748 research outputs found

    Evaluated Experimental Isobaric Analogue States from T=1/2T = 1/2 to T=3T = 3 and associated IMME coefficients

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    Isobaric multiplets can be used to provide reliable mass predictions through the Isobaric Multiplet Mass Equation (IMME). Isobaric analogue states (IAS) for isospin multiplets from T=1/2T=1/2 to T=3T=3 have been studied within the 2012 Atomic Mass Evaluation (Ame2012). Each IAS established from published experimental reaction data has been expressed in the form of a primary reaction QQ-value, and if necessary, has been recalibrated. The evaluated IAS masses are provided here along with the associated IMME coefficients. Quadratic and higher order forms of the IMME have been considered, and global trends have been extracted. Particular nuclides, requiring experimental investigation, have been identified and discussed. This dataset is the most precise and extensive set of evaluated IAS to date.Comment: 44 pages, 7 figures, 11 tables. Accepted for publication in Nuclear Physics

    Adaptive reflection and focusing of Bose-Einstein condensates

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    We report adjustable magnetic `bouncing' and focusing of a dilute 87^{87}Rb Bose gas. Both the condensate production and manipulation are realised using a particularly straight-forward apparatus. The bouncing region is comprised of approximately concentric ellipsoidal magnetic equipotentials with a centre that can be adjusted vertically. We extend, and discuss the limitations of, simple Thomas-Fermi and Monte-Carlo theoretical models for the bouncing, which at present find close agreement with the condensate's evolution. Very strong focusing has been inferred and the observation of atomic matter-wave diffraction should be possible. Prospects look bright for applications in matter-wave atom-optics, due to the very smooth nature of the mirror

    The TULIP project : first on-line result and near future

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    The TULIP project aims to produce radioactive ion beams of short-lived neutron-deficient isotopes by using fusion-evaporation reactions in an optimized Target Ion Source System (TISS). The first step consisted of the design of a TISS to produce rubidium isotopes. It was tested with a primary beam of 22^{22}[email protected] MeV/A irradiating a natural Ni target at the SPIRAL1/GANIL facility in March 2022. Rates of 76,78^{76,78}Rb were measured as well as an exceptionally short atom-to-ion transformation time for an ISOL system, of the order of 200 \mathrm{\micro}s. The second step of the project aims at producing neutron-deficient short-lived metallic isotopes in the region of 100^{100}Sn. A "cold" prototype has been realized to study the electron impact ionization in the TISS cavity and a "hot" version is under construction to prepare an on-line experiment expected in the near future

    The impact of myosteatosis on outcomes following surgery for gastrointestinal malignancy: a meta-analysis.

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    INTRODUCTION: The aim of this review was to evaluate the impact of preoperative myosteatosis on long-term outcomes following surgery for gastrointestinal malignancy. METHODS: We conducted a systematic search of the electronic information sources, including PubMed MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL and AMED. Studies were included if they reported the impact of preoperatively defined myosteatosis, or a similar term, on long-term survival outcomes following surgery for gastrointestinal malignancy. A subgroup analysis was performed for those studies reporting outcomes for colorectal cancer patients only. FINDINGS: Thirty-nine full-text articles were reviewed for inclusion, with 19 being retained after the inclusion criteria were applied. The total number of included patients across all studies was 14,481. Patients with myosteatosis had significantly poorer overall survival, according to univariate (hazard ratio (HR) 1.82, 95% confidence interval (CI) 1.67-1.99) and multivariable (HR 1.66, 95% CI 1.49-1.86) analysis. This was also demonstrated for cancer-specific survival (univariate HR 1.62, 95% CI 1.18-2.22; multivariable HR 1.73, 95% CI 1.48-2.03) and recurrence-free survival (univariate HR 1.28, 95% CI 1.10-1.48; multivariable HR 1.38, 95% CI 1.07-1.77). CONCLUSIONS: This meta-analysis demonstrates that patients with preoperative myosteatosis have poorer long-term survival outcomes following surgery for gastrointestinal malignancy. Therefore, myosteatosis should be used for preoperative optimisation and as a prognostic tool before surgery. More standardised definitions of myosteatosis and further cohort studies of patients with non-colorectal malignancies are required

    Experimental demonstration of painting arbitrary and dynamic potentials for Bose-Einstein condensates

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    There is a pressing need for robust and straightforward methods to create potentials for trapping Bose-Einstein condensates which are simultaneously dynamic, fully arbitrary, and sufficiently stable to not heat the ultracold gas. We show here how to accomplish these goals, using a rapidly-moving laser beam that "paints" a time-averaged optical dipole potential in which we create BECs in a variety of geometries, including toroids, ring lattices, and square lattices. Matter wave interference patterns confirm that the trapped gas is a condensate. As a simple illustration of dynamics, we show that the technique can transform a toroidal condensate into a ring lattice and back into a toroid. The technique is general and should work with any sufficiently polarizable low-energy particles.Comment: Minor text changes and three references added. This is the final version published in New Journal of Physic

    Deterministic single-atom excitation via adiabatic passage and Rydberg blockade

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    We propose to use adiabatic rapid passage with a chirped laser pulse in the strong dipole blockade regime to deterministically excite only one Rydberg atom from randomly loaded optical dipole traps or optical lattices. The chirped laser excitation is shown to be insensitive to the random number \textit{N} of the atoms in the traps. Our method overcomes the problem of the N\sqrt {N} dependence of the collective Rabi frequency, which was the main obstacle for deterministic single-atom excitation in the ensembles with unknown \textit{N}, and can be applied for single-atom loading of dipole traps and optical lattices.Comment: 6 pages, 5 figures. Version 5 is expanded and submitted to PRA. Typo in Fig.4 corrected in Version 2. Version 3 and 4 are duplicates of V

    c ○ 2001 Kluwer Academic Publishers. Manufactured in The Netherlands. Bayesian Object Localisation in Images

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    Abstract. A Bayesian approach to intensity-based object localisation is presented that employs a learned probabilistic model of image filter-bank output, applied via Monte Carlo methods, to escape the inefficiency of exhaustive search. An adequate probabilistic account of image data requires intensities both in the foreground (i.e. over the object), and in the background, to be modelled. Some previous approaches to object localisation by Monte Carlo methods have used models which, we claim, do not fully address the issue of the statistical independence of image intensities. It is addressed here by applying to each image a bank of filters whose outputs are approximately statistically independent. Distributions of the responses of individual filters, over foreground and background, are learned from training data. These distributions are then used to define a joint distribution for the output of the filter bank, conditioned on object configuration, and this serves as an observation likelihood for use in probabilistic inference about localisation. The effectiveness of probabilistic object localisation in image clutter, using Bayesian Localisation, is illustrated. Because it is a Monte Carlo method, it produces not simply a single estimate of object configuration, but an entire sample from the posterior distribution for the configuration. This makes sequential inference of configuration possible. Two examples are illustrated here: coarse to fine scale inference, and propagation of configuration estimates over time, in image sequences. Keywords: vision, object location, Monte Carlo, filter-bank, statistical independenc

    Possible Indication of Narrow Baryonic Resonances Produced in the 1720-1790 MeV Mass Region

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    Signals of two narrow structures at M=1747 MeV and 1772 MeV were observed in the invariant masses M_{pX} and M_{\pi^{+}X} of the pp->ppX and pp->p\pi^{+}X reactions respectively. Many tests were made to see if these structures could have been produced by experimental artefacts. Their small widths and the stability of the extracted masses lead us to conclude that these structures are genuine and may correspond to new exotic baryons. Several attempts to identify them, including the possible "missing baryons" approach, are discussed.Comment: 17 pages including 8 figures and 3 tables. ReVte

    Atomic masses of intermediate-mass neutron-deficient nuclei with relative uncertainty down to 35-ppb via multireflection time-of-flight mass spectrograph

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    High-precision mass measurements of 63^{63}Cu, 6466^{64-66}Zn, 65^{65}Ga, 6567^{65-67}Ge, 67^{67}As, 78,81^{78,81}Br, 80^{80}Rb, and 79^{79}Sr were performed utilizing a multireflection time-of-flight mass spectrograph combined with the gas-filled recoil ion separator GARIS-II. In the case of 65^{65}Ga, a mass uncertainty of 2.1 keV, corresponding to a relative precision of δm/m=3.5×108\delta m / m = 3.5\times10^{-8}, was obtained and the mass value is in excellent agreement with the 2016 Atomic Mass Evaluation. For 67^{67}Ge and 81^{81}Br, where masses were previously deduced through indirect measurements, discrepancies with literature values were found. The feasibility of using this device for mass measurements of nuclides more neutron-deficient side, which have significant impact on the rprp-process pathway, is discussed.Comment: 15 pages, 6 figures, 1 tabl

    \pi N and \eta p deexcitation channels of the N^* and \Delta baryonic resonances between 1470 and 1680 MeV

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    Two reactions, pp->ppX and pp->p\pi^+X, are used to study the 1.47<M<1.68 GeV baryonic mass range. Three different final states are considered in the invariant masses: N^* or \Delta^+, p\pi^0, and p\eta. The last two channels are defined by software cuts applied to the missing mass of the first reaction. Several narrow structures are extracted with widths \sigma(\Gamma) varying between 3 and 9 MeV. Some structures are observed in one channel but not in others. Such nonobservation may be due either to the spectrometer momenta limits or to the physics (e.g. no such disintegration channel is allowed from the narrow state considered). We tentatively conclude that the broad Particle Data Group (PDG) baryonic resonances N(1520)D13, N(1535)S11, Delta(1600)P33, and N(1675)D15 are collective states built from several narrow and weakly excited resonances, each having a (much) smaller width than the one reported by PDG.Comment: 29 pages, plus 50 (.png) figures Will be published in a slightly reduced size in Phys. Rev.
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