Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region
The differential cross section and the asymmetry coefficient for the two-body ³He break up by linearly polarized photons are calculated with the wave functions for Reid soft core, Paris and Bonn potentials.
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| Дата: | 2001 |
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| Формат: | Стаття |
| Мова: | English |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
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| Назва видання: | Вопросы атомной науки и техники |
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| Цитувати: | Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region / V.V. Kotlyar // Вопросы атомной науки и техники. — 2001. — № 1. — С. 53-54. — Бібліогр.: 16 назв. — англ. |
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irk-123456789-784442015-03-18T03:01:50Z Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region Kotlyar, V.V. Nuclear reactions The differential cross section and the asymmetry coefficient for the two-body ³He break up by linearly polarized photons are calculated with the wave functions for Reid soft core, Paris and Bonn potentials. 2001 Article Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region / V.V. Kotlyar // Вопросы атомной науки и техники. — 2001. — № 1. — С. 53-54. — Бібліогр.: 16 назв. — англ. 1562-6016 PACS: 21.45.+v, 25.10.+s, 25.20.-x, 27.10.+h. http://dspace.nbuv.gov.ua/handle/123456789/78444 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine |
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DSpace DC |
| language |
English |
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Nuclear reactions Nuclear reactions |
| spellingShingle |
Nuclear reactions Nuclear reactions Kotlyar, V.V. Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region Вопросы атомной науки и техники |
| description |
The differential cross section and the asymmetry coefficient for the two-body ³He break up by linearly polarized photons are calculated with the wave functions for Reid soft core, Paris and Bonn potentials. |
| format |
Article |
| author |
Kotlyar, V.V. |
| author_facet |
Kotlyar, V.V. |
| author_sort |
Kotlyar, V.V. |
| title |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region |
| title_short |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region |
| title_full |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region |
| title_fullStr |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region |
| title_full_unstemmed |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region |
| title_sort |
dependence of the γ³he → pd cross sections on the nuclear wave functions in the giant resonance region |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2001 |
| topic_facet |
Nuclear reactions |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/78444 |
| citation_txt |
Dependence of the γ³He → pd cross sections on the nuclear wave functions in the giant resonance region / V.V. Kotlyar // Вопросы атомной науки и техники. — 2001. — № 1. — С. 53-54. — Бібліогр.: 16 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT kotlyarvv dependenceoftheg3hepdcrosssectionsonthenuclearwavefunctionsinthegiantresonanceregion |
| first_indexed |
2025-07-06T02:32:29Z |
| last_indexed |
2025-07-06T02:32:29Z |
| _version_ |
1836863088156999680 |
| fulltext |
DEPENDENCE OF THE γ3He→pd CROSS SECTIONS ON THE NUCLEAR
WAVE FUNCTIONS IN THE GIANT RESONANCE REGION
V.V. Kotlyar
National Science Center "Kharkov Institute of Physics and Technology", Kharkov, Ukraine
The differential cross section and the asymmetry coefficient for the two-body 3He break up by linearly polarized
photons are calculated with the wave functions for Reid soft core, Paris and Bonn potentials.
PACS: 21.45.+v, 25.10.+s, 25.20.-x, 27.10.+h.
The differential cross section for the reaction 3He
pd at photon energies E<25 MeV was shown [1] to de-
pend substantially on choice of the nuclear wave func-
tions (WFs). The calculations were performed in
momentum space with the Faddeev WFs for 3N bound
state for Reid soft core (RSC), Paris and Bonn poten-
tials. The Siegert theorem was applied in [1] to take into
consideration a part of the interaction current effects in
the electric multipoles.
Explicitly the meson exchange currents (MEC) were
treated in [2,3] where parametrization [4] of the 3He WF
for RSC potential was used. It was demonstrated [2,3]
that the MEC contributions sizably increase the values of
the cross section reducing discrepancies between the re-
sults of the calculations and the experimental data.
Role of the interaction currents and rescattering in
the pd system was studied [5-9] in the proton-deuteron
radiative capture. Area of energies examined in [5-9]
corresponds to lab
γE ≤ 139.1 MeV in the 3He photodisin-
tegration. Results [7-9] allow one to single out a kine-
matic region where the effects of final state interaction
(FSI) do not appear to be crucial for the cross section of
3Hepd and give an opportunity to scrutinize manifesta-
tion of the P- and D-components of the 3N bound state
WF.
Aim of this paper is to carry on investigation [3] and
to study dependence of the energy and angular distribu-
tions of the cross section and the beam asymmetry on
the 3He WFs using precise numerical solutions of the
Faddeev equations obtained in Ref. [10].
The observables are computed with the nuclear cur-
rent including contributions from convection and spin
currents, the two-body currents generated by pion ex-
change (πEC). The Riska model is taken for the latter.
The πNN form factors in the operators of MEC are
chosen in the monopole form with the cut-off parameter
Λπ=1.2 GeV. The reaction amplitudes are calculated in
the framework of Refs. [2,3], where details regarding
the techniques can be found.
In Fig. 1 the differential cross sections obtained with
the Hannover-Helsinki WF [4] for RSC potential and
the Bochum-Cracow WFs [10] for Bonn and Paris
potentials are compared with the results of Ref. [1].
According to the present calculations there is only a
rather moderate dependence of the cross section on the
nuclear WFs that corresponds to the conclusions of
Refs. [7-9] and contrasts with inferences of Ref.[1].
The angular distributions for Bonn and Paris
potentials have been analyzed to study the variations of
the cross section in detail. The different sets Nα=2, 5,
10, 18, 26, 34 of the partial wave components of the 3He
WFs have been considered.
The contributions of the S-waves correspond to the
set Nα=2. D-waves are included in Nα=5. The set Nα=10
consists of S-, P- and D-components with the total angu-
lar momentum in the two-body subsystem J=0 and 1.
Partial waves with J≤2 are involved in the case Nα=18.
The components of the 3He WF with J≤3(4) are taken
into account in Nα=26(34). It turns out that no signifi-
cant potential dependence appears in all the cases
analyzed.
5 10 15 20 25
0
20
40
60
80
100
120
140
160 WFs for
Bonn,
Paris and
RSC
potentials
D.J. Klepacki
et al. [1]
present
calculations
Berman B.L. et al. [11]
Skopik D.M. et al. [12]
σla
b (θ
la
b
γ
p=9
0o ),
µb
/s
r
Elab
γ
, MeV
Fig. 1. Potential model dependence of the differential
cross section σ=dσ/dΩγp for γ 3He→ pd.
Influence of the 3He WF components with orbital
angular momenta 2...5 on angular distributions of the
cross section and the beam asymmetry is demonstrated in
Figs. 2 and 3.
The calculations in the plane wave approximation
overestimate the data at forward and backward angles.
Enhancement of the cross section at lab
γpθ 30° and
lab
γpθ 150° rides on contributions of spin current and
πEC. As it follows from comparison with the results of
experiments [13] and theoretical investigations [7-9],
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2001, № 1.
Series: Nuclear Physics Investigations (37), p. 53-54.
53
the effects of the FSI cannot be neglected under these
kinematic conditions. The P- and D-states in the 3He
WF influence the cross section just in a vicinity of its
maximum at E=9-16 MeV where nonorthogonality of
the initial and final state WFs does not play a decisive
role at least for this observable.
0 30 60 90 120 150 180
0
20
40
60
80
100 WFs for Paris
potential
N
α
=2
N
α
=5
N
α
=10
N
α
=18
N
α
=26
N
α
=34
B.D.Belt et al. [13]
σcm
(E
La
b
γ
=1
5.
4
M
eV
), µ
b/
sr
θ cm
γ p
, degrees
Fig. 2. Angular distribution of the differential cross
section for γ 3He→ pd.
0 30 60 90 120 150 180
0,0
0,2
0,4
0,6
0,8
WFs for Paris
potential
N
α
=2
N
α
=5
N
α
=10
N
α
=18
N
α
=26
N
α
=34
Σ(
EL
ab
γ
=
15
.4
M
eV
)
θ cm
γ p
, degrees
Fig. 3. Angular dependence of the asymmetry coeffi-
cient for γ 3He→ pd with linearly polarized photons
Being calculated with the convection current, the
asymmetry coefficient Σ1 at 30° lab
γpθ 140°. Inclusion
of spin current or/and πEC decreases Σ values and chan-
ges the shape of the angular distribution reducing its width.
As seen from Fig. 3, the asymmetry Σ is affected by
the P-wave components of the 3N WF (cf. curves for
Nα=5 and 10). This observation does not seem to be
very surprising in view of the fact that polarization ob-
servables in Nd elastic scattering [14] and pd radiative
capture [15,16] were found to be remarkably sensitive
to the NN interaction in states with L=1.
Nevertheless, before one can draw definite
conclusions whether the reaction γ
3He→pd is of inter-
est for studying properties of the P-states in 3He WF, the
role of the FSI effects in masking the sensitivity of the
asymmetry coefficient to the components of the WF has
to be investigated.
The author is grateful to H. Kamada, W. Glöckle,
J. Golak, H. Witała for the data on the 3He WFs ob-
tained with Paris and Bonn potentials and would like to
thank J. Jourdan for fruitful discussions.
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