H. Terry Fortune

Professor
DRL 1N11
(215) 898-6024
(215) 898-2010

Ph.D. Florida State Universtiy - 1967
B.S. (summa cum laude) Memphis State University - 1963

 

  • Professor, University of Pennsylvania (1976-
  • Associate Professor, University of Pennsylvania (1972-76)
  • Assistant Professor, University of Pennsylvania (1969-72)
  • Postdoctoral Appointee, Argonne National Lab (1967-69)
Research Interests: 

 

  1. Structure of nuclei far from stability

“Neutron decays of 13Be to the excited 0+ state of 12Be”, Fortune and Sherr, Phys. Rev. C 82, 064302 (2010).

See also Phys. Rev. C 83, 024311 (2011).

  1. Masses of exotic nuclei

“18Na: Mass excess and low-lying states”, Fortune and Sherr, Phys. Rev. C 72, 034304 (2005) Coulomb energies in 17Ne and the gs mass of 18Na”, Fortune, Sherr, and Brown, Phys. Rev. C 73, 064310 (2006); “Two-proton decay energy and width of 19Mg(g.s)”, Fortune and  Sherr Phys. Rev. C 76, 014313 (2007);   Phys. Rev. C 83, 057301 (2011).

  1. Isospin symmetry and Coulomb energies

“Coulomb energies in18Ne”, Sherr and Fortune, Phys. Rev. C 58, 3292 (1998); “Structure of 12Be and 12O ground states”, Sherr and Fortune, Phys. Rev. C 60, 064323 (1999).

See also Eur. Phys. J. A5, 371 (1999); Phys. Lett. B503, 70 (2001); Phys. Rev. C 74, 054310 (2006); Phys. Rev. C 82, 027310 (2010); Phys. Lett. B  699, 281 (2011).

  1. Use of transfer reactions to determine widths for nuclear astrophysics

"Resonant rate for 15O (alpha,gamma)19Ne", Mao, Fortune, and Lacaze, Phys. Rev. Lett. 74,3760 (1995).

See also Phys. Rev. C 53, 1197 (1996); Phys. Rev. C 67, 064305(2003); Phys. Rev. C 68, 034317(2003); Phys. Rev. C 82, 034312 (2010).

  1. Collective states in pion double charge exchange

"Giant dipole resonances built on isobaric analog states in pion double charge exchange," S. Mordechai, et al., Phys. Rev. Lett. B 60, 408 (1988); "Pion double charge exchange to the double dipole resonance,"  Mordechai, et al., Phys. Rev. Letters 61, 531 (1988).  See also Phys. Rev. C 40, 850 (1990); Phys. Rev. C 41, 202 (1990).

  1.  Mechanism of pion-induced double charge exchange

“Systematics of pion double-charge-exchange reactions on T = 0 Nuclei”, Bland, et al, Phys. Lett. B 128, 157 (1983); ”DCX to the DIAS at Tpi = 292 MeV”, Zumbro, et al, Phys. Rev. C 36, 1479 (1987).

See also Phys. Rev. C 29, 2395 (1984); Phys. Rev. C 32, 349 (1985); Phys. Rev. C 34, 1895 (1986); Phys. Rev. C 35, 1334 (1987); Nucl. Phys. A 483, 514 (1988).

  1. Core-excitation amplitudes from transfer reactions

“Direct determination of (sd)3 (1p)-2 component in 17O(gs)”. Fortune, Bishop, Medsker, and Wildenthal, Phys. Rev. Lett. 41, 527 (1978).

See also Phys. Rev. C 18, 1563 (1978).

  1. Neutron-rich light nuclei via the (t,p) reaction

“Spectroscopy of 16C”, Fortune, et al, Phys. Lett. B 70, 408 (1977).

See also Phys. Rev. Lett. 40, 1236 (1978); Phys. Rev. C 18, 2727 (1978); Phys. Rev. C 28, 977 (1983); Phys. Rev. C 50, 1355 (1994).

  1. Resonances in (12C,alpha) reactions

“Resonances in 12C(12C, alpha)20Ne”, Fortune, Greenwood, Segal, and Erskine, Phys. Rev. C 15, 439 (1977).

See also Phys. Lett. B 63, 403 (1976); Phys. Rev. C 14, 1271 (1976).

  1. Nuclear coexistence and weak coupling

“Structure of 0+ states in 18O”, Fortune and Headley, Phys. Lett. B 51, 136 (1974); “Structure of low-lying positive-parity states of 18O”, Lawson, Serduke, and Fortune, Phys. Rev. C 14, 1245 (1975).

See also Nucl. Phys.A 465, 123 (1987).

  1. Multi alpha-particle clustering in nuclei

“Evidence for quartet states in 20Ne”, Middleton, Garrett, and Fortune, Phys. Rev. Lett. 27, 950 (1971).

See also Phys. Lett. B 52, 51 (1974).

  1. Use of mirror reactions to identify mirror states

“Study of mirror states in A = 19 with the (6Li, t) and (6Li, 3He) reactions on 16O”, Bingham, Fortune, Garrett, and Middleton, Phys. Rev. Lett. 26, 1448 (1971).

See also Phys. Rev. C 5, 682 (1971).

  1. Stripping to unbound states

“New method for distorted-wave analysis of stripping to unbound states”, C. M. Vincent and H. T. Fortune, Phys. Rev. C 2, 782 (1970).

See also Phys. Rev. 185, 1401 (1969); Phys. Rev. C 7, 865 (1973);  Phys. Rev. Lett. 43, 341 (1979).

  1. Heavy ion elastic scattering

“Close similarities in the excitation functions from the elastic 16O scattering from nuclei with A near 16”, Siemssen, et al, Phys. Rev. Lett. 25, 536 (1970).

See also Phys. Rev. C 5, 1839 (1972).

  1. Using reactions of type (Heavy ion in, light ion out) to populate high angular momentum states

“Selective population of highly excited states observed in the    16O(12C,alpha) 24Mg reaction”, Middleton, Garrett, and Fortune, Phys. Rev. Lett. 24, 1436 (1970).

See also Phys. Lett. B 39, 339 (1972)

 

 

Selected Publications: 

 

65. Properties of low-lying negative-parity states in C16
H. T. Fortune and Y. Satou
Phys. Rev. C 90, 034308 (2014) – Published 12 September 2014

Recent results concerning negative-parity states in C16 are analyzed in terms of the shell model and a simple weak-coupling model. We suggest the state at 6.28 MeV is 2−, and the state near 6.1 MeV is not 3−, but probably 1− (0−

64.  Width of Ne16(g.s.),

H. T. Fortune,

Phys. Rev. C 90, 024323 – Published 25 August 2014.

I have computed widths for 2p decay of Ne16 to 14O+2p. For both simultaneous and sequential decay, my calculated widths are considerably smaller than other theoretical values—all of which are considerably smaller than the most recent experimental value and a recent upper limit.

 

63.  (sd)2 0+ states coupled to p-shell cores,

H. T. Fortune,

Phys. Rev. C 89, 067302 – Published 25 June 2014.

Energies of the two lowest (sd)20+ states in Be10,12 and C14,16 are examined in a simple model that works surprisingly well. Energies are predicted for the second (sd)2 0+ state in Be10,12, where they are unknown.

 

62.  Properties of low-lying levels of Be14,

H. T. Fortune,

Phys. Rev. C 89, 044312 – Published 8 April 2014.

In a simple model, I have calculated energy splittings and wave functions of low-lying states in Be14. Data from 2n decays of 2+ states allow estimates of the (sd)4 admixtures in the predominantly (sd)2 states. I demonstrate that the first 2+ state is predominantly of ds structure, not dd as recently claimed.

 

61.  High-J states in 17C,

H.T. Fortune,

Nuclear Physics A, Volume 922, February 2014, Pages 163-167.

I examine positive-parity states of 17C with , with emphasis on an earlier shell-model calculation and a recent calculation of a different sort. I find that experimental evidence strongly favors the shell model

 

 

60.  Jπ of 6He(5.3 MeV),

H. T. Fortune,

Phys. Rev. C 89, 014326 – Published 28 January 2014.

Consideration of its energy, angular-distribution shape, and magnitude of a cross section in the reaction He(p,t) leads me to conclude that the 5.3-MeV state is likely 0+.

 

59.  Lowest negative-parity states in Be12,

H. T. Fortune,

Phys. Rev. C 89, 017302 – Published 23 January 2014.

A very simple model is applied to the first four negative-parity states of Be12. Energies of the corresponding four states in C14 are used to validate the model and to determine the doublet splitting parameters. Predictions for Be12 are in remarkable agreement with excitation energies of the known 1− at 2.70 MeV and the suspected (3−) at 4.56 MeV. Predicted excitation energies of 0− and 2− are 3.59 and 5.12 MeV, respectively.

 

58.  Relative population of 0+ states in 10He in various reactions,

H. T. Fortune,

Phys. Rev. C 88, 054623 – Published 26 November 2013.

By using simple direct-reaction models, I have estimated the ratio of excited 0+ to ground-state production in 10He for several different reactions. I present the results as a function of the amount of mixing between the two basis states.

 

57.  Potential-model estimate of the mass of 11O(g.s.),

H. T. Fortune and R. Sherr,

Phys. Rev. C 88, 034326 – Published 29 September 2013.

By using mirror symmetry and information from 11Li, we have used a simple potential model to estimate the energies of the s2 and p-shell components of 11O(g.s.). We present the predicted 11O mass in terms of the mixing of these two components.

 

56.  Structure of 10He and the reaction 8He(t,p),

H. T. Fortune,

Phys. Rev. C 88, 034328 – Published 29 September 2013.

I review the situation regarding the ground and low-lying states of 10He, with special emphasis on the reaction 8He(t,p). I present calculations of relative cross sections for 0+ and 1− states. I conclude that the strong state reported near 5.5 MeV is probably not 1−.

 

55.  Comment on “Three-body properties of low-lying 12Be resonances”,

H. T. Fortune,

Phys. Rev. C 88, 039801 – Published 10 September 2013.

A recent paper [Phys. Rev. C 86, 024310 (2012)] that concerned 12Be suggested Jπ of 0+ and 1− for known states at energies of 0.89 and 2.03 MeV, respectively, above the 2n threshold. I argue that their most likely assignments are 3− and 4+, respectively, and that the measured 2n transfer cross sections for the two known states are 20 to 50 times as large as those expected for the 0+ and 1− states of Garrido et al..

 

54.  Analysis of shell-model calculations for low-lying levels in 16C,

H. T. Fortune,

Phys. Rev. C 88, 034310 – Published 9 September 2013.

I have compared results of different shell-model calculations for the low-lying states of 16C. Comparisons include excitation energies, neutron occupancies, calculated matter radius of 16C, and the energy difference between mirrors 16C and 16Ne. I find that an older, simple calculation produces quite good agreement with experimental quantities.

 

53.   4+, T=1 states in 10B,

H. T. Fortune,

Phys. Rev. C 88, 027301 – Published 8 August 2013.

A new state at 11.48 MeV in 10B has been suggested as the likely analog of the 4+ state at 10.15 MeV in 10Be. I have computed proton single-particle widths for this state and for another (hypothetical) 4+ state 0.55 MeV higher to decay to the 5/2+ state of 9Be. Such a decay should provide a unique identification of the structure of this (or these) 4+ state(s).

 

52.  Mirror energy differences of 2s1/2 single-particle states: Masses of 10N and 13F,

H. T. Fortune,

Phys. Rev. C 88, 024309 – Published 7 August 2013.

I have examined mirror energy differences between 2s1/2 states in neutron-excess nuclei with N = 7 and 9 and their proton-excess mirrors having Z = 7 and 9. I find they can be fitted by a simple expression, which I then use to predict the masses of 10N and 13F.

 

51.  Resonance-strength parameter for 18O(p,γ) at Ep=90 keV,

H. T. Fortune,

Phys. Rev. C 88, 015801 – Published 8 July 2013.

For the 90-keV resonance in 18O(p,γ), I have combined the measured value of ωγ (p,α) = 0.16(5) μeV and the spectroscopic strength (2J+1) C2S = 0.097 from 18O(3He,d) to compute the (p,γ) resonance-strength parameter. The result is ωγ (p,γ) = 0.70(28) μeV, which is about 90(36) times the most recent upper limit.

 

50.  Mass of 11O,

H. T. Fortune,

Phys. Rev. C 87, 067306 – Published 21 June 2013.

A recent parametrization of two-proton separation energies in O and Ne nuclei allows a prediction of the energy of 11O(g.s.): S2p=−5.41(11) MeV, which is considerably more unbound than another recent estimate.

 

49.  Estimate of 12C×(sd)4 impurity in 16C(g.s.),

H. T. Fortune,

Phys. Rev. C 87, 064307 – Published 12 June 2013.

Recent results for the β decay of 17B, together with a simple model, allow an estimate of the (sd)4 component in 16C(g.s.). The result is about 0.02, a small number.

 

 

48.  Energies within the A=10 isospin quintet,

R. Sherr and H. T. Fortune,

Phys. Rev. C 87, 054333 – Published 30 May 2013.

We have used a potential model to compute energies of the lowest T = 2 states in A=10 nuclei. For 10N, we obtain Ep=1.81 to 1.94 MeV.

 

47.  Connection between separation energy and matter radius: Application to 34Na,

H. T. Fortune and R. Sherr,

Phys. Rev. C 87, 057308 – Published 28 May 2013.

We have used the relationship between matter radius and separation energy to compute the matter radius as a function of the assumed separation energy for 34Na, whose mass has just recently been measured.

 

46.  Comparison of 1n and 2n prescriptions for matter radii,

H. T. Fortune and R. Sherr,

Phys. Rev. C 87, 054315 – Published 15 May 2013.

We have computed the matter radius of 17N(g.s.), using both the 1n and 2n prescriptions. The two results differ by only 0.02 fm.

 

45.  0+ cross-section ratio in 12Be(p,t)10Be,

H. T. Fortune,

Phys. Rev. C 87, 054602 – Published 2 May 2013.

Using the well-established wave function of 12Be(g.s.), I have estimated the cross-section ratio for the reaction 12Be(p,t) populating the ground-state and first excited 0+ state of 10Be. I find that the excited-state to ground-state ratio is small for any reasonable value of configuration mixing in 10Be.

 

44.  Mass of 18Mg(g.s.),

H. T. Fortune and R. Sherr,

Phys. Rev. C 87, 044315 – Published 11 April 2013.

We use a potential model, together with spectroscopic factors from a combination of weak coupling and a shell-model calculation, to compute the mass of the ground state of 18Mg, considered as a mirror of 18C. The result is E2p=3.87(10)MeV.

 

43.  Update on 12O(g.s.) width for simultaneous 2p decay,

H T Fortune and R Sherr,      

J. Phys. G: Nucl. Part. Phys. 40, 055102 (2013). Published 21 March 2013.

We update information concerning the width of the ground state of 12O, and correct a small error in our earlier evaluation.

 

42.  Matter radii of 17–24O,

H.T. Fortune and R. Sherr,

Eur. Phys. J. A 49, 26 (2013)-- Published online: 22 February 2013. 

New experimental results recently reported for matter radii of 22,23O are significantly smaller than previous values. Our potential-model calculations agree with experiment for the entire chain from A = 17 to 23, so that, within the experimental uncertainties, the data can be explained without considering any modification of the core.

 

41.  Excited states of 19Mg,

H. T. Fortune and R. Sherr,

Phys. Rev. C 87, 014316 – Published 15 January 2013.

We have calculated energies of the first two excited states of 19Mg by using a model that was previously successful for the ground state. Computed excitation energies are 1.12 and 1.54 MeV for (3/2−) and (5/2−), respectively—somewhat in disagreement with values of 1.38 and 2.14 MeV from a recent experiment.

 

40.  Continuum three-body decays of 9Be(5/2−),

H. T. Fortune and R. Sherr,

Phys. Rev. C 87, 014306 – Published 7 January 2013.

We describe and discuss various three-body decay mechanisms for 9Be(5/2−). We find that its decay to n + 8Be(2+) is a small fraction of the total decay.

 

39.  Unraveling the structure of 13Be,

H. T. Fortune,

Phys. Rev. C 87, 014305 – Published 7 January 2013.

Using a simple model for low-lying positive-parity resonances in 13Be as 10Be x (sd)3 and 12Be1p x (sd), I find that the lowest 5/2+ state is predominantly (sd)3. I give predictions for several additional states.

 

38.  Update on 9B(1/2+)

H.T. Fortune, R. Sherr,

Nucl. Phys. A 898, 78 (2013)-- Available online 2 January 2013.

We update information concerning the 1/2+excited state of 9B, point out a minor mistake in our earlier work, and a major mistake in another paper, and suggest a reaction to populate this state.

 

37.  Matter radii of 29–35Mg,

H. T. Fortune and R. Sherr,

Phys. Rev. C 86, 064322 – Published 27 December 2012.

We have computed matter radii for the ground states of 29–35Mg for a variety of reasonable assumptions about the structure of the relevant states. For cases in which the dominant configuration is generally agreed, our computed radii are in good agreement with experimental ones. For cases in which the dominant configuration is unknown or ambiguous, comparisons between the calculated and experimental Rm do not allow a decision as to the preferred configuration.

 

36.  Branching ratio of 18Ne(7.06 MeV, 4+),

H. T. Fortune,

Phys. Rev. C 86, 068802 – Published 13 December 2012.

The recently reported branching ratio (BR) for the 4+ state in 18Ne at Ex = 7.06 MeV strongly disagrees with the BR computed using the known properties of this state.

 

35.  Core excitation in 14C and two-proton pickup,

H. T. Fortune,

Phys. Rev. C 86, 067303 – Published 7 December 2012.

In two-proton pickup from 14C, the calculated cross-section ratio for the first two 0+ states of 12Be depends on the configuration mixing in these two states and on the amount of core excitation in the ground state (g.s.) of 14C. Using the 12Be wave functions that are reasonably well known, I have calculated this ratio as a function of the core excitation in 14C(g.s.). A measurement of this ratio should allow an independent determination of the 14C mixing—previously estimated to be about 12%.

 

34.  Systematic behavior of mirror energy differences for Z = 8,10 nuclei and the mass of 15Ne,

H.T. Fortune,

Phys. Lett. B, 718, 1342 (2013)-- Available online 5 December 2012.
I use a simple model to parameterize mirror energy differences for several nuclei with N = 8 or 10 and their mirrors with Z = 8 or 10. I then use the results of the fit to predict the energy of the ground state of the unbound nucleus 15Ne: E2p = 2.68(24) MeV.

 

33.  Properties of 3.89/3.96-MeV states in 11Be,

H. T. Fortune,

Phys. Rev. C 86, 037302 – Published 18 September 2012.

I have reanalyzed previous data from the 9Be(t,p) reaction to extract energies and widths for the two states near 3.9 MeV. Results are energies of 3889.27 ± 1.03 and 3954.53 ± 1.16 and widths of 3.2(8) and 7.9(7), all in keV, for the 5/2− and 3/2− states, respectively.

 

32.  Predictions for the first two positive-parity states of 13F,

H. T. Fortune and R. Sherr,

Phys. Rev. C 86, 034301 – Published 4 September 2012.

We have used a potential model, together with information from 13Be, to compute expected energies and widths for the first two positive-parity states of 13F. Results are (all in MeV) Ep = 2.30 and 4.94 (or 5.26), width ∼0.6 and 0.3 (or 0.4), for 1/2+ and 5/2+, respectively.

 

31. Intruder–normal-state mixing in 30Mg,

H. T. Fortune,

Phys. Rev. C 86, 024305 – Published 8 August 2012.

In 30Mg, existing data for B(E2) strengths connecting the ground and excited 0+ states to the first 2+ state have been used, together with earlier shell-model predictions of normal and intruder E2 strengths, to estimate the intruder-normal state mixing in the 0+ and 2+ states. Resulting mixing is small, as expected, and for the ground state my value of 0.11(7) has a larger uncertainty, but is in quantitative agreement with the estimate of 0.0319(76) obtained earlier from the measured E0 strength connecting the 0+ states.

 

30. Matter radii and wave function admixtures in 2n halo nuclei,

H. T. Fortune and R. Sherr,

Eur. Phys. J. A 48, 103 (2012).  Published online: 30 July 2012.

In a simple potential model, we have computed matter radii for several 2n halo nuclei. Results are used to estimate wave function admixtures for these nuclei. Comparison is made with experimental and other calculated values. We propose a tighter limit on the binding energy of 19B: B2n = 0.55+0.20 −0.16 MeV, replacing the previous value of 0.5(4)MeV.

 

29. Possible problem with neutron widths from decay-in-flight experiments,

H.T. Fortune,

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 681, 7—published 21 July 2012.

Recently, several papers have reported neutron widths obtained from decay-in-flight experiments. Many of these widths are larger than they are reasonably expected to be. This paper discusses the results and possible reasons for the discrepancies.

 

28. Comments on a recent calculation for 17Na,

H.T. Fortune,

Nuclear Physics A 890,25 (2012)-- Available online 20 July 2012.
I point out serious flaws in a recent calculation of energies and widths for levels of 17Na.

 

27. Comment on ``Neutron knockout of 12Be populating neutron-unbound states in 11Be'',

H. T. Fortune,

Phys. Rev. C 86, 019801 – Published 6 July 2012.

A recent paper [ Phys. Rev. C 83 057304 (2011)] used knockout from 12Be to populate two states near 3.9 MeV in 11Be and observed their neutron decay—but treated the two as a single state. The authors used a branching ratio for the upper state from an experiment that also did not separate the two states. Thus, their energy for 11Be(3.96 MeV) and the spectroscopic factor connecting it to 12Be(gs) are questionable.

 

26. Two-neutron transfer in the “island of inversion”,

H. T. Fortune,

Phys. Rev. C 85, 064615 – Published 22 June 2012.

Cross sections for (p,t) and (t,p) reactions near neutron-shell closures depend sensitively on the amount of intruder configuration in the relevant states. For several nuclei in the “island of inversion,” I present calculated cross section ratios for the first two 0+ states as functions of the intruder-normal-state mixing.

 

25. Consistent description of 11Be and 12Be and of the 11Be(d,p)12Be reaction,

H. T. Fortune and R. Sherr,

Phys. Rev. C 85, 051303 – Published 22 May 2012.

Simple wave functions for 11,12Be have been around for a long time. They have been tested against many independent processes involving (and properties of) these nuclei. All are consistent, except 11Be(d,p), where the discrepancy is a 4.7σ effect for the 2+ state and 15σ for the ground state. Here, we propose a resolution to this dilemma.

 

24. α width of 18Ne(6.15 MeV, 1−),

H. T. Fortune,

Phys. Rev. C 85, 052801 – Published 18 May 2012.

Data for the 14C(6Li,d)18O(6.20) reaction, at 20 MeV, provides an α spectroscopic factor of 0.23 for this 1− state. Assuming equal spectroscopic factors for mirror states, the computed α width for 18Ne(6.15) is 3.9(1.0) eV.

 

23. Reexamining 18Na and 19Mg,

H. T. Fortune and R. Sherr,

Phys. Rev. C 85, 051302 – Published 18 May 2012.

New results for energies of resonances in 18Na have led us to reexamine the problems of 18Na and 19Mg. We have calculated the effect of the new data on energy and decay width of 19Mg (ground state).

22. Concerning positive-parity collective states in 18O,

H. T. Fortune,

Eur. Phys. J. A 48, 63 (2012).  Published online: 8 May 2012.

I discuss collective positive-parity states in 18O in light of two recent experiments. Single-particle widths have been calculated and used to extract spectroscopic factors. Special attention is given to 4p-2h and 6p-4h cluster bands.

 

21. Lowest 2+, T=2 states in 20Mg and 20F,

H. T. Fortune, R. Sherr, and B. A. Brown,

Phys. Rev. C 85, 054304 – Published 3 May 2012.

A recent experiment located the lowest 2+ state in 20Mg and discovered that the corresponding 2+, T = 2 state in 20F does not fit expectations of the isobaric multiplet mass equation without a d term. We have calculated the energies of the ground and 2+ states in 20Mg and the 2+ in 20F in a potential model, using shell-model spectroscopic factors. We conclude that this important 20F state has likely never been observed, and suggest a reaction to find it.

 

20. B(E2) values in 12Be and core excitation,

H. T. Fortune,

Phys. Rev. C 85, 044309 – Published 11 April 2012.

I have examined the B(E2)'s in 12Be connecting the first 2+ state to the first two 0+ states. I find that they can be understood in the simple model that has been successful for a variety of other observables in this nucleus, but only if the 2+ state has an excited-core component.

 

19. Properties of the lowest 1/2+, T=3/2 states in A=11 nuclei,

H. T. Fortune,

Phys. Rev. C 85, 044304 – Published 4 April 2012.

Abstract. Analysis of energies and widths of the lowest 1/2+ T = 3/2 states in A = 11 nuclei suggests that the excitation energy in 11C should be about 200 keV below the energy in the literature, and the width should be 4 to 5 times the literature value. Properties of the state in 11B and 11N are in agreement with the present model.

18. Widths and spectroscopic factors in 21O

H. T. Fortune and R. Sherr, Phys. Rev. C 85, 027305 (2012)

Published February 14, 2012

A recent 20O(d,p)21O experiment, in reverse kinematics,

discovered two new states in 21O at 4.77(10) and 6.17(11) MeV,

with Jp assignments of 3/2+ and of 3/2+ or 7/2-, respectively.

Both widths and spectroscopic factors were reported, along with

the branching ratio for the upper state to decay to the 2+ state

of 20O. We have computed single-particle widths for all the

relevant decays and have used them to extract additional

information for these two states, including the spectroscopic

factors for 2+ decay of the upper state with the two possible

Jp values. Our analysis prefers 7/2- for Jp.

 

 

17.  Binding energy of 22C

H. T. Fortune and R. Sherr, Phys. Rev. C 85, 027303 (2012)

Published February 9, 2012

The sensitivity of the calculated matter radius to the binding

energy is exploited to estimate the 2n binding energy of 22C,

using a recent experimental value of Rm = 5.4(9) fm. The result

is B2n < 220 keV, significantly smaller than another recent estimate.

[

16. B(E2) value and configuration mixing in 32Mg

H. T. Fortune, Phys. Rev. C 85, 014315 (2012)

Published January 18, 2012

I demonstrate that the B(E2) value in 32Mg can be understood

with a model in which both the ground and 2+ first-excited

states are predominantly of sd-shell character.

 

15.  New calculations of matter radii for neutron-rich C nuclei,

H.T. Fortune and R. Sherr, Eur. Phys. J. A 47, 154 (2011)

Published 15 December 2011.

We have used a simple model to re-calculate matter radii for 14-20C,

using updated information on the relevant nuclear structure.

Agreement with experiment is improved, but some small

differences remain.

 

14. Behavior of (sd)4+2 states coupled to p-shell cores,

H. T. Fortune,, Phys. Rev. C 84, 054312 (2011)

Published November 16, 2011

Energies of the lowest 4+ states in 10,12Be and 14,16C

are examined in a simple model that works surprisingly

well in three of the nuclei. The analysis suggests that

three configurations are important for the first 4+

state in 10Be.

 

13. Update on the 18Ne 7.37-MeV state and its mirror in 18O,

H. T. Fortune and R. Sherr,, Phys. Rev. C 84, 047301 (2011)

Published October 13, 2011

The recent discovery of a new state at 7.796 MeV in 18O has

caused us to revisit the problem of the 7.37-MeV state in 18Ne.

 

12.  Low-energy resonances in 17C,

H.T. Fortune, Physics Letters B 703, 71 (2011)

Published 1 September 2011

Simple shell-model calculations and single-particle widths

suggest that the apparent width for the lowest-energy

resonance in 17C, observed in 17C(p,p’) and 14C(12C, 9C),

must be the result of two or three unresolved narrow states,

and not the natural width of either. I offer suggestions

for and give limits on expected widths.

 

11. The puzzle of 32Mg,

H. T. Fortune, Phys. Rev. C 84, 024327 (2011)

Published August 29, 2011

An analysis of results of the 30Mg(t,p)32Mg reaction

demonstrates that the ground state is the normal state

and the excited 0+ state is the intruder, contrary to

popular belief. Additional experiments are suggested.

 

10.  (sd)2 states or superclusters in 10Be,

H. T. Fortune and R. Sherr, Phys. Rev. C 84, 024304 (2011)

Published August 9, 2011

A set of states in 10Be have very large a widths and very

small neutron strengths. We review the data and investigate

whether they are (sd)2 states and/or a clusters.

 

9.  Neutron widths and configuration mixing in 11Be,

H. T. Fortune and R. Sherr, Phys. Rev. C 83, 054314 (2011)

Published May 18, 2011

We use known widths and branching ratios in 11Be to discuss

Jp and configuration admixtures. Analysis favors 3/2- for

the 3.96-MeV state and three-state mixing for this Jp.

 

8.  Low-lying resonances in 14F and 14B,

R. Sherr, H.T. Fortune, Physics Letters B 699, 281 (2011)

Published 16 May 2011.

In a simple potential model, we have computed energies and

widths of low-lying resonances of 14F and have compared

them with recent experimental results. Consequences for

14B are summarized.

 

7. Update on energy and width of 19Mg(g.s.),

H. T. Fortune and R. Sherr, Phys. Rev. C 83, 057301 (2011)

Published May 5, 2011

We update our predictions for the width of 19Mg(g.s.) by

extending our calculations to the lower energy range found

experimentally.

 

6. Structure of 2+, T=2 states in A=12 nuclei,

H. T. Fortune and R. Sherr, Phys. Rev. C 83, 044313 (2011)

Published April 21, 2011

Using a reasonable but simple model, properties of 2+

states in 12Be and 12O are calculated and compared with

results of experiments.

 

5.  Widths in 15C and 15F,

H. T. Fortune, Phys. Rev. C 83, 024311 (2011)

Published February 22, 2011

Earlier data for the reaction 13C(t,p) have been analyzed

to extract widths for several states of 15C. Results

affect predictions of widths in 15F.

 

4.  Neutron decays of 13Be* to the 0+2 state of 12Be,

H. T. Fortune and R. Sherr, Phys. Rev. C 82, 064302 (2010)

Published December 3, 2010

We suggest that an appreciable portion of the 1/2- peak in

a recent 13Be* ? 12Be + n experiment is actually due to

5/2+ decays to the excited 0+ state.

 

3.  Energy and width of the excited 0+ state in 12O,

H. T. Fortune and R. Sherr, Phys. Rev. C 82, 034325 (2010)

Published September 27, 2010

We review predictions for the energy of the excited 0+

state of 12O and present new calculations of its width

Results are compared with those of a recent experiment.

 

2.  Update on a-particle and nucleon widths in 19F and 19Ne,

H. T. Fortune, A. Lacaze, and R. Sherr, Phys. Rev. C 82, 034312 (2010)

Published September 13, 2010

We present updated information and analysis for several states in

19F and 19Ne and correct a mistake in an earlier article.

 

1.  Coulomb energies in 16Ne and low-lying levels of 17Na,

H. T. Fortune and R. Sherr, Phys. Rev. C 82, 027310 (2010)

Published August 23, 2010

We have computed energies of 16Ne levels in a core plus

two-nucleon space, using known 16C energies and existing

wave functions. We have then used these energies to compute

properties of the first three levels of 17Na.  Significant

differences are found with results of a recent

microscopic-cluster-model formulation.