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CATEGORIES:Lectures & Presentations
DESCRIPTION:INPP Seminar | Two-neutron halos and the neutron-neutron scatte
ring length\, Nov. 1\n\nThe Institute of Nuclear and Particle Physics Semin
ar series presents Matthias Göbel discussing "Two-neutron halos and the neu
tron-neutron scattering length"on Nov. 1 at 4 p.m. in Lindley 321.\n\n \n\n
Göbel is from Technical University\, Darmstadt.\n\n \n\nIn-person seminars
will be in Lindley 321. For remote seminars\, connection info for the video
conference (TEAMS or ZOOM) and abstract of the talk will be communicated b
y email before the seminar. The emails are sent to the inpp-seminar mailing
list. To be added to this mailing list\, contact Prakash.\n\n \n\nThe host
is Daniel Phillips.\n\n \n\nAbstract:\n\nTwo-neutron halos are exotic nucl
ear systems with two neutrons well separated from a more tightly bound core
. They offer interesting opportunities to study nuclear physics away from s
tability. These halos\, which can be well described using halo effective fi
eld theory (halo EFT)\, are not only exciting systems on their own but also
offer new possibilities to study the fundamental neutron-neutron interacti
ons.\n\n \n\nThe s-wave neutron-neutron scattering length\, the leading-ord
er parameter of this interaction\, is not yet well known. Precision experim
ents conducted in the late ‘90s and early ‘00s produced a range of values f
rom -16.3(4) fm to -18.7(7) fm. I will talk about a new experiment proposal
approved at RIKEN to measure the final neutron-neutron relative-energy dis
tribution of the high-energy knockout reaction He-6(p\, p’ alpha)nn. The sc
attering length can then be deduced from this distribution by comparing it
to theoretical predictions parameterized by the scattering length. I will f
ocus on our theoretical efforts to calculate this distribution in a systema
tic manner with robust uncertainty estimates using halo effective field the
ory [Phys. Rev. C 104 (2021) 2\, 024001]. Our work emphasized accurate desc
ription of the neutron-neutron final-state interaction and found that the d
istribution is quite sensitive to the variation of the scattering length: v
arying this parameter by 2 fm changes characteristic parts of the distribut
ion by 10%.\n\n \n\nIn the last part of my talk I will show that the neutro
n-neutron relative-energy distribution also provides opportunities to learn
about different s-wave two-neutron halo nuclei\, such as Li-11\, Be-14\, B
-17\, B-19\, and C-22. I will show that this distribution can be predicted
by an approach that exploits the universality of two-neutron halos as Borro
mean three-body bound states beyond the classical regime.
DTEND:20221101T210000Z
DTSTAMP:20241110T124442Z
DTSTART:20221101T200000Z
GEO:39.326188;-82.101779
LOCATION:Lindley Hall\, 321
SEQUENCE:0
SUMMARY:INPP Seminar | Two-neutron halos and the neutron-neutron scattering
length\, Nov. 1
UID:tag:localist.com\,2008:EventInstance_40926950916700
URL:https://calendar.ohio.edu/event/inpp_seminar_nov_1
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