Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 53

In-beam γ-ray spectroscopy of 136 Te at relativistic energies†
V. Vaquero,∗1 A. Jungclaus,∗1 P. Doornenbal,∗2 K. Wimmer,∗3,∗2 A. M. Moro,∗4 K. Ogata,∗5 T. Furumoto,∗6S. Chen,∗2,∗7 E. Nácher,∗1 E. Sahin,∗8 Y. Shiga,∗9 D. Steppenbeck,∗2 R. Taniuchi,∗2,∗3 Z. Y. Xu,∗10 T. Ando,∗3
H. Baba,∗2 F. L. Bello Garrote,∗8 S. Franchoo,∗11 K. Hadynska-Klek,∗8 A. Kusoglu,∗12,∗13 J. Liu,∗10T. Lokotko,∗10 S. Momiyama,∗3 T. Motobayashi,∗2 S. Nagamine,∗3 N. Nakatsuka,∗14 M. Niikura,∗3R. Orlandi,∗15 T. Saito,∗3 H. Sakurai,∗2,∗3 P. A. Söderström,∗2 G. M. Tveten,∗8 Zs. Vajta,∗16 andM. Yalcinkaya∗120.25
B(E2;0+ → 2+) e2b2+
The reduced transition probability B(E2; 0+1 → 21 )+to the ﬁrst excited 2 state of the neutron-rich nucleus 136 Te, with two protons and two neutrons outside the doubly-magic 132 Sn core, has been measured
via Coulomb excitation at relativistic energies at theRIKEN Radioactive Isotope Beam Factory. A value ofB(E2) = 0.191(26) e2 b2 was extracted from the measured inelastic scattering cross section on a Au target taking into account the contributions from both
Coulomb and nuclear excitations. This value is compared to previous experimental results reported in theliterature and various theoretical calculations in Fig. 1.
Our measurement, performed at relativistic energies,
agrees with the large value which has recently been obtained in Coulomb excitation at safe energies at OakRidge.1) It is, however, in conﬂict with the low-energy
Coulomb excitation measurement of Refs. 2–3) and thepreliminary result of the experiment using the fast timing technique reported by Fraile et al.4) For a detailed
discussion of the comparison to theory we refer thereader to the original publication.
The high statistics gathered in the present experiment allowed for the ﬁrst time to evaluate in detailthe validity of the approach employed in the analysisof Coulomb excitation experiments at beam energies
around 150 MeV/nucleon and to estimate the systematic uncertainties involved in the diﬀerent steps of theanalysis. In this publication, a detailed discussion ofthe analysis procedure is provided so that it can serve
as guideline for the analysis of future experiments using the same technique but accumulating less statistics. In particular, the correct determination of the0.2

0.15
0.1

SM 1
SM 2

0.05

QRPA
MCSM
QRPA2
NSM

0SM 3

132

This work
J. M. Allmond et al. 2017
A. E. Stuchbery et al. 2013
Danchev et al. 2011
L. M. Fraile et al. 2008
C. J. Barton et al. 2003

134
136
Mass Number (A)+Fig. 1. Comparison of the experimental B(E2; 0+1 → 21 )136value for
Te determined in the present work to literature values for the 132, 134, 136 Te isotopes and diﬀerent
theoretical calculations (for details see the original publication).

exclusive scattering cross section to the 2+
1 state, taking into account the scattering-angle dependent losses
due to the limited acceptance of the ZeroDegree spectrometer and losses due to reactions which take place
on any material in the beam line between the identiﬁcations in BigRIPS and the ZeroDegree spectrometer,
is discussed in detail. The other important part of
the analysis concerns the determination of a B(E2)value from the measured exclusive cross section, which
requires a consistent description of both nuclear andelectromagnetic excitations. In the present case, thecode FRESCO5,6) was employed for this purpose.

Condensed from the article in Phys. Rev. C 99, 034306(2019)∗1 IEM-CSIC Madrid∗2 RIKEN Nishina Center∗3 Department of Physics, University of Tokyo∗4 Universidad de Sevilla, Sevilla∗5 Research Center for Nuclear Physics, Osaka University∗6 Graduate School of Education, Yokohama National University∗7 Peking University, Bejing∗8 University of Oslo, Oslo∗9 Department of Physics, Rikkyo University∗10 University of Hong Kong
∗11 IN2P3-CNRS, Orsay∗12 Istanbul University, Istanbul∗13 ELI-NP, Magurele∗14 Department of Physics, Kyoto University∗15 Advanced Science Research Center, JAEA, Tokai∗16 MTA Atomki, Debrecen†

References

1) J. M. Allmond et al., Phys. Rev. Lett. 118, 092503(2017).
2) D. C. Radford et al., Phys. Rev. Lett. 88, 222501 (2002).
3) M. Danchev et al., Phys. Rev. C 84, 061306(R) (2011).
4) L. M. Fraile et al., Nucl. Phys. A 805, 218 (2008).
5) I. J. Thompson, Comput. Phys. Rep. 7, 3 (1988).
6) http://fresco.org.uk .

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