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Related papers: The Nuclear Pairing Gap -- How Low Can It Go?

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We perform ab initio calculations of three-point mass differences in the odd- and even-mass $^{39-49}$Ca isotopes to probe nuclear superfluidity via empirical neutron pairing gaps. We also quantify the sensitivity of those gaps to the…

Nuclear Theory · Physics 2026-05-15 A. Scalesi , A. Ekström , C. Forssén , G. Hagen

We report the results of a calculation of the nuclear matrix element of neutrinoless double-$\beta$ decay of $^{48}$Ca, carried out taking into account nucleon-nucleon correlations in both coordinate- and spin-space. Our numerical results,…

Nuclear Theory · Physics 2015-06-18 Omar Benhar , Riccardo Biondi , Enrico Speranza

The existence of compact stellar remnants in the mass range $2-5\,M_{\odot}$ has long been debated. This so-called lower mass gap was initially suggested by the lack of low-mass X-ray binary observations with accretors about…

High Energy Astrophysical Phenomena · Physics 2024-11-05 Claire S. Ye , Kyle Kremer , Scott M. Ransom , Frederic A. Rasio

Stellar theory predicts a forbidden range of black-hole masses between ${\sim}50$--$130\,M_\odot$ due to pair-instability supernovae, but evidence for such a gap in the mass distribution from gravitational-wave astronomy has proved elusive.…

Beta-decay properties of neutron-rich Ca isotopes have been obtained. Half-life values were determined for the first time for 54Ca [86(7) ms], 55Ca [22(2) ms], and 56Ca [11(2) ms]. The half-life of 230(6) ms deduced for 53Ca is…

With the help of the static and dynamic mean field spectroscopic amplitudes, taking into account successive and simultaneous transfer channels properly corrected because of non-orthogonality effects, as well as describing the associated…

Nuclear Theory · Physics 2017-08-23 Gregory Potel , Ricardo A. Broglia

We discuss the spatial structure of the Cooper pair in dilute neutron matter and neutron-rich nuclei by means of the BCS theory and the Skyrme-Hartree-Fock-Bogioliubov model, respectively. The neutron pairing in dilute neutron matter is…

Nuclear Theory · Physics 2017-08-23 Masayuki Matsuo

The last proton bound calcium isotope $^{35}$Ca has been studied for the first time, using the $^{37}$Ca($p, t$)$^{35}$Ca two neutron transfer reaction. The radioactive $^{37}$Ca nuclei, produced by the LISE spectrometer at GANIL,…

The recent discovery of a central compact object (CCO) within the supernova remnant HESS J1731-347, characterized by a mass of approximately $0.77^{+0.20}_{-0.17} M_{\odot}$ and a radius of about $10.4^{+0.86}_{-0.78}$ km, has opened up a…

Nuclear Theory · Physics 2024-04-10 Bikai Gao , Yan Yan , Masayasu Harada

We present a new semiclassical theory for describing pairing in finite Fermi systems. It is based on taking the $\hbar \to 0$, i.e. Thomas-Fermi, limit of the gap equation written in the basis of the mean field (weak coupling). In addition…

Nuclear Theory · Physics 2015-05-28 X. Viñas , P. Schuck , M. Farine

We determine the influence of the three-body force and the medium modification of meson masses on pairing in nuclear and neutron matter. A reduction of the pairing gap is found and increasing with density.

Nuclear Theory · Physics 2009-11-07 W. Zuo , U. Lombardo , H. -J. Schulze , C. W. Shen

The electromagnetic and weak neutral current matrix elements that enter in the analysis of parity-violating quasielastic electron scattering are calculated using a continuum nuclear shell model. New approximations to the on-shell…

Nuclear Theory · Physics 2008-11-26 J. E. Amaro , J. A. Caballero , T. W. Donnelly , A. M. Lallena , E. Moya de Guerra , J. M. Udias

We present results for the $^3P_2 - ^3F_2$ pairing gap in neutron matter with several realistic nucleon-nucleon potentials, in particular with recent, phase-shift equivalent potentials. We find that their predictions for the gap cannot be…

Nuclear Theory · Physics 2008-11-26 M. Baldo , O. Elgaroey , L. Engvik , M. Hjorth-Jensen , H. -J. Schulze

The recently confirmed neutron-shell closure at N = 32 has been investigated for the first time below the magic proton number Z = 20 with mass measurements of the exotic isotopes 52,53K, the latter being the shortest-lived nuclide…

The pairing gaps, heat capacities and level densities are calculated within the BCS-based quasiparticle approach including the effect of thermal fluctuations on the pairing field within the pairing model plus noncollective rotation along…

Nuclear Theory · Physics 2012-07-25 N. Quang Hung , N. Dinh Dang

The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different…

Nuclear Theory · Physics 2015-02-20 D. Ding , S. J. Witte , W. H. Dickhoff , H. Dussan , A. Rios , A. Polls

The problem of closing the detection loophole with asymmetric systems, such as entangled atom-photon pairs, is addressed. We show that, for the Bell inequality I_3322, a minimal detection efficiency of 43% can be tolerated for one of the…

Quantum Physics · Physics 2009-11-13 Nicolas Brunner , Nicolas Gisin , Valerio Scarani , Christoph Simon

The gap equation in the $^1S_0$-channel is solved for a nuclear slab with the separable form of the Paris potential. The gap equation is considered in the model space in terms of the effective pairing interaction which is found in the…

Nuclear Theory · Physics 2009-11-11 S. S. Pankratov , M. Baldo , U. Lombardo , E. E. Saperstein , M. V. Zverev

The nucleon separation energies and shell gaps in nuclei over the whole nuclear chart are systematically studied with eight global nuclear mass models. For unmeasured neutron-rich and super-heavy regions, the uncertainty of the predictions…

Nuclear Theory · Physics 2015-06-22 Qiuhong Mo , Min Liu , Ning Wang

The electromagnetic transitions to various low-lying excited states of 16O, 48Ca and 208Pb are calculated within a model which considers the short-range correlations. In general the effects of the correlations are small and do not explain…

Nuclear Theory · Physics 2008-11-26 Sherif R. Mokhtar , Giampaolo Co' , Antonio M. Lallena