Alignments, additivity, and signature inversion in odd-oddTa170: A comprehensive high-spin study

Abstract

High-spin states (I 50h) of the odd-odd nucleus 170 Ta have been investigated with the 124 Sn( 51 V,5n) reaction. The resolving power of Gammasphere has allowed for the observation of eleven rotational bands (eight of which are new) and over 430 transitions (∼350 of which are new) in this nucleus. Many interband transitions have been observed such that the relative spins and excitation energies of the 11 bands have been established. This is an unusual circumstance in an odd-odd study. Configurations have been assigned to most of these bands based upon features such as alignment properties, band crossings, B(M1)/B(E2) ratios, and the additivity of Routhians. A systematic study of the frequency at which normal signature ordering occurs in the πh 9/2 νi 13/2 band has been performed and it is found that its trend is opposite to that observed in the πh 11/2 νi 13/2 bands. A possible interpretation of these trends is discussed based on a proton-neutron interaction.

Band crossings inTa166

“…This Brief Report discusses the five rotational sequences now established in 166 Ta and proposes configurations for each of the bands. The investigation of this nucleus coincides with our recent work on heavier odd-odd tantalum nuclei: 170 Ta [2] and 168 Ta [3].…”

“…The crossing frequency of ∼0.33 MeV, and the alignment gain of ∼8h, in band 1 tracks those observed in the νi 13/2 structure in 165 Hf [9] and the πh 11/2 νi 13/2 bands of 168,170 Ta [2,3]. This crossing is typically referred to as the BC alignment, where the second and third lowest i 13/2 quasineutrons align.…”

“…Radware [6] cubes and hypercubes were constructed from this database, and an angular-correlation analysis was also performed that is identical to that described in Ref. [2].…”

“…One may observe at low spin that the experimental values lie in between the two configurations. These two quasiproton orbitals are known to mix [2,3]; therefore, a mixing between these even-parity configurations may correctly describe band 3. In addition, above the crossing (I > 17), the πd 5/2 νi 13/2 configuration correctly reproduces the larger B(M1)/B(E2) ratios.…”

Nonperturbative Ball-Chiu construction of the three-gluon vertex

“…(2.8) is not assumed, but, instead, emerges automatically. (v ) A crucial one-to-one correspondence between m 2 (q) and V αµν (q, r, p) is imposed by the need to evade, in a STI preserving way, the so-called "seagull-identity" [37,38,114]. (vi ) It turns out that Eq.…”