SwePub - search: WFRF:(Ruber R. J. M. Y.)

Enumeration	Reference	Cover	Find
1.	Adolph, C, et al. (author) Measurement of the eta -> 3 pi(0) Dalitz plot distribution with the WASA detector at COSY 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 677:1-2, s. 24-29 Journal article (peer-reviewed)abstract In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton-proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pious was Studied using 1.2 x 10(5) fully reconstructed events. and the quadratic slope parameter alpha was determined to be -0.027 +/- 0.008(stat) +/- 0.005(syst). The result is consistent with previous measurements and further corroborates the importance of pion-pion final state interactions. (C) 2009 Elsevier B.V. All rights reserved.
2.	Adlarson, Patrik, et al. (author) Abashian-Booth-Crowe Effect in Basic Double-Pionic Fusion : A New Resonance? 2011 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:24, s. 242302- Journal article (peer-reviewed)abstract We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn -> d pi(0)pi(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the pi pi-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t- channel Delta Delta process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m = 2.37 GeV, Gamma approximate to 70 MeV and I(J(P)) = 0(3(+)) in both pn and Delta Delta systems. Necessary further tests of the resonance interpretation are discussed.
3.	Saito, T. R., et al. (author) Studies of three-and four-body hypernuclei with heavy-ion beams, nuclear emulsions and machine learning 2023 In: Journal of Physics, Conference Series. - : Institute of Physics (IOP). - 1742-6588 .- 1742-6596. ; 2586 Journal article (peer-reviewed)abstract Interests on few-body hypernuclei have been increased by recent results of experiments employing relativistic heavy ion beams. Some of the experiments have revealed that the lifetime of the lightest hypernucleus, hypertriton, is significantly shorter than 263 ps which is expected by considering the hypertriton to be a weakly-bound system. The STAR collaboration has also measured the hypertriton binding energy, and the deduced value is contradicting to its formerly known small binding energy. These measurements have indicated that the fundamental physics quantities of the hypertriton such as its lifetime and binding energy have not been understood, therefore, they have to be measured very precisely. Furthermore, an unprecedented Lambda nn bound state observed by the HypHI collaboration has to be studied in order to draw a conclusion whether or not such a bound state exists. These three-body hypernuclear states are studied by the heavy-ion beam data in the WASA-FRS experiment and by analysing J-PARC E07 nuclear emulsion data with machine learning.
4.	Saito, T. R., et al. (author) The WASA-FRS project at GSI and its perspective 2023 In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier. - 0168-583X .- 1872-9584. ; 542, s. 22-25 Journal article (peer-reviewed)abstract A novel technique to study bound states of exotic hadrons in subatomic nuclei, such as hypernuclei and mesic nuclei, has been developed by employing the Fragment Separator FRS and the WASA central detector at GSI. Two experiments, S447 for studying light hypernuclei, especially hypertriton and a Ann bound state, and S490 for searching for ri' mesic-nuclei, were recently performed. Data analyses are currently in progress, and light charged particles such as protons and x & PLUSMN; are clearly observed and identified in the both experiments. For S447, light nuclear fragments that can also be residual nuclei from decays of hypernuclei of interests have been analysed by the FRS, and a momentum resolution, Ap/p, of 5 x 10-4 has been achieved. Further data analyses are to be completed. The WASA-FRS project will be continued and extended with the FRS at FAIR Phase 0, and upgrading of the WASA magnet and detectors is currently in progress. Furthermore, construction of a larger detector system with the Super-FRS at FAIR Phase 1 is also under consideration.
5.	Tanaka, Y. K., et al. (author) WASA-FRS EXPERIMENTS IN FAIR PHASE-0 AT GSI 2023 In: ACTA PHYSICA POLONICA B PROCEEDINGS SUPPLEMENT. - : Jagiellonian University. Conference paper (peer-reviewed)abstract We have developed a new and unique experimental setup integrating the central part of the Wide Angle Shower Apparatus (WASA) into the Fragment Separator (FRS) at GSI. This combination opens up possibilities of new experiments with high-resolution spectroscopy at forward 0 and measurements of light decay particles with nearly full solid-angle acceptance in coincidence. The first series of the WASA-FRS experiments have been successfully carried out in 2022. The developed experimental setup and two physics experiments performed in 2022 including the status of the preliminary data analysis are introduced.
6.	Sekiya, R., et al. (author) Search for η'-mesic nuclei in 12C(p, dp) reaction with the WASA detector at GSI-FRS 2024 In: Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics. - : Società Italiana di Fisica. - 1124-1896 .- 1826-9885. ; 47:4 Journal article (peer-reviewed)abstract We conducted an experimental search for η′-mesic nuclei, bound systems of an η′ meson and a nucleus, in 12C(p, dp) reactions. We measured the missing mass in the (p, d) reaction to obtain the mass spectrum of the reaction product near the η′ emission threshold. Forward-emitted deuterons were momentum-analyzed in the FRS of GSI. We installed a nearly 4π detector WASA near the 12C target to effectively select formation and decay of the η′-mesic nuclei. We are presently finalizing the analysis.
7.	Tanaka, Y. K., et al. (author) Search for eta '-mesic nuclei using (p,d) reaction with FRS/Super-FRS at GSI/FAIR 2020 In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1643 Journal article (peer-reviewed)abstract We plan a semi-exclusive measurement of the C-12(p,dp) reaction to search for eta'-mesic nuclei, aiming at investigating in-medium properties of the eta'-meson. We employ a 2.5 GeV proton beam impinging on a carbon target to produce eta'-mesic C-11 nuclei via the C-12(p,d)eta'circle times C-11 reaction. Using coincidence measurements of the forward going deuterons, important for missing-mass spectroscopy, and decay protons emitted from the eta'-mesic nuclei for event selection will provide a high experimental sensitivity to observe eta'-mesic nuclei. We will perform the measurements by combining the WASA detector system with the fragment separator FRS at GSI and also with the Super-FRS at FAIR in the future. The plan of the experiments and the present status are reported.
8.	Bargholtz, Chr., et al. (author) The WASA detector facility at CELSIUS 2008 In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 594:3, s. 339-350 Journal article (peer-reviewed)abstract The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique feature of the system is the use of hydrogen pellets as internal targets for the first time. A detailed description of the design, together with the anticipated and achieved performance parameters are given. (C) 2008 Elsevier B.V. All rights reserved.
9.	Keleta, S, et al. (author) Exclusive measurement of two-pion production in the dd -> He-4 pi pi reaction 2009 In: Nuclear Physics A. - : Elsevier BV. - 0375-9474 .- 1873-1554. ; 825:1-2, s. 71-90 Journal article (peer-reviewed)abstract The results from the first kinematically complete measurement of the dd -> He-4 pi pi reaction are reported. The aim was to investigate a long standing puzzle regarding the origin of the peculiar pi pi-invariant mass distributions appearing in double pion production in light ion collisions, the so-called ABC effect. The measurements were performed at the incident deuteron energies of 712 MeV and 1029 MeV. with the WASA detector assembly at CELSIUS in Uppsala, Sweden. We report the observation of a characteristic enhancement at low pi pi-invariant mass at 712 MeV, the lowest energy yet. At the higher energy, in addition to confirming previous experimental observations, Our results reveal a strong angular dependence of the pions in the overall centre of mass system. The results are qualitatively reproduced by a theoretical model, according to which the ABC effect is described as resulting from a kinematical enhancement in the production of the pion pairs from two parallel and independent NN -> d pi sub-processes. (C) 2009 Elsevier B.V. All rights reserved.
10.	Schönning, Karin, et al. (author) Polarisation of the omega meson in the pd -> He-3 omega reaction at 1360 and 1450 MeV 2008 In: Physics Letters B. - elsevier : Elsevier BV. - 0370-2693 .- 1873-2445. ; 668:4, s. 258-262 Journal article (peer-reviewed)abstract The tensor polarisation of omega mesons produced in the pd -> He-3 omega reaction has been studied at two energies near threshold. The 3 He nuclei were detected in coincidence with the pi(0)pi(+)pi(-) or pi(0)gamma decay products of the omega. in contrast to the case of phi-meson production, the omega mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-lizuka rule when comparing the production of vector mesons in low energy hadronic reactions.
11.	Schönning, Karin, et al. (author) Production of the omega meson in the pd -> He-3 omega reaction at 1450 MeV and 1360 MeV 2009 In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 79:4, s. 044002- Journal article (peer-reviewed)abstract The production of omega mesons in the pd -> He-3 omega reaction has been studied at two energies near the kinematic threshold, T-p = 1450 MeV and T-p = 1360 MeV. The differential cross section was measured as a function of the omega c.m. angle at both energies over the whole angular range. Whereas the results at 1360 MeV are consistent with isotropy, strong rises are observed near both the forward and backward directions at 1450 MeV. Calculations made using a two-step model with an intermediate pion fail to reproduce the shapes of the measured angular distributions and also underestimate the total cross sections.
12.	Wildner, E., et al. (author) The Opportunity Offered by the ESSnuSB Project to Exploit the Larger Leptonic CP Violation Signal at the Second Oscillation Maximum and the Requirements of This Project on the ESS Accelerator Complex 2016 In: Advances in High Energy Physics. - : Hindawi Publishing Corporation. - 1687-7357 .- 1687-7365. Journal article (peer-reviewed)abstract The European Spallation Source (ESS), currently under construction in Lund, Sweden, is a research center that will provide, by 2023, the world's most powerful neutron source. The average power of the proton linac will be 5 MW. Pulsing this linac at higher frequency will make it possible to raise the average total beam power to 10 MW to produce, in parallel with the spallation neutron production, a very intense neutrino Super Beam of about 0.4 GeV mean neutrino energy. This will allow searching for leptonic CP violation at the second oscillation maximum where the sensitivity is about 3 times higher than at the first. The ESS neutrino Super Beam, ESSnuSB operated with a 2.0 GeV linac proton beam, together with a large undergroundWater Cherenkov detector located at 540 km from Lund, will make it possible to discover leptonic CP violation at 5 sigma. significance level in 56% (65% for an upgrade to 2.5 GeV beam energy) of the leptonic CP-violating phase range after 10 years of data taking, assuming a 5% systematic error in the neutrino flux and 10% in the neutrino cross section. The paper presents the outstanding physics reach possible for CP violation with ESSnuSB obtainable under these assumptions for the systematic errors. It also describes the upgrade of the ESS accelerator complex required for ESSnuSB.
13.	Berlowski, M., et al. (author) Measurement of eta meson decays into lepton-antilepton pairs 2008 In: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 77:3, s. 032004- Journal article (peer-reviewed)abstract A search for rare lepton decays of the eta meson was performed using the WASA detector at CELSIUS. Two candidates for double Dalitz decay eta -> e(+)e(-)e(+)e(-) events are reported with a background of 1.3 +/- 0.2 events. This allows to set an upper limit to the branching ratio of 9.7x10(-5) (90% CL). The branching ratio for the decay eta -> e(+)e(-)gamma is determined to (7.8 +/- 0.5(stat)+/- 0.8(syst))x10(-3) in agreement with world average value. An upper limit (90% CL) for the branching ratio for the eta -> e(+)e(-) decay is 2.7x10(-5) and a limit for the sum of the eta ->mu(+)mu(-)mu(+)mu(-) and eta ->pi(+)pi(-)mu(+)mu(-) decays is 3.6x10(-4).
14.	Bashkanov, M., et al. (author) Double-Pionic Fusion of Nuclear Systems and the "ABC" Effect : Approaching a Puzzle by Exclusive and Kinematically Complete Measurements 2009 In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 052301- Journal article (peer-reviewed)abstract The ABC effect-a puzzling low-mass enhancement in the pi pi invariant mass spectrum, first observed by Abashian, Booth, and Crowe-is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn -> d pi(0)pi(0) at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (pi pi)(I=L=0) channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a Delta Delta system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data.
15.	Kren, F., et al. (author) Exclusive measurements of pp -> d pi(+)pi(0) : Double-pionic fusion without ABC effect 2010 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 684:2-3, s. 110-113 Journal article (peer-reviewed)abstract Exclusive measurements of the reaction pp -> d pi(+)pi(0) have been carried out at T-p = 1.1 GeV at the CELSIUS storage ring using the WASA detector. The isovector pi(+)pi(0) channel exhibits no enhancement at low invariant pi pi masses, i.e. no ABC effect. Therefore this most basic isovector double-pionic fusion reaction qualifies as an ideal test case for the conventional t-channel Delta Delta excitation process. Indeed, the obtained differential distributions reveal the conventional t-channel Delta Delta mechanism as the appropriate reaction process, which also accounts for the observed energy dependence of the total cross section.
16.	Akimov, D., et al. (author) Physics with WASA and PROMICE 1994 In: Physics with GeV-particle beams, Juelich 1994. ; , s. 519-530 Conference paper (peer-reviewed)
17.	Bargholtz, Chr., et al. (author) Measurement of the eta -> pi(+)pi(-)e(+)e(-) decay branching ratio 2007 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 644:5-6, s. 299-303 Journal article (peer-reviewed)abstract The reaction pd -> He-3 eta at threshold was used to provide a clean source of eta mesons for decay studies with the WASA detector at CELSIUS. The branching ratio of the decay eta -> pi(+)pi(-)e(+)e(-) is measured to be (4.3 +/- 1.3 +/- 0.4) x 10(-4).
18.	Kren, F., et al. (author) THE pp -> d pi(+)pi(0) REACTION - A CASE OF Delta Delta EXCITATION WITHOUT ABC-EFFECT 2009 In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 561-563 Journal article (peer-reviewed)abstract The ABC effect, a low-mass enhancement in the invariant pp mass, is observed in double-pionic fusion reactions leading to a bound nuclear system in the final state. From previous measurements there have been indications that this phenomenon is resctricted to the sigma channel of the pp system. With exclusive measurements of the pp -> d pi(+)pi(0) reaction at T-p = 1.1 GeV we demonstrate that, indeed, the ABC effect does not occur in the vector-isovector Delta Delta channel (rho channel) despite the fact that the Delta Delta excitation is oberved to be the dominant reaction process. We also show that this reaction is well described by a t-channel Delta Delta excitation with the subsequent decay into the vector-isovector Delta Delta channel given by the rho channel operator.
19.	Pettersson, Henrik, et al. (author) eta PRODUCTION IN PROTON-PROTON COLLISIONS AT 72 MeV EXCESS ENERGY 2009 In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 446-449 Journal article (peer-reviewed)abstract The production of eta mesons at an excess energy of 72 MeV has been studied in the reaction pp -> pp(eta)gamma gamma. It is shown that a simple model with Pp. final states included reproduces observed differential distributions better than the same model restricted to Ss, Sd and Ds final states. The strong influence of the Pp states could be taken as an indication of rho dominance within an one boson exchange model for the excitation of N*(1535).
20.	Skorodko, T., et al. (author) Exclusive measurement of the pp -> nn pi(+)pi(+) reaction at 1.1 GeV 2011 In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 47:9, s. 108- Journal article (peer-reviewed)abstract First exclusive data for the pp -> nnp(+)pi(+) reaction have been obtained at CELSIUS with the WASA detector setup at a beam energy of T(p) - 1.1 GeV. Total and differential cross-sections disagree with theoretical calculations, which predict the Delta Delta excitation to be the dominant process at this beam energy. Instead, the data require the excitation of one of the nucleons to a higher-lying Delta state, preferably the Delta(1600)P(33), to be the leading process.
21.	Skorodko, T., et al. (author) ISOSPIN DECOMPOSITION OF pp -> NN pi pi CROSS SECTIONS : DO WE SEE A SIGN OF Delta(1600) EXCITATION IN THE nn pi(+)pi(+) CHANNEL? 2009 In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 24:2-3, s. 450-453 Journal article (peer-reviewed)abstract The two-pion production in pp-collisions has been investigated in exclusive measurements from threshold up to T-p = 1.36 GeV. Total and differential cross sections have been obtained for the channels pn pi(+) pi(0), pp pi(+) pi(-), pp pi(0)pi(0) and also nn pi(+)pi(+). For intermediate incident energies T-p > 1 GeV, i.e. in the region, which is beyond the Roper excitation but at the onset of Delta Delta excitation the total pp pi(0)pi(0) cross section falls behind theoretical predictions by as much as an order of magnitude near 1.2 GeV, whereas the nn pi(+)pi(+) cross section is a factor of five larger than predicted. A model-unconstrained isospin decompostion of the cross section points to a significant contribution of an isospin 3/2 resonance other than the Delta(1232). As a possible candidate the Delta(1600) is discussed.
22.	Bashkanov, M., et al. (author) Exclusive measurements of pd -> He-3 pi pi : The ABC effect revisited 2006 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 637:4-5, s. 223-228 Journal article (peer-reviewed)abstract Exclusive measurements of the reactions pd -> He-3 pi(+)7 pi(-) and pd -> He-3 pi(0)pi(0) have been carried out at T-p = 0.893 GeV at the CELSIUS storage ring using the WASA detector. The pi(+)pi(-) channel evidences a pronounced enhancement at low invariant pi pi masses-as anticipated from previous inclusive measurements of the ABC effect. This enhancement is seen to be even much larger in the isoscalar pi(0)pi(0) channel. The differential distributions prove this enhancement to be of scalar-isoscalar nature. Delta Delta calculations give a good description of the data, if a boundstate condition is imposed for the intermediate Delta Delta system.
23.	Bashkanov, M., et al. (author) Measurement of the slope parameter for the η → 3π0 decay in the pp → ppη reaction 2007 In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:4, s. 048201- Journal article (peer-reviewed)abstract The CELSIUS-WASA setup is used to measure the 3π0 decay of η mesons produced in pp interactions with beam kinetic energies of 1.36 and 1.45 GeV. The efficiency-corrected Dalitz plot and density distributions for this decay are shown, together with a fit of the quadratic slope parameter α yielding α = −0.026 ± 0.010(stat) ± 0.010(syst). This value is compared to recent experimental results and theoretical predictions.
24.	Baussan, E., et al. (author) A very intense neutrino super beam experiment for leptonic CP violation discovery based on the European spallation source linac 2014 In: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 885, s. 127-149 Journal article (peer-reviewed)abstract Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spoliation Source currently under construction in Lund, Sweden, to deliver, in parallel with the spoliation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spoliation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few mu s with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 sigma significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 sigma if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.
25.	Pauly, C., et al. (author) The pp→ppπππ reaction channels in the threshold region 2007 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 649:2-3, s. 122-127 Journal article (peer-reviewed)abstract The cross section for direct neutral and charged three pion production in pp interactions was measured at excess energies in the range 160–216 MeV. That comprises the first measurement of the pp→ppπ0π0π0 reaction and the direct comparison with the pp→ppπ+π−π0 process. The experiment was performed above the η meson production threshold and the cross section could be directly normalized to the cross section of the pp→ppη reaction, with the η decaying into 3 pions. Since the same final states are selected, the measurement has a low systematical error. The measured cross section ratio σ(pp→ppπ+π−π0)/σ(pp→ppπ0π0π0) is compared to predictions of dominance of different isobars in the intermediate state.
26.	Skorodko, T, et al. (author) Two-pion production in proton-proton collisions : experimental total cross sections and their isospin decomposition 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 679:1, s. 30-35 Journal article (peer-reviewed)abstract The two-pion production in pp-collisions has been investigated at CELSIUS in exclusive measurements from threshold up to T-P = 1.36 GeV. Total and differential Cross sections have been obtained for the channels pn pi(+)pi(0), pp pi(+)pi(-), pp pi(0)pi(0) and also nn pi(+)pi(+). For intermediate incident energies T-P > 1GeV, i.e. in the region which is beyond the Roper excitation but at the onset of Delta Delta excitation, the total pp pi(0)pi(0) cross section falls behind theoretical predictions by as much as all order of magnitude near 1.2 GeV, whereas the nn pi(+)pi(+) cross section is a factor of five larger than predicted. An isospin decomposition of the total cross sections exhibits a s-channel-like energy dependence in the region of the Roper excitation as well as a significant contribution of an isospin 3/2 resonance other than the Delta(1232). As possible candidates the Delta(1600) and the Delta(1700) are discussed. (C) 2009 Elsevier B.V. All rights reserved.
27.	Farabolini, W., et al. (author) Two Beam Test Stand Experiments in the CTF3 Facility 2011 In: IPAC'11. Conference paper (other academic/artistic)
28.	Ruber, R. J. M. Y., et al. (author) An Ultra-Thin-Walled Solenoid for the CELSIUS/WASA Experiments 2003 In: Nucl. Instr. Meth. Phys. Res.. ; A503, s. 431-444 Journal article (peer-reviewed)
29.	Skorodko, T., et al. (author) Delta Delta excitation in proton-proton induced pi(0)pi(0) production 2011 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 695:1-4, s. 115-123 Journal article (peer-reviewed)abstract Exclusive measurements of the pp -> pp pi(0)pi(0) reaction have been performed at CELSIUS/WASA at energies from threshold up to T-p = 1.3 GeV. Total and differential cross sections have been obtained. Here we concentrate on energies T-p >= GeV. where the Delta Delta excitation becomes the leading process. No evidence is found for a significant ABC effect beyond that given by the conventional t-channel Delta Delta excitation. This holds also for the double-pionic fusion to the quasibound He-2. The data are compared to model predictions, which are based on both pi- and rho-exchange. Total and differential cross sections are at variance with these predictions and call for a profound modification of the rho-exchange. A phenomenological modification allowing only a small rho-exchange contribution leads to a quantitative description of the data.
30.	Skorodko, T., et al. (author) THE pp -> pp pi(0)pi(0) REACTION AND ITS LIMITING CASE, FUSION TO QUASI-BOUND He-2, IN SEARCH OF THE ABC EFFECT 2011 In: International Journal of Modern Physics A. - 0217-751X .- 1793-656X. ; 26:3-4, s. 702-704 Journal article (peer-reviewed)abstract The pi(0)pi(0) production in pp-collisions has been investigated in exclusive and kinematically complete measurements from threshold up to T-p = 1.4 GeV. For incident energies T-p > 1 GeV, i.e. in the region beyond the Roper excitation, the Delta Delta excitation process takes over. The data are well explained by the t-channel Delta Delta process dominated by pion exchange. There is no low-mass enhancement (ABC effect) in the pi(0)pi(0)-invariant mass distribution beyond that given by the conventional t-channel Delta Delta process. This is also true for the limiting case, where the protons are in the quasi-bound He-2 state.
31.	Yamamoto, A., et al. (author) The ATLAS central solenoid 2008 In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 584:1, s. 53-74 Journal article (peer-reviewed)abstract The ATLAS detector at the CERN LHC is equipped with a superconducting magnet system consisting of three large toroids and a solenoid. The 2.3 m diameter, 5.3 m long solenoid is located at the heart of the experiment where it provides a 2 T field for spectrometry of the particles emanating from the interaction of the counter-rotating beams of hadrons. As the electromagnetic calorimeter of the experiment is situated outside the solenoid, the coil must be as transparent as possible to traversing particles. The magnet, which was designed at KEK, incorporates progress in technology coming from the development of previous solenoids of this type, in particular that of a new type of reinforced superconductor addressing the requirement of transparency. Special attention has been paid to ensuring reliability and ease of operation of the magnet, through the application of sufficiently conservative guidelines for the mechanical and electrical design, stringent testing during manufacture, and a comprehensive commissioning program. This report gives an overview of the design, manufacture, test, installation and commissioning of the ATLAS central solenoid.
32.	Yogi, Rutambhara, et al. (author) Uppsala high power test stand for ESS spoke cavities 2012 In: Proceedings of LINAC2012. ; , s. 711-713 Conference paper (peer-reviewed)

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