We propose the development of a new generation of an integrated ion source system for the production of very pure radioactive ion beams at low energy, including isomeric beams. This ion source is also, in its own right, an experimental tool for laser spectroscopy. The Rare Elements in-Gas Laser Ion Source and Spectroscopy device will be installed at the S3 spectrometer, currently under construction as part of the SPIRAL-2 facility at the GANIL laboratory in Caen. Thus, REGLIS3 will be a source for the production of new and pure radioactive ion beams at low energy as well as a spectroscopic tool to measure nuclear hyperfine interactions, giving access to charge radii, electromagnetic moments and nuclear spins of exotic nuclei so far not studied. It consists of a gas cell in which the heavy-ion beam coming from S3 will stopped and neutralized, coupled to a laser system that assures a selective re-ionisation of the atoms of interest. Ionization can be performed in the gas cell or in the gas jet streaming out of the cell. A radiofrequency quadrupole is added to capture the photo-ions and to guide them to the low-pressure zone thereby achieving good emittance of the produced low-energy beam that will be sent to a standard measurement station. Owing to the unique combination of such a device with the radioactive heavy ion beams from S3, a new realm of unknown isotopes at unusual isospin (N/Z ratio, refered to as exotic isotopes) will become accessible. The scientific goals focus on the study of ground-state properties of the N=Z nuclei up to the doubly-magic 100Sn and those of the very heavy and superheavy elements even beyond fermium. Once routine operation is achieved the beams will be used by a new users community as e.g. decay studies and mass measurements. The goal of the proposal is to develop this new, efficient, and universal source for pure, even isomeric, beams and for pioneering high-resolution laser spectroscopy that will overcome the present experimental constraints to study very exotic nuclei.

GW170817, the first detection of gravitational waves (GWs) from a binary neutron star merger together with its electromagnetic counterpart has proven the immense potential of this multi-messenger astronomy for our understanding of the nature of gravity and the properties of dense matter. We propose here to advance on the latter, addressing the following questions: To which extent can current and future GW observations constrain the underlying microphysics, specifically the equation of state and neutrino interaction rates? Can a potential phase transition be detected? To answer these questions we will study as well the remnant of binary neutron star mergers as proto-neutron stars, the compact postbounce objects in a core-collapse supernova with a new fast and flexible numerical tool. We shall largely explore the microphysics model's parameter space and simulate the possible imprints on GW emission from these objects. In view of the difficult GW data analysis, this work will be crucial to fully exploit the science of upcoming GW data.

The neutrino is one of the most enigmatic ingredient of the standard model of particle physics. Because of its weak interaction with matter and despite enormous experimental progress, its nature and its fundamental properties remain unknown: Dirac / Majorana, CP violation, absolute mass scale, other flavors... Recent results from the t13 experiments Double Chooz, Daya Bay and RENO have uncovered an intriguing excess of events detected in the 4-6 MeV reconstructed energy range with respect to predictions. This spectral distortion may be a suggestion of discrepancies in models of antineutrino production in reactors. Moreover, three independent experimental anomalies (reactor anomaly, Gallium and LSND/ MiniBooNE) support the hypothesis of the existence of a new neutrino family, called sterile because not interacting through weak interaction. In this context, new data from a precise pure U235 Antineutrino spectrum are needed to resolve this open issue and to clarify the reactor anomaly. The SoLid project is an unique opportunity for the community to obtain sufficiently large and accurate data of neutrino flux at very short distance from a nuclear reactor, and then provide a reference measurement of pure 235U, essential for neutrino flux predictions used in current and future neutrino measurements. It proposes to confirm or refute the anomaly reactor and test ultimately the fourth sterile flavor. The strength of the SoLid proposal relies on both the antineutrino source and the technology of detection, which are unique. The experience takes place at BR2 research reactor of SCK-CEN (Mol, Belgium). It allows oscillation measurements at distance varying from 5.5 to 12 m from the core. In addition to this large range, the site is distinguished by its exceptionally low background environment and by having no-access to site constraint. The detector is based on an innovative technology of neutron detector, finely segmented. The use of 6LiF: ZnS layers allows a distinct discrimination of the neutron signal. In addition, the segmentation allows to locate the antineutrinos interactions and then effectively reject significant background sources. Combined with the favorable environment at BR2, our experiment provides an unprecedented sensitivity. Early 2015 a large-scale module 288kg (SM1) has been built and took “reactor ON” data during several days. This systems clearly demonstrates the capabilities of the segmented design of the detector, when combined with sophisticated data analysis techniques, leads to gains of orders of magnitude in background rejection. The physics run, with the full detector, will begin in October 2016 for a duration of two years minimum.This project is led by an international collaboration composed of eleven laboratories involving fifty physicists. Since the beginning, the three partners, Subatech, LAL and LPC have key contributions to the project: mechanical design, BR2 modelization, antineutrino spectra, Geant4/MCNP simulations and data analysis. This strong involvement allowed the coordinator to take responsablity of the SoLid analysis. Our proposal is to build 10 detection planes (320 kg) to increase the fiducial mass and the detector length, allowing us to probe the lower Dm2 phase space region. The French groups foresee to lead several specific studies into the oscillation framework to effectively probe the anomaly reactor, but also, comparing the pure U235 spectrum measured at BR2 with the data coming from the Double Chooz near detector to get an first insight in the “ 5 MeV bump” understanding. This specific contribution will consolidate our leadership in a experiment that promises to settle the question about the existence of sterile neutrino. In the longer term and for the international neutrino community, more precise neutrino flux measurements will allow to push the precision for future experiments.

The weak interaction mediating nuclear beta decay is described in the standard model of particle physics as consisting of two different currents, the vector current responsible for Fermi decays and the axial-vector current responsible for Gamow-Teller decays. All experimental findings can be described with these two interactions. However, from a more global theoretical picture, also scalar, tensor and pseudo-scalar (at relativistic energies only) currents are allowed. In such a scenario, scalar currents would appear with the vector currents and tensor currents with axial-vector currents. Limits on these ‘exotic’ currents can either be obtained from high-energy physics experiments trying to directly produce the bosons responsible for such new interactions or from precision experiments at low energy, e.g. in nuclear beta decay, searching for small deviations from the standard model predictions. In the present proposal we follow this latter path. Presently the most stringent limits on the presence of scalar currents come from the average corrected Ft-value of the super-allowed Fermi transitions and measurements of the ß-? correlation in the decay of 38mK (precision 0.5%) and 32Ar (0.65%). For tensor current searches the present best precision is 1 % from a measurement of the energy difference between the alpha particles from the breakup of the 8Be daughter nucleus of 8Li beta decay. The previous experiment performed with 32Ar is close to the one we will present here. 32Ar decays, beneath other channels, by a super-allowed Fermi decay to a state in 32Cl, its isobaric analogue state, which is unbound to proton emission. Due to the recoil the daughter nucleus gets from the emission of the positron and the neutrino, the proton is emitted from a moving source and is subject to Doppler Effect. As the angular distribution of the positron and the neutrino is different between the dominant vector part and a possible scalar current, the measurement of the Doppler broadening of the proton energy peak from the decay of this state and the comparison to model predictions with or without exotic contributions allowed the determination of the one of the most stringent limit on scalar currents. In order to achieve this precise result, the experimental set-up was installed in a strong magnetic field to guide the positrons away from the proton detectors. However, the positrons themselves were not detected. In the present proposal we suggest to perform a first-time measurement of the Doppler shift, measuring positron-proton coincidences in b-delayed proton decay, instead of the Doppler broadening, keeping in mind that a shift is easier to measure with high precision than a broadening. The precision aimed at for the correlation coefficient, to be extracted from the Doppler shift is 0.1 % (factor 5 improvement). The higher precision with respect to the previous experiment is possible because a measurement of the Doppler shift is less encumbered by systematic errors. Another important factor is that we propose a long-term installation of WISArD at ISOLDE which will allow us to improve successively the set-up. The beauty of the present project is also that 32Ar can be replaced with e.g. 20Mg allowing similar measurement to be performed. Gamow-Teller fed states could allow for the search for tensor currents with the same technique. It was recently shown that for precisions at the few per mill level, beta-neutrino correlation measurements remain competitive with LHC searches for exotic weak currents. Our result would thus bring the sensitivity to right-handed scalar weak currents to the same level as projected bounds of the 14TeV run of the LHC. The installation of this new experiment at ISOLDE was recently approved by the ISOLDE Collaboration Committee, the political body of ISOLDE. A letter of intent submitted to the ISOLDE and n-TOF Program Advisory Committee requesting a first test beam time was well received and approved as well.

Searches for a permanent electric dipole moment (EDM) of fundamental particles or systems are actively pursued worldwide [Kir12]. The discovery of a finite value would be of particular interest since it may reveal new sources of CP violation and therefore physics beyond the standard model (SM). The existence of new CP violation mechanisms is indeed required in cosmology in order to account for the baryogenesis in the early Universe. It is one of the 3 necessary conditions derived by Sakharov [Sak67] to produce some baryon asymmetry. The SM cannot account for the matter-antimatter asymmetry but several extensions offer viable baryogenesis scenarios as, for instance, supersymmetric (SUSY) models. In this context, EDM measurements already bring stringent constraints and the next generation of experiment will either discover a signal or rule out electroweak baryogenesis as the origin of matter-antimatter asymmetry. These searches are complementary to the high energy experiments performed at LHC since they allow to explore the TeV energy scale. The n2EDM project aims at measuring the neutron EDM with a statistical sensitivity improved by at least a factor 10 with respect to the present best limit, dn < 3 x 10-26 e.cm [Bak06]. Such a goal will be reached with a new highly sensitive spectrometer. The experiment will be running at the Paul Scherrer lnstitute (PSI) next to the newly built high intensity ultra-cold neutron (UCN) source whose commissioning started end of 2010. A statistical sensitivity of 2 x 10-27 e.cm is foreseen after 4 years of data taking (with the current source performances). If the UCN source performances reach their target value, the 10-28 e.cm range will start to be explored The project is the follow-up of an ongoing experiment at PSI which is based on an upgraded version of the RAL-Sussex-ILL apparatus, which holds the best limit on the neutron EDM [Bak06]. The French contribution to this upgrade was the object of a previous ANR grant (nEDM, ANR-09-BLAN-0046), jointly submitted by LPC Caen and LPSC Grenoble. This experiment is supported by an international collaboration of 12 laboratories. The three French laboratories involved in this proposal (LPC, LPSC and CSNSM) are all working on the current experiment. The new spectrometer will include two major improvements: a double storage chamber set-up that will allow the simultaneous measurement of the 2 configurations (parallel and antiparallel) of the electric and magnetic fields, and a large dimension magnetic shielding for a better control of the magnetic field environment. The statistical sensitivity gain will be achieved thanks to a larger number of stored UCN (better adaptation between the source and the spectrometer and use of the double storage chamber), a larger electric field intensity and a larger UCN polarization. The survey of systematic effects will be improved by the use of the new shielding and of three atomic magnetometers presenting novel features (vector Cs magnetometers, laser driven Hg magnetometer and He3 magnetometer). The ANR grant will be used to finance the French contribution to the design and construction of the new n2EDM spectrometer. To take full advantage of the experience acquired so far, the French groups will mostly keep working on the same tasks: UCN detection, guiding field system, spin analysis, coil design, current source and Hg magnetometry. Data taking with the new apparatus will start around 2018. Finally, it should be mentioned that the n2EDM project has been recently reviewed by the IN2P3 scientific council in October 2013. The scientific council recommendation to fully support this project was endorsed by the IN2P3 direction.