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Petrén, Henrik
Alternative names
Publications (8 of 8) Show all publications
Petrén, H. (2009). η Meson Production in Proton-Proton Collisions at Excess Energies of 40 and 72 MeV. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>η Meson Production in Proton-Proton Collisions at Excess Energies of 40 and 72 MeV
2009 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

The production of η mesons in proton-proton collisions has been studied with the WASA detector using internal pellet targets in the CELSIUS storage ring at the The Svedberg Laboratory in Uppsala.

Data were taken at two beam energies, 1360 MeV and 1445 MeV, corresponding to CM excess energies of 40 and 72 MeV, respectively. The η was detected via its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward direction. The measurements were kinematically complete. The analysis yielded 69·103 events at 1360 MeV and 93·103 events at 1445 MeV, with a background contribution of less than 5%. Data were acceptance-corrected using a parametrization of a matrix element which includes all states up to two units of total angular momentum. The final state interaction between protons in the 1S0 state was included by a momentum-dependent enhancement factor in the relevant amplitudes. Angular distributions of the final state, invariant mass spectra and Dalitz plots are presented. The cos θη-distribution is found to be anisotropic with its maximum at 90° at both energies. From the parametrization it is inferred that this is due to interference between the Ss and Sd final states. A significant contribution from the Pp final state is also needed to describe data.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2009
Series
Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-2516 ; 85
Series
National Category
Subatomic Physics Subatomic Physics
Research subject
Nuclear Physics
Identifiers
urn:nbn:se:uu:diva-100791 (URN)978-91-554-7506-2 (ISBN)
Public defence
2009-05-16, Polhemsalen, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Opponent
Supervisors
Projects
CELSIUS/WASA
Available from: 2009-04-23 Created: 2009-04-07 Last updated: 2009-04-23Bibliographically approved
Bashkanov, M., Bogoslawsky, D., Calén, H., Capellaro, F., Clement, H., Demirörs, L., . . . Zlomanczuk, J. (2007). Measurement of the slope parameter for the η → 3π0 decay in the pp → ppη reaction. Physical Review C. Nuclear Physics, 76(4), 048201
Open this publication in new window or tab >>Measurement of the slope parameter for the η → 3π0 decay in the pp → ppη reaction
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2007 (English)In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 76, no 4, p. 048201-Article in journal (Refereed) Published
Abstract [en]

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.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-16829 (URN)10.1103/PhysRevC.76.048201 (DOI)000250620900091 ()
Available from: 2008-06-16 Created: 2008-06-16 Last updated: 2017-12-08Bibliographically approved
Pauly, C., Jacewicz, M., Koch, I., Calen, H., Capellaro, F., Fransson, K., . . . Zlomanczuk, J. (2007). The p p -> p p pi pi pi reaction channels in the threshold region.
Open this publication in new window or tab >>The p p -> p p pi pi pi reaction channels in the threshold region
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2007 (English)Report (Other scientific)
Series
e-Print ; nucl-ex/0602006
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-22824 (URN)
Available from: 2007-01-22 Created: 2007-01-22
Pauly, C., Jacewicz, M., Koch, I., Bashkanov, M., Bogoslawsky, D., Calén, H., . . . Zlomanczuk, J. (2007). The pp→ppπππ reaction channels in the threshold region. Physics Letters B, 649(2-3), 122-127
Open this publication in new window or tab >>The ppppπππ reaction channels in the threshold region
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2007 (English)In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 649, no 2-3, p. 122-127Article in journal (Refereed) Published
Abstract [en]

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 ppppπ0π0π0 reaction and the direct comparison with the ppppπ+ππ0 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 ppppη 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(ppppπ+ππ0)/σ(ppppπ0π0π0) is compared to predictions of dominance of different isobars in the intermediate state.

Keywords
Threshold measurement, Three pion production, Final state interaction
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-16830 (URN)10.1016/j.physletb.2007.04.004 (DOI)000247170700003 ()
Available from: 2008-06-16 Created: 2008-06-16 Last updated: 2017-12-08Bibliographically approved
Calen, H., Fransson, K., Gustafsson, L., Hoistad, B., Jacewicz, M., Johansson, T., . . . Zlomanczuk, J. (2006). Evidence for a 'Narrow' Roper Resonance - The Breathing Mode of the Nucleon.
Open this publication in new window or tab >>Evidence for a 'Narrow' Roper Resonance - The Breathing Mode of the Nucleon
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2006 (English)Report (Other scientific)
Series
e-Print arXiv ; nucl-ex/0612015
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-23534 (URN)
Available from: 2007-01-30 Created: 2007-01-30
Calen, H., Fransson, K., Gustafsson, L., Hoistad, B., Jacewicz, M., Johansson, T., . . . Zlomanczuk, J. (2006). Measurement of the eta->pi+ pi- e+ e- decay branching ration.
Open this publication in new window or tab >>Measurement of the eta->pi+ pi- e+ e- decay branching ration
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2006 (English)Report (Other scientific)
Series
e-Print arXiv ; hep-ex/0609007
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-23535 (URN)
Available from: 2007-01-30 Created: 2007-01-30
Calen, H., Fransson, K., Gustafsson, L., Hoistad, B., Jacewicz, M., Johansson, T., . . . Zlomanczuk, J. (2006). Two-Pion Production in Nucleon-Nucleon Collisions and the ABC Effect - Approaching a Puzzle by Exclusive and Kinematically Complete Measurements.
Open this publication in new window or tab >>Two-Pion Production in Nucleon-Nucleon Collisions and the ABC Effect - Approaching a Puzzle by Exclusive and Kinematically Complete Measurements
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2006 (English)Report (Other (popular scientific, debate etc.))
Series
e-Print arXiv ; nucl-ex/0612016
National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-23533 (URN)
Available from: 2007-01-30 Created: 2007-01-30
Edwards, M. O., Andersson, M., Gruszecki, T., Pettersson, H., Thunman, R., Thuraisingham, G., . . . Hagfeldt, A. (2004). Charge-discharge kinetics of electric-paint displays. Journal of Electroanalytical Chemistry, 565(2), 175-184
Open this publication in new window or tab >>Charge-discharge kinetics of electric-paint displays
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2004 (English)In: Journal of Electroanalytical Chemistry, ISSN 0022-0728, E-ISSN 1873-2569, Vol. 565, no 2, p. 175-184Article in journal (Refereed) Published
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-66737 (URN)10.1016/j.jelechem.2003.10.006 (DOI)
Available from: 2005-08-17 Created: 2005-08-17 Last updated: 2017-11-28Bibliographically approved
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