212 research outputs found

    FIRST experiment: Fragmentation of Ions Relevant for Space and Therapy

    Get PDF
    Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon targe

    Kaons production at finite temperature and baryon density in an effective relativistic mean field model

    Full text link
    We investigate the kaons production at finite temperature and baryon density by means of an effective relativistic mean-field model with the inclusion of the full octet of baryons. Kaons are considered taking into account of an effective chemical potential depending on the self-consistent interaction between baryons. The obtained results are compared with a minimal coupling scheme, calculated for different values of the anti-kaon optical potential.Comment: 3 pages, contribution presented to the International Conference on Exotic Atoms and Related Topic

    Antiproton slowing Down in H2 and He and evidence of nuclear stopping power

    Get PDF
    We report stopping powers of hydrogen and helium for antiprotons of kinetic energies ranging from about 0.5 keV to 1.1 MeV. The Barkas effect, i.e., a difference in the stopping power for antiprotons and protons of the same energy in the same material, shows up clearly in either of the gases. Moreover, below ≈0.5 keV there is indirect evidence for an increase of the antiproton stopping power. This "nuclear" effect, i.e., energy losses in quasimolecular interactions, shows up in fair agreement with theoretical predictions

    Experimental antiproton nuclear stopping power in H2 and D2

    Get PDF
    Data about antiprotons slowing down in gaseous targets at very low energies (E<1 keV) show that the stopping power in D2 is lower than in H2; the right way to explain this behavior seems to be through a nuclear stopping power derived from the classical Rutherford formula

    Protonium annihilation into π0π0 at rest in a liquid hydrogen target

    Get PDF
    The annihilation frequency of the reaction pÂŻ p!p0p0 at rest in liquid hydrogen has been measured by the Obelix experiment by using different apparatus configurations and trigger conditions. The value obtained is f (p0p0, LH)5(2.860.1stat60.4syst)31024. With the same data samples, the p0h annihilation frequency has been determined to be f (p0h, LH)5(0.960.2stat60.1syst)31024. The results are discussed within the frame of the present experimental situation

    Study of the f(0)(1500)/f(2)(1565) production in the exclusive annihilation anti-n.anti-p -> pi+.pi+.pi- in flight

    Get PDF
    The spin-parity analysis of the (n) over bar p --> pi(+)pi(+)pi(-) exclusive reaction in flight is presented. The main aim is to study the (pi(+)pi(-)) invariant mass spectrum in the region around 1500 MeV. The analysis was performed with a Breit-Wigner parametrization for all the resonant states and, for the scalar sector in the mass region below 1.2 GeV, by means of a K-matrix-like treatment. It clearly shows the need for two states, a scalar one (0(++)) with mass and width (1522+/-25) MeV and (108+/-33) MeV, and a tensorial one (2(++)) with mass (1575 +/-18) MeV and width (119+/-24) MeV, respectively. In addition, the analysis requires the presence of a scalar state at (1280+/-55) MeV, (323+/-13) MeV broad, and of a second vectorial one, in addition to the rho(0)(770) signal, with mass and width (1348+/-33) MeV and (275+/-10) MeV, respectively

    Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

    Get PDF
    Abstract. The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay halflife. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are describe

    NURE: An ERC project to study nuclear reactions for neutrinoless double beta decay

    Get PDF
    Neutrinoless double beta decay (0νββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0νββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0νββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0νββ

    New results from the NUMEN project

    Get PDF
    NUMEN aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. First evidence about the possibility to get quantitative information about NME from experiments is found for the (18O,18Ne) and (20Ne,20O) reactions. Moreover, to infer the neutrino average masses from the possible measurement of the half-life of 0νββ decay, the knowledge of the NME is a crucial aspect. The key tools for this project are the high resolution Superconducting Cyclotron beams and the MAGNEX magnetic spectrometer at INFN Laboratori Nazionali del Sud in Catania (Italy). The measured cross sections are extremely low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to increase the experimental yield of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest. peerReviewe

    The PANDA physics program: Strangeness and more

    No full text
    The physics program of the PANDA experiment at FAIR is illustrated, with a particular attention to the planned activity in the field of the doubly strange systems. The investigation of these systems can help, among others, to shed light on the role of the hyperons in the composition of the neutron stars. The great advantages that can be reached in the field of the charmed systems and nucleon structure by using high quality and intense antiproton beams are also recalled
    • …
    corecore