Spectroscopy of 62Ni with the 61Ni(d, p) reaction

Differential cross sections, vector and tensor analysing powers have been measured for the ⁶¹Ni(d, p) reaction at a deuteron energy of 12.3 MeV. Most of the 30 transitions observed below 8.5 MeV excitation are dominated by a single j-value, which was determined from behaviour of the analysing power data. For a number of transitions it was possible to make unambiguous j-assignment relying on the established j-dependence of the T₂₂ tensor analysing power. The deduced spectroscopic factors indicate that the full strength of neutron transfer to the ($\text{2p, 1f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$) and $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ orbits was found and seven $\text{5}\text{2}{}^{\mathrm{+}}$ transitions were located above 5.3 MeV. The separated strengths of the $\text{3}\text{2}{}^{\mathrm{?}}\text{,}\text{1}\text{2}{}^{\mathrm{?}}\text{and}\text{5}\text{2}{}^{\mathrm{?}}$ transitions are compared with shell-model calculations for the low-lying states of ⁶²Ni.     

The (d,t) and (d,t) reactions on 18O and the 1p spin-orbit splitting

The reactions ¹⁸O(d, t)¹⁷O and ¹⁸O(d, τ)¹⁷N have been investigated at ifE_{d = 52 MeV}. Energy spectra of tritons and τ particles have been measured up to excitation energies of 25 MeV in ¹⁷O and 12 MeV ¹⁷N, respectively, and spectroscopic factors have been obtained by a DWBA analysis of the measured angular distributions. From a comparison of the t-and τ-spectra the distribution of $\text{T =}\text{1}\text{2}\text{and}\text{3}\text{2}$ spectroscopic strengths in ¹⁷O could be deduced and analog relations between $\text{T =}\text{3}\text{2}$ states in ¹⁷N and ¹⁷O could be established. Nearly the total $\text{T =}\text{3}\text{2}$ strengths of the $\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{and}\text{1}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ shells and nearly the complete $\text{T =}\text{1}\text{2}$ strength of the $\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ shell have been found, whereas only one third of the $\text{T =}\text{1}\text{2}$ strength of the $\text{1}\text{p}\text{3}\text{2}$. Shell could be clearly identified. The observed centroid energies are understood from the different $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$$\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?}}\text{1)}$ and $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ effective residual interactions. This supports a strong isospin dependence of the 1p spin-orbit splitting.     

207Pb(p,p') measurements at 135 and 61 MeV,the effective interaction and core polarization

Data at Einp = 61 and 135 MeV for neutron-hole transitions are used to study the proton-neutron part of the assumed NN force. Collective core-polarization strengths (A_L) from the present fits at 135 MeV are consistent with those extracted from the (e, e') reaction for two L = 2 transitions and one L = 4 transition. This is not the case at 61 MeV where the A_L values needed to fit the (p, p') data are much smaller for transitions to the $\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{and}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ hole states. A fully microscopic DWBA fit is successful for the L = 3 transition to the doublet at 2.64 MeV of excitation at E_p = 61 MeV, but fails at 135 MeV; a fully microscopic DWIA calculation provides a reasonable fit to the data at 135 MeV.     

The particle-hole spectra of 16O and 16N as observed in pick-up reactions from 17O

The reactions ¹⁷O(d, t) ¹⁶O and ¹⁷O(d, τ)¹⁶N have been investigated at E_d = 52 MeV. Energy spectra of tritons and τ-particles have been measured simultaneously up to excitation energies of 22 MeV in ¹⁶O and 10 MeV in ¹⁶N, respectively. Spectroscopic factors have been obtained by a DWBA analysis of the measured angular distributions. From the comparison of the t- and τ-spectra analog (T = 1) states in ¹⁶O could be identified and the distribution of T = 0 and T = 1 spectroscopic strengths could be deduced. Nearly the total $\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and $\text{1}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ hole strengths have been found and the $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{1}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{and}\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{1}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$ particle-hole multiplets could be located both for T = 0 and T = 1. The average residual interactions in both shell-model configurations turned out to be strikingly different.     

The interaction of 33 MeV polarised helions with 30Si

Distributions of cross sections and analysing powers have been measured over the range ～ 14°–100° c.m. for the $\text{(}{}^3\text{H}\text{,}{}^3\text{He), (}{}^3\text{H}\text{,}{}^4\text{He), (}{}^{\mathrm{<mtext>3</mtext><mtext>H</mtext>}}\text{,}{}^2\text{H)}$ reactions at 33.4 MeV incident e using a ～ 95 % enriched ³⁰Si target. Phenomenological optical-model analyses of the elastic-scattering data have been carried out. A DWBA analysis of the inelastic-scattering data for the 2.24 MeV (2⁺) and 5.49 MeV (3^?) states of ³⁰Si has yielded values of the deformation β₂ and β₃. The j-dependence of the analysing powers for the (³He, ⁴He) and (³He, ²H) reactions has identified the 6.71 MeV level of ²⁹Si as a $\text{5}\text{2}{}^{\mathrm{+}}$ state, and a level near 9.5 MeV in ³¹P as a possible $\text{7}\text{2}{}^{\mathrm{?}}$ state. Spectroscopic factors for ten states in ²⁹Si and seven states in ³¹P have been deduced and are compared with other work. The extent to which the data defines the ³He spin-orbit potential is discussed.     

(f72)7,0−2 configuration high-spin states in 60Co strongly excited in the 62Ni(d, α) reaction

The ${}^{62}\text{Ni}\text{(}\text{d}\text{, α)}{}^{60}\text{Co}$ reaction has been studied with 78 MeV vector polarized deuterons. Angular distributions of the differential cross section and vector analyzing power have been measured for strongly populated states in ⁶⁰Co up to an excitation energy of 5 MeV. The transferred orbital and total angular momenta L and J were determined from the characteristic shapes of the differential cross sections and vector analyzing powers yielding a number of new spin assignments. The J^π = 7⁺ stretched configuration was found to be distr least over nine states located at 1.51, 3.09, 3.46, 3.67, 3.78, 4.04, 4.55, 4.70 and 4.80 MeV.     

The reaction 55Mn(d, t)54Mn

Neutron pick-up cross sections and vector analyzing powers have been measured for the reaction ⁵⁵Mn($\text{d}$, t)⁵⁴Mn at 17 MeV. The mixture of $\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ to $\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ transfer to the low-lying l_n = 1 states has been found. Evidence of the $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ hole nature of several strong l_n = 3 states above 1 MeV has been obtained.     

Spin of deep-hole states in 111Sn via the 112Sn(d, t) reaction

Analyzing powers measured in the study of ${}^{112}\text{Sn}\text{(}\text{d}\text{,}\text{t}\text{)}\text{at}\text{40}\text{MeV}$ bombarding energy show strong J-dependence and have been used to clearly assign the spin of a number of low-lying states in the residual nucleus. At high excitation energy (3.5–6 MeV). the inner-hole strength is shared between clearly isolated peaks on one hand and a fragmented structure on the other. This work reports on the determination of the spin of the inner-hole states and consequently on a more precise measurement of the overlapping regions between $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{, 2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, 2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ Subshell components. The analyzing power data shows that the group of peaks located between 3.4 and 4.5 MeV consist of spins $\text{J =}\text{9}\text{2}\text{+}\text{1}\text{2}$, in agreement with the excitation of the $\text{1}\text{g}\text{1}\text{2}\text{and}\text{2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ inner- hole strengths in ¹¹¹Sn. In addition a substantial amount of the $\text{2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ component is observed between 4.5 and 6.0 MeV.The results of the data analysis allow us to clearly eastablish the spreading of the $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ innerhole strength and to a lesser extent the strong fragmentation of the $\text{2}\text{p}\text{1}\text{2}\text{and}\text{2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ inner-hole subshells.     

Angular distributions for the 12C(K−,π−)12ΛC reaction

The distorted wave impulse approximation (DWIA) is used to calculate angular distributions for ${}^{12}\text{C}\text{(}\text{K}{}^{\mathrm{?}}\text{,π}{}^{\mathrm{?}}\text{)}{}^{12}{}_{\mathrm{\Lambda }}\text{C}{}^1$ at 800 MeV/c. The results are compared with recent Brookhaven data.     

M1 states in 58Ni observed by proton inelastic scattering at 65 MeV

Inelastic proton scattering at 65 MeV was used to study 1⁺ states in ⁵⁸Ni. A new 1⁺ state was found at an excitation of 5.166 MeV. The angular distributions for the 1⁺ states at 2.903 and 5.166 MeV were well reproduced by a DWBA calculation under the assumptions of pure $\text{v(}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}\text{and}\text{v(}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}$ configurations, respectively. The angular distribution for the previously suggested 1⁺ state at 7.721 MeV was not well discribed by the DWBA calculation with the isoscalar $\text{(}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}$ wave function. The shape of the angular distribution for the 10.672 MeV, 1⁺ state was well reproduced by the DWBA calculation with the isovector $\text{(}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{)}$ wave function.     

Study of Kπ scattering using the reactions K±p → K±π+nand K±p → K±π−Δ ++at 13 GeV

An elastic Kπ partial-wave analysis is presented. It is based on high statistics data for the reactions $\text{K}{}^{\mathrm{\pm }}\text{p}\text{→}\text{K}{}^{\mathrm{\pm }}\text{π}{}^{\mathrm{+}}\text{n}\text{and K}{}^{\mathrm{\pm }}\text{p}\text{→}\text{K}{}^{\mathrm{\pm }}\text{π}{}^{\mathrm{?}}\text{Δ}{}^{\mathrm{++}}\text{at}\text{13}\text{GeV}$ obtained in a spectrometer experiment performed at SLAC. For each reaction, a t-dependent parametrization of the production amplitudes provides information on both the Kπ mass dependence of the production mechanisms and on Kπ scattering. Knowledge of the t-dependence then allows a calculation of the Kπ partial-wave amplitudes for Kπ masses from 0.7 to 1.9 GeV. The results of such analyses using data for (i) the neutral recoil reactions, (ii) the Δ⁺⁺ recoil reactions, and (iii) both neutron and Δ⁺⁺ recoil reactions simultaneously, are presented. Besides the leading J^P = 1^?, 2⁺, and 3^? resonances at M_Kπ = 0.896, 1.434, and 1.78 GeV, there is evidence in two of the four possible partial-wave solutions for a broad P-wave resonant-like structure in the region of 1700 MeV. The $\text{I =}\text{1}\text{2}$ S-wave magnitude rises slowly and smoothly to a maximum near 1400 MeV, but then decreases rapidly between 1400 and 1600 MeV. This structure is strongly indicative of an S-wave resonance near 1450 MeV. The charge-two Kπ reaction is dominated by S-wave scattering with a total cross section decreasing from 4 mb at 0.9 GeV to 2 mb at 1.5 GeV. Both the $\text{I =}\text{1}\text{2}$ S-wave below 1400 MeV and the $\text{I =}\text{3}\text{2}$ S-wave are well described by an effective range parametrization.     

Study of the germanium isotopes with the (p,t) reaction

The levels of ^{70, 71, 72, 74}Ge have been investigated with the (p, t) reaction at 20 MeV. Strong transitions to the ground state and to the 2₁⁺ and 3₁^? collective levels were observed for all even isotopes. A comparison of the experimental angular distributions with those calculated assuming a closed ⁷⁰Ge core indicates that only ≈ 15% of the observed ground state L = 0 transition strength comes from $\text{(1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{)}{}^2\text{and}\text{(2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{)}{}^2$ pick up. The excitation energies and L-transfers obtained in the present work are found to be in generally good agreement with previous data.     

The distribution of 3p12 strength in 209Bi

An optimized Woods-Saxon potential, which gives excellent fits to the observed proton states in ²⁰⁹Bi and ²⁰⁷Tl, is used to calculate the excitation energy of the unbound $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ proton state in ²⁰⁹Bi. Using the wave functions given by the above potential, the strength of the core-particle interaction is calculated. The effect of the vibration of the core on the fragmentation of the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state is estimated. It is found that the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state at 5.123 MeV loses more than 80% of its strength to five $\text{1}\text{2}{}^{\mathrm{?}}$ collective states in ²⁰⁹Bi and the observed $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ state at 3.64 MeV is actually an almost equal mixture of the $\text{3p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ single-proton state and the ($\text{4}{}^{\mathrm{+}}\text{, 1}\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$) collective state.     

Two-quasiproton states in 168Er studied by the 169Tm(t, α)168Er reaction

The ${}^{169}\text{Tm}\text{(}\text{t}\text{, α)}{}^{168}\text{Er}$ reaction has been studied using 17 MeV polarized tritons from the Los Alamos National Laboratory tandem Van de Graaff accelerator. The α-spectra were analyzed with a Q3D magnetic spectrometer. The overall energy resolution was typically ~ 15 keV (FHWM) and angular distributions of cross sections and analyzing powers were obtained for levels up to ~ 2.7 MeV. The fact that spins and parities for all levels up to ? 2 MeV were previously known from an extensive series of (n, γ) studies made it possible to determine specific two-quasiproton structures for many bands from the present results. The K^π = 2⁺ γ-vibrational band was found to have a large $\text{3}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ admixture, consistent with the predicted microscopic composition of this phonon, but no $\text{5}\text{2}\text{[413]}{}_{\mathrm{<mtext>p</mtext>}}\text{?}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ component was observed. The K^π = 0₄⁺ band at 1833 keV has ～ 25% of the $\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}\text{?}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ two-quasiproton strength. This is in excellent agreement with the Soloviev model but is inconsistent with the interacting boson model, in which the K^π = 0₄⁺ band is composed almost completely of multiphonon configurations that should not be populated in a single-nucleon transfer reaction. The $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{?}}\text{,}\text{7}\text{2}{}^{\mathrm{?}}\text{[523]}{}_{\mathrm{<mtext>p</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{+}}\text{[411]}{}_{\mathrm{<mtext>p</mtext>}}$ two-quasiproton and the $\text{K}{}^{\mathrm{\pi }}\text{= 4}{}^{\mathrm{?}}\text{,}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}{}_{\mathrm{<mtext>n</mtext>}}\text{+}\text{1}\text{2}{}^{\mathrm{?}}\text{[521]}{}_{\mathrm{<mtext>n</mtext>}}$ two-quasineutron states are mixed strongly with each other, but the two K^π = 3^? bands composed of antiparallel couplings of the same particles are not. A good qualitative explanation of this mixing pattern is provided in terms of the effective neutron-proton interaction.     

Spin determination of states with stretched configurations in 16N and 32P via the (d, α) reaction at 52 MeV

The reactions ${}^{12}\text{C}\text{(}\text{d}\text{, α)}{}^{10}\text{B}\text{,}{}^{18}\text{O}\text{(}\text{d}\text{, α)}{}^{16}\text{N and}{}^{34}\text{S}\text{(}\text{d}\text{, α)}{}^{32}\text{P}$ have been investigated at E_d = 52 MeV. Vector analyzing powers as large as $\text{¦iT}{}_{11}\text{¦=0.85}$ are observed. They exhibit patterns characteristic for final spins I = |L?1|, L or L + 1 and provide spin determinations at least for states of unique L-transfer. Local, zero-range DWBA calculations assuming deuteron-cluster pick-up reproduce qualitatively the observed effects. The method has been tested for states of known spin, and then has been applied to determine spins of states with stretched coupling in ¹⁶N: J^π = 3⁺(3.96 MeV), 4^?(6.17 MeV) and in ³²P: J^π = 5⁺(4.75 MeV). There is strong evidence for further 5⁺ states in ³²P at 6.43, 7.96, 8.09 and 8.54 MeV.     

Direct capture in the 24Mg(p, γ)25Al reaction

Excitation functions for the ²⁴Mg(p, γ)²⁵Al capture reaction have been obtained for the beam energy range E_p = 0.2–2.3 MeV. The analysis of these data revealed the presence of the direct capture process to the low-lying states in ²⁵Al at , $\text{945(}\text{3}\text{2}{}^{\mathrm{+}}\text{), 2485(}\text{1}\text{2}{}^{\mathrm{+}}\text{)}\text{and}\text{3062}\text{keV}\text{(}\text{3}\text{2}{}^{\mathrm{?}}\text{)}$. The presence of the weaker direct capture transitions is manifested through interference effects on the tails of the two broad resonances at E_p = 823 and 1623 keV. The deduced spectroscopic factors for these final states in ²⁵Al are compared with the corresponding values from stripping data as well as model calculations. An astrophysical S-factor of S(0) ≈ 30 keV· b for this reaction has been obtained.     

The octupole giant resonance strength in 16O

Angular distributions for polarized proton inelastic scattering cross sections along with the analysing power for the reaction ${}^{16}\text{O}\text{(}\text{p}\text{,}\text{p}\text{′)}{}^{16}\text{O}{}^1\text{(2}{}^{\mathrm{?}}\text{, 8.88}\text{MeV}\text{)}$ at E_p=42.5, 44.0 and 49.3 MeV have been measured. A semidirect reaction analysis augments the evidence for octupole giant resonance strength in the 30 to 50 MeV energy region.     

Quantitative evidence of weak isospin mixing in the low-lying isobaric analog resonances in 209Bi

The excitation functions of ${}^{208}\text{Pb}\text{(}\text{p}\text{,}\text{p}{}_0\text{)}{}^{208}\text{Pb}$ have been measured in the energy range E_p = 14.2 to 17.4 MeV in 50 keV steps at θ_lab = 120°, 140° and 160°. The isobaric analog resonances of the parent states in ²⁰⁹Pb up to E_x = 2.5 MeV and the optical-model background were fit simultaneously at all energies and angles. The spreading widths and the values of a parameter β², which measures the isospin purity of the IAR, were determined for the $\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}\text{,}\text{i}{}_{\mathrm{<mtext>11</mtext><mtext>2</mtext>}}\text{,}\text{j}{}_{\mathrm{<mtext>15</mtext><mtext>2</mtext>}}\text{,}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$, and $\text{s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ resonances. An average value of the isospin purity of β² = 66% was found.