Search results for "Proton"
showing 10 items of 5886 documents
Thermonuclear reactionS30(p,γ)Cl31studied via Coulomb breakup ofCl31
2014
Coulomb breakup at high energy in inverse kinematics of proton-rich Cl-31 was used to constrain the thermonuclear S-30(p,gamma)Cl-31 capture reaction rate under typical Type I x-ray burst conditions. This reaction is a bottleneck during rapid proton-capture nucleosynthesis (rp process), where its rate depends predominantly on the nuclear structure of Cl-31. Two low-lying states just above the proton-separation threshold of S-p = 296( 50) keV in Cl-31 have been identified experimentally using the (RB)-B-3-LAND setup at the GSI Helmholtzzentrum fur Schwerionenforschung GmbH. Both states are considered to play a key role in the thermonuclear S-30( p,gamma)Cl-31 capture reaction. Excitation ene…
Characterization of a new modular decay total absorption gamma-ray spectrometer (DTAS) for FAIR
2013
Beta-decay studies are one of the main goals of the DEcay SPECtroscopy experiment (DESPEC) to be installed at the future Facility for Antiproton and Ion Research (FAIR). DESPEC aims at the study of nuclear structure of exotic nuclei. A new modular Decay Total Absorption gamma-ray Spectrometer (DTAS) is being built at IFIC and is specially adapted to studies at fragmentation facilities such as the Super Fragment Separator (Super-FRS) at FAIR. The designed spectrometer is composed of 16 identical NaI(Tl) scintillation crystals. This work focuses on the characterization of these independent modules, as an initial step for the characterization of the full spectrometer. Monte Carlo simulations h…
Towards a direct measurement of the g-factor of a single isolated protonThis paper was presented at the International Conference on Precision Physics…
2011
Our Penning trap experiment aims at a direct high-precision measurement of the proton g-factor. We present the experimental setup and the measurement technique using the continuous Stern-Gerlach effect. Recent test measurements with a single proton stored in a Penning trap with a strong magnetic bottle and a new toroidal detection system are discussed. For a stringent test of the CPT symmetry the described technique can also be applied to the antiproton.
Comment on the Feasibility of Antiproton Polarization in LEAR by Means of the Transverse Stern-Gerlach Effect
1984
The study of polarization effects in nucleon-nucleon scattering experiments has increased considerably our understanding of the Nuclear forces. Correspondingly it can be expected that the study of polarization phenomena in antiproton-nucleon scattering will also help us to resolve — at least partly — the complicated spin structure of the antiproton-nucleon amplitudes.
The Beta-Delayed Proton and Gamma Decay of 27P for Nuclear Astrophysics
2013
The creation site of 26Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When 26Al is created in novae, the reaction chain is: 24Mg(p,γ)25AI(β+v)25 Mg(p,γ)26Al, but this chain can be by-passed by another chain, 25Al(p, γ)26Si(p, γ)27P and it can also be destroyed directly. The reaction 26m Al (p, γ)27 Si* is another avenue to bypass the production of 26Al and it is dominated by resonant capture. We find and study these resonances by an indirect method, through the…
Proton distortion effects and meson exchange current contributions in the (e,e′p) reaction
1988
It is demonstrated that proton distortion effects could explain the relative enhancement of transverse to longitudinal response in the recent ($e,{e}^{\ensuremath{'}}p$) reactions on $^{12}\mathrm{C}$. The spin-orbit field is essential to bring about this enhancement. The role of the convection current is pointed out. Favorable contributions from pion-pair and isobar-excitation currents are also found.
An experiment on the electroproduction of multi-hadron final states
1995
Abstract Electroproduction of final states including protons and pions was measured on 12C in close to 4π geometry using a BGO crystal ball at the 3-spectrometer facility at MAMI. The energy transfer regime studied at three incident electron energies ranged from the quasielastic proton knockout to the quasifree Δ excitation region. The 3-momentum of the virtual photon ranged from about 400 to 800 MeV/c. The performance of the experimental setup is discribed and missing energy distributions of the reactions 12C(e,e′p) and 12C(e,e′pp) are presented.
First measurement of the circular beam asymmetry in the γ→p→π0ηp reaction
2010
Abstract The circular photon asymmetry for π 0 η photoproduction on the proton was measured for the first time at the tagged photon facility of the MAMI C accelerator using the Crystal Ball/TAPS photon spectrometer. The experimental results are interpreted within a phenomenological isobar model that confirms the dominant role of the Δ ( 1700 ) D 33 resonance. The measured asymmetry allows us to identify small contributions from positive-parity resonances via interference terms with the dominant D 33 amplitude.
Maximally aligned states in the proton drip line nucleus 106Sb
2005
High-spin states in Sb-106 have been investigated in the Fe-54(Ni-58, 1α 1p1n) reaction by in-beam γ-spectroscopic methods using the EUROBALL detector array equipped with charged particle and neutr ...
Shape coexistence at the proton drip-line: First identification of excited states inPb180
2010
Excited states in the extremely neutron-deficient nucleus {sup 180}Pb have been identified for the first time using the JUROGAM II array in conjunction with the RITU recoil separator at the Accelerator Laboratory of the University of Jyvaeskylae. This study lies at the limit of what is presently achievable with in-beam spectroscopy, with an estimated cross section of only 10 nb for the {sup 92}Mo({sup 90}Zr,2n){sup 180}Pb reaction. A continuation of the trend observed in {sup 182}Pb and {sup 184}Pb is seen, where the prolate minimum continues to rise beyond the N=104 midshell with respect to the spherical ground state. Beyond-mean-field calculations are in reasonable correspondence with the…