Search results for "Proton"
showing 10 items of 5886 documents
Decays of new nuclides and isomers beyond the proton drip line - The influence of neutron configurations
2008
Bozok University;Erciyes University;et al.;Istanbul University;Nigde University;The Turkish Atomic Energy Authority (TAEK)
Special Relativity and the Single Antiproton: Fortyfold Improved Comparison ofp¯andpCharge-to-Mass Ratios
1995
The measured ratio of charge-to-mass ratios for the antiproton and proton is $1.0000000015\ifmmode\pm\else\textpm\fi{}0.0000000011$. This $1$ part in ${10}^{9}$ comparison ( $1$ ppb) is possible because a single $\overline{p}$ or $p$ is now directly observed while trapped in an open access Penning trap. The comparison is the most accurate mass spectrometry of particles with opposite charge, and is the most sensitive test of $\mathrm{CPT}$ invariance for a baryon system. It is 40 times more accurate than our earlier comparison with many trapped antiprotons and protons, and is more than 45 000 times more accurate than earlier comparisons made with other techniques.
Renormalized Proton-Neutron Quasiparticle Random-Phase Approximation and Its Application to Double Beta Decay
1995
A self-consistent method of treating excitations of the proton-neutron quasiparticle random-phase approximation is presented. The non-self-consistent methods violate the Pauli exclusion principle and lead to an eventual collapse of the ground state. This behavior renders a reliable calculation of the nuclear matrix elements, relevant for the prediction of double-beta-decay half-lives, difficult. The present formalism promotes the Pauli exclusion principle and avoids the collapse of the double-beta-decay matrix elements. We have applied this formalism to the double beta decay of ${}^{100}$Mo.
Cross Sections of232Th (p,xn+yp) Reactions at Ep= 6.8 to 20.2 MeV
1981
Cross-sections for the (p, n), (p, 2n), (p, 3n) and (p, pn) + (p, d) reactions on 232Th targets were measured, by comparison with the K-shell ionization cross-section, for proton energies between 6.8 and 20.2 MeV. The results are compared with the predictions of the statistical and the pre-equilibrium model. For the (p, pn) reaction, the "clean knock-out" model is also considered.
Evolution of proton single-particle states in neutron-rich Sb isotopes beyond N=82
2020
11 pags., 8 figs., 2 tabs.
Precision Mass Measurements of Cr58–63 : Nuclear Collectivity Towards the N=40 Island of Inversion
2018
The neutron-rich isotopes $^{58-63}$Cr were produced for the first time at the ISOLDE facility and their masses were measured with the ISOLTRAP spectrometer. The new values are up to 300 times more precise than those in the literature and indicate significantly different nuclear structure from the new mass-surface trend. A gradual onset of deformation is found in this proton and neutron mid-shell region, which is a gateway to the second island of inversion around \emph{N}=40. In addition to comparisons with density-functional theory and large-scale shell-model calculations, we present predictions from the valence-space formulation of the \emph{ab initio} in-medium similarity renormalization…
Medium-spin structure of neutron-rich Pd and Cd isotopes
2003
Cadmium isotopes are traditionally considered as good examples of nearly spherical, vibrational nuclei, which can be described by quadrupole vibrators in the collective model, as well as the U(5) dynamical symmetry in the interacting boson model (IBM). However, the shape coexistence of more deformed intruder states originating from proton 2p–4h excitation across the Z = 50 major shell is another interesting structural aspect, whose presence in Pd-isotopes has also been demonstrated [1,2].
Reply to "Comment on `Breakdown of the expansion of finite-size corrections to the hydrogen Lamb shift in moments of charge distribution'"
2016
To comply with the critique of the Comment [J. Arrington, arXiv:1602.01461], we consider another modification of the proton electric form factor, which resolves the "proton-radius puzzle". The proposed modification satisfies all the consistency criteria put forward in the Comment, and yet has a similar impact on the puzzle as that of the original paper. Contrary to the concluding statement of the Comment, it is not difficult to find an ad hoc modification of the form factor at low $Q$ that resolves the discrepancy and is consistent with analyticity constraints. We emphasize once again that we do not consider such an ad hoc modification of the proton form factor to be a solution of the puzzl…
Computing the dipole polarizability of 48Ca with increased precision
2018
We compute the electric dipole polarizability of 48Ca with an increased precision by including more correlations than in previous studies. Employing the coupled-cluster method we go beyond singles and doubles excitations and include leading-order three-particle-three-hole (3p-3h) excitations for the ground state, excited states, and the similarity transformed operator. We study electromagnetic sum rules, such as the bremsstrahlung sum rule m_0 and the polarizability sum rule alpha_D using interactions from chiral effective field theory. To gauge the quality of our coupled-cluster approximations we perform several benchmarks with the effective interaction hyperspherical harmonics approach in…
Effects of Pauli blocking on pion production in central collisions of neutron-rich nuclei
2020
Pauli blocking is carefully investigated for the processes of $NN \rightarrow N \Delta$ and $\Delta \rightarrow N \pi$ in heavy-ion collisions, aiming at a more precise prediction of the $\pi^-/ \pi^+$ ratio which is an important observable to constrain the high-density symmetry energy. We use the AMD+JAM approach, which combines the antisymmetrized molecular dynamics for the time evolution of nucleons and the JAM model to treat processes for $\Delta$ resonances and pions. As is known in general transport-code simulations, it is difficult to treat Pauli blocking very precisely due to unphysical fluctuations and additional smearing of the phase-space distribution function, when Pauli blockin…