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[show abstract]
[hide abstract]
ABSTRACT: In a recent paper by S.I. Sidorchuk et al., Phys. Rev. Lett. 108 (2012) 202502, angular correlations in the
decay of 10He were interpreted as a coherent superposition of a 0+, 1− and 2+ states. It was concluded
that it is the 1− state that dominates in the energy region 4.5–6 MeV. It is here demonstrated here that
the experimental data might be understood without assuming the presence of a low-lying 1− state.
Physics Letters B 03/2013; 720(4–5):344. · 3.95 Impact Factor
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A.N. Antonov,
M.K. Gaidarov,
M.V. Ivanov,
D.N. Kadrev,
M. Aïche,
G. Barreau,
S. Czajkowski,
B. Jurado,
G. Belier,
A. Chatillon, [......],
G. Nyman,
M. Zhukov,
P. Golubev,
D. Rudolph,
K. Hencken,
J. Jourdan,
B. Krusche,
T. Rauscher,
D. Kiselev,
D. Trautmann
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U. Datta Pramanik, T. Aumann,
K. Boretzky,
D. Cortina,
Th. W. Elze,
H. Emling,
H. Geissel,
M. Hellström,
K. L. Jones,
L. H. Khiem, [......],
Y. Leifels,
G. Münzenberg,
C. Nociforo,
R. Palit,
H. Scheit,
H. Simon,
K. Sümmerer,
S. Typel,
W. Walus,
H. Weick
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U Datta Pramanik, T Aumann,
K Boretzky,
B.V Carlson,
D Cortina,
Th.W Elze,
H Emling,
H Geissel,
A Grünschloß,
M Hellström, [......],
R Kulessa,
Y Leifels,
A Leistenschneider,
E Lubkiewicz,
G Münzenberg,
P Reiter,
H Simon,
K Sümmerer,
E Wajda,
W Walus
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[show abstract]
[hide abstract]
ABSTRACT: In a recent paper by S.I. Sidorchuk et al., Phys. Rev. Lett. 108 (2012) 202502, angular correlations in the decay of 10He were interpreted as a coherent superposition of a 0 + ,1− and 2+ states. It was concluded that it is the 1− state that dominates in the energy region 4.5–6 MeV. It is here demonstrated here that the experimental data might be understood without assuming the presence of a low-lying 1− state.
Physics Letters B 01/2013; 720:344. · 3.95 Impact Factor
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Yu. Aksyutina, T. Aumann,
K. Boretzky,
M.J.G. Borge,
C. Caesar,
A. Chatillon,
L.V. Chulkov,
D. Cortina-Gil,
U. Datta Pramanik,
H. Emling, [......],
R. Reifarth,
D. Rossi,
A. Richterb,
K. Riisager,
G. Schrieder,
H. Simon,
K. Sьmmerer,
O. Tengblad,
H. Weick,
M.V. Zhukov
[show abstract]
[hide abstract]
ABSTRACT: One-neutron knockout reactions from Borromean nuclei are analyzed using a profile function analysis
technique. The profile function, which is derived as the square root of the variance of the measured
fragment + neutron momenta as a function of their relative energy, is shown to be very sensitive to the
angular momentum of the knocked out neutron. Three cases are studied here: 7He, where the profile
function analysis shows a presence of (s1/2)2 component in the 8He ground-state wave-function, 10Li,
where the presence of a 11(2)% d-wave contribution to the relative energy spectrum above 1.5 MeV is
found and, finally, the presence of a major s contribution around 0.5 MeV relative energy in the 13Be
case and that the observed decay to the 12Be 2+ state originates in a d state in 13Be.
Physics Letters B 12/2012; · 3.95 Impact Factor
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S Schwertel,
P Maierbeck,
R Krücken,
R Gernhäuser,
T Kröll,
H Alvarez-Pol,
F Aksouh, T Aumann,
K Behr,
E A Benjamim, [......],
B Sitar,
M Stanoiu,
K Sümmerer,
O Tengblad,
H Weick,
S Winkler,
B A Brown,
T Otsuka,
J A Tostevin,
W D M Rae
[show abstract]
[hide abstract]
ABSTRACT: Results are presented from a one-neutron knockout experiment at relativistic energies of ~ 420 A MeV on 51-55Sc using the GSI Fragment Separator as a two-stage magnetic spectrometer and the MINIBALL array for gamma-ray detection. Inclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the contributions corresponding to knockout from the nup_1/2, nup_3/2, (L = 1) and nuf_7/2, nuf_5/2 (L = 3) neutron orbitals. The observed L = 1 and L = 3 contributions are compared with theoretical cross-sections using eikonal knockout theory and spectroscopic factors from shell model calculations using the GXPF1A interaction. The measured inclusive knockout cross-sections generally follow the trends expected theoretically and given by the spectroscopic strength predicted from the shell model calculations. However, the deduced L = 1 cross-sections are generally 30-40% higher while the L = 3 contributions are about a factor of two smaller than predicted. This points to a promotion of neutrons from the nuf_7/2 to nup_3/2 the orbital indicating a weakening of the N = 28 shell gap in these nuclei. While this is not predicted for the phenomenological GXPF1A interaction such a weakening is predicted by recent calculations using realistic low-momentum interactions V_lowk obtained by evolving a chiral N3LO nucleon-nucleon potential.
European Physical Journal A 12/2012; 48(12):191 1-10. · 2.19 Impact Factor
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C Rodriguez-Tajes,
H Alvarez-Pol, T Aumann,
E Benjamim,
J Benlliure,
MJG Borge,
M Caamano,
E Casarejos,
A Chatillon,
D Cortina-Gil, [......],
A Perea,
D Perez-Loureiro,
A Prochazka,
S Schwertel,
H Simon,
K Summerer,
O Tengblad,
H Weick,
M Winkler,
M Zhukov
Physical Review C 11/2012; 82. · 3.31 Impact Factor
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P. Russotto,
M. Chartier,
E. De Filippo,
A. Le Févre,
S. Gannon,
I. Gašparić,
M. Kiš,
S. Kupny,
Y. Leifels,
R. C. Lemmon, [......],
G. Verde,
M. Vigilante,
A. Wieloch,
P. Wigg,
H. H. Wolter,
P. Wu,
S. Yennello,
P. Zambon,
L. Zetta,
M. Zoric
[show abstract]
[hide abstract]
ABSTRACT: The elliptic-flow ratio of neutrons with respect to protons in reactions of
neutron rich heavy-ions systems at intermediate energies has been proposed as
an observable sensitive to the strength of the symmetry term in the nuclear
Equation Of State (EOS) at supra-saturation densities. The recent results
obtained from the existing FOPI/LAND data for $^{197}$Au+$^{197}$Au collisions
at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate
of the symmetry term of the EOS but suffer from a considerable statistical
uncertainty. In order to obtain an improved data set for Au+Au collisions and
to extend the study to other systems, a new experiment was carried out at the
GSI laboratory by the ASY-EOS collaboration in May 2011.
09/2012;
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D. M. Rossi,
P. Adrich,
F. Aksouh,
H. Alvarez-Pol, T. Aumann,
J. Benlliure,
M. Böhmer,
K. Boretzky,
E. Casarejos,
M. Chartier, [......],
R. Palit,
S. Paschalis,
R. Plag,
R. Reifarth,
H. Simon,
K. Sümmerer,
A. Wagner,
W. Walus,
H. Weick,
M. Winkler
[show abstract]
[hide abstract]
ABSTRACT: Exotic Ni isotopes have been measured at the R3B-LAND setup at GSI in
Darmstadt, using Coulomb excitation in inverse kinematics at beam energies
around 500 MeV/u. As the experimental setup allows kinematically complete
measurements, the excitation energy was reconstructed using the invariant mass
method. The GDR and additional low-lying strength have been observed in 68Ni,
the latter exhausting 4.1(1.9)% of the E1 energy-weighted sum rule. Also, the
branching ratio for the non-statistical decay of the excited 68Ni nuclei was
measured and amounts to 24(4)%.
09/2012;
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C. Rodríguez-Tajes,
D. Cortina-Gil,
H. Álvarez-Pol, T. Aumann,
E. Benjamim,
J. Benlliure,
M.J.G. Borge,
M. Caamaño,
E. Casarejos,
A. Chatillon, [......],
A. Perea,
D. Pérez-Loureiro,
A. Prochazka,
S. Schwertel,
H. Simon,
K. Sümmerer,
O. Tengblad,
H. Weick,
M. Winkler,
M.V. Zhukov
[show abstract]
[hide abstract]
ABSTRACT: One-neutron knockout reactions in a 9 Be target have been investigated at relativistic energies, near 700 MeV/u, for a set of sd-shell, neutron-rich nuclei. The experiment was performed in the FRS spectrometer, at GSI. γ-ray measurements were carried out by means of the MINIBALL γ-ray spectrometer and allowed the determination of partial cross-sections and branching ratios corresponding to the final states of the emerging knockout fragments. Experimental results are presented for 17 C, 19 N, 21 O and 25 F projectiles. The role of excited states of the N − 1 fragments in the composition of the ground state of these neutron-rich projectiles is outlined in this work.
European Physical Journal A 07/2012; · 2.19 Impact Factor
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M Grieser,
Yu A Litvinov,
R Raabe,
K Blaum,
Y Blumenfeld,
P A Butler,
F Wenander,
P Woods,
M Aliotta,
A Andreyev, [......],
E Wildner,
N Winckler,
D F A Winters,
A Wolf,
H S Xu,
A Yakushev,
T Yamaguchi,
Y J Yuan,
Y H Zhang,
K Zuber
The European Physical Journal Special Topics 05/2012; 207:1-117. · 1.56 Impact Factor
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A. Krasznahorkay,
L. Stuhl,
M. Csatlós,
A. Algora,
J. Gulyás,
J. Timár,
N. Paar,
D. Vretenar,
K. Boretzky,
M. Heil, [......],
V. Volkov,
F. Wamers,
E. Fiori,
B. Löher,
J. Marganiec,
D. Savran,
H. T. Johansson,
P. Diaz Fernández,
U. Garg,
D. L. Balabanski
[show abstract]
[hide abstract]
ABSTRACT: The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has
been measured to the isobaric analog state excited in the p(124Sn,n) reaction
at a beam energy of 600 MeV/nucleon. The energy of the transition was also
calculated with state-of-the-art self-consistent random-phase approximation
(RPA) and turned out to be very sensitive to the neutron-skin thickness
(\DeltaR_(pn)). By comparing the theoretical results with the measured one, the
\DeltaR_(pn) value for 124Sn was deduced to be 0.175 \pm 0.048 fm, which agrees
well with the previous results. The energy of the AGDR measured previously for
^(208)Pb was also used to determine the \DeltaR_(pn) for ^(208)Pb. In this way
a very precise \DeltaR_(pn) = 0.181 \pm 0.031 neutron-skin thickness has been
obtained for 208Pb. The present method offers new possibilities for measuring
the neutron-skin thicknesses of very exotic isotopes.
05/2012;
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U Datta Pramanik, T Aumann,
D Cortina,
H Emling,
H Geissel,
M Hellström,
R Holzmann,
N Iwasa,
Y Leifels,
G Münzenberg, [......],
A Grünschloss,
S Ilievski,
K Boretzky,
J V Kratz,
R Kulessa,
E Lubkiewicz,
E Wajda,
W Walus,
P Reiter,
H Simon
[show abstract]
[hide abstract]
ABSTRACT: Coulomb breakup of neutron-rich nuclei around mass A ∼ 20 has been studied experimentally using secondary beams (∼ 500–600 MeV/u) of unstable nuclei produced at GSI. The spectroscopic
factor deduced for the neutron occupying s
1/2 level in 15C ground state is consistent with the earlier reported value. The data analysis for Coulomb breakup of 17C shows that most of the cross section yields the 16C core in its excited state. For 17–22O, the low-lying E1 strength amounts up to about 12% of the energy weighted dipole sum rule strength depending on neutron
excess. The cluster sum rule limit with 16O as a core is almost exhausted for 17,18O, while for more neutron rich isotopes the strength with respect to that limit decreases.
Pramana 04/2012; 57(2):535-544. · 0.57 Impact Factor
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R Pleskac,
Z Abou-Haidar,
C Agodi,
M A G Alvarez, T Aumann,
G Battistoni,
A Bocci,
T T Ohlen,
A Boudard,
A Brunetti, [......],
H Simon,
V Sipala,
E Spiriti,
L Stuttge,
S Tropea,
H Younis,
V Patera,
P Cna,
Sevilla,
Spain
[show abstract]
[hide abstract]
ABSTRACT: The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at the SIS accelerator of GSI laboratory in Darmstadt has been designed for the measurement of ion fragmentation cross-sections at different angles and energies between 100 and 1000 MeV/nucleon. Nuclear fragmentation processes are relevant in several fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The start of the scientific program of the FIRST experiment was on summer 2011 and was focused on the measurement of 400 MeV/nucleon 12 C beam fragmentation on thin (8 mm) graphite target. The detector is partly based on an already existing setup made of a dipole magnet (ALADiN), a time projection chamber (TP-MUSIC IV), a neutron detector (LAND) and a time of flight scintillator system (TOFWALL). This pre-existing setup has been integrated with newly designed detectors in the Interaction Region, around the carbon target placed in a sample changer. The new detectors are a
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2012; 678:130. · 1.21 Impact Factor
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P. Pawłowski,
J. Brzychczyk,
Y. Leifels,
W. Trautmann,
P. Adrich, T. Aumann,
C. O. Bacri,
T. Barczyk,
R. Bassini,
S. Bianchin, [......],
K. Sümmerer,
M. B. Tsang,
G. Verde,
M. Veselsky,
C. Volant,
M. Wallace,
H. Weick,
J. Wiechula,
A. Wieloch,
B. Zwiegliński
[show abstract]
[hide abstract]
ABSTRACT: The performance of the LAND neutron detector is studied. Using an
event-mixing technique based on one-neutron data obtained in the S107
experiment at the GSI laboratory, we test the efficiency of various analytic
tools used to determine the multiplicity and kinematic properties of detected
neutrons. A new algorithm developed recently for recognizing neutron showers
from spectator decays in the ALADIN experiment S254 is described in detail. Its
performance is assessed in comparison with other methods. The properties of the
observed neutron events are used to estimate the detection efficiency of LAND
in this experiment.
Nuclear Instruments and Methods in Physics Research A. 03/2012; 694:47.
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C Nociforo,
A Prochazka,
R Kanungo, T Aumann,
D Boutin,
D Cortina-Gil,
B Davids,
M Diakaki,
F Farinon,
H Geissel, [......],
T Nilsson,
C Perro,
C Scheidenberger,
B Sitar,
P Strmen,
B Sun,
I Szarka,
I Tanihata,
H Weick,
M Winkler
[show abstract]
[hide abstract]
ABSTRACT: The one-neutron removal cross sections of neutron-rich Al isotopes and longitudinal momentum distributions of the residues have been measured for A = 33 to 36 at relativistic energies (approximate to 900 MeV/u). The inclusive data have been interpreted within the eikonal approximation. The evolution of the single-particle occupancy in the ground state of Al-33,Al-34,Al-35 has been studied and compared with shell model predictions. The inferred 2s(1/2) neutron occupancy in the Al-33 ground-state wave function is 20% to 40% lower than the predicted one. The inclusive data do not exclude the presence of intruder states. Some intruder l = 1 occupancy is found in Al-34, similarly to Mg-33. The single-particle 1f(7/2) occupancy shows a gradual increase at N = 22. Correspondingly, a decrease of the 1d(3/2) strength has been observed.
Physical Review C 03/2012; 85:044312. · 3.31 Impact Factor
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C Rodriguez-Tajes,
D Cortina-Gil,
H Alvarez-Pol, T Aumann,
E Benjamim,
J Benlliure,
M J G Borge,
M Caamano,
E Casarejos,
A Chatillon, [......],
A Perea,
D Perez-Loureiro,
A Prochazka,
S Schwertel,
H Simon,
K Summerer,
O Tengblad,
H Weick,
M Winkler,
M V Zhukov
Eur.Phys.J. A. 01/2012; 48:95.
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Z Abou-Haidar,
C Agodi,
M A G Alvarez,
M Anelli, T Aumann,
G Battistoni,
A Bocci,
T T Bohlen,
A Boudard,
A Brunetti, [......],
A Sarti,
C Schuy,
A Sciubba,
C Sfienti,
H Simon,
V Sipala,
E Spiriti,
L Stuttge,
S Tropea,
H Younis
Journal of Instrumentation. 01/2012; 7(02):P02006.
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R Ogul,
A S Botvina,
U Atav,
N Buyukcizmeci,
I N Mishustin,
P Adrich, T Aumann,
C O Bacri,
T Barczyk,
R Bassini, [......],
K Suemmerer,
W Trautmann,
M B Tsang,
G Verde,
C Volant,
M Wallace,
H Weick,
J Wiechula,
A Wieloch,
B Zwieglinski
Physical Review C. 01/2012; 85(1).
