Search for the 4He-eta bound state in dd->(4He-eta)_{bound}->3He n pi0 and dd->(4He-eta)_{bound}->3He p pi- reactions with the WASA-at-COSY facility

In November 2010, the search for the 4He-{\eta} bound state was per formed with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta - mesic nuclei is searched for in the measured excitation functions for the two reaction channels: dd ->3He n pi0 and dd ->3He p pi- near the eta production threshold. This report includes the description of the experimental method and the status of the data analysis.Comment: 4 page

Luminosity determination for the deutron-deutron reactions using free and quasi-free reactions with WASA-at-COSY detector

Two methods of the luminosity determination for the experiment performed by WASA collaboration to search for $^{4} {-0.03cm}{He}$-$\eta$ bound state are presented. During the measurement the technique of continous change of the beam momentum in one accelerator cycle (called ramped beam) was applied. This imposes the requirement to determine not only the total integrated luminosity, but also its variation as a function of the beam momentum.Comment: Symposium on Applied Nuclear Physics and Innovative Technologies, Krakow (Poland), 24-27.09.201

Upper limits for the production of the eta-mesic Helium in the dd ->3Henpi0 and dd -> 3Heppi- reactions

We performed a search for 4He-eta bound state in dd -> 3Henpi0 and dd -> 3Heppi- reactions with the WASA-at-COSY facility using a ramped beam technique. The measurement was carried out with high statistics and high acceptance. The signature of eta-mesic nuclei was searched for by the measurement of the excitation functions in the vicinity of the eta production threshold for each of the considered channels. We did not observe the narrow structure which could be interpreted as a bound state. The preliminary upper limits of the total cross sections for the bound state production and decay varies from 21 nb to 36 nb for the dd -> 3Henpi0 channel, and from 5 nb to 9 nb for the dd -> 3Heppi- channel for the bound state width ranging from 5 to 50 MeV.Comment: Acta Phys. Polon. B 201

Search for the eta-mesic Helium bound state with the WASA-at-COSY facility

We performed a search for 4He-eta bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta-mesic nuclei is searched for in dd -> 3Henpi0 and dd -> 3Heppi- reactions by the measurement of the excitation functions in the vicinity of the {\eta} production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd -> 3Henpi0 process.Comment: Proceedings from the 12th International Conference on Nucleus-Nucleus Collisions (NN2015), Catania 2015, June 21-2

Search for eta-mesic Helium with the WASA-at-COSY detector

A search for the 4He-eta bound state via exclusive measurement of the excitation function for the dd->3Heppi- reaction, was performed at the Cooler Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c crossing the kinematic threshold for the eta production in the dd -> 4He-eta reaction at 2.336 GeV/c. The corresponding excess energy in the 4He-eta system varied from -51.4 MeV to 22 MeV. The shape of the excitation function for the dd -> 3Heppi- was examined. No signal of the 4He-eta bound state was observed in the excitation function.Comment: 4 pages, 5 figures, to appear in proceedings of MESON201

Constraining the optical potential in the search for eta-mesic 4He

A consistent description of the $d d \rightarrow$ ^{4}\hspace{-0.03cm}\mbox{He} \eta and $d d \rightarrow$ ($^4$He$\eta$)$_{bound} \rightarrow X$ cross sections was recently proposed with a broad range of real ($V_{0}$) and imaginary (W0), $\eta$-$^4$He optical potential parameters leading to a good agreement with the d d -> 4He eta data. Here we compare the predictions of the model below the $\eta$ production threshold, with the WASA-at-COSY excitation functions for the dd -> 3He N pi reactions to put stronger constraints on (V0, W0). The allowed parameter space (with |V_0| < \sim 60 MeV and |W_0| < \sim 7 MeV estimated at 90% CL ) excludes most optical model predictions of eta-4He nuclei except for some loosely bound narrow states

Search for Deeply Bound Kaonic Nuclear States with AMADEUS

We briefly report on the search for Deeply Bound Kaonic Nuclear States with AMADEUS in the Sigma0 p channel following K- absorption on 12C and outline future perspectives for this work

Search for He-eta bound states with the WASA-at-COSY facility

The existence of eta-mesic nuclei in which the eta meson is bound in a nucleus by means of the strong interaction was postulated already in 1986, albeit not yet confirmed it by experiment. The discovery of this new kind of an exotic nuclear matter would be very important as it might allow for a better understanding of the eta meson structure and its interaction with nucleons. The search for eta-mesic helium 4He-eta is carried out with high statistics and high acceptance with the WASA detector, installed at the cooler synchrotron COSY of the Research Center Juelich. The search is conducted via the measurement of the excitation function for selected decay channels of the 4He-eta system. In the experiment, performed in November 2010, two reactions dd->(4He-eta)bs ->3He p pi- and dd->(4He-eta)bs ->3He p pi0 were measured with a beam momentum ramped from 2.127GeV/c to 2.422GeV/c. The report includes the description of the experimental method and status of the measurement.Comment: Presented at the Erice School on Nuclear Physics 2011. 5 pages, 3 figure

J-PET: a new technology for the whole-body PET imaging

The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.Comment: Presented at the 2nd Jagiellonian Symposium on Fundamental and Applied Subatomic Physics, Krak\'ow, Poland, June 4-9, 2017. To be published in Acta Phys. Pol.

Unprecedented studies of the low-energy negatively charged kaons interactions in nuclear matter by AMADEUS

The AMADEUS experiment aims to provide unique quality data of $K^-$ hadronic interactions in light nuclear targets, in order to solve fundamental open questions in the non-perturbative strangeness QCD sector, like the controversial nature of the $\Lambda(1405)$ state, the yield of hyperon formation below threshold, the yield and shape of multi-nucleon $K^-$ absorption, processes which are intimately connected to the possible existence of exotic antikaon multi-nucleon clusters. AMADEUS takes advantage of the DA$\Phi$NE collider, which provides a unique source of monochromatic low-momentum kaons and exploits the KLOE detector as an active target, in order to obtain excellent acceptance and resolution data for $K^-$ nuclear capture on H, ${}^4$He, ${}^{9}$Be and ${}^{12}$C, both at-rest and in-flight. During the second half of 2012 a successful data taking was performed with a dedicated pure carbon target implemented in the central region of KLOE, providing a high statistic sample of pure at-rest $K^-$ nuclear interactions. For the future dedicated setups involving cryogenic gaseous targets are under preparation.Comment: 14 pages, 6 figure