Latest documents http://publikationen.stub.uni-frankfurt.de/index/index/ Thu, 13 Dec 2012 14:59:23 +0100 Thu, 13 Dec 2012 14:59:23 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27309 We present measurements of exclusive ensuremathπ+,0 and η production in pp reactions at 1.25GeV and 2.2GeV beam kinetic energy in hadron and dielectron channels. In the case of π+ and π0 , high-statistics invariant-mass and angular distributions are obtained within the HADES acceptance as well as acceptance-corrected distributions, which are compared to a resonance model. The sensitivity of the data to the yield and production angular distribution of Δ (1232) and higher-lying baryon resonances is shown, and an improved parameterization is proposed. The extracted cross-sections are of special interest in the case of pp → pp η , since controversial data exist at 2.0GeV; we find \ensuremathσ=0.142±0.022 mb. Using the dielectron channels, the π0 and η Dalitz decay signals are reconstructed with yields fully consistent with the hadronic channels. The electron invariant masses and acceptance-corrected helicity angle distributions are found in good agreement with model predictions. Geydar Agakishiev; Alvarez-Pol; Balanda; Bassini; Michael Böhmer; Bokemeyer; Boyard; Cabanelas; Chernenko; Christ; Destefanis; Dohrmann; Dybczak; Eberl; Laura Fabbietti; Oleg Fateev; Finocchiaro; Jürgen Friese; Ingo Fröhlich; Tetyana Galatyuk; Juan A. Garzón; Roman Gernhäuser; Camilla Gilardi; Marina Golubeva; Diego González-Dıaz; Fedor Guber; Gumberidze; Hennino; Holzmann; Holzmann; Ierusalimov; Iori; Alexander Ivashkin; Martin Jurkovic; Kämpfer; Kanaki; Tatiana Karavicheva; Ilse Koenig; Wolfgang Koenig; Burkhard W. Kolb; Kotte; Kozuch; Krizek; Wolfgang Kühn; Andrej Kugler; Alexei Kurepin; S Lang; Kirill Lapidus; T. Liu; Ludwig Maier; Jochen Markert; Volker Metag; Beata Michalska; Emilie Morinière; Jehad Mousa; Mathias Münch; Christian Münch; Naumann; Jacek Tomasz Otwinowski; Yvonne C. Pachmayer; Vladimir Pechenov; Olga Pechenova; Tiago Pérez Cavalcanti; Jerzy Pietraszko; Vladimir Pospısil; Witold Przygoda; Béatrice Ramstein; Andrey Reshetin; M. Roy-Stephan; Anar Rustamov; Alexander Sadovsky; Benjamin Sailer; Piotr Salabura; M. Sánchez; Alexander Schmah; Erwin Schwab; Yuri Sobolev; Stefano Spataro; Björn Spruck; Herbert Ströbele; Joachim Stroth; Christian Sturm; Attilio Tarantola; Khaled Teilab; Pavel Tlusty; Alberica Toia; Michael Traxler; Radoslaw Trebacz; Haralabos Tsertos; Vladimir Wagner; Marcin Wisniowski; Tomasz Wojcik; Jörn Wüstenfeld; Sergey Yurevich; Yuri Zanevsky; Peter Zumbruch article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27309 Thu, 13 Dec 2012 14:59:23 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/6019 Pluto is a Monte-Carlo event generator designed for hadronic interactions from Pion production threshold to intermediate energies of a few GeV per nucleon, as well as for studies of heavy ion reactions. The package is entirely based on ROOT, without the need of additional packages, and uses the embedded C++ interpreter of ROOT to control the event production. The generation of events based on a single reaction chain and the storage of the resulting particle objects can be done with a few lines of a ROOT-macro. However, the complete control of the package can be taken over by the steering macro and user-defined models may be added without a recompilation of the framework. Multi-reaction cocktails can be facilitated as well using either mass-dependent or user-defined static branching ratios. The included physics uses resonance production with mass-dependent Breit-Wigner sampling. The calculation of partial and total widths for resonances producing unstable particles is performed recursively in a coupled-channel approach. Here, particular attention is paid to the electromagnetic decays, motivated by the physics program of HADES. The thermal model supports 2-component thermal distributions, longitudinal broadening, radial blast, direct and elliptic flow, and impact-parameter sampled multiplicities. The interface allows angular distribution models (e.g. for the primary meson emission) to be attached by the user as well as descriptions of multi-particle correlations using decay chain templates. The exchange of mass sampling or momentum generation models is also possible. The first feature allows for consistent coupled-channel calculations, needed for a correct description of hadronic interactions. For elementary reactions, angular distribution models for selected channels are already part of the framework, based on parameterizations of existing data. This report gives an overview of the design of the package, the included models and the user interface. Ingo Fröhlich; Lorenzo Cazon Boado; Tetyana Galatyuk; Volker Hejny; Romain Holzmann; Marios Kagarlis; Wolfgang Kuehn; Johannes G. Messchendorp; Volker Metag; Marc-André Pleier; Witold Przygoda; Beatrice Ramstein; James Ritman; Piotr Salabura; Joachim Stroth; Malgorzata Sudol other http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/6019 Wed, 12 Nov 2008 15:17:56 +0100