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Barucca, G., Davi, F., Lancioni, G., Mengucci, P., Montalto, L., Natali, P. P., . . . Zmeskal, J. (2019). Precision resonance energy scans with the PANDA experiment at FAIR: Sensitivity study for width and line shape measurements of the X(3872). European Physical Journal A, 55(3), Article ID 42.
Open this publication in new window or tab >>Precision resonance energy scans with the PANDA experiment at FAIR: Sensitivity study for width and line shape measurements of the X(3872)
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2019 (English)In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 55, no 3, article id 42Article in journal (Refereed) Published
Abstract [en]

.This paper summarises a comprehensive Monte Carlo simulation study for precision resonance energy scan measurements. Apart from the proof of principle for natural width and line shape measurements of very narrow resonances with PANDA, the achievable sensitivities are quantified for the concrete example of the charmonium-like X(3872) state discussed to be exotic, and for a larger parameter space of various assumed signal cross-sections, input widths and luminosity combinations. PANDA is the only experiment that will be able to perform precision resonance energy scans of such narrow states with quantum numbers of spin and parities that differ from JPC=1--.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-249877 (URN)10.1140/epja/i2019-12718-2 (DOI)000462672600001 ()2-s2.0-85063462704 (Scopus ID)
Note

QC 20190503

Available from: 2019-05-03 Created: 2019-05-03 Last updated: 2019-05-03Bibliographically approved
Haefner, G., Bäck, T., Zhu, Y. & et al., . (2019). PROPERTIES OF gamma-DECAYING ISOMERS IN THE Sn-100 REGION REVISITED. Paper presented at Zakopane Conference on Nuclear Physics - Extremes of the Nuclear ndscape, AUG 26-SEP 02, 2018, Zakopane, POLAND. Acta Physica Polonica B, 50(3), 431-437
Open this publication in new window or tab >>PROPERTIES OF gamma-DECAYING ISOMERS IN THE Sn-100 REGION REVISITED
2019 (English)In: Acta Physica Polonica B, ISSN 0587-4254, E-ISSN 1509-5770, Vol. 50, no 3, p. 431-437Article in journal (Refereed) Published
Abstract [en]

The study of nuclei in the region around the N = Z doubly-magic nucleus -100 has been of long standing interest for the nuclear structure and clear astrophysics. Recently, Park et al. have reported on properties gamma-decaying isomers and isomeric ratios in the vicinity of Sn-100. at experiment was performed at the Radioactive Ion Beam Factory (RIBF) the RIKEN Nishina Center in Japan as a part of the EURICA campaign. utron-deficient nuclei were produced in a fragmentation reaction of a -124 primary beam on a 9 Be target at an energy of 345 MeV/A. condary ions were separated and identified in the BigRIPS fragment parator and implanted in the silicon detector array WAS3ABi. The data esented here were obtained in another experiment performed at the RIBF ing the same reaction but slightly different separator settings. New sults of ratios of isomeric population and half-lives of mma-decaying isomers populated in the experiment are presented.

Place, publisher, year, edition, pages
JAGIELLONIAN UNIV PRESS, 2019
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-250502 (URN)10.5506/APhysPolB.50.431 (DOI)000463866500026 ()2-s2.0-85063690947 (Scopus ID)
Conference
Zakopane Conference on Nuclear Physics - Extremes of the Nuclear ndscape, AUG 26-SEP 02, 2018, Zakopane, POLAND
Note

QC 20190430

Available from: 2019-04-30 Created: 2019-04-30 Last updated: 2019-05-09Bibliographically approved
B Singh, ., Bäck, T., Cederwall, B., Zmeskal, J. & et al., . (2019). Technical design report for the (P)over-barANDA Barrel DIRC detector. JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS (4)
Open this publication in new window or tab >>Technical design report for the (P)over-barANDA Barrel DIRC detector
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2019 (English)In: JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, no 4Article in journal (Refereed) Published
Abstract [en]

The (P) over bar ANDA (anti-Proton ANnihiliation at DArmstadt) experiment will be one of the four flagship experiments at the new international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. (P) over bar ANDA will address fundamental questions of hadron physics and quantum chromodynamics using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c and a design luminosity of up to 2 x 10(32) cm(-2) S-1. Excellent particle identification (PID) is crucial to the success of the (P) over bar ANDA physics program. Hadronic PID in the barrel region of the target spectrometer will be performed by a fast and compact Cherenkov counter using the detection of internally reflected Cherenkov light (DIRC) technology. It is designed to cover the polar angle range from 22 degrees to 140 degrees and will provide at least 3 standard deviations (s.d.) pi/K separation up to 3.5 GeV/c, matching the expected upper limit of the final state kaon momentum distribution from simulation. This documents describes the technical design and the expected performance of the (P) over bar ANDA Barrel DIRC detector. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean pi/K separation with at least 3 s.d. over the entire phase space of charged kaons in the Barrel DIRC.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2019
Keywords
particle identification; ring imaging Cherenkov detector; DIRC counter; PANDA experiment; hadron physics
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-247986 (URN)10.1088/1361-6471/aade3d (DOI)000460153900001 ()
Note

QC 20190401

Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2019-04-01Bibliographically approved
Davies, P. J., Bäck, T. & Zhu, Y. (2019). Toward the limit of nuclear binding on the N = Z line: Spectroscopy of Cd-96. Physical Review C: Covering Nuclear Physics, 99(2), Article ID 021302.
Open this publication in new window or tab >>Toward the limit of nuclear binding on the N = Z line: Spectroscopy of Cd-96
2019 (English)In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 99, no 2, article id 021302Article in journal (Refereed) Published
Abstract [en]

A gamma -decaying isomeric state (tau(1/2) = 197(-17)(+19) ns) has been identified in Cd-96, which is one alpha particle away from the last known bound N = Z nucleus, Sn-100. Comparison of the results with shell-model calculations has allowed a tentative experimental level scheme to be deduced and the isomer to be interpreted as a medium-spin negative-parity spin trap based on the coupling of isoscalar (T = 0) and isovector (T = 1) neutron-proton pairs. The data also suggest evidence for the population of a 9(+) T = 1 state, which is predicted by shell-model calculations to be yrast. Such a low-lying T = 1 state, which is unknown in lighter mass even-even self-conjugate nuclei, can also be interpreted in terms of the coupling of T = 0 and T = 1 neutron-proton pairs.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2019
National Category
Subatomic Physics
Identifiers
urn:nbn:se:kth:diva-245141 (URN)10.1103/PhysRevC.99.021302 (DOI)000458369600001 ()2-s2.0-85061786087 (Scopus ID)
Note

QC 20190307

Available from: 2019-03-07 Created: 2019-03-07 Last updated: 2019-03-07Bibliographically approved
Singh, B., Erni, W., Krusche, B., Steinacher, M., Walford, N., Liu, H., . . . Semenov-Tian-Shansky, K. M. (2017). Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0). Physical Review D: covering particles, fields, gravitation, and cosmology, 95(3), Article ID 032003.
Open this publication in new window or tab >>Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
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2017 (English)In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 95, no 3, article id 032003Article in journal (Refereed) Published
Abstract [en]

The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.

National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-204693 (URN)10.1103/PhysRevD.95.032003 (DOI)000393744600003 ()2-s2.0-85021668121 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, HP3 GA283286Swedish Research Council
Note

QC 20170602

Available from: 2017-06-02 Created: 2017-06-02 Last updated: 2017-11-29Bibliographically approved
Ralet, D., Bäck, T., Cederwall, B., Doncel, M., Ghazi Moradi, F., Zielinska, M. & et al., . (2017). Lifetime measurement of neutron-rich even-even molybdenum isotopes. Physical Review C: Covering Nuclear Physics, 95(3), Article ID 034320.
Open this publication in new window or tab >>Lifetime measurement of neutron-rich even-even molybdenum isotopes
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2017 (English)In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 95, no 3, article id 034320Article in journal (Refereed) Published
Abstract [en]

Background: In the neutron-rich A approximate to 100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A = 100 up to mass A = 108, and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the gamma ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a gamma-ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A = 100 to A = 108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: tau = 29.7(-9.1)(+11.3) ps for the 4(+) state of Mo-108 and tau = 3.2(-0.7)(+ 0.7) ps for the 6(+) state of Mo-102. Conclusions: The reduced transition strengths B(E2), calculated from lifetimes measured in this experiment, compared to beyond-mean-field calculations, indicate a gradual shape transition in the chain of molybdenum isotopes when going from A = 100 to A = 108 with a maximum reached at N = 64. The transition probabilities decrease for Mo-108 which may be related to its well-pronounced triaxial shape indicated by the calculations.

Place, publisher, year, edition, pages
AMER PHYSICAL SOC, 2017
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-207464 (URN)10.1103/PhysRevC.95.034320 (DOI)000399143200002 ()2-s2.0-85016484924 (Scopus ID)
Note

QC 20170519

Available from: 2017-05-19 Created: 2017-05-19 Last updated: 2017-11-29Bibliographically approved
Ertoprak, A., Cederwall, B., Jakobsson, U., Nyako, B. M., Nyberg, J., Davies, P., . . . Xiao, Z. G. (2017). LIFETIME MEASUREMENTS WITH THE DOPPLER SHIFT ATTENUATION METHOD USING A THICK HOMOGENEOUS PRODUCTION TARGET - VERIFICATION OF THE METHOD. Paper presented at Zakopane Conference on Nuclear Physics - Extremes of the Nuclear Landscape, AUG 28-SEP 04, 2016, Zakopane, POLAND. Acta Physica Polonica B, 48(3), 325-329
Open this publication in new window or tab >>LIFETIME MEASUREMENTS WITH THE DOPPLER SHIFT ATTENUATION METHOD USING A THICK HOMOGENEOUS PRODUCTION TARGET - VERIFICATION OF THE METHOD
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2017 (English)In: Acta Physica Polonica B, ISSN 0587-4254, E-ISSN 1509-5770, Vol. 48, no 3, p. 325-329Article in journal (Refereed) Published
Abstract [en]

Doppler Shift Attenuation Method (DSAM) analysis of excited-state lifetimes normally employs thin production targets mounted on a thick stopper foil ("backing") serving to slow down and stop the recoiling nuclei of interest in a well-defined manner. Use of a thick, homogeneous production target leads to a more complex analysis as it results in a substantial decrease in the energy of the incident projectile which traverses the target with an associated change in the production cross section of the residues as a function of penetration depth. Here, a DSAM lifetime analysis using a thick homogeneous target has been verified using the Doppler broadened lineshapes of gamma rays following the decay of highly excited states in the semi-magic (N = 50) nucleus Ru-94. Lifetimes of excited states in the Ru-94 nucleus have been obtained using a modified version of the LINESHAPE package from the Doppler broadened lineshapes resulting from the emission of the gamma rays, while the residual nuclei were slowing down in the thick (6 mg/cm(2)) metallic Ni-58 target. The results have been validated by comparison with a previous measurement using a different (RDDS) technique.

Place, publisher, year, edition, pages
Jagiellonian University Press, 2017
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-206296 (URN)10.5506/APhysPolB.48.325 (DOI)000398717500013 ()2-s2.0-85017146840 (Scopus ID)
Conference
Zakopane Conference on Nuclear Physics - Extremes of the Nuclear Landscape, AUG 28-SEP 04, 2016, Zakopane, POLAND
Note

QC 20170508

Available from: 2017-05-08 Created: 2017-05-08 Last updated: 2017-11-09Bibliographically approved
Saygi, B., Joss, D. T., Page, R. D., Grahn, T., Simpson, J., O'Donnell, D., . . . Uusitalo, J. (2017). Reduced transition probabilities along the yrast line in W-166. Physical Review C: Covering Nuclear Physics, 96(2), Article ID 021301.
Open this publication in new window or tab >>Reduced transition probabilities along the yrast line in W-166
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2017 (English)In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 96, no 2, article id 021301Article in journal (Refereed) Published
Abstract [en]

Lifetimes of excited states in the yrast band of the neutron-deficient nuclide W-166 have been measured utilizing the DPUNS plunger device at the target position of the JUROGAM II gamma-ray spectrometer in conjunction with the RITU gas-filled separator and the GREAT focal-plane spectrometer. Excited states in W-166 were populated in the Mo-92(Kr-78, 4p) reaction at a bombarding energy of 380 MeV. The measurements reveal a low value for the ratio of reduced transitions probabilities for the lowest-lying transitions B(E2; 4(+)-> 2(+)) / B(E2; 2(+)-> 0(+)) = 0.33(5), compared with the expected ratio for an axially deformed rotor (B-4/2 = 1.43).

Place, publisher, year, edition, pages
American Physical Society, 2017
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-212331 (URN)10.1103/PhysRevC.96.021301 (DOI)000406755100001 ()2-s2.0-85028710771 (Scopus ID)
Note

QC 20170821

Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2017-11-29Bibliographically approved
Doncel, M., Bäck, T., Qi, C., Cullen, D. M., Hodge, D., Cederwall, B., . . . Uusitalo, J. (2017). Spin-dependent evolution of collectivity in Te 112. Physical Review C: Covering Nuclear Physics, 96(5), Article ID 051304.
Open this publication in new window or tab >>Spin-dependent evolution of collectivity in Te 112
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2017 (English)In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 96, no 5, article id 051304Article in journal (Refereed) Published
Abstract [en]

The evolution of collectivity with spin along the yrast line in the neutron-deficient nucleus Te112 has been studied by measuring the reduced transition probability of excited states in the yrast band. In particular, the lifetimes of the 4+ and 6+ excited states have been determined by using the recoil distance Doppler-shift method. The results are discussed using both large-scale shell-model and total Routhian surface calculations.

Place, publisher, year, edition, pages
American Physical Society, 2017
National Category
Subatomic Physics
Identifiers
urn:nbn:se:kth:diva-227137 (URN)10.1103/PhysRevC.96.051304 (DOI)000416237000001 ()2-s2.0-85036617472 (Scopus ID)
Note

QC 20180518

Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2019-02-11Bibliographically approved
Davies, P. J., Grawe, H., Moschner, K., Blazhev, A., Wadsworth, R., Boutachkov, P., . . . Zhu, Y. (2017). The role of core excitations in the structure and decay of the 16(+) spin-gap isomer in Cd-96. Physics Letters B, 767, 474-479
Open this publication in new window or tab >>The role of core excitations in the structure and decay of the 16(+) spin-gap isomer in Cd-96
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2017 (English)In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 767, p. 474-479Article in journal (Refereed) Published
Abstract [en]

The first evidence for beta-delayed proton emission from the 16(+) spin gap isomer in Cd-96 is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the BigRIPS spectrometer and the EURICA decay station. beta p branching ratios for the ground state and 16(+) isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of Cd-95. Large scale shell model (LSSM) calculations have been performed and WKB estimates made for l = 0, 2, 4 proton emission from three resonance-like states in Ag-96, that are populated by the beta decay of the isomer, and the results compared to the new data. The calculations suggest that l = 2 proton emission from the resonance states, which reside similar to 5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16(+) state.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
beta-decay, beta p-decay, gamma-ray spectroscopy, Half-life, Shell-model, WKB
National Category
Subatomic Physics
Identifiers
urn:nbn:se:kth:diva-205432 (URN)10.1016/j.physletb.2017.02.013 (DOI)000397861700072 ()2-s2.0-85014733974 (Scopus ID)
Note

QC 20170522

Available from: 2017-05-22 Created: 2017-05-22 Last updated: 2017-06-30Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1996-0805

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