| 1. |
- Barucca, G., et al.
(författare)
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Feasibility studies for the measurement of time-like proton electromagnetic form factors from (p)over-barp -> mu(+)mu(-) at PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - NEW YORK, USA : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:1
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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.
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| 2. |
- Barucca, G., et al.
(författare)
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Precision resonance energy scans with the PANDA experiment at FAIR : Sensitivity study for width and line shape measurements of the X(3872)
- 2019
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Ingår i: European Physical Journal A. - : SPRINGER. - 1434-6001 .- 1434-601X. ; 55:3
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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--.
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| 3. |
- Barucca, G., et al.
(författare)
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Study of excited Ξ baryons with the P¯ ANDA detector
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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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.
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| 4. |
- Barucca, G., et al.
(författare)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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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.
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| 5. |
- Erni, W., et al.
(författare)
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Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
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Tidskriftsartikel (refereegranskat)abstract
- This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
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| 6. |
- Golubev, Pavel, et al.
(författare)
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Pion Emission in H-2,C-12,Al-27(gamma,pi+) Reactions at Threshold
- 2008
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474 .- 1873-1554. ; 806:1-4, s. 216-229
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Tidskriftsartikel (refereegranskat)abstract
- The very first data from MAX-lab in Lund, Sweden on pion photoproduction at threshold energies are presented. The decrease of the total π+ yield in γ+12C, 27Al reactions below 200 MeV as well as the dσ/dΩ cross-section data essentially follow the predictions of an intranuclear-cascade model with an attractive potential for the pion–nucleus interaction. However, View the MathML source, cross-section data at 176 MeV show deviations which call for refinements of the model and possibly also for the inclusion of coherent pion-production mechanisms.
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| 7. |
- Makonyi, Karoly, et al.
(författare)
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Evaluating vacuum phototriodes designed for the PANDA electromagnetic calorimeter
- 2014
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 763, s. 36-43
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Tidskriftsartikel (refereegranskat)abstract
- In this work properties of a vacuum phototriode (VPT) and preamplifier unit designed for the electromagnetic calorimeter of the PANDA experiment being built at FAIR are investigated. With the use of lead tungstate and lanthanium bromide scintillators the VPT properties are studied at low photon energies, from tens of key in the lanthanium bromide measurements and between 10 MeV and 60 MeV in the lead tungstate measurements. At these energies the noise of the VPT unit can be expected to influence its performance significantly. It is shown that the noise contribution to the measured energy resolution, under optimal conditions, is consistent with a fluctuation of (one standard deviation) approximately 200 electrons at the VPT anode. For a lead tungstate crystal this is equivalent to a noise of 1.2 MeV. For lanthanium bromide this makes it possible to use VPTs for gamma ray spectroscopy above a few hundreds of keV without noticeable effects on the energy resolution compared to measurements with a standard photomultiplier.
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| 8. |
- Marcks von Wurtemberg, Klas, et al.
(författare)
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The response of lead-tungstate scintillators (PWO) to photons with energies in the range 13 MeV-64 MeV
- 2012
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 679, s. 36-43
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Tidskriftsartikel (refereegranskat)abstract
- The response of a matrix of 25 lead tungstate (PWO) scintillator detectors, operated at -25 degrees C, to photons in the range 13 MeV-64 MeV has been measured at the tagged-photon facility at MAX-lab, Lund. The tapered PWO crystals, each with a length of 200 mm and a cross-section of 24.4 x 24.4 mm(2) in the front end, read out by 19 mm photomultiplier tubes, were arranged in a 5 x 5 matrix. The response was measured for photons directed towards the centre of the central crystal as well as for photons directed towards the corner of the central crystal, where four crystals meet. The obtained energy resolution surpasses what has been published so far and is close to the limit given by Poisson statistics and escaped energy. For photons directed towards the centre(corner) of the central crystal the relative energy resolution, defined as (FWHM/2.35)/E-gamma, decreases from 7.3%(11.0%) at E-gamma = 13 MeV to 3.3%(3.6%) at E-gamma = 64 MeV. The reconstructed point of impact of a photon in this energy range is determined with an uncertainty (one standard deviation) of 7.3 +/- 0.1 mm.
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| 9. |
- Qin, Weilun, et al.
(författare)
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The FEL in the SXL project at MAX IV
- 2021
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Ingår i: Journal of Synchrotron Radiation. - : International Union Of Crystallography. - 1600-5775 .- 0909-0495. ; 28, s. 707-717
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the design of the free-electron laser (FEL) in the SXL (Soft X-ray Laser) project at the MAX IV Laboratory is presented. The target performance parameters originate in a science case put forward by Swedish users and the SXL FEL is foreseen to be driven by the existing MAX IV 3 GeV linac. The SXL project is planned to be realized in different stages and in this paper the focus is on Phase 1, where the basic operation mode for the FEL will be SASE (self-amplified spontaneous emission), with an emphasis on short pulses. Simulation results for two linac bunches (high and low charge) with different pulse duration are illustrated, as well as the performance for two-color/two-pulses mode and power enhancement through tapering. Besides standard SASE and optical klystron configurations, the FEL setup is also tailored to allow for advanced seeding schemes operations. Finally possible upgrades that will be implemented in a second phase of the project are discussed.
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| 10. |
- Samnegård, Björn, et al.
(författare)
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C-peptide and captopril are equally effective in lowering glomerular hyperfiltration in diabetic rats.
- 2004
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Ingår i: Nephrol Dial Transplant. - : Oxford University Press (OUP). - 0931-0509. ; 19:6, s. 1385-91
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- 150042582004051920040921200611150931-05091962004JunNephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal AssociationNephrol. Dial. Transplant.C-peptide and captopril are equally effective in lowering glomerular hyperfiltration in diabetic rats.1385-91BACKGROUND: C-peptide has been shown to reduce glomerular hyperfiltration, glomerular hypertrophy and urinary albumin excretion in type 1 diabetes, but its effect has not been compared with that of an angiotensin-converting enzyme inhibitor (ACEI) in the early stage of renal involvement in diabetes. METHODS: Glomerular filtration rate (GFR) was measured in terms of inulin clearance and renal blood flow, using ultrasound technique, in four groups of streptozotocin-induced diabetic rats before and after a 60 min infusion of C-peptide (D-Cp), captopril (D-ACEI), C-peptide and captopril (D-Cp-ACEI) or placebo (D-placebo). In addition, a non-diabetic control group was studied before and after captopril infusion (C-ACEI). RESULTS: GFR was 37-51% higher in the diabetic groups than in the control animals. GFR decreased after treatment in the D-Cp, D-ACEI and D-Cp-ACEI groups, but did not change in the D-placebo group. Blood flow increased by 26-32% in the three groups receiving captopril and by 5% in the diabetic groups treated with C-peptide alone or placebo. The increase in blood flow in the three ACEI-treated groups was significantly greater than in the D-placebo group. Filtration fraction fell significantly in all groups, but only in the combined D-Cp-ACEI group did it fall significantly more than in the D-placebo group. CONCLUSIONS: C-peptide and captopril lower diabetes-induced glomerular hyperfiltration to a similar extent, but the influence of captopril on blood flow is greater than that of C-peptide, suggesting different mechanisms of action. No statistically significant additive effects of C-peptide and captopril were shown in this acute infusion study.Department of Nephrology, Danderyd Hospital, SE-182 88 Stockholm, Sweden. bjorn.samnegard@medks.ki.seSamnegårdBjörnBJacobsonStefan HSHJohanssonBo-LennartBLEkbergKarinKIsakssonBrittaBWahrenJohnJSjöquistMatsMengComparative StudyJournal Article20040305EnglandNephrol Dial Transplant87064020Angiotensin-Converting Enzyme Inhibitors0C-Peptide62571-86-2CaptoprilIMAngiotensin-Converting Enzyme InhibitorspharmacologyAnimalsC-PeptidepharmacologyCaptoprilpharmacologyDiabetes Mellitus, ExperimentalphysiopathologyGlomerular Filtration Ratedrug effectsKidney Glomerulusdrug effectsphysiopathologyMaleRatsRats, Sprague-DawleyRegional Blood Flowdrug effects200439502004924502004Mar5ppublish1500425810.1093/ndt/gfh163gfh163
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