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1.	Li, Z. S, et al. (författare) The FERRUM project: radiative lifetimes of intermediate-excitation states of Fe II measured in a fluorescence signal induced by laser pumping from a metastable state 1999 Ingår i: European Physical Journal D. Atomic, Molecular, Optical and Plasma Physics. - : Springer Science and Business Media LLC. - 1434-6060. ; 6:1, s. 9-12 Tidskriftsartikel (refereegranskat)abstract A new collaborative program, the FERRUM project. aims at extending and improving the database of oscillator strengths for the astrophysical important Fe II spectrum. In this paper we report on the experimental method applied for measurements of radiative lifetimes of Fe II levels at intermediate excitation (5-10 eV) that can be populated ba laser excitation from metastable states. The technique involves a laser-produced plasma as a source for metastable ions, a stimulated Brillouin scatttering cell for shortening the laser pulse, and fast time resolved detection. We have applied the technique on two Fe II levels at about 7.5 eV and obtained the lifetimes: tau(z(4)S(3/2)(0)) = 3.8(2) ns; tau(y(4)P(5/2)(0)) = 3.6(3) Its.
2.	Adamczewski-Musch, J., et al. (författare) Production and electromagnetic decay of hyperons : a feasibility study with HADES as a phase-0 experiment at FAIR 2021 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4 Tidskriftsartikel (refereegranskat)abstract A feasibility study has been performed in order to investigate the performance of the HADES detector to measure the electromagnetic decays of the hyperon resonances Sigma(1385)(0), Lambda(1405) and Lambda(1520) as well as the production of double strange baryon systems Xi(-) and Lambda Lambda in p + p reactions at a beam kinetic energy of 4.5GeV. The existing HADES detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized.
3.	Adlarson, Patrik, et al. (författare) Backward single-pion production in the pd -> He-3 pi(0)reaction with WASA-at-COSY 2018 Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 54:9 Tidskriftsartikel (refereegranskat)abstract New data on the production of single neutral pions in the pd -> He-3 pi(0) reaction are presented. For fifteen proton beam momenta between p(p) = 1.60GeV/c and p(p) = 1.74 GeV/c, differential cross sections are determined over a large fraction of the backward hemisphere. Since the only previous systematic measurements of single-pion production at these energies were made in collinear kinematics, the present work constitutes a significant extension of the current knowledge on this reaction. Even this far above the production threshold, significant changes are found in the behaviour of the angular distributions over small intervals in beam momentum.
4.	Adlarson, Patrik, et al. (författare) Cross section ratio and angular distributions of the reaction p + d -> He-3 + eta at 48.8MeV and 59.8MeV excess energy 2014 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 50:6, s. 100- Tidskriftsartikel (refereegranskat)abstract We present new data for angular distributions and on the cross section ratio of the p+d -> He-3+eta reaction at excess energies of Q - 48.8MeV and Q - 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Julich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.
5.	Adlarson, Patrik, et al. (författare) Measurement of the (n)over-right-arrowp -> d pi(0) pi(0) reaction with polarized beam in the region of the d()(2380) resonance 2016 Ingår i:* European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 52:5, s. 1-7 Tidskriftsartikel (refereegranskat)abstract We report on a high-statistics measurement of the most basic double-pionic fusion reaction over the energy region of the d ()(2380) resonance by use of a polarized deuteron beam and observing the double fusion reaction in the quasifree scattering mode. The measurements were performed with the WASA detector setup at COSY. The data reveal substantial analyzing powers and confirm conclusions about the d() resonance obtained from unpolarized measurements. We also confirm the previous unpolarized data obtained under complementary kinematic conditions.
6.	Adolfsson, J., et al. (författare) QCD challenges from pp to A–A collisions 2020 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:11 Forskningsöversikt (refereegranskat)abstract This paper is a write-up of the ideas that were presented, developed and discussed at the third International Workshop on QCD Challenges from pp to A–A, which took place in August 2019 in Lund, Sweden (Workshop link: https://indico.lucas.lu.se/event/1214/). The goal of the workshop was to focus on some of the open questions in the field and try to come up with concrete suggestions for how to make progress on both the experimental and theoretical sides. The paper gives a brief introduction to each topic and then summarizes the primary results.
7.	Ahlgren Cederlöf, Ebba, et al. (författare) Lifetime measurement of the yrast 2+ state in 118Te 2023 Ingår i: European Physical Journal A. - : Springer. - 1434-6001 .- 1434-601X. ; 59:12 Tidskriftsartikel (refereegranskat)abstract The electromagnetic transition probabilities of the yrast 2+ states in the midshell Te isotopes, two protons above the closed shell at Sn, are of great importance for the understanding of nuclear collectivity in these isotopes and the role played by the neutron-proton interactions and cross-shell excitations. However, the large uncertainty of the experimental data for the midshell nucleus 118Te and the missing data for 116Te make it difficult to pin down the general trend of the evolution of transition probabilities as a function of the neutron number. In this work, the lifetime of the yrast 2+ state in 118Te was measured, with the aim of reducing the uncertainty of the previous measurement. The result is τ2+ = 7.46(19) ps. In addition, the lifetime of the 4+ state was measured to be τ4+ = 4.25(23) ps. The experimental transition rates are extracted from the measured lifetimes and compared with systematic large-scale shell-model calculations. The trend of the B(E2; 0+ → 2+) values in the midshell area is in good agreement with the calculations and the calculated B4/2 ratio provide evidence for 118Te as a near perfect harmonic vibrator.
8.	Ahmed, I., et al. (författare) Shell-model studies relevant for the low-energy Coulomb excitation in Zn isotopes 2023 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 59:12 Tidskriftsartikel (refereegranskat)abstract The low-lying nuclear structure of even-even Zn isotopes ranging from 62 Zn to 70 Zn has been comprehensively examined through large scale shell model calculations. These calculations encompassed the f 5 / 2p 3 / 2 , 1 / 2g 9 / 2 (fpg) model space without any truncation, employing 56 Ni as an inert core. Two different effective interactions, JUN45 and jj44b, were utilized in these calculations. Various critical observables, including excitation energies, reduced transition strengths, and electric quadrupole moments, were computed and then evaluated in the context of existing experimental data. The configurations of the resulting wave functions were also thoroughly analyzed. Furthermore, occupation probabilities for distinct single-particle orbitals were determined, with particular attention given to the pivotal role of the g 9 / 2 orbital in elucidating the nuclear structure of heavy Zn isotopes. Additionally, rotational invariants were calculated for the ground state, shedding light on a prolate deformation in 62 Zn and 64 Zn, while suggesting moderate prolate-triaxial excitations in 66 Zn, 68 Zn, and 70 Zn. These findings hold significant relevance for interpreting the intriguing outcomes of sub-barrier Coulomb excitation experiments, offering invaluable insights into the static electromagnetic properties of the nucleus through a model-independent approach.
9.	Ahrens, J, et al. (författare) First measurement of the helicity-dependent (gamma)over-right-arrow(p)over-right-arrow -> p eta differential cross-section 2003 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 17:2, s. 241-244 Tidskriftsartikel (refereegranskat)abstract The helicity dependence of the (γ) over right arrow(p) over right arrow -+ peta reaction has been measured for the first time at a center-of-mass angle theta(eta)*= 70degrees in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam. and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis.
10.	Ahrens, J, et al. (författare) Helicity dependence of the gamma p -> N pi channels and multipole analysis in the Delta region 2004 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 21:2, s. 323-333 Tidskriftsartikel (refereegranskat)abstract A high-quality double-polarization data set for the helicity dependence of the total and differential cross-sections for both gammap --> Npi channels in the Delta region has been obtained in the framework of the GDH experiment. The experiment, performed at the Mainz microtron MAMI, used a 4pi detection system, a circularly polarized photon beam, and a longitudinally polarized frozen-spin target. These data are included in the database to perform a multipole analysis to determine the properties of the Delta(1232)-resonance. For the resonant Delta(1232) multipoles we find a very good agreement with previous analyses, while the nonresonant ones show significant deviations.
11.	Al-Adili, Ali, et al. (författare) Extraction of angular momenta from isomeric yield ratios : Employing TALYS to de-excite primary fission fragments 2019 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 55:4 Tidskriftsartikel (refereegranskat)abstract The generation of angular momentum in fission is difficult to model, in particular at higher excitation energies where data are scarce. Isomeric yield ratios (IYR) play an important role in deducing angular momentum properties of fission fragments (FF), albeit this requires some assumptions and simplifications. To estimate FF angular momentum, fission codes can be used to calculate IYRs and compare them to experimental data. Such measurements have systematically been performed at the IGISOL facility using novel experimental techniques. In conjunction, a new method has been developed to infer the angular momentum of the primary FF using the nuclear reaction code TALYS. In this work, we evaluate this new method by comparing our TALYS calculations with values found in the literature and with results from the GEF fission code, for a few well-studied reactions. The overall results show a consistent performance of TALYS and GEF, as well as of many reported literature values. However, some deviations were found, possibly pinpointing the need to re-examine some of the reported literature values. A sensitivity analysis was also performed, in which the role of excitation energy, neutron emission, discrete level structure and level density models were studied. Finally, the role of multiple chance fission, of relevance for the reactions studied at IGISOL, is discussed. Some literature data for this reaction were also re-analyzed using TALYS, revealing significant differences.
12.	Al-Adili, Ali, et al. (författare) Simulations of the fission-product stopping efficiency in IGISOL 2015 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:59, s. 1-7 Tidskriftsartikel (refereegranskat)abstract At the Jyväskylä Ion Guide Isotope Separator On-Line (IGISOL) facility, independent fission yields are measured employing the Penning-trap technique. Fission products are produced, e.g. by impinging protons on a uranium target, and are stopped in a gas-filled chamber. The products are collected by a flow of He gas and guided through a mass separator to a Penning trap, where their masses are identified. This work investigates how fission-product properties, such as mass and energy, affect the ion stopping efficiency in the gas cell. The study was performed using the Geant4 toolkit and the SRIM code. The main results show a nearly mass-independent ion stopping with regard to the wide spread of ion masses and energies, with a proper choice of uranium target thickness. Although small variations were observed, in the order of 5%, the results are within the systematic uncertainties of the simulations. To optimize the stopping efficiency while reducing the systematic errors, different experimental parameters were varied; for instance material thicknesses and He gas pressure. Different parameters influence the mass dependence and could alter the mass dependencies in the ion stopping efficiency.
13.	Al Jebali, Ramsey, et al. (författare) A helium gas scintillator active target for photoreaction measurements 2015 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 51:10 Tidskriftsartikel (refereegranskat)abstract A multi-cell He gas scintillator active target, designed for the measurement of photoreaction cross sections, is described. The target has four main chambers, giving an overall thickness of 0.103 g/cm(3) at an operating pressure of 2MPa. Scintillations are read out by photomultiplier tubes and the addition of small amounts of N-2 to the He, to shift the scintillation emission from UV to visible, is discussed. First results of measurements at the MAX IV Laboratory tagged-photon facility show that the target has a timing resolution of around 1 ns and can cope well with a high-flux photon beam. The determination of reaction cross sections from target yields relies on a Monte Carlo simulation, which considers scintillation light transport, photodisintegration processes in He-4, background photon interactions in target windows and interactions of the reaction-product particles in the gas and target container. The predictions of this simulation are compared to the measured target response.
14.	Al-Khatib, A, et al. (författare) Transition to non-collective states at high spin in Xe-124 2008 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 36:1, s. 21-29 Tidskriftsartikel (refereegranskat)abstract Excited states in Xe-124 were populated in the reaction Se-82(Ca-48, 6n) Xe-124 and gamma-ray coincidence relationships were measured with the Gammasphere spectrometer. Two new bands are observed and several of the previously known bands are extended in the high-as well as in the low-spin region. Two irregular high-spin structures are also added. The irregularities are a fingerprint of a transition from collective to non-collective behaviour. Configuration assignments to the new structures are proposed on the basis of systematics and by comparing experimental properties with calculations within the framework of the cranking model.
15.	Albertsson, Martin, et al. (författare) Calculated fission-fragment mass yields and average total kinetic energies of heavy and superheavy nuclei 2020 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:2 Tidskriftsartikel (refereegranskat)abstract Fission-fragment mass and total-kinetic-energy (TKE) distributions following fission of even-even nuclides in the region 74 ≤ Z≤ 126 and 92 ≤ N≤ 230 , comprising 896 nuclides have been calculated using the Brownian shape-motion method. The emphasis is the region of superheavy nuclei. To show compatibility with earlier results the calculations are extended to include earlier studied regions. An island of asymmetric fission is obtained in the superheavy region, 106 ≤ Z≤ 114 and 162 ≤ N≤ 176 , where the heavy fragment is found to be close to 208Pb and the light fragment adjusts accordingly. Most experimentally observed α-decay chains of superheavy nuclei with Z> 113 terminate by spontaneous fission in our predicted region of asymmetric fission. In these cases, the pronounced large asymmetry is accompanied by a low TKE value compatible with measurements.
16.	Alef, S., et al. (författare) The BGOOD experimental setup at ELSA 2020 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:4 Tidskriftsartikel (refereegranskat)abstract The BGOOD experiment at the ELSA facility in Bonn has been commissioned within the framework of an international collaboration. The experiment pursues a systematic investigation of non-strange and strange meson photoproduction, in particular t-channel processes at low momentum transfer. The setup uniquely combines a central almost 4 π acceptance BGO crystal calorimeter with a large aperture forward magnetic spectrometer providing excellent detection of both neutral and charged particles, complementary to other setups such as Crystal Barrel, Crystal Ball, LEPS and CLAS.
17.	Ananthanarayan, B., et al. (författare) An analytic approach to sunset diagrams in chiral perturbation theory : Theory and practice 2016 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 52:12 Tidskriftsartikel (refereegranskat)abstract We demonstrate the use of several code implementations of the Mellin-Barnes method available in the public domain to derive analytic expressions for the sunset diagrams that arise in the two-loop contribution to the pion mass and decay constant in three-flavoured chiral perturbation theory. We also provide results for all possible two mass configurations of the sunset integral, and derive a new one-dimensional integral representation for the one mass sunset integral with arbitrary external momentum. Thoroughly annotated Mathematica notebooks are provided as ancillary files in the Electronic Supplementary Material to this paper, which may serve as pedagogical supplements to the methods described in this paper.
18.	Andersson, Lise-Lotte, et al. (författare) Extensive Gamma-ray Spectroscopy of Normally and Superdeformed Structures in 61Cu 2008 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 36:3, s. 251-278 Tidskriftsartikel (refereegranskat)abstract A largely extended experimental knowledge of the Cu-61(29)32 nucleus has been obtained from three experiments. Excited states in Cu-61 were produced via the fusion-evaporation reaction Si-28(Ar-36, 3p)Cu-61. In addition to the Ge array GAMMASPHERE, neutron and charged-particle detectors placed around the target position were used for high-performance particle spectroscopy. The constructed level scheme includes more than 160 energy levels and 320 gamma-ray transitions belonging to both normally deformed as well as superdeformed rotational structures. The multipolarities have been determined for the gamma-ray transitions and as a result spin-parity assignments are given for nearly all energy levels. Experimental results in the normally deformed region are compared with predictions from large-scale shell model calculations. The collective structures are compared with results from cranked Nilsson-Strutinsky calculations. The results reveal the need to modify the standard Nilsson parameters in the mass A similar to 60 region.
19.	Andersson, Lise-Lotte, et al. (författare) Gamma-ray Spectroscopy of Excited States in 61Zn 2006 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 30:2, s. 381-390 Tidskriftsartikel (refereegranskat)abstract The Zn-61(30)31 isotope has been produced at the Oak Ridge National Laboratory in the fusion-evaporation reaction Ca-40(Mg-24, 2pn)Zn-61 at 104 MeV. The experimental set-up allowed gamma-rays to be detected in the CLARION Ge detector array in coincidence with the detection of recoiling nuclei in the focal plane at the end of the recoil mass spectrometer. This provides a unique identification of gamma-rays belonging to Zn-61. The excited states have been explored by means of recoil-gamma gamma coincidences, and the resulting decay scheme comprises almost 70 transitions. The data reveal numerous non-yrast states and suggest a revised spin and parity assignment for a previously observed superdeformed band. The resulting decay scheme is compared to predictions from different sets of large-scale shell model calculations.
20.	Andreoiu, Corina, et al. (författare) Evolution of Shapes in 59Cu 2002 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 14:3, s. 317-348 Tidskriftsartikel (refereegranskat)abstract High-spin states in Cu-59 were populated using the fusion-evaporation reaction Si-28 + Ca-40 at a beam energy of 122 MeV. The Gammasphere Ge-detector array in conjunction with the 4pi charged-particle detector array Microball allowed for the detection of gamma-rays in coincidence with evaporated light particles. The resulting extensive high-spin decay scheme of Cu-59 is presented, which comprises more than 320 gamma-ray transitions connecting about 150 excited states. Their spins and parities have been assigned via directional correlations of gamma-rays emitted from oriented states. Average quadrupole moments of rotational bands have been determined from the analysis of residual Doppler shifts. Shell model calculations in the fp shell are invoked to study some of the low-spin states, while the experimental characteristics of the rotational bands are analyzed in the configuration-dependent cranked Nilsson-Strutinsky (CNS) approach.
21.	Andreoiu, Corina, et al. (författare) First Identification of Excited States in 59Zn 2002 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 15, s. 459-462 Tidskriftsartikel (refereegranskat)abstract Excited states in 59Zn were observed for the first time following the fusion-evaporation reaction 24Mg + 40Ca at a beam energy of 60 MeV. The GASP array in conjunction with the ISIS Silicon ball and the NeutronRing allowed for the detection of n-rays in coincidence with evaporated light particles. The mirror symmetry of 59Zn and 59Cu is discussed.
22.	Andreyev, A. N., et al. (författare) New microsecond isomers in Bi-189,Bi-190 2001 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 10:2, s. 129-133 Tidskriftsartikel (refereegranskat)abstract New microsecond isomers in the neutron-deficient isotopes Bi-189g,Bi-190 have been identified after in-flight separation by the velocity filter SHIP. The evaporation residues were identified on the basis of delayed recoil-gamma /X-ray, recoil-gamma /X-ray-alpha and excitation function measurements. The systematics of the [pi 1i(13/2)]13/2(+) excited states in the odd-mass Bi nuclei is discussed.
23.	Assié, M., et al. (författare) Neutron correlations in 6He viewed through nuclear break-up 2009 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 42:3, s. 441-446 Tidskriftsartikel (refereegranskat)abstract The nuclear break-up of He-6 on a Pb-208 target was studied at 20 A MeV using a secondary beam of He-6 produced by the SPIRAL facility at GANIL. alpha-particles were detected in coincidence with two neutrons with a large angular coverage and the reaction mechanism was identified. From the distribution of the relative angles between the two neutrons the correlation function was extracted. It shows a strong correlation at small relative angles attributed to the contribution of the di-neutron configuration of He-6.
24.	Assie, M., et al. (författare) The Giant Pairing Vibration in heavy nuclei Present status and future studies 2019 Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 55:12 Tidskriftsartikel (refereegranskat)abstract The Giant Pairing Vibration, a two-nucleon collective mode originating from the second shell above the Fermi surface, has long been predicted and expected to be strongly populated in two-nucleon transfer reactions with cross sections similar to those of the low-lying Pairing Vibration. Recent experiments have provided evidence for this mode in C-14,C- 15 but, despite sensitive studies, it has not been definitively identified in Sn or Pb nuclei where pairing correlations are known to play a crucial role near their ground states. In this paper we review the basic theoretical concepts of this "elusive" state and the status of experimental searches in heavy nuclei. We discuss the hindrance effects due to Q-value mismatch and the use of weakly-bound projectiles as a way to overcome the limitations of the (p,t) reactions. We also discuss the role of the continuum and conclude with some possible future developments.
25.	Axelsson, A, et al. (författare) Excited superdeformed band in Eu-143 1999 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 6:2, s. 175-183 Tidskriftsartikel (refereegranskat)abstract A new superdeformed band has been discovered in a EUROBALL experiment and assigned to Eu-143. It has a maximum intensity of 35% of the Eu-143 yrast superdeformed band and the transition energies of the two bands are very similar. Based on comparison with cranked shell model calculations the new band is tentatively assigned the high-N intruder configuration pi 6(2)nu 7(0) and the parity and signature quantum numbers (pi, alpha) = (-1, +1/2). In addition to the already known high-energy transition at 3361 keV another discrete line at 2715 keV was found to be in coincidence with the yrast superdeformed band. However, it was not possible to connect the decay out of either of the superdeformed bands to, known normally deformed states.
26.	Ballof, J., et al. (författare) A concept for the extraction of the most refractory elements at CERN-ISOLDE as carbonyl complex ions 2022 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 58:5 Tidskriftsartikel (refereegranskat)abstract We introduce a novel thick-target concept tailored to the extraction of refractory 4d and 5d transition metal radionuclides of molybdenum, technetium, ruthenium and tungsten for radioactive ion beam production. Despite the more than 60-year old history of thick-target ISOL mass-separation facilities like ISOLDE, the extraction of these most refractory elements as radioactive ion beam has so far not been successful. In ordinary thick ISOL targets, their radioisotopes produced in the target are stopped within the condensed target material. Here, we present a concept which overcomes limitations associated with this method. We exploit the recoil momentum of nuclear reaction products for their release from the solid target material. They are thermalized in a carbon monoxide-containing atmosphere, in which volatile carbonyl complexes form readily at ambient temperature and pressure. This compound serves as volatile carrier for transport to the ion source. Excess carbon monoxide is removed by cryogenic gas separation to enable low pressures in the source region, in which the species are ionized and hence made available for radioactive ion beam formation. The setup is operated in batch mode. Initially, we investigate the feasibility of the approach with isotopes of more than 35s half-life. At the cost of reduced efficiency, the concept could also be applied to isotopes with half-lives of at least one to 10s. We report parameter studies of the key processes of the method, which validate this concept and which define the parameters for the setup. This would allow for the first time the extraction of radioactive molybdenum, tungsten and several other transition metals at thick-target ISOL facilities.
27.	Barucca, G., et al. (författare) Feasibility studies for the measurement of time-like proton electromagnetic form factors from (p)over-barp -> mu(+)mu(-) at PANDA at FAIR 2021 Ingår i: European Physical Journal A. - NEW YORK, USA : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:1 Tidskriftsartikel (refereegranskat)abstract This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, vertical bar G(E)vertical bar and vertical bar G(M)vertical bar, using the (p) over barp -> mu(+)mu(-) reaction at PANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at PANDA, using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is (p) over barp -> pi(+)pi(-), due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented.
28.	Barucca, G., et al. (författare) PANDA Phase One 2021 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:6 Tidskriftsartikel (refereegranskat)abstract The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or PANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton-nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.
29.	Barucca, G, et al. (författare) PANDA Phase One: PANDA collaboration 2021 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 57:6 Tidskriftsartikel (refereegranskat)abstract The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P ¯ ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper. © 2021, The Author(s).
30.	Barucca, G., et al. (författare) Precision resonance energy scans with the PANDA experiment at FAIR : Sensitivity study for width and line shape measurements of the X(3872) 2019 Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 55:3 Tidskriftsartikel (refereegranskat)abstract 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--.
31.	Barucca, G., et al. (författare) Study of excited Ξ baryons with the P¯ ANDA detector 2021 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4 Tidskriftsartikel (refereegranskat)abstract The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯ANDA will provide direct access to final states containing a Ξ¯ Ξ pair, for which production cross sections up to μb are expected in p¯p reactions. With a luminosity of L= 10 31 cm- 2 s- 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼106events/day. With a nearly 4 π detector acceptance, P¯ANDA will thus be a hyperon factory. In this study, reactions of the type p¯p → Ξ¯ +Ξ∗ - as well as p¯p → Ξ¯ ∗ +Ξ- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
32.	Barucca, G., et al. (författare) The potential of Λ and Ξ- studies with PANDA at FAIR 2021 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4 Tidskriftsartikel (refereegranskat)abstract The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
33.	Becker, F, et al. (författare) Status of the RISING Project at GSI 2005 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 25:Suppl 1, s. 719-722 Tidskriftsartikel (refereegranskat)abstract The FRS-RISING set-up at GSI uses secondary radioactive beams at relativistic energies for nuclear structure studies. At GSI the fragmentation or fission of stable primary beams up to U-238 provide secondary beams with sufficient intensity to perform gamma-ray spectroscopy. The RISING set-up is described and results of the first RISING campaign are presented. New experimental methods at relativistic energies are being investigated. Future experiments focus on state-of-the art nuclear structure physics covering exotic nuclei all over the nuclear chart.
34.	Bemmerer, D., et al. (författare) Feasibility of low-energy radiative-capture experiments at the LUNA underground accelerator facility 2005 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 24:2, s. 313-319 Tidskriftsartikel (refereegranskat)abstract The LUNA (Laboratory Underground for Nuclear Astrophysics) facility has been designed to study nuclear reactions of astrophysical interest. It is located deep underground in the Gran Sasso National Laboratory, Italy. Two electrostatic accelerators, with 50 and 400 kV maximum voltage, in combination with solid and gas target setups allowed to measure the total cross-sections of the radiative-capture reactions 2H2H(p, γ) 3He3Heand 14N14N(p, γ) 15O15Owithin their relevant Gamow peaks. We report on the gamma background in the Gran Sasso laboratory measured by germanium and bismuth germanate detectors, with and without an incident proton beam. A method to localize the sources of beam-induced background using the Doppler shift of emitted gamma rays is presented. The feasibility of radiative-capture studies at energies of astrophysical interest is discussed for several experimental scenarios. © Società Italiana di Fisica/Springer-Verlag 2005.
35.	Benedikt, M., et al. (författare) Conceptual design report for a Beta-Beam facility 2011 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 47:2 Forskningsöversikt (refereegranskat)abstract The Beta-Beam is a concept of large-scale facility that aims at providing pure electronic neutrino and antineutrino beams for the measurement of v(e) -> v(mu) oscillations. Beta-decaying nuclides are produced in large amounts in a facility of the scale of EURISOL, and are then post-accelerated and stored at large gamma in a racetrack decay ring. We present here a conceptual design of the accelerator chain of a Beta-Beam based at CERN.
36.	Bengtsson, Ragnar, et al. (författare) Magic gaps and intruder levels in triaxially superdeformed nuclei 2004 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 22:3, s. 355-362 Tidskriftsartikel (refereegranskat)abstract Nuclear shell model calculations based on a modified harmonic-oscillator potential result in amazingly stable triaxial nuclear shapes. Major gaps in the single-particle energy spectra at proton number 71 and neutron number 94 combine constructively at low and intermediate rotational frequencies. At high frequencies, gaps at proton number 72 and neutron number 97 combine in an equally favourable way. The sizes of the gaps may be as large as 35% of the values for the gaps at the classical magic numbers 50 and 82 at spherical shape. The dependence on the positions of the intruder levels in forming the gaps is discussed. Experimentally observed rotational bands in lutetium (Z = 71) and hafnium (Z = 72) appear in isotopes and frequency ranges, which are consistent with the gaps in the theoretical single-particle energy spectra.
37.	Bergmann, U. C., et al. (författare) Analysis of decay data from neutron-rich nuclei 2001 Ingår i: European Physical Journal A. - 1434-601X .- 1434-6001. ; 11:3, s. 279-284 Tidskriftsartikel (refereegranskat)abstract The beta -decays of the neutron-rich nuclei Be-12 and Ne-29 have been studied. The statistical correlations between the almost identical half-lives of Be-12 and its daughter B-12 are analysed for a large sample of Be-12 decay data. Stringent mutual bounds are obtained on the parameter set, leading to a precise determination of the Be-12 half-life of 21.50 +/- 0.04 ms. From a simultaneous detection of beta -particles and neutrons from the decay of Ne-29 the neutron emission probability, P-n, is determined to 17 +/- 5%. No indication of two-neutron emission is seen from this nucleus. An upper limit of 2.2% (90% confidence level) is established for P-2n.
38.	Bhagwat, A., et al. (författare) Cluster emission from superheavy nuclei 2018 Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 54:11 Tidskriftsartikel (refereegranskat)abstract The process leading to cluster emission from superheavy nuclei in the range 100 122 has been systematically investigated. This topic is of importance because it opens up the possibility of identifying superheavy elements through deposition of clusters in the detection system. In this paper we evaluate the cluster decay half lives by considering the cluster as a particle. The motion of this particle in the field induced by the daughter nucleus is determined by solving the corresponding Schrodinger equation imposing outgoing boundary conditions (Gamow state). The corresponding Wood-Saxon potential is fitted to obtain the energies provided by a mass formula that has been established recently to have a very high degree of precision. The resulting expression for the decay width is exact, i.e. no approximation besides the assumption of a preformed cluster is introduced. It is found that the heavy cluster emission probability in the superheavy region is much smaller than the corresponding a emission probability.
39.	Bhagwat, A., et al. (författare) Mic–Mac model based on the Wigner–Kirkwood method 2023 Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 59:12 Tidskriftsartikel (refereegranskat)abstract About a decade ago we proposed a new Microscopic–Macroscopic (Mic–Mac) model where the semiclassical Wigner–Kirkwood expansion of the energy up to fourth-order in ħ is used to compute the shell corrections in a deformed Woods-Saxon potential instead of the usual Strutinsky averaging scheme [1, 2]. For a set of 551 even-even nuclei computed with this new model, we found a rms deviation of 610 keV from the experimental masses, similar to the value obtained using the well-known Finite Range Droplet Model and the Lublin–Strasbourg Drop Model for the same set of nuclei. In a next step, we compute the ground-state properties of these 551 nuclei with the same method but using the mean-field provided by the Gogny forces within an Extended Thomas-Fermi approximation. We find that this Mic–Mac model using the Gogny D1S (D1M) force gives a fairly good description of the ground-state energies with a rms deviation of 834 keV (819 keV). This implies that Mic–Mac models based on effective two-body forces, for example Gogny D1S and D1M interactions, perform practically as well as the most efficient Mic–Mac models regarding ground-state properties.
40.	Bijnens, Johan, et al. (författare) Chiral symmetry and charmonium decays to two pseudoscalars 2011 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 47:11 Tidskriftsartikel (refereegranskat)abstract We apply hard pion Chiral Perturbation Theory to charmonium decays to pi pi, KK and eta eta. We first discuss why we expect to be able to provide results for the chiral logarithms in chi(c0) and chi(c2) decays to two pseudoscalars while for the decays from J/psi, psi(nS) and chi(c1) no simple prediction is possible. The leading chiral logarithm turns out to be absent for chi(c0), chi(c2) -> PP. This result is true for all fully chiral singlet states of spin zero and two.
41.	Bogner, S. K., et al. (författare) Density matrix expansion for low-momentum interactions 2009 Ingår i: European Physical Journal A. - 1434-601X .- 1434-6001. ; 39:2, s. 219-241 Tidskriftsartikel (refereegranskat)abstract A first step toward a universal nuclear energy density functional based on low-momentum interactions is taken using the density matrix expansion (DME) of Negele and Vautherin. The DME is adapted for non-local momentum space potentials and generalized to include local three-body interactions. Different prescriptions for the three-body DME are compared. Exploratory results are given at the Hartree-Fock level, along with a roadmap for systematic improvements within an effective action framework for the Kohn-Sham density functional theory.
42.	Bäck, Torbjörn, et al. (författare) First observation of gamma-rays from the proton emitter Au-171 2003 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 16:4, s. 489-494 Tidskriftsartikel (refereegranskat)abstract Gamma-rays from the alpha- and proton-unstable nuclide Au-171 have been observed for the first time. The gamma-rays were correlated with both a proton- and an alpha-particle decay branch, confirming that the nucleus decays by alpha and proton emission from a single (11/2(-)) state. The measurement confirms the previously determined half-lives for these particle decays but the present values are of higher precision. In addition, a longer half-life than determined in previous work was measured for the proton-unstable tentative ground state. The results are discussed in relation to structures in neighbouring nuclei and compared with a Strutinsky-type TRS calculation.
43.	Bäck, Torbjörn, et al. (författare) Observation of superdeformed states in Mo-88 1999 Ingår i: European Physical Journal A. - New York : SPRINGER VERLAG. - 1434-6001 .- 1434-601X. ; 6:4, s. 391-397 Tidskriftsartikel (refereegranskat)abstract High-spin states in Mo-88 were studied using the GAMMASPHERE germanium detector array in conjunction with the MICROBALL CsI(TI) charged-particle detector system. Three gamma-ray cascades with dynamic moments of inertia showing similar characteristics to superdeformed rotational bands observed in the neighbouring A = 80 region have been identified and assigned to the nucleus Mo-88. The quadrupole moment of the strongest band, deduced by the Residual Doppler Shift Method, corresponds to a quadrupole deformation of beta(2) approximate to 0.6. This confirms the superdeformed nature of this band. The experimental data are interpreted in the framework of total routhian surface calculations. All three hands are assigned to two-quasi-particle proton configurations at superdeformed shape.
44.	Bäck, Torbjörn, et al. (författare) Spectroscopy of the neutron-deficient nuclide Pt-171 2003 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 17:1, s. 1-5 Tidskriftsartikel (refereegranskat)abstract A number of previously unobserved gamma-rays emitted from the neutron-deficient nuclide Pt-171 have been identified using the recoil decay tagging technique. The level scheme has been updated using information from gamma-gamma coincidences and angular distribution measurements. To further confirm the assignments of the gamma-rays to Pt-171, the events were correlated with the alpha-decay of the daughter nucleus Os-167.
45.	Caamano, M, et al. (författare) Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation 2005 Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 23:2, s. 201-215 Tidskriftsartikel (refereegranskat)abstract Relativistic projectile fragmentation of Pb-208 has been used to produce isomers in neutron-rich, A approximate to 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in Ta-188, W-190, Re-192, Re-193, Os-195, Ir-197, Ir-198, Pt-200, Pt-201, Pt-202 and Au-203, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for Er-174, Er-175, Hf-185, Re-191, Re-194 and Ir-199. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In Pt-200 and Pt-201. the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics.
46.	Cannarozzo, Simone, et al. (författare) Global comparison between experimentally measured isomeric yield ratios and nuclear model calculations 2023 Ingår i: European Physical Journal A. - : Springer. - 1434-6001 .- 1434-601X. ; 59:12 Tidskriftsartikel (refereegranskat)abstract The level density steers transition probabilities between different states in the decay and de-excitation of excited nuclei. Reliable level density modelling is, therefore, key in describing, e.g., de-excitation of fission fragments, with implications on neutron and gamma-rays multiplicities, and also manifested in the population of isomeric states. We test six currently used level density models and the spin distribution in the level density by comparing calculations with measured isomeric yield ratios. The model calculations are performed with the TALYS code and experimental data for nuclear reactions populating spin isomers are retrieved from the EXFOR database. On average, calculations are in agreement with measured data. However, we find that the population of the high-spin state in an isomeric pair is clearly favoured in all of the six studied level density models. Further studies are then performed on the three used phenomenological level density models, to investigate the significance of their effect. We find that a significant reduction of the spin width distribution improves the agreement between calculated and experimentally observed isomeric yield ratios. This result is independent of the incident particle in the nuclear reaction. The needed reduction of the spin width distribution to comply with empirical data has, e.g., implications for studies in angular momentum generation in fission using isomeric yield rations, calculations of anti-neutrino spectra from nuclear reactors, as well as neutron and gamma-ray multiplicities in nuclear reactor calculations.
47.	Capel, Pierre, et al. (författare) Effective field theory analysis of the Coulomb breakup of the one-neutron halo nucleus 19 C 2023 Ingår i: European Physical Journal A. - 1434-601X .- 1434-6001. ; 59:11 Tidskriftsartikel (refereegranskat)abstract We analyse the Coulomb breakup of 19 C measured at 67A MeV at RIKEN. We use the Coulomb-Corrected Eikonal (CCE) approximation to model the reaction and describe the one-neutron halo nucleus 19 C within Halo Effective Field Theory (Halo EFT). At leading order we obtain a fair reproduction of the measured cross section as a function of energy and angle. The description is insensitive to the choice of optical potential, as long as it accurately represents the size of 18 C. It is also insensitive to the interior of the 19 C wave function. Comparison between theory and experiment thus enables us to infer asymptotic properties of the ground state of 19 C: these data put constraints on the one-neutron separation energy of this nucleus and, for a given binding energy, can be used to extract an asymptotic normalisation coefficient (ANC). These results are confirmed by CCE calculations employing next-to-leading order Halo EFT descriptions of 19 C: at this order the results for the Coulomb breakup cross section are completely insensitive to the choice of the regulator. Accordingly, this reaction can be used to constrain the one-neutron separation energy and ANC of 19 C.
48.	Cederwall, Bo, et al. (författare) Favoured superdeformed states in 89TC 1999 Ingår i: European Physical Journal A. - New York : Springer-Verlag New York. - 1434-6001 .- 1434-601X. ; 6:3, s. 251-255 Tidskriftsartikel (refereegranskat)abstract A superdeformed band consisting of a cascade of ten gamma-ray transitions has been identified and assigned to the nucleus Tc-89, close to the proton dripline. The quadrupole moment of the band (Q(t) = 6.7(-2.3)(+3.0) eb, as measured by the Residual Doppler Shift Method) as well as a large dynamic moment of inertia point to a highly elongated shape. With a relative population of approximately 15% of the gamma-ray flux in the Tc-89 exit channel, thp band is among the most intense superdeformed bands observed to date.
49.	Chulkov, L. V., et al. (författare) Light nuclei in the vicinity of the dripline and beyond 2015 Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 51:8 Forskningsöversikt (refereegranskat)abstract After a brief historical overview of the field of physics with radioactive beams, we give an update of the most recent experimental achievements for nuclei at or beyond the nuclear driplines. Long-lived exotic nuclear states are discussed including multi-nucleon radioactivity and exotic isomers. Studies of correlations between decay products in three-body decays and analysis in a Jacobi-coordinate framework are discussed with special emphasis on the difficulty in the interpretations of data obtained in different reactions. We give examples of systematic studies that the vast amount of now existing data allows, such as shell closures, competition between single-particle states in isotopes, isotones and mirror nuclei. The Thomas-Ehrman shift, Garvey-Kelson-type mass relations and IMME analysis of isobaric multiplets with isospin $ T = 3/2$ and 2 are also discussed as well as alternative interpretations in certain cases.
50.	Collaboration, The PANDA, et al. (författare) Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR 2016 Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10 Tidskriftsartikel (refereegranskat)abstract Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.

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