Search for unbound Be15 states in the 3n+Be12 channel

Kuchera, A. N.; Spyrou, A.; Smith, J. K.; Baumann, T.; Christian, G.; DeYoung, P. A.; Finck, J. E.; Frank, N.; Jones, M. D.; Kohley, Z.; Mosby, S.; Peters, W. A.; Thoennessen, M.

doi:10.1103/PhysRevC.91.017304

Search for unbound ${}^{15}{Be}$ states in the $3 n + {}^{12}{Be}$ channel

Journal Article · Wed Jan 28 00:00:00 EST 2015 · Physical Review C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.91.017304· OSTI ID:1454846

Kuchera, A. N. ^[1]; Spyrou, A. ^[2]; Smith, J. K. ^[2]; Baumann, T. ^[2]; Christian, G. ^[2]; DeYoung, P. A. ^[3]; Finck, J. E. ^[4]; Frank, N. ^[5]; Jones, M. D. ^[2]; Kohley, Z. ^[2]; Mosby, S. ^[2]; Peters, W. A. ^[6]; Thoennessen, M. ^[2]

Michigan State Univ., East Lansing, MI (United States); UC Berkeley
Michigan State Univ., East Lansing, MI (United States)
Hope College, Holland, MI (United States)
Central Michigan Univ., Mount Pleasant, MI (United States)
Augustana College, Rock Island, IL (United States)
Rutgers Univ., Piscataway, NJ (United States)

Background: Be-15 is expected to have low-lying 3/2(+) and 5/2(+) states. A first search did not find the 3/2(+) [A. Spyrou et al., Phys. Rev. C 84, 044309 (2011)]; however, a resonance in Be-15 was populated in a second attempt and determined to be unbound with respect to Be-14 by 1.8(1) MeV with a tentative spin-parity assignment of 5/2(+) [J. Snyder et al., Phys. Rev. C 88, 031303(R) (2013)]. Purpose: Search for the predicted Be-15 3/2(+) state in the three-neutron decay channel. Method: A two-proton removal reaction from a 55 MeV/u C-17 beam was used to populate neutron-unbound states in Be-15. The two-, three-, and four-body decay energies of the Be-12+ neutron(s) detected in coincidence were reconstructed using invariant mass spectroscopy. Monte Carlo simulations were performed to extract the resonance and decay properties from the observed spectra. Results: The low-energy regions of the decay energy spectra can be described with the first excited unbound state of Be-14 (E-x = 1.54 MeV, E-r = 0.28 MeV). Including a state in Be-15 that decays through the first excited Be-14 state slightly improves the fit at higher energies though the cross section is small. Conclusions: A Be-15 component is not needed to describe the data. If the 3/2(+) state in Be-15 is populated, the decay by three-neutron emission through Be-14 is weak,

View Accepted Manuscript (DOE)

Research Organization:: Nuclear Science and Security Consortium, Berkeley, CA (United States)

Sponsoring Organization:: USDOE National Nuclear Security Administration (NNSA)

Grant/Contract Number:: NA0000979

OSTI ID:: 1454846

Journal Information:: Physical Review C, Nuclear Physics, Journal Name: Physical Review C, Nuclear Physics Journal Issue: 1 Vol. 91; ISSN 0556-2813; ISSN PRVCAN

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

References (23)

Properties of exotic p-shell nuclei Poppelier, N. A. F. M.; Wood, L. D.; Glaudemans, P. W. M. Physics Letters B, Vol. 157, Issue 2-3 https://doi.org/10.1016/0370-2693(85)91529-1	journal	July 1985
Observation of 10He Korsheninnikov, A. A.; Yoshida, K.; Aleksandrov, D. V. Physics Letters B, Vol. 326, Issue 1-2 https://doi.org/10.1016/0370-2693(94)91188-6	journal	April 1994
MoNA—The Modular Neutron Array Luther, B.; Baumann, T.; Thoennessen, M. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 505, Issue 1-2 https://doi.org/10.1016/S0168-9002(03)01014-3	journal	June 2003
Modeling interactions of intermediate-energy neutrons in a plastic scintillator array with Geant4 Kohley, Z.; Lunderberg, E.; DeYoung, P. A. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 682 https://doi.org/10.1016/j.nima.2012.04.060	journal	August 2012
Systematic investigation of the drip-line nuclei 11Li and 14Be and their unbound subsystems 10Li and 13Be Simon, H.; Meister, M.; Aumann, T. Nuclear Physics A, Vol. 791, Issue 3-4 https://doi.org/10.1016/j.nuclphysa.2007.04.021	journal	July 2007
The first 2+ state of 14Be Sugimoto, T.; Nakamura, T.; Kondo, Y. Physics Letters B, Vol. 654, Issue 5-6 https://doi.org/10.1016/j.physletb.2007.08.052	journal	October 2007
Lithium isotopes beyond the drip line Aksyutina, Yu.; Johansson, H. T.; Adrich, P. Physics Letters B, Vol. 666, Issue 5 https://doi.org/10.1016/j.physletb.2008.07.093	journal	September 2008
Low-lying intruder state of the unbound nucleus 13Be Kondo, Y.; Nakamura, T.; Satou, Y. Physics Letters B, Vol. 690, Issue 3 https://doi.org/10.1016/j.physletb.2010.05.031	journal	June 2010
Nuclear structure experiments along the neutron drip line Baumann, T.; Spyrou, A.; Thoennessen, M. Reports on Progress in Physics, Vol. 75, Issue 3 https://doi.org/10.1088/0034-4885/75/3/036301	journal	February 2012
Single-neutron knockout reactions: Application to the spectroscopy of 1 6 , 1 7 , 1 9 C Maddalena, V.; Aumann, T.; Bazin, D. Physical Review C, Vol. 63, Issue 2 https://doi.org/10.1103/PhysRevC.63.024613	journal	January 2001
Observation of a two-neutron cascade from a resonance in O 24 Hoffman, C. R.; Baumann, T.; Brown, J. Physical Review C, Vol. 83, Issue 3 https://doi.org/10.1103/PhysRevC.83.031303	journal	March 2011
Search for the 15 Be ground state Spyrou, A.; Smith, J. K.; Baumann, T. Physical Review C, Vol. 84, Issue 4 https://doi.org/10.1103/PhysRevC.84.044309	journal	October 2011
First observation of the 13 Li ground state Kohley, Z.; Lunderberg, E.; DeYoung, P. A. Physical Review C, Vol. 87, Issue 1 https://doi.org/10.1103/PhysRevC.87.011304	journal	January 2013
Structure of the unbound nucleus 13 Be: One-neutron knockout reaction data from 14 Be analyzed in a holistic approach Aksyutina, Yu.; Aumann, T.; Boretzky, K. Physical Review C, Vol. 87, Issue 6 https://doi.org/10.1103/PhysRevC.87.064316	journal	June 2013
First observation of 15 Be Snyder, J.; Baumann, T.; Christian, G. Physical Review C, Vol. 88, Issue 3 https://doi.org/10.1103/PhysRevC.88.031303	journal	September 2013
Structure of 13 Be probed via secondary-beam reactions Randisi, G.; Leprince, A.; Al Falou, H. Physical Review C, Vol. 89, Issue 3 https://doi.org/10.1103/PhysRevC.89.034320	journal	March 2014
Low-lying neutron unbound states in Be 12 Smith, J. K.; Baumann, T.; Bazin, D. Physical Review C, Vol. 90, Issue 2 https://doi.org/10.1103/PhysRevC.90.024309	journal	August 2014
Anomalous population of He 10 states in reactions with Li 11 Sharov, P. G.; Egorova, I. A.; Grigorenko, L. V. Physical Review C, Vol. 90, Issue 2 https://doi.org/10.1103/PhysRevC.90.024610	journal	August 2014
First Observation of Ground State Dineutron Decay: Be 16 Spyrou, A.; Kohley, Z.; Baumann, T. Physical Review Letters, Vol. 108, Issue 10 https://doi.org/10.1103/PhysRevLett.108.102501	journal	March 2012
Evidence for the Ground-State Resonance of O 26 Lunderberg, E.; DeYoung, P. A.; Kohley, Z. Physical Review Letters, Vol. 108, Issue 14 https://doi.org/10.1103/PhysRevLett.108.142503	journal	April 2012
Study of the Be 14 Continuum: Identification and Structure of its Second 2 + State Aksyutina, Yu.; Aumann, T.; Boretzky, K. Physical Review Letters, Vol. 111, Issue 24 https://doi.org/10.1103/PhysRevLett.111.242501	journal	December 2013
Discovery of Two Isotopes, Be 14 and B 17 , at the Limits of Particle Stability Bowman, J. D.; Poskanzer, A. M.; Korteling, R. G. Physical Review Letters, Vol. 31, Issue 9 https://doi.org/10.1103/PhysRevLett.31.614	journal	August 1973
System Testing and Installation of the NHMFL/NSCL Sweeper Magnet Bird, M. D.; Kenney, S. J.; Toth, J. IEEE Transactions on Appiled Superconductivity, Vol. 15, Issue 2 https://doi.org/10.1109/TASC.2005.849553	journal	June 2005

Cited By (2)

Three-body model for the two-neutron emission of Be 16 Lovell, A. E.; Nunes, F. M.; Thompson, I. J. Physical Review C, Vol. 95, Issue 3 https://doi.org/10.1103/physrevc.95.034605	journal	March 2017
Structure of exotic light nuclei: Z = 2, 3, 4 Fortune, H. T. The European Physical Journal A, Vol. 54, Issue 3 https://doi.org/10.1140/epja/i2018-12489-2	journal	March 2018