reported as well as the performances, long term operations and stability in terms of the most relevant thermodynamic parameters.Comment: Prepared for submission to JINST - LIDINE2022 September 21-23, 2022 - University of Warsaw Librar

First Tests of a New Fast Waveform Digitizer for PMT Signal Read-out from Liquid Argon Dark Matter Detectors

Abstract A new generation Waveform Digitizer board as been recently made available on the market by CAEN. The new board CAEN V1751 with 8 Channels per board, 10 bit, 1 GS/s Flash ADC Waveform Digitizer (or 4 channel, 10 bit, 2 GS/s Flash ADC Waveform Digitizer -Dual Edge Sampling mode) with threshold and Auto-Trigger capabilities provides an ideal (relatively low-cost) solution for reading signals from liquid Argon detectors for Dark Matter search equipped with an array of PMTs for the detection of scintillation light. The board was extensively used in real experimental conditions to test its usefulness for possible future uses and to compare it with a state of the art digital oscilloscope. As results, PMT Signal sampling at 1 or 2 GS/s is appropriate for the reconstruction of the fast component of the signal scintillation in Argon (characteristic time of about 4 ns) and the extended dynamic range, after a small customization, allows for the detection of signals in the range of energy needed. The bandwidth is found to be adequate and the intrinsic noise is very low

Solar neutrino detection in a large volume double-phase liquid argon experiment

Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the "neutrino floor" (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.Comment: 21 pages, 7 figures, 6 table

Demonstration and Comparison of Operation of Photomultiplier Tubes at Liquid Argon Temperature

Liquified noble gases are widely used as a target in direct Dark Matter searches. Signals from scintillation in the liquid, following energy deposition from the recoil nuclei scattered by Dark Matter particles (e.g. WIMPs), should be recorded down to very low energies by photosensors suitably designed to operate at cryogenic temperatures. Liquid Argon based detectors for Dark Matter searches currently implement photo multiplier tubes for signal read-out. In the last few years PMTs with photocathodes operating down to liquid Argon temperatures (87 K) have been specially developed with increasing Quantum Efficiency characteristics. The most recent of these, Hamamatsu Photonics Mod. R11065 with peak QE up to about 35%, has been extensively tested within the R&D program of the WArP Collaboration. During these testes the Hamamatsu PMTs showed superb performance and allowed obtaining a light yield around 7 phel/keVee in a Liquid Argon detector with a photocathodic coverage in the 12% range, sufficient for detection of events down to few keVee of energy deposition. This shows that this new type of PMT is suited for experimental applications, in particular for new direct Dark Matter searches with LAr-based experiments

Precise 3D track reconstruction algorithm for the ICARUS T600 liquid argon time projection chamber detector

Liquid Argon Time Projection Chamber (LAr TPC) detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach of three-dimensional reconstruction for the LAr TPC with a practical application to track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of real data tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.Comment: Submitted to Advances in High Energy Physic