Construction and commissioning of the SuperNEMO detector tracker

The SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory; the detector design allows complete topological reconstruction of the decay event enabling excellent levels of background rejection and, in the event of a discovery, the ability to determine the nature of the lepton number violating process.In order to demonstrate the feasibility of the full experiment, we are building a Demonstrator Module containing 7kg of 82Se, with an expected sensitivity of |mββ|<0.2-0.4eV after 2.5yr.The demonstrator tracker is currently being assembled in the UK; the main challenge in the tracker design is the high radiopurity required to limit the background. For this reason the cell wiring is automated and every step of the tracker assembly happens in a clean environment. All components are carefully screened for radiopurity and each section of the tracker, once assembled, is sealed and checked for Radon emanation.We present the detector design, the current status of the construction and present the first results from the surface commissioning of one section of the Demonstrator Module tracker

Updates on the most recent results in dual readout calorimetry

The Dual REAdout Method (DREAM) consists in comparing the scintillation and Cherenkov light generated in the shower development process. By comparing the two, the electromagnetic fraction of the hadronic shower can be measured event-by-event, to eliminate the effects of fluctuations in this fraction. In this paper the DREAM fiber calorimeter and its successor, the newDREAM prototype that is currently under construction, will be described. We will also report on the efforts to study the Cherenkov component of the output of high-Z crystals and to realize a dual-readout electromagnetic section that can achieve outstanding electromagnetic resolution whitout compromising the hadronic resolution

Jet energy scale calibration using photon-jet events in the ATLAS experiment

A precise calibration of the jet energy in the ATLAS experiment at LHC is fundamental for many physics issues. Di-jet and multi jet events will be used to cross-check the relative response across different pseudo-rapidity and transverse momentum regions. The photon+jet channel (being the one with largest cross section) is the first candidate to check in situ the jet absolute energy scale. In events with photon and a recoiling jet, the transverse momentum balance can be exploited to estimate the jet energy using the measurement on the photon, whose scale is much better under control. The main background to this channel is given by QCD events where one jet is misidentified as a photon. The status of this analysis with the data collected by ATLAS in 2010 will be presented

Fiber and crystals dual readout calorimeters

The RD52 (DREAM) collaboration is performing R&D on dual readout calorimetry techniques with the aim of improving hadronic energy resolution for future high energy physics experiments. The simultaneous detection of Cherenkov and scintillation light enables us to measure the electromagnetic fraction of hadron shower event-by-event. As a result, we could eliminate the main fluctuation which prevented from achieving precision energy measurement for hadrons. We have tested the performance of the lead and copper fiber prototypes calorimeters with various energies of electromagnetic particles and hadrons. During the beam test, we investigated the energy resolutions for electrons and pions as well as the identification of those particles in a longitudinally unsegmented calorimeter. Measurements were also performed on pure and doped PbWO4 crystals, as well as BGO and BSO, with the aim of realizing a crystal based dual readout detector. We will describe our results, focusing on the more promising properties of homogeneous media for the technique. Guidelines for additional developments on crystals will be also given. Finally we discuss the construction techniques that we have used to assemble our prototypes and give an overview of the ones that could be industrialized for the construction of a full hermetic calorimeter

Construction and commissioning of the tracker module for the SuperNEMO experiment

The SuperNEMO experiment will search for neutrinoless double-beta decay in the Modane Underground Laboratory. This decay mode, if observed, confirms that neutrinos are Majorana fermions. It would be a new lepton violating process, and would provide a measurement of the absolute neutrino mass. The SuperNEMO experiment is designed to reach a half-life sensitivity of 1026 years corresponding to an effective Majorana neutrino mass of 50−100 meV. The SuperNEMO demonstrator module is the first stage of the experiment, containing 7kg of 82Se, with an expected sensitivity of T½ (0ν) > 6.5×1024 y after 2.5 years. Full topological event reconstruction is achieved through the use of a wire tracker operating in Geiger mode combined with scintillator calorimeter modules. Construction of the demonstrator module is well underway. We present the design of the tracker, and the current status of the construction and commissioning efforts

Exploring Biosignals for Quantitative Pain Assessment in Cancer Patients: A Proof of Concept

Perception and expression of pain in cancer patients are influenced by distress levels, tumor type and progression, and the underlying pathophysiology of pain. Relying on traditional pain assessment tools can present limitations due to the highly subjective and multifaceted nature of the symptoms. In this scenario, objective pain assessment is an open research challenge. This work introduces a framework for automatic pain assessment. The proposed method is based on a wearable biosignal platform to extract quantitative indicators of the patient pain experience, evaluated through a self-assessment report. Two preliminary case studies focused on the simultaneous acquisition of electrocardiography (ECG), electrodermal activity (EDA), and accelerometer signals are illustrated and discussed. The results demonstrate the feasibility of the approach, highlighting the potential of EDA in capturing skin conductance responses (SCR) related to pain events in chronic cancer pain. A weak correlation (R = 0.2) is found between SCR parameters and the standard deviation of the interbeat interval series (SDRR), selected as the Heart Rate Variability index. A statistically significant (p < 0.001) increase in both EDA signal and SDRR is detected in movement with respect to rest conditions (assessed by means of the accelerometer signals) in the case of motion-associated cancer pain, thus reflecting the relationship between motor dynamics, which trigger painful responses, and the subsequent activation of the autonomous nervous system. With the objective of integrating parameters obtained from biosignals to establish pain signatures within different clinical scenarios, the proposed framework proves to be a promising research approach to define pain signatures in different clinical contexts

Can Polarity-Inverted Surfactants Self-Assemble in Nonpolar Solvents

We investigate the self-assembly process of a surfactant with inverted polarity in water and cyclohexane using both all-atom and coarse grained hybrid particle-field molecular dynamics simulations. Unlike conventional surfactants, the molecule under study, proposed in a recent experiment, is formed by a rigid and compact hydrophobic adamantane moiety, and a long and floppy triethylene glycol tail. In water, we report the formation of stable inverted micelles with the adamantane heads grouping together into a hydrophobic core, and the tails forming hydrogen bonds with water. By contrast, microsecond simulations do not provide evidence of stable micelle formation in cyclohexane. Validating the computational results by comparison with experimental diffusion constant and small-angle X-ray scattering intensity, we show that at laboratory thermodynamic conditions the mixture resides in the supercritical region of the phase diagram, where aggregated and free surfactant states co-exist in solution. Our simulations also provide indications about how to escape this region, to produce thermodynamically stable micellar aggregates.Comment: 14 pages, 10 Figures, accepted for publication (2020