HAL Mines Nantes
Not a member yet
7271 research outputs found
Sort by
Report from the Workshop on Xenon Detector Searches: Steps Towards the Kilotonne Scale
No full textInternational audienceThese proceedings summarize the program and discussions of the ``Workshop on Xenon Detector Searches: Steps Towards the Kilotonne Scale'' held on October 25-27 2023 at SLAC National Accelerator Laboratory. This workshop brought together experts from the communities of neutrinoless double-beta decay and dark matter detection, to discuss paths forward for the realization of monolithic experiments with xenon approaching the kilotonne scale
DIFFUSION COEFFICIENT OF RADIONUCLIDES IN CEMENT-BASED MATERIALS: INVESTIGATING THE EFFECT OF THE CHARGED SURFACES
No full textInternational audienceThis work aims to provide new insights into the effect of charged surfaces in cement-based materials through a significant sum of diffusion and electro-diffusion experiments on various radionuclides acquired in the framework of EURAD/CORI and different Andra projects. All the measurements have been analysed with the reactive transfer model PhreeqC setting apart the diffusion and retention mechanisms. HTO appeared to be the most mobile species compared with anions and cations; in particular, no anionic or cationic exclusion/acceleration effects have been found in these experiments. A modelling exercise focusing on the behavior of anionic species, which are the main contributors to the dose, improves the understanding of their diffusion within pristine and degraded cement-based materials. The outcomes of this work will specifically reduce the uncertainties regarding the fate of 36Cl
A digital real-time high-resolution imaging system to quantify and identify all emitted charged particles
No full textInternational audienceThis paper describes an instrumentation imaging system that provides, at real-time, localization, quantification and identification of a radioactive source with a precision up to 20μm. The localization of each decay position is obtained with using a parallel ionization multiplier gaseous detector and a reconstruction algorithm. The spatial identification of the composition of the radioactive source is performed by an original specific set of temporal and energy spectrometry techniques. The system allows with a single detector to combine the measurement of the spatial distribution with the ability to separate and quantify at real time each radionuclide. From an application point of view, this system opens up possibilities for theragnostic applications that typically use two radionuclides. Further upstream, it can optimize the production and distribution challenge of α radionuclides by allowing the identification and characterization of individual radionuclides in radionuclide chains such as 225Ac. Moreover, themeasurement system and the associated method could strongly contribute to facilitate research on the biodistribution of αradionuclides that are by their nature difficult to characterize by standard methods
Development of a high pressure single-anode radial TPC for the search of 2β0ν decays of 2β0ν decays
No full textInternational audienceThe objective of R&D R2D2 is to develop a very simple TPC filled with pressurized xenon for the search of neutrinoless double beta decays (2β0ν). We tested several chamber concepts (spherical (SPC) or cylindrical (CPC) geometries) with an argon-methane gas mixture at pressures up to 8 bars. We report the results obtained in ionization and proportional modes, especially in terms of signal shape and energy resolution. Furthermore, based on both an in-house simulation for the signal formation and our experimental observations, we have studied the possibilities of localization and discrimination of the interaction tracks within these detectors. Future developments will also be presented
Measurements of Groomed-Jet Substructure of Charm Jets Tagged by <math display="inline"><mrow><msup><mrow><mi mathvariant="italic">D</mi></mrow><mrow><mn>0</mn></mrow></msup></mrow></math> Mesons in Proton-Proton Collisions at <math display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math>
No full textInternational audienceUnderstanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D0 meson. The measurement is made in proton-proton collisions at s=13 TeV, in the low jet transverse-momentum interval of 15≤pTjet ch<30 GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions
First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons
No full textInternational audienceWe report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the sub-electron charge resolution and low level of dark current of DAMIC-M Charge-Coupled Devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7 e-. With this data set we place limits on dark matter particles of mass between 0.53 and 1000 MeV/c2, excluding unexplored regions of parameter space in the mass ranges [1.6,1000] MeV/c2 and [1.5,15.1] MeV/c2 for ultra-light and heavy mediator interactions, respectively
Investigation of the tetraquark states in the improved chromomagnetic interaction model
No full textInternational audienceIn the framework of the improved chromomagnetic interaction model, we complete a systematic study of the -wave tetraquark states (, and ) with different quantum numbers, , , and . The mass spectra of tetraquark states are predicted and the possible decay channels are analyzed by considering both the angular momentum and -parity conservation. The recently observed hidden-charm tetraquark states with strangeness, such as , , and , can be well explained in our model. Besides, based on the wave function of each tetraquark state, we find that the low-lying states of each configuration are likely molecule states of and mesons, instead of and mesons. These predictions can be examined in future experiments
Neutrinoless Double Beta Decay
No full textInternational audienceThis White Paper, prepared for the Fundamental Symmetries, Neutrons, and Neutrinos Town Meeting related to the 2023 Nuclear Physics Long Range Plan, makes the case for double beta decay as a critical component of the future nuclear physics program. The major experimental collaborations and many theorists have endorsed this white paper
Performance of a spherical high pressure gas TPC for neutrino magnetic moment measurement
No full textInternational audienceThe measurement of neutrino magnetic moment larger than 10μB would be a clear signature of physics beyond the standard model other than the existence of massive Dirac neutrinos. The use of a spherical proportional counter detector filled with gas at 40 bar located near a nuclear reactor would be a simple way to perform such a measurement exploiting the developments made on such a technology for the search of dark matter and neutrinoless double beta decay. Different targets can be used just by replacing the gas: xenon, CF and argon were compared and the sensitivity in one year of data taking could reach the level of 4.3 × 10μB, 6.5 × 10μB, and 8.5 × 10μB, respectively
The NEWS-G detector at SNOLAB
No full textInternational audienceThe New Experiments With Spheres-Gas (NEWS-G) collaboration intends to achieve Weakly Interacting Massive Particles (WIMPs) detection using Spherical Proportional Counters (SPCs). SPCs are gaseous detectors relying on ionization with a single ionization electron energy threshold. The latest generation of SPC for direct dark matter searches has been installed at SNOLAB in Canada in 2021. This article details the different processes involved in the fabrication of the NEWS-G experiment. Also outlined in this paper are the mitigation strategies, measurements of radioactivity of the different components, and estimations of induced background event rates that were used to quantify and address detector backgrounds