Neutron-neutron quasifree scattering in nd breakup at 10 MeV

The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notab...

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Main Authors: Malone R.C., Crowe B., Crowell A.S., Cumberbatch L.C., Esterline J.H., Fallin B.A., Friesen F.Q.L., Han Z., Howell C.R., Markoff D., Ticehurst D., Tornow W., Witała H.
Format: Article
Language:English
Published: EDP Sciences 2016-01-01
Series:EPJ Web of Conferences
Online Access:http://dx.doi.org/10.1051/epjconf/201611304010
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author Malone R.C.
Crowe B.
Crowell A.S.
Cumberbatch L.C.
Esterline J.H.
Fallin B.A.
Friesen F.Q.L.
Han Z.
Howell C.R.
Markoff D.
Ticehurst D.
Tornow W.
Witała H.
author_facet Malone R.C.
Crowe B.
Crowell A.S.
Cumberbatch L.C.
Esterline J.H.
Fallin B.A.
Friesen F.Q.L.
Han Z.
Howell C.R.
Markoff D.
Ticehurst D.
Tornow W.
Witała H.
author_sort Malone R.C.
collection DOAJ
description The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.
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spelling doaj.art-f88e1540f4d143129f17d0480fd7e1932022-12-21T18:40:15ZengEDP SciencesEPJ Web of Conferences2100-014X2016-01-011130401010.1051/epjconf/201611304010epjconf_fb2016_04010Neutron-neutron quasifree scattering in nd breakup at 10 MeVMalone R.C.0Crowe B.1Crowell A.S.2Cumberbatch L.C.3Esterline J.H.4Fallin B.A.5Friesen F.Q.L.6Han Z.7Howell C.R.8Markoff D.9Ticehurst D.10Tornow W.11Witała H.12Department of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, North Carolina Central University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, North Carolina Central University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryDepartment of Physics, Duke University and Triangle Universities Nuclear LaboratoryM. Smoluchowski Institute of Physics, Jagiellonian UniversityThe neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.http://dx.doi.org/10.1051/epjconf/201611304010
spellingShingle Malone R.C.
Crowe B.
Crowell A.S.
Cumberbatch L.C.
Esterline J.H.
Fallin B.A.
Friesen F.Q.L.
Han Z.
Howell C.R.
Markoff D.
Ticehurst D.
Tornow W.
Witała H.
Neutron-neutron quasifree scattering in nd breakup at 10 MeV
EPJ Web of Conferences
title Neutron-neutron quasifree scattering in nd breakup at 10 MeV
title_full Neutron-neutron quasifree scattering in nd breakup at 10 MeV
title_fullStr Neutron-neutron quasifree scattering in nd breakup at 10 MeV
title_full_unstemmed Neutron-neutron quasifree scattering in nd breakup at 10 MeV
title_short Neutron-neutron quasifree scattering in nd breakup at 10 MeV
title_sort neutron neutron quasifree scattering in nd breakup at 10 mev
url http://dx.doi.org/10.1051/epjconf/201611304010
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