| 1. |
|
|
| 2. |
|
|
| 3. |
- 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.
|
|
| 4. |
- 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--.
|
|
| 5. |
- 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.
|
|
| 6. |
- 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.
|
|
| 7. |
- Björn, Christina, et al.
(författare)
-
Organisera för utveckling och lärande. Om skolprojekt i nätverksform
- 2002
-
Bok (refereegranskat)abstract
- Många skolor arbetar idag med förbättringsarbete. Det kan omfatta både elvernas lärmiljö och personalens arbetsvillkor. För att åstadkomma ett bestående och gott utvecklingsklimat kan de också behöva arbeta med frågan hur själva förbättringsarbetet kan göras bättre. Olika utvecklingsstrategierhar nämligen visat på problem: Projekt som styrs uppifrån får sällan genomslag i verksamheten eftersom de inte engagerar personal och elever.Projekt som initieras underifrån skapar ofta ett starkt engagemang som kan vara svårt att upprätthålla då arbetet ofta saknar aktivt stöd ovanifrån, vilket försvårar långsiktighet oich spridning av utvecklingsarbetet.I boken studeras och diskuteras samarbete mellan skolor i nätverksform som en alternativ utvecklingsstrategi. Vilka fördelar och nackdelar finns med nätverk som form för skolors förbättringsarbete? Vad bör man tänka på när man organiserar ett samarbete med andra skolor för att förbättra sin egen? Hur kan man skapa en bred delaktighet i skolans utvecklingsarbete? Och hurkan man organisera skolans utvecklingsarbete så att det samtidigt medför ett utvecklingsinriktat lärande hos skolpersonalen? Boken belyser dessa och liknande frågor utifrån en analys av arbetet i två större nätverksprojekt, Albatrossprojektet och "Skolor lär skolor". Den teoretiska modell sompresenteras är tänkt att fungerea som stöd för skolors egen reflektion över sitt sätt att organisera för utveckling och lärande.
|
|
| 8. |
- Erni, W., et al.
(författare)
-
Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
-
Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
-
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.
|
|
| 9. |
- Gerén, Linda, 1962-
(författare)
-
Pionic Fusion Study of the 6He Halo
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The structure of the halo nucleus 6He has been investigated in a pionic fusion experiment at the CELSIUS storage ring facility in Uppsala. The 4He(d, 6He)π+ reaction was studied 0.6 - 5.0 MeV above threshold in the centre-of-mass frame with a deuteron beam incident on a 4He gas target. The 6He ions were detected in a ΔE - E solid-state detector telescope inserted into the CELSIUS ring. The results for the total and differential cross section are presented and compared to results for the analogue reaction producing the 3.56 MeV analogue state in 6Li. A simple model of the reaction gives results consistent with earlier findings of 6He as having a spatial extent considerably exceeding that of the alpha particle. It is also shown that information about the high momentum part of the halo wave function can be extracted from the results of this pionic fusion measurement.
|
|
| 10. |
- Makonyi, Karoly, et al.
(författare)
-
Evaluating vacuum phototriodes designed for the PANDA electromagnetic calorimeter
- 2014
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 763, s. 36-43
-
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.
|
|
