1,721,001 research outputs found
Differential cross section for the dp breakup reaction at 190MeV/nucleon
No full textThe differential cross section for the 1H(d,pp)n breakup reaction at deuteron beam energy of 380 MeV has been determined with high precision for 189 angular configurations of outgoing protons. The data have been measured by the international WASA-at-COSY Collaboration using the WASA detector at COSY in Forschungszentrum Juelich (Germany). The data cover polar angles of two protons in the exit channel, theta1 and theta2, between 5o and 15o and their relative azimuthal angle phi12 between 20o and 180o.</p
Recent results from ANKE, WASA-at-COSY, and PAX
No full textThe complementary internal beam experiments ANKE, WASA, and PAX at the COoler-SYnchrotron COSY-Jülich offer unique and exciting opportunities for hadron physics with polarized and unpolarized hadronic probes. Due to the excellent properties of COSY, in combination with the high performance detection systems, a broad experimental program can be covered. One main emphasis of the studies at these facilities are measurements on symmetries in reactions and particle decays as well as high precision studies on particles and their properties. Furthermore, the availability of polarized beams and/or targets allows for investigations on hadronic reactions using the spin degree of freedom or studies towards polarized antiprotons. After an introduction to the experimental facilities at COSY, both recently published results as well as new and unpublished data will be presented and discussed
Study of light mesons with WASA-at-COSY
No full textThe WASA detector, operating at the COSY facility in Jülich (Germany) has been collecting data since 2007. The experiment allows to perform studies of light mesons, such as π0, η and ω rare decay processes, in order to perform precise measurements of branching ratios, determine Dalitz plot parameters, test symmetry and symmetry breaking, and evaluate transition form factors. In the experiments a proton or deuteron beam impinged on a pellet target of hydrogen or deuterium, which allows the reactions proton-proton (pp) or proton-deuteron (pd). A high-statistics sample of η mesons has been collected: in the reaction pd →3He η, 3×107η mesons were tagged at a beam energy of 1.0 GeV, while 5×108η mesons were produced in the reaction pp → ppη at 1.4 GeV. This corresponds to the production of 10 η/s and 100 η/s, respectively, for the two reaction processes. In the pp dataset a higher background level is found compared to the pd data set. In both cases, we identify the η mesons by means of the missing mass derived from the recoil particles. A kinematic fit largely rejects the background in our analysis. The advantage in using the pp dataset is that the production of η mesons is almost a factor of 10 higher than in the pd fusion to 3He. As we plan to measure the branching ratios of very rare processes, high statistics is needed. A summary of the recent activity on the study of light mesons with WASA-at-COSY here is given
Search for the Manifestation of the Mesic Nuclei on the He Excitation Function Measured with WASA-at-COSY
No full textWe search for an evidence of η-mesic 4He with the WASA-at-COSY detector. Two dedicated experiments were performed at the Cooler Synchrotron COSY-Jülich. The experimental method is based on the measurement of the excitation functions for the two reaction channels: dd →3Hepπ− and dd →3Henπ0, where the outgoing N–π pairs originate from the conversion of the η meson on a nucleon inside the He nucleus. In this contribution, the experimental method is shortly described and preliminary excitation functions from the 2010 data are presented
Hadronic decays of the omega meson
No full textThe WASA-at-COSY collaboration has collected a high statistics data set of. mesons produced through the p + d -> He-3 + omega reaction. This article presents the status of the ongoing studies of two. decay channels. The decay dynamics of the omega -> pi(+)pi(-)pi(0) channel is investigated by means of a Dalitz plot distribution and the omega -> pi(+)pi(-) channel is examined to search for a possible manifestation of rho - omega interference in hadronic production.</p
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