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We report on the observation of previously-unknown isotope $^{21}$Al, the first unbound aluminum isotope located beyond the proton dripline. The $^{21}$Al nucleus decays by one-proton (1p) emission, and its in-flight decays were detected by tracking trajectories of all decay products with micro-strip silicon detectors. The 1p-emission processes were studied by analyses of the measured angular correlations of decay products $^{20}$Mg+p. The 1p-decay energies of ground and low-lying excited states of $^{21}$Al, its mass excess and proton separation energy value $S_p$=$-1.1(1)$ MeV were determined., Comment: 6 pages, 7 figures

We report the charge-changing cross sections ($\sigma_{\text{cc}}$) of 24 $p$-shell nuclides on both hydrogen and carbon at about 900$A$ MeV, of which $^{8,9}$Li, $^{10\textendash12}$Be, $^{10,14,15}$B, $^{14,15,17\textendash22}$N and $^{16}$O on hydrogen and $^{8,9}$Li on carbon are for the first time. Benefiting from the data set,we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets.This allows us to deduce proton radii ($R_p$) for the first time from the cross sections on hydrogen. Nearly identical $R_p$ values are deduced from both target data for the neutron-rich carbon isotopes, however, the $R_p$ from the hydrogen target is systematically smaller in the neutron-rich nitrogen isotopes.This calls for further experimental and theoretical investigations., Comment: 5 pages, 3 figures

Isomer spectroscopy of heavy neutron-rich nuclei beyond the N=126 closed shell has been performed for the first time at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. New millisecond isomers have been identified at low excitation energies, 985.3(19) keV in 213Tl and 874(5) keV in 215Tl. The measured half-lives of 1.34(5) ms in 213Tl and 3.0(3) ms in 215Tl suggest spins and parities 11/2- with the single proton-hole configuration h11/2 as leading component. They are populated via E1 transitions by the decay of higher-lying isomeric states with proposed spin and parity 17/2+, interpreted as arising from a single s1/2 proton hole coupled to the 8+ seniority isomer in the (A+1)Pb cores. The lowering of the 11/2- states is ascribed to an increase of the h11/2 proton effective single-particle energy as the second g9/2 orbital is filled by neutrons, owing to a significant reduction of the proton-neutron monopole interaction between the h11/2 and g9/2 orbitals. The new ms-isomers provide the first experimental observation of shell evolution in the almost unexplored N>126 nuclear region below doubly-magic 208Pb., Comment: 9 pages, 3 figures, 1 table

The root mean square radii of the proton density distribution in $^{16-24}$O derived from measurements of charge changing cross sections with a carbon target at $\sim$900$A$ MeV together with the matter radii portray thick neutron skin for $^{22 - 24}$O despite $^{22,24}$O being doubly magic. Imprints of the shell closures at $N$ = 14 and 16 are reflected in local minima of their proton radii that provide evidence for the tensor interaction causing them. The radii agree with it ab initio calculations employing the chiral NNLO$_{\mathrm{sat}}$ interaction, though skin thickness predictions are challenged. Shell model predictions agree well with the data., Comment: 6 pages, 3 figures, accepted for publication in Physical Review Letters

The collection and the analysis of kidney stone morphological criteria are essential for an aetiological diagnosis of stone disease. However, in-situ LASER-based fragmentation of urinary stones, which is now the most established chirurgical intervention, may destroy the morphology of the targeted stone. In the current study, we assess the performance and added value of processing complete digital endoscopic video sequences for the automatic recognition of stone morphological features during a standard-of-care intra-operative session. To this end, a computer-aided video classifier was developed to predict in-situ the morphology of stone using an intra-operative digital endoscopic video acquired in a clinical setting. The proposed technique was evaluated on pure (i.e. include one morphology) and mixed (i.e. include at least two morphologies) stones involving "Ia/Calcium Oxalate Monohydrate (COM)", "IIb/ Calcium Oxalate Dihydrate (COD)" and "IIIb/Uric Acid (UA)" morphologies. 71 digital endoscopic videos (50 exhibited only one morphological type and 21 displayed two) were analyzed using the proposed video classifier (56840 frames processed in total). Using the proposed approach, diagnostic performances (averaged over both pure and mixed stone types) were as follows: balanced accuracy=88%, sensitivity=80%, specificity=95%, precision=78% and F1-score=78%. The obtained results demonstrate that AI applied on digital endoscopic video sequences is a promising tool for collecting morphological information during the time-course of the stone fragmentation process without resorting to any human intervention for stone delineation or selection of good quality steady frames. To this end, irrelevant image information must be removed from the prediction process at both frame and pixel levels, which is now feasible thanks to the use of AI-dedicated networks., Comment: 16 pages, 4 figures, 3 tables

Deep learning has shown great promise in diverse areas of computer vision, such as image classification, object detection and semantic segmentation, among many others. However, as it has been repeatedly demonstrated, deep learning methods trained on a dataset do not generalize well to datasets from other domains or even to similar datasets, due to data distribution shifts. In this work, we propose the use of a meta-learning based few-shot learning approach to alleviate these problems. In order to demonstrate its efficacy, we use two datasets of kidney stones samples acquired with different endoscopes and different acquisition conditions. The results show how such methods are indeed capable of handling domain-shifts by attaining an accuracy of 74.38% and 88.52% in the 5-way 5-shot and 5-way 20-shot settings respectively. Instead, in the same dataset, traditional Deep Learning (DL) methods attain only an accuracy of 45%., Comment: Paper submitted to MICAI 2022

We measured the $^{57}$Zn $\beta$-delayed proton ($\beta$p) and $\gamma$ emission at the National Superconducting Cyclotron Laboratory. We find a $^{57}$Zn half-life of 43.6 $\pm$ 0.2 ms, $\beta$p branching ratio of (84.7 $\pm$ 1.4)%, and identify four transitions corresponding to the exotic $\beta$-$\gamma$-$p$ decay mode, the second such identification in the $f p$-shell. The $p/\gamma$ ratio was used to correct for isospin mixing while determining the $^{57}$Zn mass via the isobaric multiplet mass equation. Previously, it was uncertain as to whether the rp-process flow could bypass the textbook waiting point $^{56}$Ni for astrophysical conditions relevant to Type-I X-ray bursts. Our results definitively establish the existence of the $^{56}$Ni bypass, with 14-17% of the $rp$-process flow taking this route.

Determining the type of kidney stones allows urologists to prescribe a treatment to avoid recurrence of renal lithiasis. An automated in-vivo image-based classification method would be an important step towards an immediate identification of the kidney stone type required as a first phase of the diagnosis. In the literature it was shown on ex-vivo data (i.e., in very controlled scene and image acquisition conditions) that an automated kidney stone classification is indeed feasible. This pilot study compares the kidney stone recognition performances of six shallow machine learning methods and three deep-learning architectures which were tested with in-vivo images of the four most frequent urinary calculi types acquired with an endoscope during standard ureteroscopies. This contribution details the database construction and the design of the tested kidney stones classifiers. Even if the best results were obtained by the Inception v3 architecture (weighted precision, recall and F1-score of 0.97, 0.98 and 0.97, respectively), it is also shown that choosing an appropriate colour space and texture features allows a shallow machine learning method to approach closely the performances of the most promising deep-learning methods (the XGBoost classifier led to weighted precision, recall and F1-score values of 0.96). This paper is the first one that explores the most discriminant features to be extracted from images acquired during ureteroscopies., Comment: Paper submitted to IEEE Access

The fragment separator FRS has been for the first time used to measure the (n,p) and (p,n)-type isobaric charge-exchange cross sections of stable 112,124Sn isotopes accelerated at 1A GeV with an uncertainty of 3% and to separate quasi-elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic contribution can be associated to the excitation of isobar {\Delta}(1232) resonances and to the pion emission in s-wave, both in the target and projectile nuclei, while the quasi-elastic contribution is associated to the nuclear spin-isospin response of nucleon-hole excitations. The data lead to interesting results where we observe a clear quenching of the quasi-elastic component and their comparisons to theoretical calculations demonstrate that the baryonic resonances can be excited in the target and projectile nuclei. To go further in this investigation, we propose to study the excitation of baryonic resonances taking advantage of the combination of high-resolving power magnetic spectrometers with the WASA calorimeter. These new measurements will allow us to determine the momenta of the ejectiles and pions emitted in coincidence after the single isobaric charge-exchange collisions, providing us unique opportunities to study the evolution of the baryonic resonance dynamics with the neutron-proton asymmetry through the use of exotic radioactive ion beams., Comment: 14 pages, 9 figures. arXiv admin note: text overlap with arXiv:2004.06404

The occurrence of octupole shapes in even-mass neutron-rich Ba isotopes has been well established. However, the situation with the odd-mass Ba and odd or odd-odd La nuclei around them is far from settled. In order to shed light on these less-studied isotopes, a fast-timing experiment was performed using GRIFFIN at TRIUMF-ISAC. A wealth of excited-state lifetimes in the 100~ps to few ns range have been measured in $^{144, 145, 146}$Ba and $^{145,146}$La populated in the $\beta^-$ and $\beta^--n$ decay of $^{145,146}$Cs. The results do not allow to draw firm conclusions on the possible octupole deformation of these nuclei but suggest different spin and parity assignments than previous works. This work highlights the need for more detailed study of the odd and odd-odd isotopes in this region to properly understand their structure., Comment: 16 pages, 7 figures

Neutron-rich nuclei in the vicinity of the $N=40$ island of inversion are characterized by shell evolution and exhibit deformed ground states. In several nuclei isomeric states have been observed and attributed to excitations to the intruder neutron $1g_{9/2}$ orbital. In the present study we searched for isomeric states in nuclei around $N=40$, $Z=22$ produced by projectile fragmentation at RIBF. Delayed $\gamma$ rays were detected by the EURICA germanium detector array. High statistics data allowed for an updated decay scheme of $^{60}$V. The lifetime of an isomeric state in $^{64}$V was measured for the first time in the present experiment. A previously unobserved isomeric state was discovered in $^{58}$Sc. The measured lifetime suggests a parity changing transition, originating from an odd number of neutrons in the $1g_{9/2}$ orbital. The nature of the isomeric state in $^{58}$Sc is thus different from isomers in the less exotic V and Sc nuclei., Comment: PRC accepted

Objective: To assess automatic computer-aided in-situ recognition of morphological features of pure and mixed urinary stones using intraoperative digital endoscopic images acquired in a clinical setting. Materials and methods: In this single-centre study, an experienced urologist intraoperatively and prospectively examined the surface and section of all kidney stones encountered. Calcium oxalate monohydrate (COM/Ia), dihydrate (COD/IIb) and uric acid (UA/IIIb) morphological criteria were collected and classified to generate annotated datasets. A deep convolutional neural network (CNN) was trained to predict the composition of both pure and mixed stones. To explain the predictions of the deep neural network model, coarse localisation heat-maps were plotted to pinpoint key areas identified by the network. Results: This study included 347 and 236 observations of stone surface and stone section, respectively. A highest sensitivity of 98 % was obtained for the type "pure IIIb/UA" using surface images. The most frequently encountered morphology was that of the type "pure Ia/COM"; it was correctly predicted in 91 % and 94 % of cases using surface and section images, respectively. Of the mixed type "Ia/COM+IIb/COD", Ia/COM was predicted in 84 % of cases using surface images, IIb/COD in 70 % of cases, and both in 65 % of cases. Concerning mixed Ia/COM+IIIb/UA stones, Ia/COM was predicted in 91 % of cases using section images, IIIb/UA in 69 % of cases, and both in 74 % of cases. Conclusions: This preliminary study demonstrates that deep convolutional neural networks are promising to identify kidney stone composition from endoscopic images acquired intraoperatively. Both pure and mixed stone composition could be discriminated. Collected in a clinical setting, surface and section images analysed by deep CNN provide valuable information about stone morphology for computer-aided diagnosis., Comment: 19 pages, 3 figures, 2 tables

This paper reports on the second "Throughput" phase of the Tracking Machine Learning (TrackML) challenge on the Codalab platform. As in the first "Accuracy" phase, the participants had to solve a difficult experimental problem linked to tracking accurately the trajectory of particles as e.g. created at the Large Hadron Collider (LHC): given O($10^5$) points, the participants had to connect them into O($10^4$) individual groups that represent the particle trajectories which are approximated helical. While in the first phase only the accuracy mattered, the goal of this second phase was a compromise between the accuracy and the speed of inference. Both were measured on the Codalab platform where the participants had to upload their software. The best three participants had solutions with good accuracy and speed an order of magnitude faster than the state of the art when the challenge was designed. Although the core algorithms were less diverse than in the first phase, a diversity of techniques have been used and are described in this paper. The performance of the algorithms are analysed in depth and lessons derived., Comment: submitted to Computing and Software for Big Science

Knowing the type (i.e., the biochemical composition) of kidney stones is crucial to prevent relapses with an appropriate treatment. During ureteroscopies, kidney stones are fragmented, extracted from the urinary tract, and their composition is determined using a morpho-constitutional analysis. This procedure is time consuming (the morpho-constitutional analysis results are only available after some days) and tedious (the fragment extraction lasts up to an hour). Identifying the kidney stone type only with the in-vivo endoscopic images would allow for the dusting of the fragments, while the morpho-constitutional analysis could be avoided. Only few contributions dealing with the in vivo identification of kidney stones were published. This paper discusses and compares five classification methods including deep convolutional neural networks (DCNN)-based approaches and traditional (non DCNN-based) ones. Even if the best method is a DCCN approach with a precision and recall of 98% and 97% over four classes, this contribution shows that a XGBoost classifier exploiting well-chosen feature vectors can closely approach the performances of DCNN classifiers for a medical application with a limited number of annotated data., Comment: This paper is currently under review for the IEEE Engineering in Medicine and Biology Conference (EMBC 2021)

The absolute differential cross sections for small-angle proton elastic scattering off the nuclei $^{12,14-17}$C have been measured in inverse kinematics at energies near 700 MeV/u at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR served simultaneously as a gas target and a detector for the recoil protons. The projectile scattering angles were measured with multi-wire tracking detectors. The radial nuclear matter density distributions and the root-mean-square nuclear matter radii were deduced from the measured cross sections using the Glauber multiple-scattering theory. A possible neutron halo structure in $^{15}$C, $^{16}$C and $^{17}$C is discussed. The obtained data show evidence for a halo structure in the $^{15}$C nucleus.

Isobaric charge-exchange reactions induced by beams of 112Sn have been investigated at the GSI facilities using the fragment separator FRS. The high-resolving power of this spectrometer makes it possible to obtain the isobaric charge-exchange cross sections with an accuracy of 3% and to separate quasi-elastic and inelastic contributions in the missing-energy spectra, in which the inelastic component is associated to the in-medium excitation of baryonic resonances such as the $\Delta$ resonance. We report on the results obtained for the (p,n) and (n,p) channels excited by using different targets that cover a large range in neutron excess., Comment: arXiv admin note: text overlap with arXiv:2004.06404

We report the measurement of reaction cross sections ($\sigma_R^{\rm ex}$) of $^{27,29}$F with a carbon target at RIKEN. The unexpectedly large $\sigma_R^{\rm ex}$ and derived matter radius identify $^{29}$F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the $2p_{3/2}$ orbital, thereby vanishing the shell closure associated with the neutron number $N = 20$. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of $^{27}$F but are challenged for $^{29}$F., Comment: 8 pages, 4 figures

Fast timing detectors are an essential element in the experimental setup for time-of-flight (ToF) mass measurements of unstable nuclei. We have upgraded the scintillator detectors used in experiments at the National Superconducting Cyclotron Laboratory (NSCL) by increasing the number of photomultiplier tubes that read out their light signals to four per detector, and characterized them in a test experiment with $^{48}$Ca beam at the NSCL. The new detectors achieved a time resolution ($\sigma$) of 7.5 ps. We systematically investigated different factors that affect their timing performance. In addition, we evaluated the ability of positioning the hitting points on the scintillator using the timing information and obtained a resolution ($\sigma$) below 1 mm for well-defined beam spots., Comment: 11 pages, 10 figures, submitted to NIMA

We present mass excesses (ME) of neutron-rich isotopes of Ar through Fe, obtained via TOF-$B\rho$ mass spectrometry at the National Superconducting Cyclotron Laboratory. Our new results have significantly reduced systematic uncertainties relative to a prior analysis, enabling the first determination of ME for $^{58,59}{\rm Ti}$, $^{62}{\rm V}$, $^{65}{\rm Cr}$, $^{67,68}{\rm Mn}$, and $^{69,70}{\rm Fe}$. Our results show the $N=34$ subshell weaken at Sc and vanish at Ti, along with the absence of an $N=40$ subshell at Mn. This leads to a cooler accreted neutron star crust, highlighting the connection between the structure of nuclei and neutron stars., Comment: Accepted for publication as a Rapid Communication in Physical Review C

We have developed and tested an experimental technique for the measurement of low-energy (p,n) reactions in inverse kinematics relevant to nuclear astrophysics. The proposed setup is located at the ReA3 facility at the National Superconducting Cyclotron Laboratory. In the current approach, we operate the beam-transport line in ReA3 as a recoil separator while tagging the outgoing neutrons from the (p,n) reactions with the low-energy neutron detector array (LENDA). The developed technique was verified by using the $^{40}$Ar(p,n)$^{40}$K reaction as a probe. The results of the proof-of-principle experiment with the $^{40}$Ar beam show that cross-section measurements within an uncertainty of $\sim$25\% are feasible with count rates up to 7 counts/mb/pnA/s. In this article, we give a detailed description of the experimental setup, and present the analysis method and results from the test experiment. Future plans on using the technique in experiments with the separator for capture reactions (SECAR) that is currently being commissioned are also discussed., Comment: Submitted to NIMA. Revised manuscript after referees' first review

Isobaric single charge-exchange reactions, changing nuclear charges by one unit but leaving the mass partitions unaffected, have been for the first time investigated by peripheral collisions of $^{112}$Sn ions accelerated up to 1\textit{A} GeV at the GSI facilities. The high-resolving power of the FRS spectrometer allows us to obtain $(p, n)$-type isobaric charge-exchange cross sections with an uncertainty of $3.5\%$ and to separate quasi-elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic component is associated to the excitation of the $\Delta$(1232) isobar resonance and the emission of pions in s-wave both in the target and projectile nucleus, while the quasi-elastic contribution is associated to the nuclear spin-isospin response of nucleon-hole excitations. An apparent shift of the $\Delta$-resonance peak of $\sim$63 MeV is observed when comparing the missing-energy spectra obtained from the measurements with proton and carbon targets. A detailed analysis, performed with a theoretical model for the reactions, indicates that this observation can be simply interpreted as a change in the relative magnitude between the contribution of the excitation of the resonance in the target and in the projectile.

This work aims to study the dislocation or nodal lines of 3D Berry's random wave model. Their expected length is computed both in the isotropic and anisotropic cases, being them compared. Afterwards, in the isotropic case the asymptotic variance and distribution of the length are obtained as the domain grows to the whole space. Under some integrability condition on the covariance function, a central limit theorem is established. The study includes the Berry's monochromatic random waves, the Bargmann-Fock model and the Black-Body radiation as well as a power law model that exhibits an unusual asymptotic behaviour and yields a non-central limit theorem., Comment: 19 pages

Angle-integrated cross-section measurements of the $^{56}$Ni(d,n) and (d,p) stripping reactions have been performed to determine the single-particle strengths of low-lying excited states in the mirror nuclei pair $^{57}$Cu-$^{57}$Ni situated adjacent to the doubly magic nucleus $^{56}$Ni. The reactions were studied in inverse kinematics utilizing a beam of radioactive $^{56}$Ni ions in conjunction with the GRETINA $\gamma$-array. Spectroscopic factors are compared with new shell-model calculations using a full $pf$ model space with the GPFX1A Hamiltonian for the isospin-conserving strong interaction plus Coulomb and charge-dependent Hamiltonians. These results were used to set new constraints on the $^{56}$Ni(p,$\gamma$)$^{57}$Cu reaction rate for explosive burning conditions in x-ray bursts, where $^{56}$Ni represents a key waiting point in the astrophysical rp-process., Comment: Final version accepted and published. 5 pages, 2 figures

Absolute differential cross sections for elastic $p^7$Be and $p^8$B small-angle scattering were measured in inverse kinematics at an energy of 0.7 GeV/u at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR was used as an active target to detect the recoil protons. The projectile tracking and isotope identification were performed with multi-wire proportional chambers and scintillation detectors. The measured cross sections were analysed using the Glauber multiple-scattering theory. The root-mean-square (rms) nuclear matter radii $R_{\rm m} = 2.42 (4)$ fm for $^7$Be and $R_{\rm m} = 2.58 (6)$ fm for $^8$B were obtained. The radial density distribution deduced for $^8$B exhibits a proton halo structure with the rms halo radius $R_{\rm h} = 4.24 (25)$ fm. A comparison of the deduced experimental radii is displayed with existing experimental and theoretical data., Comment: 18 pages, 6 figures. arXiv admin note: text overlap with arXiv:1803.02044

The most-remote from stability isotope $^{31}$K, which is located four atomic mass units beyond the proton drip line, has been observed. It is unbound in respect to three-proton (${3p}$) emission, and its decays have been detected in flight by measuring trajectories of all decay products using micro-strip detectors. The $3p$-emission processes have been studied by means of angular correlations $^{28}$S+3$p$ and the respective decay vertexes. The energies of the previously-unknown ground and excited states of $^{31}$K have been determined. This provides its $3p$ separation-energy value $S_{3p}$ of $-4.6(2)$ MeV. Upper half-life limits of 10 ps of the observed $^{31}$K states have been derived from distributions of the measured decay vertexes., Comment: 6 pages, 5 figures

We investigate Lipschitz-Killing curvatures for excursion sets of random fields on $\mathbb R^2$ under small spatial-invariant random perturbations. An expansion formula for mean curvatures is derived when the magnitude of the perturbation vanishes, which recovers the Gaussian Kinematic Formula at the limit by contiguity of the model. We develop an asymptotic study of the perturbed excursion area behaviour that leads to a quantitative non-Gaussian limit theorem, in Wasserstein distance, for fixed small perturbations and growing domain. When letting both the perturbation vanish and the domain grow, a standard Central Limit Theorem follows. Taking advantage of these results, we propose an estimator for the perturbation which turns out to be asymptotically normal and unbiased, allowing to make inference through sparse information on the field.

This paper reports the results of an experiment in high energy physics: using the power of the "crowd" to solve difficult experimental problems linked to tracking accurately the trajectory of particles in the Large Hadron Collider (LHC). This experiment took the form of a machine learning challenge organized in 2018: the Tracking Machine Learning Challenge (TrackML). Its results were discussed at the competition session at the Neural Information Processing Systems conference (NeurIPS 2018). Given 100.000 points, the participants had to connect them into about 10.000 arcs of circles, following the trajectory of particles issued from very high energy proton collisions. The competition was difficult with a dozen front-runners well ahead of a pack. The single competition score is shown to be accurate and effective in selecting the best algorithms from the domain point of view. The competition has exposed a diversity of approaches, with various roles for Machine Learning, a number of which are discussed in the document, Comment: 36 pages, 22 figures

Isomeric states in 59,61Ti have been populated in the projectile fragmentation of a 345 AMeV 238U beam at the Radioactive Isotope Beam Factory. The decay lifetimes and delayed gamma-ray transitions were measured with the EURICA array. Besides the known isomeric state in 59Ti, two isomeric states in 61Ti are observed for the first time. Based on the measured lifetimes, transition multipolarities as well as tentative spins and parities are assigned. Large-scale shell model calculations based on the modified LNPS interaction show that both 59Ti and 61Ti belong to the Island of Inversion at N=40 with ground state configurations dominated by particle-hole excitations to the g_9/2 and d_5/2 orbits., Comment: Phys. Lett. B accepted

Interface-dominated materials such as nanocrystalline thin films have emerged as an enthralling class of materials able to engineer functional properties of transition metal oxides widely used in energy and information technologies. In particular, it has been proved that strain-induced defects in grain boundaries of manganites deeply impact their functional properties by boosting their oxygen mass transport while abating their electronic and magnetic order. In this work, the origin of these dramatic changes is correlated for the first time with strong modifications of the anionic and cationic composition in the vicinity of strained grain boundary regions. We are also able to alter the grain boundary composition by tuning the overall cationic content in the films, which represents a new and powerful tool, beyond the classical space charge layer effect, for engineering electronic and mass transport properties of metal oxide thin films useful for a collection of relevant solid state devices.

A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for $^{17-22}$N from charge changing cross section measurements around 900$A$ MeV at GSI. Neutron halo effects are signaled for $^{22}$N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at $N$ = 14 arising from the attractive proton-neutron tensor interaction, in good agreement with shell model calculations. $Ab$ $initio$, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon-nucleon and three-nucleon interaction reproduce well the data approaching the neutron drip-line isotopes but are challenged in explaining the complete isotopic trend of the radii., Comment: 18 pages, 3 figures

A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-rich nuclei. The setup consists of three main parts: a moderated neutron counter, a detection system sensitive to the implantation and decay of radioactive ions, and gamma-ray detectors. We describe here the setup, the commissioning experiment and some selected results demonstrating its performance for the measurement of half-lives and beta-delayed neutron emission probabilities. The methodology followed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutron background.

Many choices are available in order to evaluate large radioactive decay networks. %multi-particle decay data. There are many parameters that influence the calculated $\beta$-decay delayed single and multi-neutron emission branching fractions. We describe assumptions about the decay model, background, and other parameters and their influence on $\beta$-decay delayed multi-neutron emission analysis. An analysis technique, the ORNL BRIKEN analysis procedure, for determining $\beta$-delayed multi-neutron branching ratios in $\beta$-neutron precursors produced by means of heavy-ion fragmentation is presented. The technique is based on estimating the initial activities of zero, one, and two neutrons occurring in coincidence with an ion-implant and $\beta$ trigger. The technique allows one to extract $\beta$-delayed multi-neutron decay branching ratios measured with the hybrid \textsuperscript{3}He BRIKEN neutron counter. As an example, two analyses of the $\beta$-neutron emitter \textsuperscript{77}Cu based on different {\it a priori} assumptions are presented along with comparisons to literature values., Comment: 21 pages, 10 figures

Prospects of experimental studies of argon and chlorine isotopes located far beyond the proton dripline are studied by using systematics and cluster models. The deviations from the widespread systematics observed in $^{28,29}$Cl and $^{29,30}$Ar have been theoretically substantiated, and analogous deviations predicted for the lighter chlorine and argon isotopes. The limits of nuclear structure existence are predicted for Ar and Cl isotopic chains, with $^{26}$Ar and $^{25}$Cl found to be the lightest sufficiently long-living nuclear systems. By simultaneous measurements of protons and $\gamma$-rays following decays of such systems as well as their $\beta$-delayed emission, an interesting synergy effect may be achieved, which is demonstrated by the example of $^{30}$Cl and $^{31}$Ar ground state studies. Such synergy effect may be provided by the new EXPERT setup (EXotic Particle Emission and Radioactivity by Tracking), being operated inside the fragment separator and spectrometer facility at GSI, Darmstadt., Comment: 10 pages, 9 figures. Chapter added, language and some figures corrected

The proton-unbound argon and chlorine isotopes have been studied by measuring trajectories of their decay-in-flight products by using a tracking technique with micro-strip detectors. The proton ($1p$) and two-proton ($2p$) emission processes have been detected in the measured angular correlations "heavy-fragment"+$p$ and "heavy-fragment"+$p$+$p$, respectively. The ground states of the previously unknown isotopes $^{30}$Cl and $^{28}$Cl have been observed for the first time, providing the $1p$-separation energies $S_p$ of $-0.48(2)$ and $-1.60(8)$ MeV, respectively. The relevant systematics of $1p$ and $2p$ separations energies have been studied theoretically in the core+$p$ and core+$p$+$p$ cluster models. The first-time observed excited states of $^{31}$Ar allow to infer the $2p$-separation energy $S_{2p}$ of 6(34) keV for its ground state. The first-time observed state in $^{29}$Ar with $S_{2p} = -5.50(18)$ MeV can be identified either as a ground or an excited state according to different systematics., Comment: 13 pages, 14 figures. Name changed, some affiliations changed and figures corrections added

The emission of neutron pairs from the neutron-rich $N\!=\!12$ isotones $^{18}$C and $^{20}$O has been studied by high-energy nucleon knockout from $^{19}$N and $^{21}$O secondary beams, populating unbound states of the two isotones up to 15~MeV above their two-neutron emission thresholds. The analysis of triple fragment-$n$-$n$ correlations shows that the decay $^{19}$N$(-1p)^{18}$C$^*\!\rightarrow^{16}$C+$n$+$n$ is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a $^{14}$C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay $^{21}$O$(-1n)^{20}$O$^*\!\rightarrow^{18}$O+$n$+$n$, attributed to its formation through the knockout of a deeply-bound neutron that breaks the $^{16}$O core and reduces the number of pairs., Comment: 6 pages, 4 figures, accepted for publication in Phys. Rev. Lett

The absolute differential cross section for small-angle proton elastic scattering on the proton-rich $^8$B nucleus has been measured in inverse kinematics for the first time. The experiment was performed using a secondary radioactive beam with an energy of 0.7 GeV/u at GSI, Darmstadt. The active target, namely hydrogen-filled time projection ionization chamber IKAR, was used to measure the energy, angle and vertex point of the recoil protons. The scattering angle of the projectiles was simultaneously determined by the tracking detectors. The measured differential cross section is analyzed on the basis of the Glauber multiple scattering theory using phenomenological nuclear-density distributions with two free parameters. The radial density distribution deduced for $^8$B exhibits a halo structure with the root-mean-square (rms) matter radius $R_{\rm m} = 2.58 (6)$ fm and the rms halo radius $R_{\rm h} = 4.24 (25)$ fm. The results on $^8$B are compared to those on the mirror nucleus $^8$Li investigated earlier by the same method. A comparison is also made with previous experimental results and theoretical predictions for both nuclei.

Several states of proton-unbound isotopes $^{30}$Ar and $^{29}$Cl were investigated by measuring their in-flight decay products, $^{28}$S+proton+proton and $^{28}$S+proton, respectively. A refined analysis of $^{28}$S-proton angular correlations indicates that the ground state of $^{30}$Ar is located at $2.45^{+0.05}_{-0.10}$ MeV above the two-proton emission threshold. The theoretical investigation of the $^{30}$Ar ground state decay demonstrates that its mechanism has the transition dynamics with a surprisingly strong sensitivity of the correlation patterns of the decay products to the two-proton decay energy of the $^{30}$Ar ground state and the one-proton decay energy as well as the one-proton decay width of the $^{29}$Cl ground state. The comparison of the experimental $^{28}$S-proton angular correlations with those resulting from Monte Carlo simulations of the detector response illustrates that other observed $^{30}$Ar excited states decay by sequential emission of protons via intermediate resonances in $^{29}$Cl. Based on the findings, the decay schemes of the observed states in $^{30}$Ar and $^{29}$Cl were constructed. For calibration purposes and for checking the performance of the experimental setup, decays of the previously-known states of a two-proton emitter $^{19}$Mg were remeasured. Evidences for one new excited state in $^{19}$Mg and two unknown states in $^{18}$Na were found., Comment: 17 pages, 16 figures