Author: "Zanevsky Y." - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Zanevsky Y."' showing total 641 results

Start Over Author "Zanevsky Y."

641 results on '"Zanevsky Y."'

1. Impact of the Coulomb field on charged-pion spectra in few-GeV heavy-ion collisions

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Ciepał, I., Deveaux, C., Dreyer, J., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Linev, S., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Nabroth, M., Naumann, L., Nowakowski, K., Parpottas, Y., Parschau, M., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Pysz, K., Ramos, S., Ramstein, B., Rathod, N., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schild, N., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Sobolev, Yu. G., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Sturm, C., Sumara, K., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: In nuclear collisions the incident protons generate a Coulomb field which acts on produced charged particles. The impact of these interactions on charged pion transverse-mass and rapidity spectra, as well as on pion-pion momentum correlations is investigated in Au+Au collisions at $\sqrt{s_{NN}}$ = 2.4 GeV. We show that the low-mt part of the data ($m_t < 0.2$ GeV/c$^2$) can be well described with a Coulomb-modified Boltzmann distribution that also takes changes of the Coulomb field during the expansion of the fireball into account. The observed centrality dependence of the fitted mean Coulomb potential deviates strongly from a $A_{part}^{2/3}$ scaling, indicating that, next to the fireball, the non-interacting charged spectators have to be taken into account. For the most central collisions, the Coulomb modifications of the HBT source radii are found to be consistent with the potential extracted from the single-pion transverse-mass distributions. This finding suggests that the region of homogeneity obtained from two-pion correlations coincides with the region in which the pions freeze-out. Using the inferred mean-square radius of the charge distribution at freeze-out, we have deduced a baryon density, in fair agreement with values obtained from statistical hadronization model fits to the particle yields., Comment: 14 pages, 12 figures, to be published in EPJA
Published: 2022
Full Text: View/download PDF

2. Investigating hadronic resonances in pp interactions with HADES

Author: Przygoda Witold, Adamczewski-Musch J., Arnold O., Atomssa E.T., Behnke C., Berger-Chen J.C., Biernat J., Blanco A., Blume C., Böhmer M., Bordalo P., Chernenko S., Deveaux C., Dybczak A., Epple E., Fabbietti L., Fateev O., Fonte P., Franco C., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., Guber F., Gumberidze M., Harabasz S., Hennino T., Hlavac S., Höhne C., Holzmann R., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Kardan B., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Kuc H., Kugler A., Kunz T., Kurepin A., Kurilkin A., Kurilkin P., Ladygin V., Lalik R., Lapidus K., Lebedev A., Lopes L., Lorenz M., Mahmoud T., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Parpottas Y., Pechenov V., Pechenova O., Petousis V., Pietraszko J., Ramstein B., Rehnisch L., Reshetin A., Rost A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schmidt-Sommerfeld K., Schuldes H., Sellheim P., Siebenson J., Silva L., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Wendisch C., Wirth J., Wüstenfeld J., Zanevsky Y., and Zumbruch P.
Subjects: Physics, QC1-999
Abstract: In this paper we report on the investigation of baryonic resonance production in proton-proton collisions at the kinetic energies of 1.25 GeV and 3.5 GeV, based on data measured with HADES. Exclusive channels npπ+ and ppπ0 as well as ppe+e− were studied simultaneously in the framework of a one-boson exchange model. The resonance cross sections were determined from the one-pion channels for Δ(1232) and N(1440) (1.25 GeV) as well as further Δ and N* resonances up to 2 GeV/c2 for the 3.5 GeV data. The data at 1.25 GeV energy were also analysed within the framework of the partial wave analysis together with the set of several other measurements at lower energies. The obtained solutions provided the evolution of resonance production with the beam energy, showing a sizeable non-resonant contribution but with still dominating contribution of Δ(1232)P33. In the case of 3.5 GeV data, the study of the ppe+e− channel gave the insight on the Dalitz decays of the baryon resonances and, in particular, on the electromagnetic transition form-factors in the time-like region. We show that the assumption of a constant electromagnetic transition form-factors leads to underestimation of the yield in the dielectron invariant mass spectrum below the vector mesons pole. On the other hand, a comparison with various transport models shows the important role of intermediate ρ production, though with a large model dependency. The exclusive channels analysis done by the HADES collaboration provides new stringent restrictions on the parameterizations used in the models.
Published: 2015
Full Text: View/download PDF

3. Highlights of Resonance Measurements With HADES

Author: Epple Eliane, Adamczewski-Musch J., Arnold O., Atomssa E.T., Behnke C., Berger-Chen J.C., Biernat J., Blanco A., Blume C., Böhmer M., Bordalo P., Chernenko S., Deveaux C., Dybczak A., Fabbietti L., Fateev O., Fonte P., Franco C., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., Guber F., Gumberidze M., Harabasz S., Hennino T., Hlavac S., Höhne C., Holzmann R., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Kardan K., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Kuc H., Kugler A., Kunz T., Kurepin A., Kurilkin A., Kurilkin P., Ladygin V., Lalik R., Lapidus K., Lebedev A., Lopes L., Lorenz M., Mahmoud T., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Parpottas Y., Pechenov V., Pechenova O., Petousis V., Pietraszko J., Przygoda W., Ramstein B., Rehnisch L., Reshetin A., Rost A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schmidt-Sommerfeld K., Schuldes H., Sellheim P., Siebenson J., Silva L., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Wendisch C., Wirth J., Wüstenfeld J., Zanevsky Y., and Zumbruch P.
Subjects: Physics, QC1-999
Abstract: This contribution aims to give a basic overview of the latest results regarding the production of resonances in different collision systems. The results were extracted from experimental data collected with HADES that is a multipurpose detector located at the GSI Helmholtzzentrum, Darmstadt. The main points discussed here are: the properties of the strange resonances Λ(1405) and Σ(1385), the role of Δ’s as a source of pions in the final state, the production dynamics reflected in form of differential cross sections, and the role of the ϕ meson as a source for K− particles.
Published: 2015
Full Text: View/download PDF

4. Low mass dielectrons radiated off cold nuclear matter measured with HADES

Author: Lorenz M., Agakishiev G., Behnke C., Belver D., Belyaev A., Berger-Chen J.C., Blanco A., Blume C., Böhmer M., Cabanelas P., Chernenko S., Dritsa C., Dybczak A., Epple E., Fabbietti L., Fateev O., Fonte P., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., González-Díaz D., Guber F., Gumberidze M., Harabasz S., Hennino T., Höhne C., Holzmann R., Huck P., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Krizek F., Kuc H., Kugler A., Kurepin A., Kurilkin A., Kurilkin P., Ladygin V., Lalik R., Lang S., Lapidus K., Lebedev A., Lopes L., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Parpottas Y., Pechenov V., Pechenova O., Pietraszko J., Przygoda W., Ramstein B., Rehnisch L., Reshetin A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schuldes H., Siebenson J., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P, Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Weber M., Wendisch C., Wüstenfeld J., Yurevich S., and Zanevsky Y.
Subjects: Physics, QC1-999
Abstract: The High Acceptance DiElectron Spectrometer HADES [1] is installed at the Helmholtzzentrum für Schwerionenforschung (GSI) accelerator facility in Darmstadt. It investigates dielectron emission and strangeness production in the 1-3 AGeV regime. A recent experiment series focusses on medium-modifications of light vector mesons in cold nuclear matter. In two runs, p+p and p+Nb reactions were investigated at 3.5 GeV beam energy; about 9·109 events have been registered. In contrast to other experiments the high acceptance of the HADES allows for a detailed analysis of electron pairs with low momenta relative to nuclear matter, where modifications of the spectral functions of vector mesons are predicted to be most prominent. Comparing these low momentum electron pairs to the reference measurement in the elementary p+p reaction, we find in fact a strong modification of the spectral distribution in the whole vector meson region.
Published: 2014
Full Text: View/download PDF

5. In-medium hadron properties measured with HADES

Author: Pietraszko J., Agakishiev G., Behnke C., Belver D., Belyaev A., Berger-Chen J.C., Blanco A., Blume C., Böhmer M., Cabanelas P., Chernenko S., Dritsa C., Dybczak A., Epple E., Fabbietti L., Fateev O., Fonte P., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., González-Díaz D., Guber F., Gumberidze M., Harabasz S., Hennino T., Höhne C., Holzmann R., Huck P., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Krizek F., Kuc H., Kugler A., Kurepin A., Kurilkin A., Kurilkin P., Ladygin V., Lalik R., Lang S., Lapidus K., Lebedev A., Lopes L., Lorenz M., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Parpottas Y., Pechenov V., Pechenova O., Przygoda W., Ramstein B., Rehnisch L., Reshetin A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schuldes H., Siebenson J., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P, Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Weber M., Wendisch C., Wüstenfeld J., Yurevich S., and Zanevsky Y.
Subjects: Physics, QC1-999
Abstract: Many QCD based and phenomenological models predict changes of hadron properties in a strongly interacting environment. The results of these models differ significantly and the experimental determination of hadron properties in nuclear matter is essential. In this paper we present a review of selected physics results obtained at GSI Helmholtzzentrum für Schwerionenforschung GmbH by HADES (High-Acceptance Di-Electron Spectrometer). The e+e− pair emission measured for proton and heavy-ion induced collisions is reported together with results on strangeness production. The future HADES activities at the planned FAIR facility are also discussed.
Published: 2014
Full Text: View/download PDF

6. Measurement of the quasi free np → npπ+π− and np → ppπ−π0 reactions at 1.25 GeV With HADES

Author: Kurilkin A., Arnold O., Atomssa E. T., Behnke C., Belyaev A., Berger-Chen J. C., Biernat J., Blanco A., Blume C., Böhmer M., Bordalo P., Chernenko S., Deveaux C., Dybczak A., Epple E., Fabbietti L., Fateev O., Fonte P., Franco C., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., González-Díaz D., Guber F., Gumberidze M., Harabasz S., Hennino T., Höhne C., Holzmann R., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Kardan K., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Krizek F., Kuc H., Kugler A., Kunz T., Kurepin A., Kurilkin P., Ladygin V., Lalik R., Lang S., Lapidus K., Lebedev A., Lopes L., Lorenz M., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Pechenov V., Pechenova O., Petousis V., Pietraszko J., Przygoda W., Ramstein B., Rehnisch L., Reshetin A., Rost A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schmidt-Sommerfeld K., Schuldes H., Sellheim P., Siebenson J., Silva L., Sobolev Yu. G., Spataro S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Wendisch C., Wirth J., Wüstenfeld J., Yurevich S., and Zanevsky Y.
Subjects: Physics, QC1-999
Abstract: We present the results of two-pion production in tagged quasi-free np collisions at a deutron incident beam energy of 1.25 GeV/c measured with the High-Acceptance Di-Electron Spectrometer (HADES) installed at GSI. The specific acceptance of HADES allowed for the first time to obtain high-precision data on π+π− and π−π0 production in np collisions in a region corresponding to large transverse momenta of the secondary particles. The obtained differential cross section data provide strong constraints on the production mechanisms and on the various baryon resonance contributions (∆∆, N(1440), N(1520), ∆(1600)). The invariant mass and angular distributions from the np → npπ+π −and np → ppπ−π0 reactions are compared with different theoretical model predictions.
Published: 2014
Full Text: View/download PDF

7. HADES results in elementary reactions

Author: Ramstein B., Adamczewski-Musch J., Arnold O., Atomssa E.T., Behnke C., Berger-Chen J.C., Biernat J., Blanco A., Blume C., Böhmer M., Bordalo P., Chernenko S., Deveaux C., Dybczak A., Epple E., Fabbietti L., Fateev O., Fonte P., Franco C., Friese J., Fröhlich I., Galatyuk T., Garzón J. A., Gill K., Golubeva M., Guber F., Gumberidze M., Harabasz S., Hennino T., Hlavac S., Höhne C., Holzmann R., Ierusalimov A., Ivashkin A., Jurkovic M., Kämpfer B., Karavicheva T., Kardan K., Koenig I., Koenig W., Kolb B. W., Korcyl G., Kornakov G., Kotte R., Krása A., Krebs E., Kuc H., Kugler A., Kunz T., Kurepin A., Kurilkin A., Kurilkin P., Ladygin V., Lalik R., Lapidus K., Lebedev A., Lopes L., Lorenz M., Mahmoud T., Maier L., Mangiarotti A., Markert J., Metag V., Michel J., Müntz C., Münzer R., Naumann L., Palka M., Parpottas Y., Pechenov V., Pechenova O., Petousis V., Pietraszko J., Przygoda W., Rehnisch L., Reshetin A., Rost A., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schmidt-Sommerfeld K., Schuldes H., Sellheim P., Siebenson J., Silva L., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Wendisch C., Wirth J., Wüstenfeld J., Zanevsky Y., and Zumbruch P.
Subjects: Physics, QC1-999
Abstract: Recent results obtained with the HADES experimental set-up at GSI are presented with a focus on dielectron production and strangeness in pp and quasi-free np reactions. Perspectives related to the very recent experiment using the pion beam at GSI are also discussed.
Published: 2014
Full Text: View/download PDF

8. Correlated pion-proton pair emission off hot and dense QCD matter

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Blanco, A., Blume, C., B"ohmer, M., Bordalo, P., Chernenko, S., Chlad, L., Ciepal, I., Deveaux, C., Dreyer, J., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fr"ohlich, I., Galatyuk, T., Garzon, J. A., Gernh"auser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., H"ohne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., K"ampfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., M"untz, C., M"unzer, R., Naumann, L., Nowakowski, K., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Pysz, K., Ramos, S., Ramstein, B., Rathod, N., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Sobolev, Yu. G., Spataro, S., Spies, S., Str"obele, H., Stroth, J., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wojcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: In this letter we report the first multi-differential measurement of correlated pion-proton pairs from 2 billion Au+Au collisions at \sqrt{s_{NN}} = 2.42 GeV collected with HADES. In this energy regime the population of \Delta(1232) resonances plays an important role in the way energy is distributed between intrinsic excitation energy and kinetic energy of the hadrons in the fireball. The triple differential d3N/dM{\pi}pdpTdy distributions of correlated {\pi}p pairs have been determined by subtracting the {\pi}p combinatorial background using an iterative method. The invariant-mass distributions in the \Delta(1232) mass region show strong deviations from a Breit-Wigner function with vacuum width and mass. The yield of correlated pion-proton pairs exhibits a complex isospin, rapidity and transverse-momentum dependence. In the invariant mass range 1.1 < Minv (GeV/c2) < 1.4, the yield is found to be similar for {\pi}+p and {\pi}-p pairs, and to follow a power law ^{\alpha}, where is the mean number of participating nucleons. The exponent {\alpha} depends strongly on the pair transverse momentum (pT) while its pT-integrated and charge-averaged value is {\alpha} = 1.5 \pm 0.08stat \pm 0.2sys., Comment: 9 pages, 9 figures
Published: 2020
Full Text: View/download PDF

9. Directed, elliptic and higher order flow harmonics of protons, deuterons and tritons in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV

Author: HADES collaboration, Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Ciepal, I., Deveaux, C., Dreyer, J., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Golosov, O., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Mamaev, M., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Pysz, K., Ramos, S., Ramstein, B., Rathod, N., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Sobolev, Yu. G., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wójcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: Flow coefficients $v_{n}$ of the orders $n = 1 - 6$ are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons as a function of centrality, transverse momentum and rapidity in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV. Combining the information from the flow coefficients of all orders allows to construct for the first time, at collision energies of a few GeV, a multi-differential picture of the angular emission pattern of these particles. It reflects the complicated interplay between the effect of the central fireball pressure on the emission of particles and their subsequent interaction with spectator matter. The high precision information on higher order flow coefficients is a major step forward in constraining the equation-of-state of dense baryonic matter., Comment: 6 pages, 5 figures; Figs. 2, 3 and 5 updated from re-analysis of data including UrQMD model predictions. Plotting error in Fig. 4 corrected; Accepted for publication in Phys. Rev. Lett
Published: 2020
Full Text: View/download PDF

10. Charged pion production in $\mathbf{Au+Au}$ collisions at $\mathbf{\sqrt{s_{NN}}}$ = 2.4$\mathbf{GeV}$

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Boehmer, M., Bordalo, P., Chernenko, S., Chlad, L., Ciepal, I., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Glaessel, S., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Muentz, C., Muenzer, R., Naumann, L., Nowakowski, K., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Pysz, K., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rathod, N., Rosier, P., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Singh, U., Smyrski, J., Sobolev, Yu. G., Spataro, S., Spies, S., Stroebele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wojcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We present high-statistic data on charged pion emission from Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 2.4 GeV (corresponding to $E_{beam}$ = 1.23 A GeV) in four centrality classes in the range 0 - 40$\%$ of the most central collisions. The data are analyzed as a function of transverse momentum, transverse mass, rapidity, and polar angle. Pion multiplicity per participating nucleon decreases moderately with increasing centrality. The polar angular distributions are found to be non-isotropic even for the most central event class. Our results on pion multiplicity fit well into the general trend of the world data, but undershoot by $2.5 \sigma$ data from the FOPI experiment measured at slightly lower beam energy. We compare our data to state-of-the-art transport model calculations (PHSD, IQMD, PHQMD, GiBUU and SMASH) and find substantial differences between the measurement and the results of these calculations., Comment: 17 pages, 19 figures, 4 tables
Published: 2020
Full Text: View/download PDF

11. Two-Pion production in the second resonance region in $\pi^- p$ collisions with HADES

Author: Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Chernenko, S., Chlad, L., Chudoba, P., Ciepał, I., Deveaux, C., Dittert, D., Dreyer, J., Epple, E., Fabbietti, L., Fateev, O., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kuboś, J., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Linev, S., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Prozorov, A. P., Przygoda, W., Ramstein, B., Rathod, N., Reshetin, A., Rodriguez-Ramos, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sing, U., Smyrski, J., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Ungethüm, C., Vazquez-Doce, O., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wójcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: Pion induced reactions provide unique opportunities for an unambiguous description of baryonic resonances and their coupling channels by means of a partial wave analysis. Using the secondary pion beam at SIS18, the two pion production in the second resonance region has been investigated to unravel the role of the $N(1520) \frac{3}{2}^-$ resonance in the intermediate $\rho$ production. Results on exclusive channels with one pion ($\pi^{-}p$) and two pions ($\pi^{+}\pi^{-}n$, $\pi^{0}\pi^{-}p$) in the final state measured in the $\pi^{-}-p$ reaction at four different pion beam momenta (0.650, 0.685, 0.733, and 0.786 GeV/c) are presented. The excitation function of the different partial waves and $\Delta\pi$, $N\sigma$ and $N\rho$ isobar configurations is obtained, using the Bonn-Gatchina partial wave analysis. The $N(1520) \frac{3}{2}^-$ resonance is found to dominate the $N\rho$ final state with the branching ratio $BR=12.2 \pm 1.9\%$.
Published: 2020
Full Text: View/download PDF

12. Proton number fluctuations in $\sqrt{s_{NN}}$ = 2.4 GeV Au+Au collisions studied with HADES

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., B"ohmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fr"ohlich, I., Galatyuk, T., Garzon, J. A., Gernh"auser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., H"ohne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., K"ampfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kohls, M., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., M"untz, C., M"unzer, R., Naumann, L., Nowakowski, K., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Spies, S., Str"obele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We present an analysis of proton number fluctuations in $\sqrt{s_{NN}}$ = 2.4 GeV Au+Au collisions measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI. With the help of extensive detector simulations done with IQMD transport model events including nuclear clusters, various nuisance effects influencing the observed proton cumulants have been investigated. Acceptance and efficiency corrections have been applied as a function of fine grained rapidity and transverse momentum bins, as well as considering local track density dependencies. Next, the effects of volume changes within particular centrality selections have been considered and beyond-leading-order corrections have been applied to the data. The efficiency and volume corrected proton number moments and cumulants Kn of orders n = 1, . . . , 4 have been obtained as a function of centrality and phase-space bin, as well as the corresponding correlators C_n . We find that the observed correlators show a power-law scaling with the mean number of protons, i.e. $C_n \propto ^n$, indicative of mostly long-range multi-particle correlations in momentum space. We also present a comparison of our results with Au+Au collision data obtained at RHIC at similar centralities, but higher $\sqrt{s_{NN}}$., Comment: 35 pages, 33 figures
Published: 2020
Full Text: View/download PDF

13. The dp-elastic cross section measurement at the deuteron kinetic energy of 2.5 GeV

Author: Rustamov A., Reshetin A., Rehnisch L., Ramstein B., Przygoda W., Pietraszko J., Pechenova O., Parpottas Y., Pechenov V., Palka M., Naumann L., Münzer R., Müntz C., Michel J., Metag V., Markert J., Mangiarotti A., Maier L., Lorenz M., Lopes L., Lebedev A., Lapidus K., Lang S., Lalik R., Ladygin V., Kurilkin A., Kurepin A., Kuc H., Kugler A., Krizek F., Krebs E., Krása A., Kotte R., Kornakov G., Korcyl G., Kolb B. W., Koenig W., Koenig I., Kämpfer B., Karavicheva T., Jurkovic M., Ivashkin A., Ierusalimov A., Höhne C., Huck P., Holzmann R., Hennino T., Harabasz S., Gumberidze M., Guber F., González-Díaz D., Golubeva M., Gill K., Galatyuk T., Garzón J. A., Fröhlich I., Fonte P., Friese J., Fateev O., Fabbietti L., Epple E., Dybczak A., Dritsa C., Chernenko S., Cabanelas P., Böhmer M., Blume C., Blanco A., Berger-Chen J.C., Belyaev A., Belver D., Behnke C., Agakishiev G., Kurilkin P., Sadovsky A., Salabura P., Scheib T., Schuldes H., Siebenson J., Sobolev Yu.G., Spataro S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Weber M., Wendisch C., Wüstenfeld J., Yurevich S., and Zanevsky Y.
Subjects: Physics, QC1-999
Abstract: New results on the differential cross section in deuteron-proton elastic scattering are obtained at the deuteron kinetic energy of 2.5 GeV with the HADES spectrometer. The angular range of 69° – 125° in the center of mass system is covered. The obtained results are compared with the relativistic multiple scattering model calculation using the CD-Bonn deuteron wave function. The data at fixed scattering angles in the c.m. are in qualitative agreement with the constituent counting rules prediction.
Published: 2012
Full Text: View/download PDF

14. Resonance production in p+p, p+A and A+A collisions measured with HADES

Author: Reshetin A., Rehnisch L., Ramstein B., Przygoda W., Pietraszko J., Pechenova O., Pechenov V., Parpottas Y., Palka M., Naumann L., Münzer R., Müntz C., Michel J., Metag V., Markert J., Mangiarotti A., Maier L., Lopes L., Lebedev A., Lapidus K., Lang S., Lalik R., Ladygin V., Kurilkin P., Kurilkin A., Kurepin A., Kuc H., Kugler A., Krizek F., Krebs E., Krása A., Kotte R., Kornakov G., Korcyl G., Kolb B. W., Koenig W., Koenig I., Karavicheva T., Kämpfer B., Jurkovic M., Ivashkin A., Ierusalimov A., Höhne C., Huck P., Holzmann R., Hennino T., Harabasz S., Gumberidze M., Guber F., Gonzáalez-Díaz D., Golubeva M., Gill K., Garzón J. A., Galatyuk T., Fröhlich I., Friese J., Fabbietti L., Fonte P., Epple E., Dybczak A., Dritsa C., Cabanelas P., Böhmer M., Blume C., Blanco A., Berger-Chen J.C., Belyaev A., Belver D., Behnke C., Agakishiev G., Lorenz M., Rustamov A., Sadovsky A., Salabura P., Scheib T., Schuldes H., Siebenson J., Sobolev Yu.G., Spataroe S., Ströbele H., Stroth J., Strzempek P., Sturm C., Svoboda O., Tarantola A., Teilab K., Tlusty P., Traxler M., Tsertos H., Vasiliev T., Wagner V., Weber M., Wendisch C., Wüstenfeld J., Yurevich S., and Zanevsky Y.
Subjects: Physics, QC1-999
Abstract: The knowledge of baryonic resonance properties and production cross sections plays an important role for the extraction and understanding of medium modifications of mesons in hot and/or dense nuclear matter. We present and discuss systematics on dielectron and strangeness production obtained with HADES on p+p, p+A and A+A collisions in the few GeV energy regime with respect to these resonances.
Published: 2012
Full Text: View/download PDF

15. Identical pion intensity interferometry at sqrt(s_{NN})=2.4 GeV

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wójcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: High-statistics $\pi^-\pi^-$ and $\pi^+\pi^+$ femtoscopy data are presented for Au+Au collisions at $\sqrt{s_\mathrm{NN}}=2.4$ GeV, measured with HADES at SIS18/GSI. The experimental correlation functions allow the determination of the space-time extent of the corresponding emission sources via a comparison to models. The emission source, parametrized as three-dimensional Gaussian distribution, is studied in dependence on pair transverse momentum, azimuthal emission angle with respect to the reaction plane, collision centrality and beam energy. For all centralities and transverse momenta, a geometrical distribution of ellipsoidal shape is found in the plane perpendicular to the beam direction with the larger extension perpendicular to the reaction plane. For large transverse momenta, the corresponding eccentricity approaches the initial eccentricity. The eccentricity is smallest for most central collisions, where the shape is almost circular. The magnitude of the tilt angle of the emission ellipsoid in the reaction plane decreases with increasing centrality and increasing transverse momentum. All source radii increase with centrality, largely exhibiting a linear rise with the number of participants, irrespective of transverse momentum. A substantial charge-sign difference of the source radii is found, appearing most pronounced at low transverse momentum. The extracted source parameters are consistent with the extrapolation of their energy dependence down from higher energies., Comment: 20 pages, 19 figures, 7 tables. arXiv admin note: text overlap with arXiv:1811.06213
Published: 2019
Full Text: View/download PDF

16. Sub-threshold production of K^{0}_{s} mesons and {\Lambda} hyperons in Au(1.23A GeV)+Au

Author: HADES collaboration, Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Selyuzhenkov, I., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., Zumbruch, P., and Leifels, Y.
Subjects: Nuclear Experiment
Abstract: We present first data on sub-threshold production of K0 s mesons and {\Lambda} hyperons in Au+Au collisions at $\sqrt{s_{NN}}$ = 2.4 GeV. We observe an universal scaling of hadrons containing strangeness, independent of their corresponding production thresholds. Comparing the yields, their scaling, and the shapes of the rapidity and the pt spectra to state-of-the-art transport model (UrQMD, HSD, IQMD) predictions, we find that none of the latter can simultaneously describe all observables with reasonable \c{hi}2 values., Comment: 8 pages, 10 figures
Published: 2018
Full Text: View/download PDF

17. Strong absorption of hadrons with hidden and open strangeness in nuclear matter

Author: Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Chernenko, S., Chlad, L., Chudoba, P., Ciepal, I., Deveaux, C., Dittert, D., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kornas, F., Kotte, R., Kubos, J., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Linev, S., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Malige, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Mikhaylov, V., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowsk, K., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Prozorov, A. P., Przygoda, W., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schmidt-Sommerfeld, K., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Smyrski, J., Spataro, S., Spies, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Ungethüm, C., Doce, O. Vazquez, Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We present the first observation of K- and \phi absorption within nuclear matter by means of \pi- -induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K-/K+)W / (K-/K+)C is found to be 0.319 \pm 0.009(stat)+0.014-0.012 (syst) indicating a larger absorption of K- in heavier targets as compared to lighter ones. The measured \phi/K- ratios in \pi-+C and \pi^- +W reactions within the HADES acceptance are found to be equal to $0.55 \pm 0.03(stat)+0.06-0.07$ (syst) and to $0.63 \pm 0.05(stat)-0.11+0.11$ (syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the \phi meson in nuclear medium is strongly coupled to the K- dynamics. The large difference in the \phi production off C and W nuclei is discussed in terms of a strong \phiN in-medium coupling., Comment: 6 pages, 3 figures
Published: 2018
Full Text: View/download PDF

18. Identical pion intensity interferometry in central Au+Au collisions at 1.23A GeV

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Matulewicz, T., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Piasecki, K., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Wojcik, D., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We investigate identical pion HBT intensity interferometry for central Au+Au collisions at 1.23A GeV. High-statistics $\pi^-\pi^-$ and $\pi^+\pi^+$ data are measured with HADES at SIS18/GSI. The radius parameters, derived from the correlation function depending on relative momenta in the longitudinal-comoving system and parametrized as three-dimensional Gaussian distribution, are studied as function of transverse momentum. A substantial charge-sign difference of the source radii is found, particularly pronounced at low transverse momentum. The extracted Coulomb-corrected source parameters agree well with a smooth extrapolation of the center-of-mass energy dependence established at higher energies, extending the corresponding excitation functions down towards a very low energy. Our data would thus rather disfavour any strong energy dependence of the radius parameters in the low energy region., Comment: 7 pages, 5 figures, updated author and grant lists
Published: 2018
Full Text: View/download PDF

19. Centrality determination of Au+Au collisions at 1.23A GeV with HADES

Author: HADES collaboration, Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Golubeva, M., Greifenhagen, R., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Hoehne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kaempfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Kuehn, W., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Muentz, C., Muenzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Stroebele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: The centrality determination for Au+Au collisions at 1.23A GeV, as measured with HADES at the GSI-SIS18, is described. In order to extract collision geometry related quantities, such as the average impact parameter or number of participating nucleons, a Glauber Monte Carlo approach is employed. For the application of this model to collisions at this relatively low centre-of-mass energy of $\sqrt{s_{\mathrm{NN}}} = 2.42$ GeV special investigations were performed. As a result a well defined procedure to determine centrality classes for ongoing analyses of heavy-ion data is established.
Published: 2017
Full Text: View/download PDF

20. $\Sigma^0$ production in proton nucleus collisions near threshold

Author: Adamczewski-Musch, J., Agakishiev, G., Arnold, O., Atomssa, E. T., Behnke, C., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Chernenko, P. Bordalo S., Deveaux, C., Dybczak, A., Epple, E., Fabbietti, L., Fonte, O. Fateev P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gill, K., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Hlavac, T. Hennino S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, M. Jurkovic B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krása, A., Krebs, E., Kuc, H., Kunz, A. Kugler T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Maurus, S., Mangiarotti, A., Markert, J., Metag, V., Michel, J., Müntz, C., Naumann, R. Münzer L., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petousis, V., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Rehnisch, L., Reshetin, A., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schmidt-Sommerfeld, K., Schuldes, H., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Wendisch, C., Wirth, J., Wüstenfeld, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: The production of $\Sigma^{0}$ baryons in the nuclear reaction p (3.5 GeV) + Nb (corresponding to $\sqrt{s_{NN}}=3.18$ GeV) is studied with the detector set-up HADES at GSI, Darmstadt. $\Sigma^{0}$s were identified via the decay $\Sigma^{0} \rightarrow \Lambda \gamma$ with subsequent decays $\Lambda \rightarrow p \pi^{-}$ in coincidence with a $e^{+}e^{-}$ pair from either external ($\gamma \rightarrow e^{+} e^{-}$) or internal (Dalitz decay $\gamma^{*}\rightarrow e^{+} e^{-}$) gamma conversions. The differential $\Sigma^0$ cross section integrated over the detector acceptance, i.e. the rapidity interval $0.5 < y < 1.1$, has been extracted as $\Delta\sigma_{\Sigma^{0}} = 2.3 \pm (0.2)^{stat} \pm \left(^{+0.6}_{-0.6}\right)^{sys} \pm (0.2)^{norm}$ mb, yielding the inclusive production cross section in full phase space $\sigma^{total}_{\Sigma^{0}} = 5.8 \pm (0.5)^{stat} \pm \left(^{+1.4}_{-1.4}\right)^{sys} \pm (0.6)^{norm} \pm (1.7)^{extrapol}$ mb by averaging over different extrapolation methods. The $\Lambda_{all}$/$\Sigma^{0}$ ratio within the HADES acceptance is equal to 2.3 $\pm$ $(0.2)^{stat}$ $\pm$ $(^{+0.6}_{-0.6})^{sys}$. The obtained rapidity and momentum distributions are compared to transport model calculations. The $\Sigma^{0}$ yield agrees with the statistical model of particle production in nuclear reactions., Comment: 7 pages, 5 figures
Published: 2017
Full Text: View/download PDF

21. Polarization Transfer Observables in Elastic Electron Proton Scattering at $Q^2 = $2.5, 5.2, 6.8, and 8.5 GeV$^2$

Author: Puckett, A. J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Afanasev, A., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nuruzzaman, Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The GEp-III and GEp-2$\gamma$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $G_E^p/G_M^p$ to the highest practically achievable $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables of elastic $\vec{e}p$ scattering. This article reports an expanded description of the common experimental apparatus and data analysis procedure, and the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance data of the GEp-2$\gamma$ experiment. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2$\gamma$ data are significantly reduced at $\epsilon = 0.632$ and $0.783$ relative to the original publication. The decrease with $Q^2$ of $G_E^p/G_M^p$ continues to $Q^2 = 8.5$ GeV$^2$, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At $Q^2 = 2.5$ GeV$^2$, the proton form factor ratio $G_E^p/G_M^p$ shows no statistically significant $\epsilon$-dependence, as expected in the Born approximation. The ratio $P_\ell/P_\ell^{Born}$ of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.4\% at $\epsilon = 0.783$ relative to $\epsilon = 0.149$, with $\approx 1.9\sigma$ significance based on the total uncertainty, implying a similar effect in the transverse component $P_t$ that cancels in the ratio $R$., Comment: 44 pages, 28 figures. Archival publication for the GEp-III and GEp-2gamma experiments that ran in Jefferson Lab's experimental Hall C from October, 2007 to June, 2008. v2: final manuscript as accepted by PRC. v3: Replaced figures 13 and 19 with corrected versions from published Erratum. Also made minor corrections to the text and to Table XI reflecting the corrections in the published Erratum
Published: 2017
Full Text: View/download PDF

22. Technical Supplement to 'Polarization Transfer Observables in Elastic Electron-Proton Scattering at Q$^2$ = 2.5, 5.2, 6.8, and 8.5 GeV$^2$'

Author: Puckett, A. J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nurruzzaman, Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The GEp-III and GEp-2$\gamma$ experiments, carried out in Jefferson Lab's Hall C from 2007-2008, consisted of measurements of polarization transfer in elastic electron-proton scattering at momentum transfers of $Q^2 = 2.5, 5.2, 6.8,$ and $8.54$ GeV$^2$. These measurements were carried out to improve knowledge of the proton electromagnetic form factor ratio $R = \mu_p G_E^p/G_M^p$ at large values of $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables at $Q^2 = 2.5$ GeV$^2$. The final results of both experiments were reported in a recent archival publication. A full reanalysis of the data from both experiments was carried out in order to reduce the systematic and, for the GEp-2$\gamma$ experiment, statistical uncertainties. This technical note provides additional details of the final analysis omitted from the main publication, including the final evaluation of the systematic uncertainties., Comment: 33 pages, 33 figures. v3 = Final manuscript as accepted for publication in Nuclear Instruments and Methods Section A (in press)
Published: 2017
Full Text: View/download PDF

23. Analysis of pion production data measured by HADES in proton-proton collisions at 1.25 GeV

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Müntz, C., Münzer, R., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., Sarantsev, A. V., and Nikonov, V. A.
Subjects: Nuclear Experiment, J.2
Abstract: Baryon resonance production in proton-proton collisions at a kinetic beam energy of 1.25 GeV is investigated. The multi-differential data were measured by the HADES collaboration. Exclusive channels with one pion in the final state ($np\pi^{+}$ and $pp\pi^{0}$) were put to extended studies based on various observables in the framework of a one-pion exchange model and with solutions obtained within the framework of a partial wave analysis (PWA) of the Bonn-Gatchina group. The results of the PWA confirm the dominant contribution of the $\Delta$(1232), yet with a sizable impact of the $N$(1440) and non-resonant partial waves., Comment: 12 pages, 6 figures
Published: 2017
Full Text: View/download PDF

24. Analysis of the exclusive final state npe$^+$e$^-$ in quasi-free np reaction

Author: Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Finocchiaro, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Maurus, S., Metag, V., Michel, J., Morinière, E., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., Zumbruch, P., and Sarantsev, A. V.
Subjects: Nuclear Experiment, J.2
Abstract: We report on the investigation of dielectron production in tagged quasi-free neutron-proton collisions by using a deuteron beam of kinetic energy 1.25 GeV/u inpinging on a liquid hydrogen target. Our measurements with HADES confirm a significant excess of $e^+e^-$ pairs above the $\pi^{0}$ mass in the exclusive channel $dp \to npe^{+}e^{-}(p_{spect})$ as compared to the exclusive channel $ppe^{+}e^{-}$ measured in proton-proton collisions at the same energy. That excess points to different bremsstrahlung production mechanisms. Two models were evaluated for the role of the charged pion exchange between nucleons and double-$\Delta$ excitation combined with intermediate $\rho$-meson production. Differential cross sections as a function of the $e^+e^-$ invariant mass and of the angles of the virtual photon, proton and electrons provide valuable constraints and encourage further investigations on both experimental and theoretical side., Comment: 12 pages, 7 figures
Published: 2017
Full Text: View/download PDF

25. Deep sub-threshold {\phi} production and implications for the K+/K- freeze-out in Au+Au collisions

Author: Adamczewski-Musch, J., Arnold, O., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcy, G., Kornakov, G., Kotte, R., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Maurus, S., Metag, V., Michel, J., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Szala, M., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We present data on charged kaons (K+-) and {\phi} mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K and {\phi} mesons in central heavy-ion collisions below a kinetic beam energy of 10A GeV. The {\phi}/K- multiplicity ratio is found to be surprisingly high with a value of 0.52 +- 0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K- transverse-mass spectra can be explained solely by feed- down, which substantially softens the spectra of K- mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze- out temperatures of K+ and K- mesons caused by different couplings to baryons., Comment: Corrected and updated version, 28 November 2017
Published: 2017
Full Text: View/download PDF

26. $\Delta$(1232) Dalitz decay in proton-proton collisions at T=1.25 GeV measured with HADES

Author: Adamczewski-Musch, J., Arnold, O., Atomssa, E. T., Behnke, C., Belounnas, A., Belyaev, A., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Chlad, L., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Filip, P., Finocchiaro, P., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Heinz, T., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Mangiarotti, A., Markert, J., Maurus, S., Metag, V., Michel, J., Morinière, E., Mihaylov, D. M., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Nowakowski, K. N., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petukhov, O., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Reshetin, A., Rodriguez-Ramos, P., Rosier, P., Rost, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schwab, E., Scozzi, F., Seck, F., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Tlusty, P., Traxler, M., Tsertos, H., Usenko, E., Wagner, V., Wendisch, C., Wiebusch, M. G., Wirth, J., Zanevsky, Y., Zumbruch, P., and Sarantsev, A. V.
Subjects: Nuclear Experiment, J.2
Abstract: We report on the investigation of $\Delta$(1232) production and decay in proton-proton collisions at a kinetic energy of 1.25 GeV measured with HADES. Exclusive dilepton decay channels $ppe^{+}e^{-}$ and $ppe^{+}e^{-}\gamma$ have been studied and compared with the partial wave analysis of the hadronic $pp\pi^{0}$ channel. They allow to access both $\Delta^+ \to p\pi^0(e^+e^-\gamma)$ and $\Delta^+ \to pe^+e^-$ Dalitz decay channels. The perfect reconstruction of the well known $\pi^0$ Dalitz decay serves as a proof of the consistency of the analysis. The $\Delta$ Dalitz decay is identified for the first time and the sensitivity to N-$\Delta$ transition form factors is tested. The $\Delta$(1232) Dalitz decay branching ratio is also determined for the first time; our result is (4.19 $\pm$ 0.62 syst. $\pm$ 0.34 stat.) $\times $ 10$^{-5}$, albeit with some model dependence., Comment: 13 pages, 7 figures
Published: 2017
Full Text: View/download PDF

27. Inclusive {\Lambda} production in proton-proton collisions at 3.5 GeV

Author: Adamczewski-Musch, J., Agakishiev, G., Arnold, O., Atomssa, E. T., Behnke, C., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Deveaux, C., Dreyer, J., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gill, K., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krása, A., Krebs, E., Kuc, H., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Maurus, S., Mangiarotti, A., Markert, J., Metag, V., Michel, J., Morozov, S., Müntz, C., Münzer, R., Naumann, L., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petousis, V., Pietraszko, J., Przygoda, W., Ramos, S., Ramstein, B., Rehnisch, L., Reshetin, A., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schmidt-Sommerfeld, K., Schuldes, H., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataroe, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Wendisch, C., Wirth, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: The inclusive production of {\Lambda} hyperons in proton-proton collisions at $\sqrt{s}$ = 3.18 GeV was measured with HADES at the GSI Helmholtzzentrum f\"ur Schwerionenforschung in Darmstadt. The experimental data are compared to a data-based model for individual exclusive {\Lambda} production channels in the same reaction. The contributions of intermediate resonances such as {\Sigma}(1385), {\Delta}++ or N* are considered in detail. In particular, the result of a partial wave analysis is accounted for the abundant pK$^+${\Lambda} final state. Model and data show a reasonable agreement at mid rapidities, while a difference is found for larger rapidities. A total {\Lambda} production cross section in p+p collisions at $\sqrt{s}$ = 3.18 GeV of {\sigma}(pp $\to$ {\Lambda} + X) = 207.3 $\pm$ 1.3 +6.0 -7.3 (stat.) $\pm$ 8.4 (syst.) +0.4 -0.5 (model) {\mu}b is found., Comment: 12 pages, 6 figures
Published: 2016
Full Text: View/download PDF

28. The $\bf{\Lambda p}$ interaction studied via femtoscopy in p + Nb reactions at $\mathbf{\sqrt{s_{NN}}=3.18} ~\mathrm{\bf{GeV}}$

Author: Adamczewski-Musch, J., Agakishiev, G., Arnold, O., Atomssa, E. T., Behnke, C., Berger-Chen, J. C., Biernat, J., Blanco, A., Blume, C., Böhmer, M., Bordalo, P., Chernenko, S., Deveaux, C., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Fonte, P., Franco, C., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gill, K., Golubeva, M., Guber, F., Gumberidze, M., Harabasz, S., Hennino, T., Hlavac, S., Höhne, C., Holzmann, R., Ierusalimov, A., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Kardan, B., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krasa, A., Krebs, E., Kuc, H., Kugler, A., Kunz, T., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Mahmoud, T., Maier, L., Maurus, S., Mangiarotti, A., Markert, J., Metag, V., Müntz, J. Michel C., Münzer, R., Naumann, L., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petousis, V., Pietraszko, J., Przygoda, W., Ramstein, B., Rehnisch, L., Reshetin, A., Rost, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schmidt-Sommerfeld, K., Schuldes, H., Sellheim, P., Siebenson, J., Silva, L., Sobolev, Yu. G., Spataro, S., Ströbele, H., Stroth, J., Strzempek, P., Sturm, C., Svoboda, O., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Wendisch, C., Wirth, J., Wüstenfeld, J., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We report on the first measurement of $p\Lambda$ and $pp$ correlations via the femtoscopy method in p+Nb reactions at $\mathrm{\sqrt{s_{NN}}=3.18} ~\mathrm{GeV}$, studied with the High Acceptance Di-Electron Spectrometer (HADES). By comparing the experimental correlation function to model calculations, a source size for $pp$ pairs of $r_{0,pp}=2.02 \pm 0.01(\mathrm{stat})^{+0.11}_{-0.12} (\mathrm{sys}) ~\mathrm{fm}$ and a slightly smaller value for $p\Lambda$ of $r_{0,\Lambda p}=1.62 \pm 0.02(\mathrm{stat})^{+0.19}_{-0.08}(\mathrm{sys}) ~\mathrm{fm}$ is extracted. Using the geometrical extent of the particle emitting region, determined experimentally with $pp$ correlations as reference together with a source function from a transport model, it is possible to study different sets of scattering parameters. The $p\Lambda$ correlation is proven sensitive to predicted scattering length values from chiral effective field theory. We demonstrate that the femtoscopy technique can be used as valid alternative to the analysis of scattering data to study the hyperon-nucleon interaction., Comment: 12 pages, 11 figures
Published: 2016
Full Text: View/download PDF

29. Statistical model analysis of hadron yields in proton-nucleus and heavy-ion collisions at SIS 18 energies

Author: Agakishiev, G., Arnold, O., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chernenko, S., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Gilardi, C., Göbel, K., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lange, J. S., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Moriniere, E., Mousa, J., Müntz, C., Münzer, R., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Rehnisch, L., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schmah, A., Schuldes, H., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wisniowski, M., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract: The HADES data from p+Nb collisions at center of mass energy of $\sqrt{s_{NN}}$= 3.2 GeV are analyzed by employing a statistical model. Accounting for the identified hadrons $\pi^0$, $\eta$, $\Lambda$, $K^{0}_{s}$, $\omega$ allows a surprisingly good description of their abundances with parameters $T_{chem}=(99\pm11)$ MeV and $\mu_{b}=(619\pm34)$ MeV, which fits well in the chemical freeze-out systematics found in heavy-ion collisions. In supplement we reanalyze our previous HADES data from Ar+KCl collisions at $\sqrt{s_{NN}}$= 2.6 GeV with an updated version of the statistical model. We address equilibration in heavy-ion collisions by testing two aspects: the description of yields and the regularity of freeze-out parameters from a statistical model fit. Special emphasis is put on feed-down contributions from higher-lying resonance states which have been proposed to explain the experimentally observed $\Xi^-$ excess present in both data samples.
Published: 2015

30. K*(892)+ production in proton-proton collisions at E_beam = 3.5 GeV

Author: HADES Collaboration, Agakishiev, G., Arnold, O., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michel, J., Mihaylov, D., Müntz, C., Münzer, R., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Svoboda, O., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment
Abstract: We present results on the K*(892)+ production in proton-proton collisions at a beam energy of E = 3.5 GeV, which is hitherto the lowest energy at which this mesonic resonance has been observed in nucleon-nucleon reactions. The data are interpreted within a two-channel model that includes the 3-body production of K*(892)+ associated with the Lambda- or Sigma-hyperon. The relative contributions of both channels are estimated. Besides the total cross section sigma(p+p -> K*(892)+ + X) = 9.5 +- 0.9 +1.1 -0.9 +- 0.7 mub, that adds a new data point to the excitation function of the K*(892)+ production in the region of low excess energy, transverse momenta and angular spectra are extracted and compared with the predictions of the two-channel model. The spin characteristics of K*(892)+ are discussed as well in terms of the spin-alignment., Comment: 7 pages, 9 figures, 1 table
Published: 2015
Full Text: View/download PDF

31. Study of the quasi-free $np \to np \pi^+\pi^-$ reaction with a deuterium beam at 1.25 GeV/nucleon

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A. V., Blanco, A., Böhmer, M., Boyard, J. L., Braun-Munzinger, P., Cabanelas, P., Castro, E., Chernenko, S., Christ, T., Destefanis, M., Díaz, J., Dohrmann, F., Dybczak, A., Fabbietti, L., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gil, A., Gilardi, C., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Kirschner, D., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krizek, F., Krücken, R., Kühn, W., Kugler, A., Kurepin, A., Kurilkin, A., Kurilkin, P., Ladygin, V., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Morinière, E., Mousa, J., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Vasiliev, T., Weber, M., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., and Zhou, P.
Subjects: Nuclear Experiment
Abstract: The tagged quasi-free $np \to np\pi^+\pi^-$ reaction has been studied experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI at a deuteron incident beam energy of 1.25 GeV/nucleon ($\sqrt s \sim$ 2.42 GeV/c for the quasi-free collision). For the first time, differential distributions for $\pi^{+}\pi^{-}$ production in $np$ collisions have been collected in the region corresponding to the large transverse momenta of the secondary particles. The invariant mass and angular distributions for the $np\rightarrow np\pi^{+}\pi^{-}$ reaction are compared with different models. This comparison confirms the dominance of the $t$-channel with $\Delta\Delta$ contribution. It also validates the changes previously introduced in the Valencia model to describe two-pion production data in other isospin channels, although some deviations are observed, especially for the $\pi^{+}\pi^{-}$ invariant mass spectrum. The extracted total cross section is also in much better agreement with this model. Our new measurement puts useful constraints for the existence of the conjectured dibaryon resonance at mass M$\sim$ 2.38 GeV and with width $\Gamma\sim$ 70 MeV.
Published: 2015
Full Text: View/download PDF

32. Subthreshold Xi- Production in Collisions of p(3.5 GeV)+Nb

Author: Agakishiev, G., Arnold, O., Balanda, A., Belver, D., Belyaev, A. V., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: Results on the production of the double-strange cascade hyperon $\mathrm{\Xi^-}$ are reported for collisions of p\,(3.5~GeV)\,+\,Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold $\mathrm{\Xi^-}$ production is observed in proton-nucleus interactions. Assuming a $\mathrm{\Xi^-}$ phase-space distribution similar to that of $\mathrm{\Lambda}$ hyperons, the production probability amounts to $P_{\mathrm{\Xi^-}}=(2.0\,\pm0.4\,\mathrm{(stat)}\,\pm 0.3\,\mathrm{(norm)}\,\pm 0.6\,\mathrm{(syst)})\times10^{-4}$ resulting in a $\mathrm{\Xi^-/(\Lambda+\Sigma^0)}$ ratio of $P_{\mathrm{\Xi^-}}/\ P_{\mathrm{\Lambda+\Sigma^0}}=(1.2\pm 0.3\,\mathrm{(stat)}\pm0.4\,\mathrm{(syst)})\times10^{-2}$. Available model predictions are significantly lower than the estimated $\mathrm{\Xi^-}$ yield., Comment: 6 pages, 3 figures
Published: 2015
Full Text: View/download PDF

33. Partial Wave Analysis of the Reaction $p(3.5 GeV)+p \to pK^+\Lambda$ to Search for the '$ppK^-$' Bound State

Author: Agakishiev, G., Arnold, O., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michel, J., Müntz, C., Münzer, R., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., and Sarantsev, A. V.
Subjects: Nuclear Experiment
Abstract: Employing the Bonn-Gatchina partial wave analysis framework (PWA), we have analyzed HADES data of the reaction $p(3.5GeV)+p\to pK^{+}\Lambda$. This reaction might contain information about the kaonic cluster "$ppK^-$" via its decay into $p\Lambda$. Due to interference effects in our coherent description of the data, a hypothetical $\overline{K}NN$ (or, specifically "$ppK^-$") cluster signal must not necessarily show up as a pronounced feature (e.g. a peak) in an invariant mass spectra like $p\Lambda$. Our PWA analysis includes a variety of resonant and non-resonant intermediate states and delivers a good description of our data (various angular distributions and two-hadron invariant mass spectra) without a contribution of a $\overline{K}NN$ cluster. At a confidence level of CL$_{s}$=95\% such a cluster can not contribute more than 2-12\% to the total cross section with a $pK^{+}\Lambda$ final state, which translates into a production cross-section between 0.7 $\mu b$ and 4.2 $\mu b$, respectively. The range of the upper limit depends on the assumed cluster mass, width and production process., Comment: 7 Pages, 5 Figures
Published: 2014
Full Text: View/download PDF

34. Medium effects in proton-induced $K^{0}$ production at 3.5 GeV

Author: Agakishiev, G., Arnold, O., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Korcyl, G., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Ladygin, V., Lalik, R., Lapidus, K., Lebedev, A., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michel, J., Müntz, C., Münzer, R., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., Gaitanos, . T., and Weil, J.
Subjects: Nuclear Experiment
Abstract: We present the analysis of the inclusive $K^{0}$ production in p+p and p+Nb collisions measured with the HADES detector at a beam kinetic energy of 3.5 GeV. Data are compared to the GiBUU transport model. The data suggest the presence of a repulsive momentum-dependent kaon potential as predicted by the Chiral Perturbation Theory (ChPT). For the kaon at rest and at normal nuclear density, the ChPT potential amounts to $\approx 35$ MeV. A detailed tuning of the kaon production cross sections implemented in the model has been carried out to reproduce the experimental data measured in p+p collisions. The uncertainties in the parameters of the model were examined with respect to the sensitivity of the experimental results from p+Nb collisions to the in-medium kaon potential., Comment: 13 pages, 14 figures
Published: 2014
Full Text: View/download PDF

35. Lambda hyperon production and polarization in collisions of p(3.5 GeV) + Nb

Author: Agakishiev, G., Arnold, O., Balanda, A., Belver, D., Belyaev, A. V., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., Gonzalez-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: Results on $\Lambda$ hyperon production are reported for collisions of p(3.5 GeV) + Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. The transverse mass distributions in rapidity bins are well described by Boltzmann shapes with a maximum inverse slope parameter of about $90\,$MeV at a rapidity of $y=1.0$, i.e. slightly below the center-of-mass rapidity for nucleon-nucleon collisions, $y_{cm}=1.12$. The rapidity density decreases monotonically with increasing rapidity within a rapidity window ranging from 0.3 to 1.3. The $\Lambda$ phase-space distribution is compared with results of other experiments and with predictions of two transport approaches which are available publicly. None of the present versions of the employed models is able to fully reproduce the experimental distributions, i.e. in absolute yield and in shape. Presumably, this finding results from an insufficient modelling in the transport models of the elementary processes being relevant for $\Lambda$ production, rescattering and absorption. The present high-statistics data allow for a genuine two-dimensional investigation as a function of phase space of the self-analyzing $\Lambda$ polarization in the weak decay $\Lambda\rightarrow p \pi^-$. Finite negative values of the polarization in the order of $5-20\,\%$ are observed over the entire phase space studied. The absolute value of the polarization increases almost linearly with increasing transverse momentum for $p_t>300\,$MeV/c and increases with decreasing rapidity for $y < 0.8$., Comment: accepted by Eur. Phys. J. A
Published: 2014
Full Text: View/download PDF

36. Associate K^0 production in p+p collisions at 3.5 GeV: The role of Delta(1232)++

Author: Agakishiev, G., Arnold, O., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kunz, T., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Münzer, R., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wustenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment
Abstract: An exclusive analysis of the 4-body final states $\mathrm{\Lambda + p + \pi^{+} + K^{0}}$ and $\mathrm{\Sigma^{0} + p + \pi^{+} + K^{0}}$ measured with HADES for p+p collisions at a beam kinetic energy of 3.5 GeV is presented. The analysis uses various phase space variables, such as missing mass and invariant mass distributions, in the four particle event selection (p, $\pi^+$, $\pi^+$, $\pi^-$) to find cross sections of the different production channels, contributions of the intermediate resonances $\mathrm{\Delta^{++}}$ and $\mathrm{\Sigma(1385)^{+}}$ and corresponding angular distributions. A dominant resonant production is seen, where the reaction $\mathrm{\Lambda + \Delta^{++} + K^{0}}$ has an about ten times higher cross section ($\mathrm{29.45\pm0.08^{+1.67}_{-1.46}\pm2.06\,\mu b}$) than the analogous non-resonant reaction ($\mathrm{2.57\pm0.02^{+0.21}_{-1.98}\pm0.18\,\mu b}$). A similar result is obtained in the corresponding $\Sigma^{0}$ channels with $\mathrm{9.26\pm0.05^{+1.41}_{-0.31}\pm0.65\,\ mu b}$ in the resonant and $\mathrm{1.35\pm0.02^{+0.10}_{-1.35}\pm0.09\,\mu b}$ in the non-resonant reactions., Comment: 12 pages, 11 figures
Published: 2014
Full Text: View/download PDF

37. Baryon resonance production and dielectron decays in proton-proton collisions at 3.5 GeV

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., König, I., König, W., Kolb, B. W., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Müntz, C., Naumann, L., Pachmayer, Y. C., Pałka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment, J.2
Abstract: We report on baryon resonance production and decay in proton-proton collisions at a kinetic energy of $3.5$ GeV based on data measured with HADES. The exclusive channels $pp \rightarrow np\pi^{+}$ and $pp \rightarrow pp\pi^{0}$ as well as $pp \rightarrow ppe^{+}e^{-}$ are studied simultaneously for the first time. The invariant masses and angular distributions of the pion-nucleon systems were studied and compared to simulations based on a resonance model ansatz assuming saturation of the pion production by an incoherent sum of baryonic resonances (R) with masses $<2~$ GeV/$c^2$. A very good description of the one-pion production is achieved allowing for an estimate of individual baryon-resonance production-cross-sections which are used as input to calculate the dielectron yields from $R\rightarrow pe^+e^-$ decays. Two models of the resonance decays into dielectrons are examined assuming a point-like $RN \gamma^*$ coupling and the dominance of the $\rho$ meson. The results of model calculations are compared to data from the exclusive $ppe^{+}e^{-}$ channel by means of the dielectron and $pe^+e^-$ invariant mass distributions., Comment: 17 pages, 14 figures
Published: 2014
Full Text: View/download PDF

38. Searching a Dark Photon with HADES

Author: HADES Collaboration, Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Boehmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Goebel, K., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kaempfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Kruecken, R., Kuc, H., Kuehn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Muentz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Petousis, V., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schuldes, H., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Stroebele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wuestenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We present a search for the e+e- decay of a hypothetical dark photon, also names U vector boson, in inclusive dielectron spectra measured by HADES in the p (3.5 GeV) + p, Nb reactions, as well as the Ar (1.756 GeV/u) + KCl reaction. An upper limit on the kinetic mixing parameter squared epsilon^{2} at 90% CL has been obtained for the mass range M(U) = 0.02 - 0.55 GeV/c2 and is compared with the present world data set. For masses 0.03 - 0.1 GeV/c^2, the limit has been lowered with respect to previous results, allowing now to exclude a large part of the parameter region favoured by the muon g-2 anomaly. Furthermore, an improved upper limit on the branching ratio of 2.3 * 10^{-6} has been set on the helicity-suppressed direct decay of the eta meson, eta-> e+e-, at 90% CL.
Published: 2013

39. An upper limit on hypertriton production in collisions of Ar(1.76 AGeV)+KCl

Author: HADES Collaboration, Agakishiev, G., Belver, D., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chernenko, S., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Miche, J., Morinière, E., Mousa, J., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Rehnisch, L., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Scheib, T., Schmah, A., Schuldes, H., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spatarof, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wisniowski, M., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: A high-statistic data sample of Ar(1.76 AGeV)+KCl events recorded with HADES is used to search for a hypertriton signal. An upper production limit per centrality-triggered event of $1.04$ x $10^{-3}$ on the $3\sigma$ level is derived. Comparing this value with the number of successfully reconstructed $\Lambda$ hyperons allows to determine an upper limit on the ratio $N_{_{\Lambda}^3H}/N_{\Lambda}$, which is confronted with statistical and coalescence-type model calculations.
Published: 2013

40. Inclusive pion and eta production in p+Nb collisions at 3.5 GeV beam energy

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Boehmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Goebel, K., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kaempfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krasa, A., Krizek, F., Kruecken, R., Kuc, H., Kuehn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Muentz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Stroebele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wuestenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment
Abstract: Data on inclusive pion and eta production measured with the dielectron spectrometer HADES in the reaction p+93Nb at a kinetic beam energy of 3.5 GeV are presented. Our results, obtained with the photon conversion method, supplement the rather sparse information on neutral meson production in proton-nucleus reactions existing for this bombarding energy regime. The reconstructed e+e-e+e- transverse-momentum and rapidity distributions are confronted with transport model calculations, which account fairly well for both pi0 and eta production., Comment: 12 pages, 9 figures, submitted to Physical Review C
Published: 2013
Full Text: View/download PDF

41. pK+\Lambda final state: towards the extraction of the ppK- contribution

Author: Fabbietti, L., Agakishiev, G., Balanda, A., Belver, D., Belyaev, A. V., Berger-Chen, J-C, Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Eberl, T., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krasa, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Lalik, R., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Moriniere, E., Mousa, J., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, A. Solaguren-Beascoa Negre S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wüstenfel, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: The reaction p(@3.5\,GeV)+p -> p+\Lambda + K^+ can be studied to search for the existence of kaonic bound states like ppK^- leading to this final state. This effort has been motivated by the assumption that in p+p collisions the \Lambda(1405) resonance can act as a doorway to the formation of the kaonic bound states. The status of this analysis within the HADES collaboration, with particular emphasis on the comparison to simulations, is shown in this work and the deviation method utilized by the DISTO collaboration in a similar analysis is discussed. The outcome suggests the employment of a partial wave analysis to disentangle the different contributions to the measured pK^+\Lambda final state., Comment: 9 pages, 6 figures, proceeding of the HYP2012 conference Nucl. Phys. A (2013)
Published: 2013
Full Text: View/download PDF

42. Baryonic resonances close to the Kbar-N threshold: the case of Lambda(1405) in pp collisions

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A. V., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfel, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: We present an analysis of the Lambda(1405) resonance produced in the reaction p+p->Sigma^{pm}+pi^{mp}+K+p at 3.5 GeV kinetic beam energy measured with HADES at GSI. The two charged decay channels Lambda(1405) -> Sigma^{\pm}+pi^{\mp} have been reconstructed for the first time in p+p collisions. The efficiency and acceptance-corrected spectral shapes show a peak position clearly below 1400 MeV/c^2. We find a total production cross section of sigma_{Lambda(1405)}=9.2 +- 0.9 +- 0.7 +3.3-1.0 mub. The analysis of its polar angle distribution suggests that the Lambda(1405) is produced isotropically in the p-p center of mass system., Comment: 5 pages 3 figures
Published: 2012
Full Text: View/download PDF

43. First measurement of low momentum dielectrons radiated off cold nuclear matter

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Chernenko, S., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Göbel, K., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kornakov, G., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Ladygin, V., Lalik, R., Lang, S., Lapidus, K., Lebedev, A., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Mishra, D., Müntz, C., Naumann, L., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Vasiliev, T., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We present data on dielectron emission in proton induced reactions on a Nb target at 3.5 GeV kinetic beam energy measured with HADES installed at GSI. The data represent the first high statistics measurement of proton-induced dielectron radiation from cold nuclear matter in a kinematic regime, where strong medium effects are expected. Combined with the good mass resolution of 2%, it is the first measurement sensitive to changes of the spectral functions of vector mesons, as predicted by models for hadrons at rest or small relative momenta. Comparing the e+e invariant mass spectra to elementary p+p data, we observe for e+e momenta Pee < 0.8 GeV/c a strong modification of the shape of the spectrum, which we attribute to an additional rho-like contribution and a decrease of omega yield. These opposite trends are tentatively interpreted as a strong coupling of the rho meson to baryonic resonances and an absorption of the omega meson, which are two aspects of in-medium modification of vector mesons.
Published: 2012
Full Text: View/download PDF

44. Inclusive dielectron production in proton-proton collisions at 2.2 GeV beam energy

Author: Agakishiev, G., Alvarez-Pol, H., Balanda, A., Bassini, R., Böhmer, M., Bokemeye, H., Boyard, J. L., Cabanelas, P., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Eberl, T., Fabbietti, L., Fateev, O., Finocchiaro, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kozuch, A., Krizek, F., Kühn, W., Kugler, A., Kurepin, A., Lang, S., Lapidus, K., Liu, T., Maier, L., Markert, J., Metag, V., Michalska, B., Morinière, E., Mousa, J., Münch, M., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Pechenov, V., Pechenova, O., Cavalcanti, T. Perez, Pietraszko, J., Pospisil, V., Przygoda, W., Ramstein, B., Reshetin, A., Roy-Stephan, M., Rustamov, A., Sadovsky, A., Sailer, B., Salabura, P., Sánchez, M., Schmah, A., Schwab, E., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Toia, A., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: Data on inclusive dielectron production are presented for the reaction p+p at 2.2 GeV measured with the High Acceptance DiElectron Spectrometer (HADES). Our results supplement data obtained earlier in this bombarding energy regime by DLS and HADES. The comparison with the 2.09 GeV DLS data is discussed. The reconstructed e+e- distributions are confronted with simulated pair cocktails, revealing an excess yield at invariant masses around 0.5 GeV/c2. Inclusive cross sections of neutral pion and eta production are obtained.
Published: 2012
Full Text: View/download PDF

45. Study of exclusive one-pion and one-eta production using hadron and dielectron channels in pp reactions at kinetic beam energies of 1.25 GeV and 2.2 GeV with HADES

Author: HADES Collaboration, Agakishiev, G., Alvarez-Pol, H., Balanda, A., Bassini, R., Böhmer, M., Bokemeyer, H., Boyard, J. L., Cabanelas, P., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Eberl, T., Fabbietti, L., Fateev, O., Finocchiaro, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kozuch, A., Krizek, F., Kühn, W., Kugler, A., Kurepin, A., Lang, S., Lapidus, K., Liu, T., Maier, L., Markert, J., Metag, V., Michalska, B., Morinière, E., Mousa, J., Münch, M., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Pechenov, V., Pechenova, O., Cavalcanti, T. Pérez, Pietraszko, J., Pospísil, V., Przygoda, W., Ramstein, B., Reshetin, A., Roy-Stephan, M., Rustamov, A., Sadovsky, A., Sailer, B., Salabura, P., Sánchez, M., Schmah, A., Schwab, E., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Toia, A., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Wisniowski, M., Wojcik, T., Wüstenfeld, J., Yurevich, S., Zanevsky, Y., and Zumbruch, P.
Subjects: Nuclear Experiment
Abstract: We present measurements of exclusive \pi^{+,0} and \eta\ production in pp reactions at 1.25 GeV and 2.2 GeV beam kinetic energy in hadron and dielectron channels. In the case of \pi^+ and \pi^0, 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 \Delta(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 \to pp \eta, since controversial data exist at 2.0 GeV; we find \sigma =0.142 \pm 0.022 mb. Using the dielectron channels, the \pi^0 and \eta\ 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., Comment: 22 pages, 18 figures, to be published in EPJA
Published: 2012
Full Text: View/download PDF

46. Production of Sigma{\pm}pi?pK+ in p+p reactions at 3.5 GeV beam energy

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Berger-Chen, J. C., Blanco, A., Boehmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chernenko, S., Destefanis, T. Christ M., Dohrmann, F., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzon, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., Gonza'lez-Di'az, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Ierusalimov, A., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Kr'asa, A., Krizek, F., Krücken, R., Kuc, H., Kuehn, W., Kugler, A., Kurepin, A., Lalik, R., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Morinie're, E., Mousa, J., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment
Abstract: We study the production of Sigma^+-pi^+-pK^+ particle quartets in p+p reactions at 3.5 GeV kinetic beam energy. The data were taken with the HADES experiment at GSI. This report evaluates the contribution of resonances like Lambda(1405$, Sigma(1385)^0, Lambda(1520), Delta(1232), N^* and K^*0 to the Sigma^+- pi^-+ p K+ final state. The resulting simulation model is compared to the experimental data in several angular distributions and it shows itself as suitable to evaluate the acceptance corrections properly., Comment: 15 pages, 5 figures
Published: 2012
Full Text: View/download PDF

47. Determination of the $\mathbf{\Sigma(1385)^{0}/\Lambda(1405)}$ ratio in p+p collisions at 3.5 GeV

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A. V., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chen, J. C., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Lalik, R., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Morinière, E., Mousa, J., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: The aim of the present analysis is to determine the relative production cross sections of the $\Lambda$(1405) and $\Sigma(1385)^{0}$ resonances in p+p collisions at E$_{kin}$=3.5 GeV measured with HADES. Upper and lower limits have been determined for the ratio $\sigma_{(\Sigma(1385)^{0}+p+K^{+})}/\sigma_{(\Lambda(1405)+p+K^{+})}=0.76_{-0.26}^{+0.54}$. The knowledge of this ratio is an essential input for the analysis of the decay $\Lambda(1405)\rightarrow\Sigma^{\pm}\pi^{\mp}$, where an unambiguous separation of the $\Lambda$(1405) and $\Sigma(1385)^{0}$ signals is not possible.
Published: 2012
Full Text: View/download PDF

48. Inclusive dielectron spectra in p+p collisions at 3.5 GeV

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A., Blanco, A., Böhmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chen, J. C., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Fabbietti, L., Fateev, O., Finocchiaro, P., Fonte, P., Friese, J., Fröhlich, I., Galatyuk, T., Garzón, J. A., Gernhäuser, R., Gilardi, C., Golubeva, M., González-Díaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Iori, I., Ivashkin, A., Jurkovic, M., Kämpfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krása, A., Krizek, F., Krücken, R., Kuc, H., Kühn, W., Kugler, A., Kurepin, A., Lalik, R., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Morinière, E., Mousa, J., Müntz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Ströbele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wüstenfeld, J., Yurevich, S., and Zanevsky, Y.
Subjects: Nuclear Experiment
Abstract: We present the inclusive invariant-mass, transverse momentum and rapidity distributions of dielectrons (e$^{+}$e$^{-}$ pairs) in p+p interactions at 3.5 GeV beam kinetic energy. In the vector-meson mass region, a distinct peak corresponding to direct $\omega$ decays is reconstructed with 2% mass resolution. The data is compared to predictions from three model calculations. Due to the large acceptance of the HADES apparatus for $e^{+}e^{-}$ invariant masses above 0.2 GeV/$c^{2}$ and for transverse pair momenta p$_{t}$ $ <$ 1 GeV/$c$, acceptance corrections are to a large extent model independent. This allows us to extract from dielectron data for the first time at this energy the inclusive production cross sections for light vector mesons. Inclusive production cross sections for $\pi^o$ and $\eta$ mesons are also reported. The obtained results will serve as an important reference for the study of vector meson production in proton-nucleus and heavy-ion collisions. Furthermore, using this data, an improved value for the upper bound of the branching ratio for direct $\eta$ decays into the electron-positron channel is obtained.
Published: 2011
Full Text: View/download PDF

49. Baryonic resonances close to the Kbar-N threshold: the case of Sigma(1385)^+ in pp collisions

Author: Agakishiev, G., Balanda, A., Belver, D., Belyaev, A. V., Blanco, A., Boehmer, M., Boyard, J. L., Cabanelas, P., Castro, E., Chen, J. C., Chernenko, S., Christ, T., Destefanis, M., Dohrmann, F., Dybczak, A., Epple, E., Eberl, T., Fabbietti, L., Fateev, O. V., Finocchiaro, P., Fonte, P., Friese, J., Froehlich, I., Galatyuk, T., Garzon, J. A., Gernhaeuser, R., Gilardi, C., Golubeva, M., Gonzalez-Diaz, D., Guber, F., Gumberidze, M., Heinz, T., Hennino, T., Holzmann, R., Iori, I., Ivashkin, A., Jurkovic, M., Kaempfer, B., Kanaki, K., Karavicheva, T., Koenig, I., Koenig, W., Kolb, B. W., Kotte, R., Krasa, A., Krizek, F., Kruecken, R., Kuc, H., Kuehn, W., Kugler, A., Kurepin, A., Lalik, R., Lang, S., Lange, J. S., Lapidus, K., Liu, T., Lopes, L., Lorenz, M., Maier, L., Mangiarotti, A., Markert, J., Metag, V., Michalska, B., Michel, J., Moriniere, E., Mousa, J., Muentz, C., Naumann, L., Otwinowski, J., Pachmayer, Y. C., Palka, M., Parpottas, Y., Pechenov, V., Pechenova, O., Pietraszko, J., Przygoda, W., Ramstein, B., Reshetin, A., Rustamov, A., Sadovsky, A., Salabura, P., Schmah, A., Schwab, E., Siebenson, J., Sobolev, Yu. G., Spataro, S., Spruck, B., Stroebele, H., Stroth, J., Sturm, C., Tarantola, A., Teilab, K., Tlusty, P., Traxler, M., Trebacz, R., Tsertos, H., Wagner, V., Weber, M., Wendisch, C., Wuestenfeld, J., Yurevich, S., and Zanevsky, Y. V.
Subjects: Nuclear Experiment
Abstract: We present results of an exclusive measurement of the first excited state of the Sigma hyperon, Sigma(1385)^+, produced in p+p -> Sigma^+ + K^+ + n at 3.5 GeV beam energy. The extracted data allow to study in detail the invariant mass distribution of the Sigma(1385)^+. The mass distribution is well described by a relativistic Breit-Wigner function with a maximum at m_0 = 1383.2 +- 0.9 MeV/c^2 and a width of 40.2 +- 2.1 MeV/c^2. The exclusive production cross-section comes out to be 22.27 +- 0.89 +- 1.56 +3.07 -2.10 mu b. Angular distributions of the Sigma(1385)^+ in different reference frames are found to be compatible with the hypothesis that 33 % of Sigma(1385)^+ result from the decay of an intermediate Delta^{++} resonance., Comment: 12 pages; 12 figures; submitted to PRC
Published: 2011
Full Text: View/download PDF

50. Polarization components in $\pi^{0}$ photoproduction at photon energies up to 5.6 GeV

Author: Luo, W., Brash, E. J., Gilman, R., Jones, M. K., Meziane, M., Pentchev, L., Perdrisat, C. F., Puckett, A. J. R., Punjabi, V., Wesselmann, F. R., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Ates, O., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, M. E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Kang, H., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Markowitz, P., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nuruzzaman, Nedev, S., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P. E., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Strakovsky, I. I., Subedi, R., Suleiman, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment
Abstract: We present new data for the polarization observables of the final state proton in the $^{1}H(\vec{\gamma},\vec{p})\pi^{0}$ reaction. These data can be used to test predictions based on hadron helicity conservation (HHC) and perturbative QCD (pQCD). These data have both small statistical and systematic uncertainties, and were obtained with beam energies between 1.8 and 5.6 GeV and for $\pi^{0}$ scattering angles larger than 75$^{\circ}$ in center-of-mass (c.m.) frame. The data extend the polarization measurements data base for neutral pion photoproduction up to $E_{\gamma}=5.6 GeV$. The results show non-zero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and $\pi^{0}$ scattering angle in c.m. frame. This indicates that HHC does not hold and that the pQCD limit is still not reached in the energy regime of this experiment., Comment: 6 pages and 2 figures
Published: 2011
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Database

Publisher

641 results on '"Zanevsky Y."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources