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Proceedings of the 9 Symposium on Applied Science, Business & Industrial Research – 2017
ISSN 2279-1558, ISBN 978-955-7442-09-9

Anomalous Absorption of Partial Waves by the Nuclear Optical Potential
as not being Confined to Only Light Projectile Ions

2
1
Jayasinghe WJMLP , Ranawaka TP , Piyadasa RAD 1
1
Department of Mathematical Sciences, Wayamba University of Sri Lanka
2 Department of Physics, University of Peradeniya
lakmini.jayasinghe@gmail.com
ABSTRACT

Anomalous absorption of partial waves by the nuclear optical potential is an
interesting phenomenon which was found by Kawai and Iseri in Japan long ago. It is
assumed that this occurs when light ions scatter on composite nuclei. This means for a
specific value of the projectile energy for a specific target nucleus, and for a special value of
the angular momentum of the projectile the value of the S-matrix element in case of elastic
scattering becomes very small. This phenomenon takes place in case of elastic scattering of
a light ion on heavy nuclei. But we have found that it occurs even when the projectile is
rather heavy as explained in this paper.

KEYWORDS: Anormalous absorption, Elastic scattering, S-matrix

1 INTRODUCTION of the outgoing waves produced by the
optical potential in different regions
In case of anomalous absorption of (Piyadasa, Munasinghe & Karunathilaka,
partial waves by the nuclear optical 2008).
potential, there are systematic in various
parameter planes which have been striking. 2 METHODOLOGY
For a systematic in case of Deuteron We have investigated whether this
scattering on heavy nuclei is shown in phenomenon takes place even when light
Figure.1 ion scattering does not take place. In this
respect we studied elastic scattering on O
16
on O and we have found that (Fig.2)
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anomalous absorption takes place in case of
the angular momentum = 7 (Fig.2) and the
center of mass energy 20Mev and the
corresponding wave function (Fig.3) does
not show any oscillation in the asymptotic
region. By virtue of the above, we conclude
that anomalous absorption may take place
according to the physical meaning of it.

Figure 1: Deuteron scattering on heavy
nuclei
Source :(RAD Piyadasa, Master Thesis
Submitted to the Kyushu University (1986)
Unpublished).
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We have found that, in case of He
scattering on heavy nuclei the Anomalous
absorption takes place (Jayasinghe,
Vithanage & Piyadasa, 2016). This
phenomenon takes place due to cancellation
16
16
Figure 2: Elastic scattering on O on O

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