Multi-intruder structures in34P

Abstract

The available experimental information on 34 P has been greatly increased through the analysis of γ decays in coincidence with protons from the interaction of an 18 O beam at 24 MeV with an 18 O target. Light charged particles from the reaction were detected with Microball, and multiple γ-ray coincidences with Gammasphere. Many newly observed γ transitions have been identified and placed in the level scheme. Additionally, for most states, spins have been assigned based on measured γ-ray angular distributions while parities were inferred from lifetimes determined through Doppler-broadened line-shape analysis. Most of the states observed have been interpreted in terms of shell-model calculations using the WBP-a and SDPF-NR interactions having one particle in the 0f 7/2 or 1p 3/2 orbital. The two calculations agree almost equally well with the data resulting in root-mean-square differences of about 200 keV. However, a few high-lying states observed with long lifetimes challenge current calculations. Two of these may be associated with stretched πf 7/2 ⊗νf 7/2 states, but the calculations over-predict their energies by 2 -3 MeV. Furthermore, a newly observed long-lived 7919-keV state is established for which no explanation is available at present.

Cross-shell excitations inSi31

“…The excitation energies of all these states decrease with increasing N with the largest drop occurring when approaching the shell closure at N = 19 in 33 Si. A similar pattern was seen in the even-A P isotopes [33]. The WBP-b calculations, also shown in Fig.…”

“…An early shell-model interaction to allow particles out of the 0p orbitals and/or into the 0f -1p shells was called WBP [30] and was adjusted to fit 20 F and 20 Na [31]. It was found [32,33] that the negative-parity states predicted for 32,34 P using the WBP interaction were computed much too high in excitation energy. Accordingly, the single-particle energies of the 0f 7/2 and 1p 3/2 orbitals were reduced by 1.8 and 0.5 MeV, respectively, relative the original WBP interaction.…”

Lee-Yang model from the functional renormalization group

“…However, this conclusion has been questioned by several authors, and two notable mechanisms to stabilize the theory have been proposed. On the one hand, the stability of the model might be tied to PT symmetry [17,18], which is present at criticality, as signaled, for instance, by the imaginary value of the cubic coupling λ. On the other hand, the theory might be rescued through the inclusion of additional degrees of freedom, such as N scalars with O(N) symmetry.…”

Computing eigenfunctions and eigenvalues of boundary-value problems with the orthogonal spectral renormalization method

“…The physical consequences of such symmetry have been intensively studied in many branches of the physical sciences. Extensive studies exist in theoretical physics, where they cover fundamental questions in quantum mechanics [5][6][7][8] and new forms of quantum field theories [9,10]. Recently, relations of PT symmetry with topologically nontrivial phases in many-body systems became important [11][12][13][14][15][16][17][18][19][20].…”