Search results for "SIP"
showing 10 items of 1280 documents
Neutral- and charged-current supernova-neutrino scattering off116Cd
2013
The interest in studies of neutrino–nucleus interactions goes beyond the study of the intrinsic properties of the neutrino extending to a variety of topics in astro-, nuclear and hadronic physics. We report in this paper the results of the calculations of the cross sections of inelastic neutrino–nucleus scattering off 116Cd, focusing on the incoherent neutral-current and charged-current processes, at energies typical of supernova neutrinos. The required nuclear wave functions for the participant initial and final states are constructed using the quasiparticle random-phase approximation in its charge-conserving mode and charge-changing mode. The response of 116Cd to supernova neutrinos and a…
Charged-current neutrino and antineutrino scattering offCd116described by Skyrme forces
2014
We perform calculations of the cross sections for charged-current neutrino and antineutrino scattering off Cd-116 using ten different Skyrme interactions, at energies typical of supernova neutrinos. We use the quasiparticle random-phase approximation in its charged-changing mode (pnQRPA) to construct the required nuclear wave functions for the participant initial and final states. We compare the results of these calculations with the results of calculations based on the Bonn one-boson-exchange potential. The response of Cd-116 to supernova neutrinos is calculated by folding the obtained cross sections with suitably parametrized Fermi-Dirac distributions of the electron-neutrino and electron…
The response of (95,97)Mo to supernova neutrinos
2011
Knowledge about nuclear responses to neutrinos is essential for both astrophysical applications and studies of neutrino properties. We perform in this paper calculations of the cross sections for neutral-current neutrino scattering off the odd A = 95,97 Mo isotopes for energies appropriate for the detection of supernova neutrinos. Both the incoherent and coherent contributions to the cross sections are evaluated. The prominently contributing nuclear final states are identified and analysed. We employ the microscopic quasiparticle-phonon model (MQPM) to construct the wave functions of the initial and final nuclear states. The response of the aforementioned nuclei to supernova neutrinos are c…
Detailed study of the neutral-current neutrino–nucleus scattering off the stable Mo isotopes
2012
Abstract For neutrino detection and for various applications in astrophysics the knowledge of the nuclear responses to astrophysical neutrinos is crucial. Recent studies of neutrino interactions with the 100 Mo nucleus and the other stable molybdenum isotopes are important for the planned MOON (Mo Observatory of Neutrinos) detector. To this aim, in the present work we perform detailed nuclear structure calculations for the neutral-current neutrino–nucleus scattering off the stable molybdenum isotopes. We focus on the differential and total neutrino–nucleus cross sections as well as on flux averaged cross sections to various supernova neutrino spectra. We also propose a more efficient method…
Collective and broken pair states of65,67Ga
1999
Excited states of 65Ga and 67Ga nuclei were populated through the 12C(58Ni,αp) and 12C(58Ni,3p) reactions, respectively, and investigated by in-beam γ-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and γ rays. The level schemes of 65,67Ga were constructed on the basis of γγ-coincidence relations up to 8.6 and 10 MeV excitation energy, and Iπ=27/2 and 33/2+ spin and parity, respectively. The structure of 65,67Ga nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in…
Microscopic anharmonic vibrator approach for beta decays
2007
Abstract We formulate a microscopic description of charge-changing excitations, including dynamical mixture of one- and two-phonon states. The present formalism generalizes our previous microscopic anharmonic vibrator approach (MAVA), designed to treat charge-conserving two- and four-quasiparticle degrees of freedom and their mixing. In the present formalism, the proton–neutron MAVA, pnMAVA, the main building blocks are the quasiparticle random-phase approximation (QRPA) phonons in the charge-conserving channels, and the proton–neutron QRPA (pnQRPA) phonons in the charge-changing channels. The QRPA and pnQRPA equations are directly used in deriving the equations of motion for two-phonon sta…
The AX-PET demonstrator—Design, construction and characterization
2011
Abstract Axial PET is a novel geometrical concept for Positron Emission Tomography (PET), based on layers of long scintillating crystals axially aligned with the bore axis. The axial coordinate is obtained from arrays of wavelength shifting (WLS) plastic strips placed orthogonally to the crystals. This article describes the design, construction and performance evaluation of a demonstrator set-up which consists of two identical detector modules, used in coincidence. Each module comprises 48 LYSO crystals of 100 mm length and 156 WLS strips. Crystals and strips are readout by Geiger-mode Avalanche Photo Diodes (G-APDs). The signals from the two modules are processed by fully analog front-end …
Isomer-tagged differential-plunger measurements in proton-unbound 144Ho
2010
The lifetime of an excited state above a weakly populated isomer in the proton-unbound odd-odd nucleus 144Ho has been measured using the recoil distance Doppler shift method. This measurement represents the first differential-plunger lifetime measurement to utilize recoil-isomer tagging. The first excited I[pi]=(10+) state above the two-quasiparticle [pi]h11/2[circle times operator][nu]h11/2(8+) isomer was determined to have a lifetime of [tau]=6(1)�ps. Potential energy surface calculations, based on the configuration-constrained blocking method, predict the isomeric state to have [gamma]-soft triaxial-nuclear shape with [gamma][approximate]24�. The lifetime of the (10+) state can be unders…
Identification of excited states in119Ba
2000
Excited states have been identified in the very neutron-deficient ${}^{119}\mathrm{Ba}$ nucleus. Two bands have been observed, which are likely to be based on ${h}_{11/2}$ and ${(g}_{7/2}{d}_{5/2})$ neutron orbitals. Despite this being the first observation of excited states in ${}^{119}\mathrm{Ba},$ the bands extend to $(75/2)\ensuremath{\Elzxh}$ and $(79/2)\ensuremath{\Elzxh},$ respectively. The bands have been assigned to ${}^{119}\mathrm{Ba}$ using gamma-recoil and gamma--x-ray coincidences. Several quasiparticle alignments have been identified, involving neutron ${(h}_{11/2}{)}^{2}$ and proton ${(h}_{11/2}{)}^{2}$ aligned configurations. Furthermore, the bands show features which are r…
Effects of orbital occupancies on the neutrinoless beta-beta matrix element of 76Ge
2008
In this work we use the recently measured neutron occupancies in the 76Ge and 76Se nuclei as a guideline to define the neutron quasiparticle states in the 1p0f0g shell. We define the proton quasiparticles by inspecting the odd-mass nuclei adjacent to 76Ge and 76Se. We insert the resulting quasiparticles in a proton-neutron quasiparticle random-phase approximation (pnQRPA) calculation of the nuclear matrix element of the neutrinoless double beta (0-nu-beta-beta) decay of 76Ge. A realistic model space and effective microscopic two-nucleon interactions are used. We include the nucleon-nucleon short-range correlations and other relevant corrections at the nucleon level. It is found that the res…