WorldWideScience

Sample records for antikaons

  1. Three-body antikaon-nucleon systems

    CERN Document Server

    Shevchenko, N V

    2016-01-01

    The paper contains a review of the exact or accurate results achieved in the field of the three-body antikaon-nucleon physics. Different states and processes in $\\bar{K}NN$ and $\\bar{K}\\bar{K}N$ systems are considered. In particular, quasi-bound states in $K^- pp$ and $K^- K^- p$ systems were investigated together with antikaonic deuterium atom. Near-threshold scattering of antikaons on deuteron, including $K^- d$ scattering length, and applications of the scattering amplitudes are also discussed. All exact three-body results were calculated using some form of Faddeev equations. Different versions of $\\bar{K}N$, $\\Sigma N$, $\\bar{K}\\bar{K}$, and $NN$ potentials, specially constructed for the calculations, allowed investigation of the dependence of the three-body results on two-body input. Special attention is paid to the antikaon-nucleon interaction, being the most important for the three-body systems. Additionally performed approximate calculations demonstrate accuracy of the commonly used approaches.

  2. Effects of Gravitational Correction on Neutron Stars with Antikaon Condensation

    Science.gov (United States)

    Wen-Bo, Ding; Jia-Wei, Hou; Zhan-Qiang, Qi; Shan-Shan, E.; Tmurbagan, Bao; Guang-Zhou, Liu; Zi, Yu; En-Guang, Zhao

    2016-06-01

    Effects of gravitational correction through the introduction of U bosons on neutron stars with antikaon condensation are studied in the relativistic mean held theory. How the global properties of neutron stars, redshift and the momentum of inertia are modified by gravitational correction and antikaon condensation are discussed here. Results show that antikaon condensation can occur at the core of pulsar PSR J1614-2230. Gravitational correction and antikaon condensation influence each other, and when coupling constant of U bosons and baryons becomes very high, effects of antikaon condensation almost vanish. Moreover, both the redshift and the momentum of inertia of neutron stars are sensitive to the constant of U bosons. Combining with observation data, we can provide a further constraint on coupling constant of U bosons. Supported by National Natural Science Foundation of China under Grant Nos. 11265009, 11271055, and 11175077, and General Project of Liaoning Provincial Department of Education under Grant No. L2015005

  3. Antikaons in infinite nuclear matter and nuclei

    International Nuclear Information System (INIS)

    In this work we studied the properties of antikaons and hyperons in infinite cold nuclear matter. The in-medium antikaon-nucleon scattering amplitude and self-energy has been calculated within a covariant many-body framework in the first part. Nuclear saturation effects have been taken into account in terms of scalar and vector nucleon mean-fields. In the second part of the work we introduced a non-local method for the description of kaonic atoms. The many-body approach of anti KN scattering can be tested by the application to kaonic atoms. A self-consistent and covariant many-body approach has been used for the determination of the antikaon spectral function and anti KN scattering amplitudes. It considers s-, p- and d-waves and the application of an in-medium projector algebra accounts for proper mixing of partial waves in the medium. The on-shell reduction scheme is also implemented by means of the projector algebra. The Bethe-Salpeter equation has been rewritten, so that the free-space anti KN scattering can be used as the interaction kernel for the in-medium scattering equation. The latter free-space scattering is based on a realistic coupled-channel dynamics and chiral SU(3) Lagrangian. Our many-body approach is generalized for the presence of large scalar and vector nucleon mean-fields. It is supplemented by an improved renormalization scheme, that systematically avoids the occurrence of medium-induced power-divergent structures and kinematical singularities. A modified projector basis has been introduced, that allows for a convenient inclusion of nucleon mean-fields. The description of the results in terms of the 'physical' basis is done with the help of a recoupling scheme based on the projector algebra properties. (orig.)

  4. Antikaon Condensation and In-medium Kaon and Antikaon Production in Protoneutron Stars

    Institute of Scientific and Technical Information of China (English)

    GU Jian-Fa; GUO Hua; LI Xi-Guo; LIU Yu-Xin; XU Fu-Rong

    2007-01-01

    Antikaon condensation and kaon and antikaon production in protoneutron stars are investigated in a chiral hadronic model (also referred to as the FST model in this paper). The effects of neutrino trapping on protoneutron stars are analyzed systematically. It is shown that neutrino trapping makes the critical density of K- condensation delay to higher density and Ko condensation not occur. The equation of state (EOS) of (proto)neutron star matter with neutrino trapping is stiffer than that without neutrino trapping. As a result, the maximum masses of (proto)neutron stars with neutrino trapping are larger than those without neutrino trapping. If hyperons are taken into account, antikaon does not form a condensate in (proto)neutron stars. Meanwhile, the corresponding EOS becomes much softer, and the maximum masses of (proto)neutron stars are smaller than those without hyprons. Finally, our results illustrate that the Q values for K+ and K- production in (proto)neutron stars are not sensitive to neutrino trapping and inclusion of hyperons.

  5. New computational methods for determining antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    Optical potential for antikaon-nucleus strong interactions are constructed using elementary antikaon-nucleus potentials determined previously. The optical potentials are used to determine the existence of a kaon hypernucleus. Modern three dimensional visualization techniques are used to study model dependences, new methods for speeding the calculation of the optical potential are developed, and previous approximation to avoid full Fermi averaging are eliminated. 19 refs., 21 figs., 3 tabs

  6. Antineutrino induced antikaon production off the nucleon

    CERN Document Server

    Alam, M Rafi; Athar, M Sajjad; Vacas, M J Vicente

    2011-01-01

    The charged current antikaon production off nucleons induced by antineutrinos is studied at low and intermediate energies. We extend here our previous calculation on kaon production induced by neutrinos. We have developed a microscopic model that starts from the SU(3) chiral Lagrangians and includes background terms and the resonant mechanisms associated to the lowest lying resonance in the channel, namely, the Sigma*(1385). Our results could be of interest for the background estimation of various neutrino oscillation experiments like MiniBooNE and SuperK. They can also be helpful for the planned antineutrino experiments like MINERvA, NOvA and T2K phase II and for beta-beam experiments with antineutrino energies around 1 GeV.

  7. Studies of antikaon interactions with nucleons at DAΦNE

    International Nuclear Information System (INIS)

    AMADEUS is an experiment planned to be performed at the DAFNE e+e- collider of the Frascati National Laboratories (Italy) of INFN, to investigate the antikaon-nuclei interaction at low energies. AMADEUS will perform, for the first time, full-acceptance studies of antikaon interaction in light nuclei, including a complete experimental program for the case of the kaonic clusters. The study of the absorption of antikaon by the nucleus will provide information concerning the K-barN interaction and the modification of the kaon mass in the nuclear medium.The experiment is being preceded by the study of the hadronic interactions of K- in the 4He of the drift chamber from the KLOE experiment data.

  8. Studies of antikaon interactions with nucleons at DAΦNE

    Science.gov (United States)

    Doce, O. Vazquez; Bazzi, M.; Berucci, C.; Bosnar, D.; Bragadireanu, M.; Cargnelli, M.; Clozza, A.; Curceanu, C.; Ghio, F.; Guaraldo, C.; Iliescu, M.; Ishiwatari, T.; Kienle, P.; Sandri, P. Levi; Marton, J.; Suzuki, K.; Okada, S.; Piscicchia, K.; Lener, M. Poli; Rizzo, A.; Vidal, A. Romero; Sbardella, E.; Scordo, A.; Sirghi, D. L.; Sirghi, F.; d'Uffizi, A.; Widmann, E.; Zmeskal, J.

    2011-10-01

    AMADEUS is an experiment planned to be performed at the DAFNE e+e- collider of the Frascati National Laboratories (Italy) of INFN, to investigate the antikaon-nuclei interaction at low energies. AMADEUS will perform, for the first time, full-acceptance studies of antikaon interaction in light nuclei, including a complete experimental program for the case of the kaonic clusters. The study of the absorption of antikaon by the nucleus will provide information concerning the K¯N interaction and the modification of the kaon mass in the nuclear medium. The experiment is being preceded by the study of the hadronic interactions of K- in the 4He of the drift chamber from the KLOE experiment data.

  9. Experimental studies of antikaon mediated bound nuclear systems

    International Nuclear Information System (INIS)

    Recent experimental studies of the synthesis and properties of deeply bound antikaon mediated nuclear systems are reviewed. Following a brief introduction in the basic properties of the antikaon–nucleon interaction which may lead to cold and dense antikaonic nuclear systems, we review the results of very first experiments which give indications of the existence of such exotic clusters of matter. Then ongoing efforts to substantiate the early findings are presented and future experimental approaches which will allow a very detailed study of the decay modes, the sizes and density distributions of these kaonic nuclear clusters are discussed including their relevance for possible phase transitions in cold dense matter. (author)

  10. Role of antikaon condensation in r-mode instability

    CERN Document Server

    Chatterjee, Debarati

    2007-01-01

    We investigate the effect of antikaon condensed matter on bulk viscosity in rotating neutron stars. We use relativistic field theoretical models to construct the equation of state of neutron stars with the condensate, where the phase transition from nucleonic to $K^-$ condensed phase is assumed to be of first order. We calculate the coefficient of bulk viscosity due to the non-leptonic weak interaction n --> p + K^-. The influence of antikaon bulk viscosity on the gravitational radiation reaction driven instability in the r-modes is investigated. We compare our results with the previously studied non-leptonic weak interaction $n + p --> p + \\Lambda$ involving hyperons on the damping of the r-mode oscillations. We find that the bulk viscosity coefficient due to the non-leptonic weak process involving the condensate is suppressed by several orders of magnitude in comparison with the non-superfluid hyperon bulk viscosity coefficient. Consequently, the antikaon bulk viscosity may not be able to damp the r-mode in...

  11. Low-energy Antikaon Interaction with Nuclei: The AMADEUS Challenge

    CERN Document Server

    Marton, Johann; Bellotti, Giovanni; Berucci, Carolina; Bosnar, Dimitri; Bragadireanu, Mario; Curceanu, Catalina; Clozza, Alberto; Cargnelli, Michael; Butt, Aslan; Del Grande, Raffaele; Fabbietti, Laura; Fiorini, Carlo; Ghio, Francesco; Guaraldo, Carlo; Iliescu, Mihai; Sandri, Paolo Levi; Pietreanu, Dorel; Piscicchia, Kristian; Vidal, Antonio Romero; Scordo, Alessandro; Shi, Hexi; Sirghi, Diana; Sirghi, Florin; Tucakovic, Ivana; Doce, Oton Vazquez; Widmann, Eberhard; Zmeskal, Johann

    2016-01-01

    The low-energy strong interaction of antikaons (K-) with nuclei has many facets and rep- resents a lively and challenging research ?eld. It is interconnected to the peculiar role of strangeness, since the strange quark is rather light, but still much heavier than the up and down quarks. Thus, when strangeness is involved one has to deal with spontaneous and explicit symmetry breaking in QCD. It is well known that the antikaon interaction with nucleons is attractive, but how strong ? Is the interaction strong enough to bind nucleons to form kaonic nuclei and, if so, what are the properties (binding energy, decay width)? There are controversial indications for such bound states and new results are expected to come soon. The existence of antikaon mediated bound states might have important consequences since it would open the possibility for the formation of cold baryonic matter of high density which might have a severe impact in astrophysics for the understanding of the composi- tion of compact (neutron) stars. ...

  12. Bose–Einstein condensation of anti-kaons and neutron star twins

    Indian Academy of Sciences (India)

    Sarmistha Banik; Debades Bandyopadhyay

    2003-05-01

    We investigate the role of Bose–Einstein condensation (BEC) of anti-kaons on the equation of state (EoS) and other properties of compact stars. In the framework of relativistic mean field model we determine the EoS for -stable hyperon matter and compare it to the situation when anti-kaons condense in the system. We observe that anti-kaon condensates soften the EoS, thereby lowering the maximum mass of the stars. We also demonstrate that the presence of antikaon condensates in the high density core of compact stars may lead to a new mass sequence beyond white dwarf and neutron stars. The limiting mass of the new sequence stars is nearly equal to that of neutron star branch though they have distinctly different radii and compositions. They are called neutron star twins.

  13. SIDDHARTA results and implications of the results on antikaon-nucleon interaction

    Science.gov (United States)

    Marton, J.; Bazzi, M.; Beer, G.; Berucci, C.; Bellotti, G.; Bosnar, D.; Bragadireanu, A. M.; Cargnelli, M.; Clozza, A.; Curceanu, C.; Butt, A. Dawood; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R.; Iliescu, M.; Iwasaki, M.; Sandri, P. Levi; Okada, S.; Pietreanu, D.; Piscicchia, K.; Vidal, A. Romero; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Doce, O. Vazquez; Widmann, E.; Zmeskal, J.

    2016-05-01

    The interaction of antikaons (K-) with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics. There are important open questions like the existence of antikaon nuclear bound states like the prototype system being K- pp. Unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states in light kaonic atoms like kaonic hydrogen and helium isotopes. In the SIDDHARTA experiment at the electron-positron collider DAΦNE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound K-p atom leading to energy shift and broadening of the 1s state. The SIDDHARTA result triggered new theoretical work, which achieved major progress in the understanding of the low-energy strong interaction with strangeness reflected by the antikaon-nucleon scattering lengths calculated with the K--proton amplitudes constrained by the SIDDHARTA data. The most important open question is the experimental determination of the hadronic energy shift and width of kaonic deuterium which is planned by the SIDDHARTA-2 Collaboration.

  14. Double antikaonic nuclear clusters in antiproton-{sup 3}He annihilation at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Fuminori, E-mail: sakuma@ribf.riken.jp [RIKEN, RIKEN Nishina Center (Japan); Curceanu, Catalina [Laboratori Nazionali di Frascati dell' INFN (Italy); Iwasaki, Masahiko [RIKEN, RIKEN Nishina Center (Japan); Kienle, Paul [Technische Universiat Munchen (Germany); Ohnishi, Hiroaki [RIKEN, RIKEN Nishina Center (Japan); Tokuda, Makoto [The University of Tokyo, Department of Physics (Japan); Tsukada, Kyo [Tohoku University, Department of Physics (Japan); Widmann, Eberhard [Stefan-Meyer-Institut fuer Subatomare Physik (Austria); Yamazaki, Toshimitsu [RIKEN, RIKEN Nishina Center (Japan); Zmeskal, Johannes [Stefan-Meyer-Institut fuer Subatomare Physik (Austria)

    2012-12-15

    We search for double anti-kaon nuclear bound states in the p-bar annihilation reaction in {sup 3}He nuclei at rest. In view of the strongly attractive K-bar N interaction, the existence of nuclear clusters with more than one K{sup }- has been predicted theoretically. The double anti-kaon production in elementary antiproton annihilation at rest is forbidden because of the negative Q-value; however, a double anti-kaon nuclear bound state, such as K{sup }- K{sup }- pp, with deep binding energy would enable double anti-kaon production in the nuclei. In order to investigate the K{sup }- K{sup }- pp production in the p-bar + {sup 3}He {yields} K{sup +} + K{sup 0} + X (X = K{sup -} K{sup -} pp) channel, the produced K{sup }- K{sup }- pp cluster is identified both using missing mass spectroscopy via the K{sup + }K{sup 0} channel with a {Lambda}-tag, and invariant mass analysis of the expected decay particles from the K{sup }- K{sup }- pp cluster such as {Lambda}{Lambda}. We propose to perform the experiment at the existing K1.8BR beam line at J-PARC with the E15 spectrometer.

  15. Double antikaonic nuclear clusters in antiproton-3He annihilation at J-PARC

    Science.gov (United States)

    Sakuma, Fuminori; Curceanu, Catalina; Iwasaki, Masahiko; Kienle, Paul; Ohnishi, Hiroaki; Tokuda, Makoto; Tsukada, Kyo; Widmann, Eberhard; Yamazaki, Toshimitsu; Zmeskal, Johannes

    We search for double anti-kaon nuclear bound states in the bar p annihilation reaction in 3He nuclei at rest. In view of the strongly attractive bar K N interaction, the existence of nuclear clusters with more than one K - has been predicted theoretically. The double anti-kaon production in elementary antiproton annihilation at rest is forbidden because of the negative Q-value; however, a double anti-kaon nuclear bound state, such as K - K - pp, with deep binding energy would enable double anti-kaon production in the nuclei. In order to investigate the K - K - pp production in the bar p + ^3He to K^+ + K^0 + X (X = K^-K^-pp) channel, the produced K - K - pp cluster is identified both using missing mass spectroscopy via the K + K 0 channel with a Λ-tag, and invariant mass analysis of the expected decay particles from the K - K - pp cluster such as ΛΛ. We propose to perform the experiment at the existing K1.8BR beam line at J-PARC with the E15 spectrometer.

  16. Statistical Production of Antikaon Nuclear Bound States in Heavy Ion Collisions

    CERN Document Server

    Andronic, A; Redlich, K

    2006-01-01

    Recently it was shown that the strongly attractive antikaon--nucleon potential can result in the formation of the antikaon nuclear bound states. We discuss the formation of such states as possible residues in heavy ion collisions. In this context, we calculate the excitation functions of single- and double-K- clusters in terms of the statistical thermal model. We show that, if such objects indeed exist, then, in heavy ion collisions, the single-K- clusters are most abundantly produced at present SIS energies, while the double-$K^-$ clusters show a pronounced maximum yield in the energy domain of the future accelerator at GSI. This is a direct consequence of: i) the baryonic dominance in low energy heavy ion collisions and the large baryonic content of the antikaonic bound states; ii) the strong energy dependence of strangeness production at low energies. The production yields of double-strange clusters is compared with that of double strange baryons. It is shown that at SIS energies there is a linear scaling ...

  17. The AMADEUS experiment - precision measurements of low-energy antikaon nucleus/nucleon interactions

    Science.gov (United States)

    Zmeskal, J.; Bazzi, M.; Bragadireanu, M.; Bühler, P.; Cargnelli, M.; Curceanu, C.; Ghio, F.; Guaraldo, C.; Iliescu, M.; Ishiwatari, T.; Kienle, P.; Levi Sandri, P.; Marton, J.; Müllner, P.; Suzuki, K.; Okada, S.; Pietreanu, D.; Poli Lener, M.; Rizzo, A.; Vazquez Doce, O.; Romero Vidal, A.; Scordo, A.; Sirghi, F.; Sirghi, D.; d'Ufizzi, A.; Widmann, E.; Wünschek, B.

    2010-04-01

    The planned series of measurements with AMADEUS will provide a high precision data set to study antikaon nucleus/nucleon dynamics at low energy. To achieve these goals AMADEUS will make use of the KLOE detector system at LNF, which is ideally suited for our measurements due to their large drift chamber with excellent charge particle tracking and identification probability. An almost 4 π calorimeter is available for the detection of neutral particles. R&D work has already started to construct a dedicated target and trigger system for further improvements on kaon stopping efficiency and background suppression.

  18. The AMADEUS experiment - precision measurements of low-energy antikaon nucleus/nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Zmeskal, J. [Stefan-Meyer-Institut, OAW, Vienna (Austria); Bazzi, M. [LNF-INFN, Frascati (Roma) (Italy); Bragadireanu, M. [IFIN-HH, Bucarest (Romania); Buehler, P.; Cargnelli, M. [Stefan-Meyer-Institut, OAW, Vienna (Austria); Curceanu, C. [LNF-INFN, Frascati (Roma) (Italy); Ghio, F. [Istituto Superiore di Sanita, Roma (Italy); Guaraldo, C.; Iliescu, M. [LNF-INFN, Frascati (Roma) (Italy); Ishiwatari, T. [Stefan-Meyer-Institut, OAW, Vienna (Austria); Kienle, P. [Stefan-Meyer-Institut, OAW, Vienna (Austria); TUM, Munich (Germany); Levi Sandri, P. [LNF-INFN, Frascati (Roma) (Italy); Marton, J.; Muellner, P.; Suzuki, K. [Stefan-Meyer-Institut, OAW, Vienna (Austria); Okada, S.; Pietreanu, D.; Poli Lener, M.; Rizzo, A.; Vazquez Doce, O. [LNF-INFN, Frascati (Roma) (Italy)] (and others)

    2010-04-01

    The planned series of measurements with AMADEUS will provide a high precision data set to study antikaon nucleus/nucleon dynamics at low energy. To achieve these goals AMADEUS will make use of the KLOE detector system at LNF, which is ideally suited for our measurements due to their large drift chamber with excellent charge particle tracking and identification probability. An almost 4{pi} calorimeter is available for the detection of neutral particles. R and D work has already started to construct a dedicated target and trigger system for further improvements on kaon stopping efficiency and background suppression.

  19. A relativistic effective model with parameterized couplings for neutron stars: the role of antikaon condensates

    International Nuclear Information System (INIS)

    We study the effects of antikaon condensates in neutron stars in the framework of a relativistic effective model with derivative couplings which includes genuine many-body forces simulated by nonlinear interaction terms involving scalar-isoscalar (σ, σ*), vector-isoscalar (ω, ϕ), vector-isovector (ϱ), scalar-isovector (δ) mesons. The effective model presented in this work has a philosophy quite similar to the original version of the model with parameterized couplings. But unlike that, in which the parametrization is directly inserted in the coupling constants of the Glendenning model, we present here a method for the derivation of the parametric dependence of the coupling terms, in a way that allows in one side to consistently justify this parametrization and in the other to extend in a coherent way the range of possibilities of parameterizations in effective models with derivative couplings. The extended model is then applied to the description of the mass of neutron stars. (author)

  20. Liquid 3He target for an experimental search for nuclear anti-kaon bound states in J-PARC

    International Nuclear Information System (INIS)

    A liquid 3He target system was successfully developed for experimental studies of the anti-kaon interaction with a nucleon at the J-PARC hadron facility. Pumped liquid 4He with the temperature of 1.4 K is used to condense gaseous 3He with a total volume of 400 L at atmospheric pressure and 21 deg C. A circulation of the liquid between a heat exchanger and a target cell works well for an effective heat transfer between them. The target system was stably operated in the first experiment at the K1.8BR beam line in May 2013. (author)

  1. Surprises in Threshold Antikaon-Nucleon Physics

    International Nuclear Information System (INIS)

    Low energy KN interactions are studied within unitary chiral perturbation theory at next-to-leading order with ten coupled channels. We pay special attention to the recent precise determination of the strong shift and width of the kaonic hydrogen 1s state by the DEAR Collaboration that has challenged our theoretical understanding of this sector of strong interactions. We typically find two classes of solutions, both of them reproducing previous data, that either can or cannot accommodate the DEAR measurements. The former class has not been previously discussed

  2. In-medium antikaon interactions and bound states

    CERN Document Server

    Gal, Avraham; Barnea, Nir; Cieplý, Aleš; Mareš, Jiří; Gazda, Daniel

    2014-01-01

    Correct treatment of subthreshold Kbar-N dynamics is mandatory in kaonic-atom and Kbar-nuclear bound-state calculations, as demonstrated by using in-medium chirally-based models of Kbar-N interactions. Recent studies of kaonic-atom data reveal appreciable multi-nucleon contributions. Kbar-nuclear widths larger than 50 MeV are anticipated.

  3. Antikaon induced Ξ production from a chiral model at NLO

    Directory of Open Access Journals (Sweden)

    Feijoo A.

    2014-01-01

    Full Text Available We study the meson-baryon interaction in the strangeness S = −1 sector using a chiral unitary approach, paying particular attention to the K̄N → KΞ reaction, especially important for constraining the next-to-leading order chiral terms, and considering also the effect of high spin hyperonic resonances. We also present results for the production of Ξ hyperons in nuclei

  4. A potential model investigation of the low-energy antikaon-nucleon interaction and antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    The parameters of separable coupled channels s-wave potentials for the strong /bar K/N interaction are determined from low energy K-p scattering data with additional constraints from π-p → πΣK0 production data. The shifts and widths of the Coulomb bound states in kaonic hydrogen are calculated with these potentials and compared with experiment. Optical potentials are constructed from /bar K/N t-matrices derived from the separable potentials, and these optical potentials are used to calculate kaonic helium and kaonic carbon shifts and widths which are also compared with experiment. 68 refs., 50 figs., 9 tabs

  5. Development of liquid helium-3 target for experimental studies of antikaon-nucleon interaction at J-PARC

    CERN Document Server

    Iio, M; Sato, M; Enomoto, S; Hashimoto, T; Suzuki, S; Iwasaki, M; Hayano, R S

    2012-01-01

    A liquid helium-3 target system was developed for experimental studies of kaonic atoms and kaonic nuclei at J-PARC. helium-3 gas is liquefied in a heat exchanger cooled below 3.2 K by decompression of liquid helium-4. To maintain a large acceptance of the cylindrical detector system for decay particles of kaonic nuclei, efficient heat transport between the separate target cell and the main unit is realized using circulation of liquid helium-3. To minimize the amount of material, a vacuum vessel containing a carbon fiber reinforced plastic cylinder having an inside diameter of 150 mm and a thickness of 1 mm was produced. A target cell made of pure beryllium and beryllium-aluminum alloy was developed not only to minimize the amount of material but to obtain also high x-ray transmission. During a cooling test, the target cell was kept at 1.3 K at a pressure of 33 mbar. The total estimated heat load to the components including the target cell and heat exchanger cooled by liquid helium-4 decompression, was 0.21 W,...

  6. Partial wave analyses of anti KN two-body reactions between 1480 and 2170 MeV

    International Nuclear Information System (INIS)

    Using a carefully selected set of the most recent antikaon nucleon data, energy dependent partial wave solutions to the reactions antikaon nucleon yields antikaon nucleon, antikaon nucleon yields Σ π and antikaon nucleon yields Λ π have been found. These partial waves parameterised as a sum of resonances and simple backgrounds fit the data well over the wide energy range 1480 to 2170 MeV. Consistent resonance structure has been obtained in the three channels, giving a better determination of the parameters of the established states, confirming several other states and providing evidence for two new states. With the condition of simple energy continuity and consistent resonance structure only one solution was found for each channel. (author)

  7. Theoretical studies in nuclear physics

    International Nuclear Information System (INIS)

    This report discusses: microscopic imaginary optical potential; isospin effects and charge exchange; multistep inelastic and charge exchange scattering; momentum space proton scattering; pion scattering from nuclei; antiproton studies; antikaons-nucleon interactions; and quantum mechanics. 11 refs

  8. The Amadeus project at Dafne

    OpenAIRE

    Curceanu, Catalina

    2007-01-01

    The change of the hadron masses and hadron interactions in the nuclear medium and the structure of cold dense hadronic matter are hot topics of hadron physics today. These important, yet unsolved, problems will be the research field of AMADEUS (Antikaonic Matter At DAFNE: Experiments with Unraveling Spectroscopy) - new experiment proposal at DAFNE accelerator at LNF-INFN. AMADEUS will search for antikaon-mediated deeply bound nuclear states produced in helium by stopping K- from DAFNE, both i...

  9. Kaonic atoms – studies of the strong interaction with strangeness

    Directory of Open Access Journals (Sweden)

    Marton J.

    2014-01-01

    Full Text Available The strong interaction of charged antikaons (K− with nucleons and nuclei in the low-energy regime is a fascinating topic. The antikaon plays a peculiar role in hadron physics due to the strong attraction antikaon-nucleon which is a key question for possible kaonic nuclear bound states. A rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions to low-lying states in light kaonic atoms like kaonic hydrogen and deuterium. After the successful completion of precision measurements on kaonic hydrogen and helium isotopes by SIDDHARTA at DAΦNE/LNF, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2. In the future with kaonic deuterium data the antikaon-nucleon isospin-dependent scattering lengths can be extracted for the first time. An overview of the experimental results of SIDDHARTA and an outlook to future perspectives in the SIDDHARTA2 experiments in this frontier research field will be given.

  10. Kaonic atoms - studies of the strong interaction with strangeness

    Science.gov (United States)

    Marton, J.; Bazzi, M.; Beer, G.; Berucci, C.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu, C.; d'Uffizi, A.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Levi Sandri, P.; Okada, S.; Pietreanu, D.; Ponta, T.; Quaglia, R.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Vazquez Doce, O.; Widmann, E.; Wünschek, B.; Zmeskal, J.

    2014-11-01

    The strong interaction of charged antikaons (K-) with nucleons and nuclei in the low-energy regime is a fascinating topic. The antikaon plays a peculiar role in hadron physics due to the strong attraction antikaon-nucleon which is a key question for possible kaonic nuclear bound states. A rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions to low-lying states in light kaonic atoms like kaonic hydrogen and deuterium. After the successful completion of precision measurements on kaonic hydrogen and helium isotopes by SIDDHARTA at DAΦNE/LNF, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2). In the future with kaonic deuterium data the antikaon-nucleon isospin-dependent scattering lengths can be extracted for the first time. An overview of the experimental results of SIDDHARTA and an outlook to future perspectives in the SIDDHARTA2 experiments in this frontier research field will be given.

  11. Chiral symmetry and strangeness at SIS energies

    International Nuclear Information System (INIS)

    In this talk we review the consequences of the chiral SU(3) symmetry for strangeness propagation in nuclear matter. Objects of crucial importance are the meson-baryon scattering amplitudes obtained within the chiral coupled-channel effective field theory. Results for antikaon and hyperon-resonance spectral functions in cold nuclear matter are presented and discussed. The importance of the Σ(1385) resonance for the subthreshold antikaon production in heavy-ion reaction at SIS is pointed out. The in-medium properties of the latter together with an antikaon spectral function based on chiral SU(3) dynamics suggest a significant enhancement of the π Λ → anti Κ N reaction in nuclear matter. (orig.)

  12. Kaon condensation and the nuclear equation of state

    International Nuclear Information System (INIS)

    We study the effects of phase transition in the equation of state of a neutron star containing a condensate of anti-kaons, using an effective model with derivative couplings. In our formalism, nucleons interact through the exchange of σ, ω, ϱ, and δ meson fields in the presence of electrons and muons to accomplish electric charge neutrality and beta equilibrium. The phase transition to the anti-kaons condensate was implemented through the Gibbs conditions combined with the mean-field approximation, giving rise to a mixed phase of coexistence between hadron matter and the condensed of anti-kaons. In conclusion, we have found that isovector meson degrees of freedom contribute to tighten the Equation of State of Neutron Stars. (author)

  13. Studies of the K-barN interaction at DAΦNE

    International Nuclear Information System (INIS)

    AMADEUS is an experiment planned to be performed at the DAΦNE e+e− collider of the Frascati National Laboratories (Italy) of INFN, to investigate the antikaon-nuclei interaction at low energies. AMADEUS will perform, for the first time, full-acceptance studies of antikaon interaction in light nuclei, including a complete experimental program for the case of the kaonic nuclear clusters. The study of the absorption of antikaon by the nucleus will provide information concerning the K-barN interaction and the modification of the kaon mass in the nuclear medium. The experiment is being preceded by the study of the hadronic interactions of K− in the 4He of the drift chamber from the KLOE experiment data.

  14. Studies of the K-barN interaction at DA{Phi}NE

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Doce, O., E-mail: oton.vazquezdoce@lnf.infn.it; Bazzi, M.; Berucci, C. [INFN, Laboratori Nazionali di Frascati (Italy); Bombelli, L. [Politechno di Milano, Sez. di Elettronica (Italy); Bragadireanu, A. M. [IFIN-HH (Romania); Cargnelli, M. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Clozza, A.; Curceanu Petrascu, C.; D' Uffizi, A. [INFN, Laboratori Nazionali di Frascati (Italy); Fiorini, C. [Politechno di Milano, Sez. di Elettronica (Italy); Ghio, F. [INFN Sez. di Roma I and Inst. Superiore di Sanita (Italy); Guaraldo, C.; Iliescu, M. [INFN, Laboratori Nazionali di Frascati (Italy); Ishiwatari, T. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Sandri, P. Levi [INFN, Laboratori Nazionali di Frascati (Italy); Longoni, A. [Politechno di Milano, Sez. di Elettronica (Italy); Marton, J. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Okada, S. [INFN, Laboratori Nazionali di Frascati (Italy); Pietreanu, D. [IFIN-HH (Romania); Piscicchia, K. [INFN, Laboratori Nazionali di Frascati (Italy); and others

    2012-05-15

    AMADEUS is an experiment planned to be performed at the DA{Phi}NE e{sup +}e{sup -} collider of the Frascati National Laboratories (Italy) of INFN, to investigate the antikaon-nuclei interaction at low energies. AMADEUS will perform, for the first time, full-acceptance studies of antikaon interaction in light nuclei, including a complete experimental program for the case of the kaonic nuclear clusters. The study of the absorption of antikaon by the nucleus will provide information concerning the K-barN interaction and the modification of the kaon mass in the nuclear medium. The experiment is being preceded by the study of the hadronic interactions of K{sup -} in the {sup 4}He of the drift chamber from the KLOE experiment data.

  15. Weak Strangeness and Eta Production

    CERN Document Server

    Alam, M Rafi; Alvarez-Ruso, Luis; Simo, I Ruiz; Vacas, M J Vicente; Singh, S K

    2013-01-01

    We have studied strange particle production off nucleons through $\\Delta S =0 $ and $|\\Delta S| = 1$ channels, and specifically single kaon/antikaon, eta, associated particle production for neutrino/antineutrino induced processes as well as antineutrino induced single hyperon production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangians. The basic parameters of the model are $f_\\pi$, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included $\\Sigma^*(1385)$ resonance and for eta production $S_{11}(1535)$ and $S_{11}(1650)$ resonances are included.

  16. The Amadeus project at Dafne

    CERN Document Server

    Curceanu, Catalina

    2007-01-01

    The change of the hadron masses and hadron interactions in the nuclear medium and the structure of cold dense hadronic matter are hot topics of hadron physics today. These important, yet unsolved, problems will be the research field of AMADEUS (Antikaonic Matter At DAFNE: Experiments with Unraveling Spectroscopy) - new experiment proposal at DAFNE accelerator at LNF-INFN. AMADEUS will search for antikaon-mediated deeply bound nuclear states produced in helium by stopping K- from DAFNE, both in the formation and in the decay processes.

  17. Three-body calculation of the 1s level shift in kaonic deuterium

    Czech Academy of Sciences Publication Activity Database

    Doleschall, P.; Revai, J.; Shevchenko, Nina V.

    2015-01-01

    Roč. 744, MAY (2015), s. 105-108. ISSN 0370-2693 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : few-body equations * mesonic atom * antikaon-nucleon interaction Subject RIV: BE - Theoretical Physics Impact factor: 6.131, year: 2014

  18. Strangeness in nuclear physics

    CERN Document Server

    Gal, A; Millener, D J

    2016-01-01

    Extensions of nuclear physics to the strange sector are reviewed, covering data and models of Lambda and other hypernuclei, multi-strange matter, and anti-kaon bound states and condensation. Past achievements are highlighted, present unresolved problems discussed, and future directions outlined.

  19. Strong interaction studies with kaonic atoms

    CERN Document Server

    Marton, J; Beer, G; Berucci, C; Bosnar, D; Bragadireanu, A M; Cargnelli, M; Clozza, A; Curceanu, C; d'Uffizi, A; Fiorini, C; Ghio, F; Guaraldo, C; Hayano, R; Iliescu, M; Ishiwatari, T; Iwasaki, M; Sandri, P Levi; Okada, S; Pietreanu, D; Piscicchia, K; Ponta, T; Quaglia, R; Vidal, A Romero; Sbardella, E; Scordo, A; Shi, H; Sirghi, D L; Sirghi, F; Tatsuno, H; Doce, O Vazquez; Widmann, E; Zmeskal, J

    2015-01-01

    The strong interaction of antikaons (K-) with nucleons and nuclei in the low energy regime represents an active research field connected intrinsically with few-body physics. There are important open questions like the question of antikaon nuclear bound states - the prototype system being K-pp. A unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states of light kaonic atoms like kaonic hydrogen isotopes. In the SIDDHARTA experiment at the electron-positron collider DA?NE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound K-p atom leading to a hadronic shift and a hadronic broadening of the 1s state. The SIDDHARTA result triggered new theoretical work which achieved major progress in the understanding of the low-energy strong interaction with strangeness. Antikaon-nucleon scattering le...

  20. Strong interaction studies with kaonic atoms

    CERN Document Server

    Marton, J; Beer, G; Berucci, C; Bosnar, D; Bragadireanu, A M; Cargnelli, M; Clozza, A; Curceanu, C; d'Uffizi, A; Fiorini, C; Ghio, F; Guaraldo, C; Hayano, R; Iliescu, M; Ishiwatari, T; Iwasaki, M; Sandri, P Levi; Okada, S; Pietreanu, D; Piscicchia, K; Ponta, T; Quaglia, R; Vidal, A Romero; Sbardella, E; Scordo, A; Shi, H; Sirghi, D L; Sirghi, F; Tatsuno, H; Doce, O Vazquez; Widmann, E; Zmeskal, J

    2016-01-01

    The strong interaction of antikaons with nucleons and nuclei in the low-energy regime represents an active research field connected intrinsically with few-body physics. There are important open questions like the question of antikaon nuclear bound states. A unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states of light kaonic atoms like kaonic hydrogen isotopes. In the SIDDHARTA experiment at the electron-positron collider DAFNE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound kaonic hydrogen atom leading to a hadronic shift and a hadronic broadening of the 1s state. The SIDDHARTA result triggered new theoretical work which achieved major progress in the understanding of the low-energy strong interaction with strangeness. Antikaon-nucleon scattering lengths have been calculated ...

  1. Hadrons in compact stars

    Indian Academy of Sciences (India)

    Debades Bandyopadhyay

    2006-05-01

    We discuss -equilibrated and charge neutral matter involving hyperons and $\\bar{K}$ condensates within relativistic models. It is observed that populations of baryons are strongly affected by the presence of antikaon condensates. Also, the equation of state including $\\bar{K}$ condensates becomes softer resulting in a smaller maximum mass neutron star.

  2. (K)0 Condensation in Hyperonic Neutron Star Matter

    Institute of Scientific and Technical Information of China (English)

    DING Wen-Bo; LIU Guang-Zhou; ZHU Ming-Feng; YU Zi; ZHAO En-Guang

    2008-01-01

    In the framework of the relativistic mean field theory,we investigate (K)0 condensation along with Kˉcondensation occur well in the core of the maximum mass stars for relatively shallow optical potentials of (K) in the range of-100 MeV~-160 MeV.With the increasing optical potential of (K),the critical densities of (K) decrease and the species of baryons appearing in neutron stars become fewer.The main role of (K)0 condensation is to make the abundances of particles become identical leading to isospin saturated symmetric matter including antikaons,state,which leads to a large reduction in the maximum masses of neutron stars.In the core of massive neutron stars,neutron star matter including rich particle species,such as antikaons,nucleons and hyperons,may exist.

  3. Weak Production of Strange Particles and $\\eta$ Mesons off the Nucleon

    CERN Document Server

    Alam, M Rafi; Alvarez-Ruso, L; Athar, M Sajjad; Vacas, M J Vicente

    2015-01-01

    The strange particle production induced by (anti)neutrino off nucleon has been studied for $|\\Delta S|=0$ and $|\\Delta S|=1$ channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are $f_\\pi$, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included $\\Sigma^*$(1385) resonance and for eta production $S_{11}$(1535) and $S_{11}$(1650) resonances are included.

  4. Weak production of strange particles and η mesons off the nucleon

    International Nuclear Information System (INIS)

    The strange particle production induced by (anti)neutrino off nucleon has been studied for |ΔS| = 0 and |ΔS| = 1 channels. The reactions those we have considered are for the production of single kaon/antikaon, eta and associated particle production processes. We have developed a microscopical model based on the SU(3) chiral Lagrangian. The basic parameters of the model are fπ, the pion decay constant, Cabibbo angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet. For antikaon production we have also included Σ*(1385) resonance and for eta production S11(1535) and S11(1650) resonances are included

  5. Low-energy kaon-nucleon/nuclei interaction studies at DAΦNE by AMADEUS

    Science.gov (United States)

    Tucaković, Ivana; Bazzi, M.; Berucci, C.; Bosnar, D.; Bragadireanu, A. M.; Cargnelli, M.; Clozza, A.; Curceanu, C.; D'Uffizi, A.; Fabbietti, L.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Iliescu, M.; Ishiwatari, T.; Levi Sandri, P.; Marton, J.; Pietreanu, D.; Piscicchia, K.; Poli Lener, M.; Quaglia, R.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Vazquez Doce, O.; Widmann, E.; Zmeskal, J.

    2015-05-01

    The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN, fundamental to respond to longstanding open questions in the non-perturbative QCD in the strangeness sector. One of the most interesting aspects is to understand how hadron masses and interactions change in the nuclear environment. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would imply a strongly attractive antikaon-nucleon potential. AMADEUS step 0 consists in the analysis of 2004/2005 KLOE data, exploring K- absorptions in H, 4He, 9Be and 12C present in setup materials. The status of the various preliminary analyses is presented, together with future perspectives.

  6. Low-energy kaon-nucleon/nuclei interaction studies at DAΦNE by AMADEUS

    Directory of Open Access Journals (Sweden)

    Tucaković Ivana

    2015-01-01

    Full Text Available The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN, fundamental to respond to longstanding open questions in the non-perturbative QCD in the strangeness sector. One of the most interesting aspects is to understand how hadron masses and interactions change in the nuclear environment. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would imply a strongly attractive antikaon-nucleon potential. AMADEUS step 0 consists in the analysis of 2004/2005 KLOE data, exploring K− absorptions in H, 4He, 9Be and 12C present in setup materials. The status of the various preliminary analyses is presented, together with future perspectives.

  7. Chiral unitary theory: Application to nuclear problems

    Indian Academy of Sciences (India)

    E Oset; D Cabrera; H C Chiang; C Garcia Recio; S Hirenzaki; S S Kamalov; J Nieves; Y Okumura; A Ramos; H Toki; M J Vicente Vacas

    2001-08-01

    In this talk we briefly describe some basic elements of chiral perturbation theory, , and how the implementation of unitarity and other novel elements lead to a better expansion of the -matrix for meson–meson and meson–baryon interactions. Applications are then done to the interaction in nuclear matter in the scalar and vector channels, antikaons in nuclei and - atoms, and how the meson properties are changed in a nuclear medium.

  8. Strong interaction studies with kaonic atoms

    Directory of Open Access Journals (Sweden)

    Marton J.

    2016-01-01

    Full Text Available The strong interaction of antikaons (K− with nucleons and nuclei in the low-energy regime represents an active research field connected intrinsically with few-body physics. There are important open questions like the question of antikaon nuclear bound states - the prototype system being K−pp. A unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states of light kaonic atoms like kaonic hydrogen isotopes. In the SIDDHARTA experiment at the electron-positron collider DAΦNE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound K−p atom leading to a hadronic shift ϵ1s and a hadronic broadening Γ1s of the 1s state. The SIDDHARTA result triggered new theoretical work which achieved major progress in the understanding of the low-energy strong interaction with strangeness. Antikaon-nucleon scattering lengths have been calculated constrained by the SIDDHARTA data on kaonic hydrogen. For the extraction of the isospin-dependent scattering lengths a measurement of the hadronic shift and width of kaonic deuterium is necessary. Therefore, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2. Many improvements in the experimental setup will allow to measure kaonic deuterium which is challenging due to the anticipated low X-ray yield. Especially important are the data on the X-ray yields of kaonic deuterium extracted from a exploratory experiment within SIDDHARTA.

  9. Strong interaction studies with kaonic atoms

    Science.gov (United States)

    Marton, J.; Bazzi, M.; Beer, G.; Berucci, C.; Bosnar, D.; Bragadireanu, A. M.; Cargnelli, M.; Clozza, A.; Curceanu, C.; d'Uffizi, A.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Levi Sandri, P.; Okada, S.; Pietreanu, D.; Piscicchia, K.; Ponta, T.; Quaglia, R.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Vazquez Doce, O.; Widmann, E.; Zmeskal, J.

    2016-03-01

    The strong interaction of antikaons (K-) with nucleons and nuclei in the low-energy regime represents an active research field connected intrinsically with few-body physics. There are important open questions like the question of antikaon nuclear bound states - the prototype system being K-pp. A unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states of light kaonic atoms like kaonic hydrogen isotopes. In the SIDDHARTA experiment at the electron-positron collider DAΦNE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound K-p atom leading to a hadronic shift ɛ1s and a hadronic broadening Γ1s of the 1s state. The SIDDHARTA result triggered new theoretical work which achieved major progress in the understanding of the low-energy strong interaction with strangeness. Antikaon-nucleon scattering lengths have been calculated constrained by the SIDDHARTA data on kaonic hydrogen. For the extraction of the isospin-dependent scattering lengths a measurement of the hadronic shift and width of kaonic deuterium is necessary. Therefore, new X-ray studies with the focus on kaonic deuterium are in preparation (SIDDHARTA2). Many improvements in the experimental setup will allow to measure kaonic deuterium which is challenging due to the anticipated low X-ray yield. Especially important are the data on the X-ray yields of kaonic deuterium extracted from a exploratory experiment within SIDDHARTA.

  10. Kaon production at finite temperature and baryon density in an effective relativistic mean field model

    International Nuclear Information System (INIS)

    We investigate the kaon production at finite temperature and baryon density by means of an effective relativistic mean-field model with the inclusion of the full octet of baryons. Kaons are considered taking into account of an effective chemical potential depending on the self-consistent interaction between baryons. The obtained results are compared with a minimal coupling scheme, calculated for different values of the anti-kaon optical potential.

  11. Measurement of the Strong Interaction Induced Shift and Width of the 1s State of Kaonic Deuterium at J-PARC

    Science.gov (United States)

    Zmeskal, J.; Sato, M.; Ajimura, S.; Bazzi, M.; Beer, G.; Berucci, C.; Bhang, H.; Bosnar, D.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Clozza, A.; Curceanu, C.; D'Uffizi, A.; Enomoto, S.; Fabbietti, L.; Faso, D.; Fiorini, C.; Fujioka, H.; Ghio, F.; Golser, R.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kawasaki, S.; Lachner, J.; Levi Sandri, P.; Ma, Y.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Moskal, P.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Pietreanu, D.; Piscicchia, K.; Poli Lener, M.; Romero Vidal, A.; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sbardella, E.; Scordo, A.; Sekimoto, M.; Shi, H.; Silarski, M.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tanida, K.; Tatsuno, H.; Tokuda, M.; Toyoda, A.; Tucakovic, I.; Tsukada, K.; Vazquez Doce, O.; Widmann, E.; Yamaga, T.; Yamazaki, T.; Zhang, Q.

    The antikaon-nucleon interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context the importance of kaonic deuterium X-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. We propose to measure the shift and width of the kaonic deuterium 1s state with an accuracy of 60 eV and 140 eV respectively at J-PARC. These results together with the kaonic hydrogen data (KpX at KEK, DEAR and SIDDHARTA at DAFNE) will then permit the determination of values of both the isospin I=0 and I=1 antikaon-nucleon scattering lengths and will provide the most stringent constraints on the antikaon-nucleon interaction, promising a breakthrough. Refined Monte Carlo studies were performed, including the investigation of background suppression factors for the described setup. These studies have demonstrated the feasibility of determining the shift and width of the kaonic deuterium atom 1s state with the desired accuracy of 60 eV and 140 eV.

  12. Measurement of the strong interaction induced shift and width of the 1s state of kaonic deuterium at J-PARC

    CERN Document Server

    Zmeskal, J; Ajimura, S; Bazzi, M; Beer, G; Berucci, C; Bhang, H; Bosnar, D; Bragadireanu, M; Buehler, P; Busso, L; Cargnelli, M; Choi, S; Clozza, A; Curceanu, C; D'uffizi, A; Enomoto, S; Fabbietti, L; Faso, D; Fiorini, C; Fujioka, H; Ghio, F; Golser, R; Guaraldo, C; Hashimoto, T; Hayano, R S; Hiraiwa, T; Iio, M; Iliescu, M; Inoue, K; Ishimoto, S; Ishiwatari, T; Itahashi, K; Iwai, M; Iwasaki, M; Kawasaki, S; Lachner, J; Sandri, P Levi; Ma, Y; Marton, J; Matsuda, Y; Mizoi, Y; Morra, O; Moskal, P; Nagae, T; Noumi, H; Ohnishi, H; Okada, S; Outa, H; Pietreanu, D; Piscicchia, K; Lener, M Poli; Vidal, A Romero; Sada, Y; Sakaguchi, A; Sakuma, F; Sbardella, E; Scordo, A; Sekimoto, M; Shi, H; Silarski, M; Sirghi, D; Sirghi, F; Suzuki, K; Suzuki, S; Suzuki, T; Tanida, K; Tatsuno, H; Tokuda, M; Toyoda, A; Tucakovic, I; Tsukada, K; Doce, O Vazquez; Widmann, E; Yamaga, T; Yamazaki, T; Zhang, Q

    2015-01-01

    The antikaon-nucleon interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context the importance of kaonic deuterium X-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. We propose to measure the shift and width of the kaonic deuterium 1s state with an accuracy of 60 eV and 140 eV respectively at J-PARC. These results together with the kaonic hydrogen data (KpX at KEK, DEAR and SIDDHARTA at DAFNE) will then permit the determination of values of both the isospin I=0 and I=1 antikaon-nucleon scattering lengths and will provide the most stringent constraints on the antikaon-nucleon interaction, promising a breakthrough. Refined Monte Carlo studies were performed, including the investigation of background suppression factors for the described setup. These studies have demonstrated the feasibility of determining the shift a...

  13. Double dissociation in the reaction K-p→K-π+π-Nπ+ at 14.3GeV/c and pomeron factorisation

    International Nuclear Information System (INIS)

    Evidence for the double dissociation process K-p→QN*1/2→(antikaon neutral* π-) (nπ+) at 14.3GeV/c is presented. The cross section for this process is of the order of 10μb. The production differential cross section is steep, as typical of diffractive processes, and exhibits a strong correlation between the production slope and the dissociation system mass. The mass variation of the differential cross section slope and the total cross section of the double dissociation component are consistent with the factorisable Pomeron exchange model predictions

  14. Covariant meson-baryon scattering with chiral and large Nc constraints

    International Nuclear Information System (INIS)

    We give a review of recent progress on the application of the relativistic chiral SU(3) Lagrangian to meson-baryon scattering. It is shown that a combined chiral and 1/Nc expansion of the Bethe-Salpeter interaction kernel leads to a good description of the kaon-nucleon, antikaon-nucleon and pion-nucleon scattering data typically up to laboratory momenta of plab ≅ 500 MeV. We solve the covariant coupled channel Bethe-Salpeter equation with the interaction kernel truncated to chiral order Q3 where we include only those terms which are leading in the large Nc limit of QCD. (orig.)

  15. Diomega production in relativistic heavy ion collisions

    OpenAIRE

    Pal, Subrata; Ko, C. M.; Zhang, Z. Y.

    2001-01-01

    Using a multiphase transport model, we study the production of a new strange dibaryon (\\Omega\\Omega)_{0+} in dense hadronic matter formed in relativistic heavy ion collisions. The (multi-)strange baryons (\\Xi and \\Omega) are produced by strangeness-exchange reactions between antikaons and hyperons in the pure hadronic phase. The rescattering between the omegas at midrapidity leads to a production probability of \\simeq 3x10^{-7} (\\Omega\\Omega)_{0+} per event at the RHIC energy of \\sqrt s=130A ...

  16. Proton-proton collisions at production thresholds

    OpenAIRE

    Moskal, P.; Adam, H. -H.; Budzanowski, A.; Grzonka, D.; Jarczyk, L.; Khoukaz, A.; Kilian, K.; Koehler, M; Kowina, P.; Lang, N.; Lister, T.; Oelert, W.; Quentmeier, C.; Santo, R.; Schepers, G.

    2000-01-01

    Recent results obtained by the COSY-11 collaboration concerning the production of eta and eta' mesons in the pp --> pp Meson reaction are presented. A comparison of the production amplitude for the pi(0), eta and eta' mesons at the same phase space volume allows to conclude that the proton-eta' interaction is in the order of, or smaller than, the proton-pi(0) one. A total cross section determined in a preliminary analysis of the data of elementary kaon and antikaon production via the pp-->ppK...

  17. New boundaries for the “ppK−” production in p+p collisions

    Directory of Open Access Journals (Sweden)

    Epple Eliane

    2014-01-01

    Full Text Available The HADES collaboration has searched for the anti-kaonic nuclear cluster “ppK−” in p+p collisions by its decay into pΛ. In the course of this analysis several cross checks had to be performed. This report discusses two examples thereof. In one test it was checked whether the presence of background events could introduce a bias on the applied partial wave analysis. The second item discussed here is the extraction of the total pK+Λ production cross section necessary to derive the absolute upper limit on the “ppK−” production cross section.

  18. Chiral dynamics, structure of Λ(1405), and K¯N phenomenology

    International Nuclear Information System (INIS)

    We investigate the structure of the Λ(1405) resonance and K¯N phenomenology in the perspective of chiral SU(3) dynamics. Utilizing the chiral coupled-channel approach which well describes the K¯N scattering observable, we perform three different analyses to clarify the structure of the Λ(1405) resonance. The results consistently indicate the meson-baryon molecule picture of the Λ(1405). We argue the consequence of the chiral dynamics in K¯N phenomenology and the antikaon bound state in nucleus, emphasizing the important role of the strong πΣ interaction. (author)

  19. Monte Carlo simulation for Kaonic deuterium studies

    International Nuclear Information System (INIS)

    Full text: The SIDDHARTA experiment at the DAFNE collider measured the shift and with of the ground level in kaonic hydrogen caused by the strong interaction between the kaons and protons. The measurement of the X-ray transitions to the 1s level in kaonic deuterium will allow, together with the available results from kaonic hydrogen, to extract the isospin- dependent antikaon-nucleon scattering lengths. I will present the Monte Carlo simulation of the SIDDHARTA-2 setup, in the framework of GEANT4. The program is used to optimize the critical parameters of the setup in order to perform the kaonic deuterium measurement. (author)

  20. Silicon drift detectors for hadronic atom research - SIDDHARTA

    International Nuclear Information System (INIS)

    The development of triggerable large area silicon drift detectors for the spectroscopy of soft x-rays will provide us means for a new experimental program at the DAΦNE facility of LNF to measure x-ray transitions in kaonic deuterium and helium. These transitions are sensitive to the low energy antikaon-nucleon interaction. The new technique will improve the suppression of background by more than 2 orders of magnitude, and thus allow to measure kaonic deuterium x-rays for the first time ever

  1. In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions

    Science.gov (United States)

    Feng, Zhao-Qing; Xie, Wen-Jie; Chen, Peng-Hui; Chen, Jie; Jin, Gen-Ming

    2015-10-01

    Dynamics of pseudoscalar mesons (π ,η ,K , and K ¯) and hyperons (Λ and Σ ) produced in heavy-ion collisions near threshold energies has been investigated within the Lanzhou quantum molecular dynamics transport model. The in-medium modifications on particle production in dense nuclear matter are implemented in the model through corrections on the elementary cross sections and by inclusion of the meson-nucleon (or hyperon-nucleon) potentials, in which the isospin effects are considered. It is found that the transportation of particles are influenced with the in-medium corrections. The total number of pions is reduced with an isospin-, density-, and momentum-dependent pion-nucleon potential. However, the ratios of charged pions is enhanced with inclusion of the potential. The production of eta in the domain of midrapidities and high momenta is sensitive to the η -nucleon potential but weakly depends on symmetry energy. The attractive antikaon-nucleon potential enhances the subthreshold K ¯ production and also influences the structure of phase-space distributions. The dynamics of etas, kaons, antikaons, and hyperons is also influenced by the pion potential because of collisions between pions and nucleons (resonances). The impacts of mean-field potentials on particle dynamics are investigated, such as the phase-space distributions from rapidity and transverse momentum spectra, inclusive invariant spectra, collective flows, etc.

  2. Kaonic atoms studies at DAFNE by the SIDDHARTA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cargnelli, M. [Stefan Meyer Institut of the Austrian Academy od Sciences, Vienna, 1090, Boltzmanngasse 3 (Austria); Bazzi, M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Beer, G. [Dep. of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria B.C. Canada V8W3P6 (Canada); Bombelli, L. [Politecnico di Milano, Dip. di Elettronica e Informazione, Via Ponzio, 34/5, I-20133 Milano (Italy); Bragadireanu, A.M.; Curceanu Petrascu, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Fiorini, C.; Frizzi, T. [Politecnico di Milano, Dip. di Elettronica e Informazione, Via Ponzio, 34/5, I-20133 Milano (Italy); Ghio, F.; Girolami, B. [INFN Sez. di Roma I and Instituto Superiore di Sanita I-00161, Roma (Italy); Guaraldo, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Hayano, R. [University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo (Japan); Iliescu, M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Ishiwatari, T. [Stefan Meyer Institut of the Austrian Academy od Sciences, Vienna, 1090, Boltzmanngasse 3 (Austria); Iwasaki, M. [RIKEN, Institute of Physical and Chemical Research, Saitama (Japan); Kienle, P. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Physik Departement, Technische Universitaet Muenchen, Garching (Germany); Lechner, P. [PNSensors GmbH, Roennerstr. 28, D-80803 Muenchen (Germany); Levi Sandri, P. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Longoni, A. [Politecnico di Milano, Dip. di Elettronica e Informazione, Via Ponzio, 34/5, I-20133 Milano (Italy); Lucherini, V. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy)] (and others)

    2010-04-01

    The K-barN system at rest makes a sensitive testing ground for chiral SU(3) symmetry in QCD, especially for the explicit symmetry breaking induced by the relatively large mass of the strange quark. At the DA{phi}NE electron-positron collider of Laboratori Nazionali di Frascati we study kaonic atoms, taking advantage of the low-energy kaons from {phi}-mesons decaying nearly at rest. The low-energy antikaon-nucleon interaction in kaonic hydrogen and kaonic deuterium can be investigated under favorable conditions. The DEAR (DA{phi}NE Exotic Atom Research) experiment at LNF delivered the most precise data on kaonic hydrogen up to now. DEAR and its follow-up experiment SIDDHARTA (Silicon Drift Detector for Hadronic Atom Research by Timing Application) are using X-ray spectroscopy of kaonic atoms to measure the strong interaction induced shift and width of the ground state. SIDDHARTA is the first experiment on kaonic deuterium ever, and kaonic hydrogen is remeasured with improved precision. From the shift and width in K{sup -}p and K{sup -}d the isospin-dependent antikaon-nucleon scattering lengths can be determined, quantities essential as constraints for low-energy QCD.

  3. X-ray spectroscopy of light kaonic atoms – new results and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Marton, J. [Stefan-Meyer-Institut für subatomare Physik, Boltzmanngasse 3, 1090 Wien (Austria); Bazzi, M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Beer, G. [Dep. of Physics and Astronomy, University of Victoria, P.O.Box 3055, Victoria B.C. Canada V8W3P6 (Canada); Berucci, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Bombelli, L. [Politecnico di Milano, Dip. di Elettronica e Informazione, Piazza L. da Vinci, 32 I-20133 Milano (Italy); Bragadireanu, A.M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); IFIN-HH, P.O. box MG-6, R76900 Magurele, Bucharest (Romania); Cargnelli, M. [Stefan-Meyer-Institut für subatomare Physik, Boltzmanngasse 3, 1090 Wien (Austria); Curceanu, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); D' Uffizi, A.; Fiorini, C.; Frizzi, T. [Politecnico di Milano, Dip. di Elettronica e Informazione, Piazza L. da Vinci, 32 I-20133 Milano (Italy); Ghio, F. [INFN Sez. di Roma I and Instituto Superiore di Sanita I-00161, Roma (Italy); Guaraldo, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Hayano, R. [University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo (Japan); Iliescu, M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Roma) (Italy); Ishiwatari, T. [Stefan-Meyer-Institut für subatomare Physik, Boltzmanngasse 3, 1090 Wien (Austria); Iwasaki, M. [RIKEN, Institute of Physical and Chemical Research, Saitama (Japan); and others

    2012-12-15

    The antikaon interaction on nucleons and nuclei in the low-energy regime is neither simple nor well understood. Rather direct access to this field is provided by x-ray spectroscopy of light kaonic atoms like kaonic hydrogen, deuterium and helium isotopes. A series of precision measurements on kaonic atoms was performed very successfully by the SIDDHARTA Collaboration at the DAΦNE electron-positron collider at LNF-INFN (Frascati, Italy). Consequently, new precision data on the strong interaction observables (i.e. energy shift and broadening of low-lying atomic states) were delivered having an important impact on the theory of low-energy QCD with strangeness. Presently, the follow-up experiment, SIDDHARTA-2, is in preparation, aiming at a determination of the strong interaction observables in kaonic deuterium as the highest priority; other type of measurements (light and heavier kaonic atoms) are as well foreseen. With the kaonic deuterium data the antikaon-nucleon isospin-resolved scattering lengths can be extracted for the first time. An overview of the progress and present status of experimental studies and an outlook to future perspectives in this fascinating research field is given.

  4. Non-resonant kaon pair production and medium effects in proton-nucleus collisions

    CERN Document Server

    Paryev, E Ya; Kiselev, Yu T

    2015-01-01

    We study the non-resonant (non-$\\phi$) production of $K^+K^-$ pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets within the collision model, based on the nuclear spectral function, for incoherent primary proton--nucleon and secondary pion--nucleon creation processes. The model takes into account the initial proton and final kaon absorption, target nucleon binding and Fermi motion as well as nuclear mean-field potential effects on these processes. We calculate the antikaon momentum dependences of the exclusive absolute and relative $K^+K^-$ pair yields in the acceptance window of the ANKE magnetic spectrometer, used in a recent experiment performed at COSY, within the different scenarios for the antikaon-nucleus optical potential. We demonstrate that the above observables are strongly sensitive to this potential. Therefore, they can be useful to help determine the $K^-$ optical potential from the direct comparison of the results of our calculations with the data from the respective ANKE-a...

  5. Azimuthal angular distributions of K+ and K- mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV

    International Nuclear Information System (INIS)

    The Kaon-Spectrometer (KaoS) at the heavy-ion synchrotron (SIS) at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt has been used to study production and propagation of K+ and K- mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV. The azimuthal angular distributions of particles as a function of the collision centrality and particle transverse momenta have been measured. We found a dependence of the K- meson azimuthal emission pattern on the transverse momentum. The antikaons registered with ptt > 0.5 GeV/c show strong out-of-plane enhancement. The emission patterns of K- can be explained in terms of two competing phenomena: one of them is indeed the influence of the attractive K-N potential, however, the second one originates from the strangeness-exchange process. (orig.)

  6. Fast Equilibration of Hadrons in an Expanding Fireball

    CERN Document Server

    Noronha-Hostler, J; Shovkovy, I A

    2007-01-01

    Due to long chemical equilibration times within standard hadronic reactions during the hadron gas phase in relativistic heavy ion collisions it has been suggested that the hadrons are "born" into equilibrium after the quark gluon plasma phase. Here we develop a dynamical scheme in which possible Hagedorn states contribute to fast chemical equilibration times of baryon anti-baryon pairs (as well as kaon anti-kaon pairs) inside a hadron gas and just below the critical temperature. Within this scheme, we use master equations and derive various analytical estimates for the chemical equilibration times. Applying a Bjorken picture to the expanding fireball, the kaons and baryons as well as the bath of pions and Hagedorn resonances can indeed quickly chemically equilibrate for both an initial overpopulation or underpopulation of Hagedorn resonances. Moreover, a comparison of our results to $(B+\\bar{B})/\\pi^{+}$ and $K/\\pi^{+}$ ratios at RHIC, indeed, shows a close match.

  7. The DEAR experiment-first results on kaonic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Zmeskal, J. [Stefan Meyer Insitut fuer subatomare Physik, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria)]. E-mail: johann.zmeskal@oeaw.ac.at; Beer, G. [University of Victoria, Department of Physics and Astronomy, P.O. Box 3055 Victoria, BC V8W 3P6 (Canada); Bragadirean, A.M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Institute of Physics and Nuclear Engineering ' Horia Hulubei' , P.O. Box R-76900 Magurele, Bucharest (Romania); Cargnelli, M. [Stefan Meyer Insitut fuer subatomare Physik, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Curceanu, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Institute of Physics and Nuclear Engineering ' Horia Hulubei' , P.O. Box R-76900 Magurele, Bucharest (Romania); Egger, J.-P. [University de Neuchatel, Institute de Physique, Universite de Neuchatel, 1 rue A.-L. Breguet, CH-2000 Neuchatel (Switzerland); Fuhrmann, H. [Stefan Meyer Insitut fuer subatomare Physik, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Guaraldo, C. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Iliescu, M. [INFN, Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Institute of Physics and Nuclear Engineering ' Horia Hulubei' , P.O. Box R-76900 Magurele, Bucharest (Romania); Ishiwatari, T. [Stefan Meyer Insitut fuer subatomare Physik, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Itahashi, K. [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-01 (Japan); Iwasaki, M. [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-01 (Japan); Kienle, P. [Stefan Meyer Insitut fuer subatomare Physik, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria)] [and others

    2005-05-30

    The goal of the DEAR (DA{phi}NE exotic atom research) experiment is the precise determination of the isospin dependent antikaon-nucleon scattering lengths. The experiment accurately measures the K{alpha} line shift and broadening, due to the strong interaction, in kaonic hydrogen and, for the first time, in kaonic deuterium. A precision measurement of kaonic hydrogen tests chiral symmetry breaking in systems with strangeness. An initial analysis of the DEAR experiment yields a shift -bar 1s=-195+/-45 eV and a width {gamma}1s=250+/-125 eV, which is more precise than the previous kaonic X-ray experiment KpX at KEK, and allows for the first time to disentangle the full pattern of the kaonic hydrogen K-series line K{alpha}, K{beta} and K{gamma}.

  8. Joint annual report 1984

    International Nuclear Information System (INIS)

    An account is given on the activities in nuclear and solid state physcis. In the field of relativistic nuclear physcis first measurements at the Synchrophasotron of the JINR Dubna are presented. Nuclear reactions with heavy ions have been investigated at the cyclotron U-300 of the JINR. Studies of few-nucleon problems and measurements of fission cross sections at the tandem accelerator at Rossendorf have been continued. High spin states in transition nuclei (A approximately 80) and semimagic nuclei have been studied. Works in nuclear theory comprise heavy ion physics, plasma transitions in hot nuclear matter, antikaon production, hypernuclei and deformed nuclei, the time-dependent Hartree-Fock method, meson exchange, and new aspects of shell models. Various studies in solid state physics are presented, including the following: high-dose implantation in metals and semiconductors, tempering in semiconductor materials, light pulse annealing in Si, neutron diffraction in texture analysis, application of Si in the field of sensor technology

  9. Antinucleon-nucleus interaction near threshold from the Paris $\\bar NN$ potential

    CERN Document Server

    Friedman, E; Loiseau, B; Wycech, S

    2015-01-01

    A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interaction with nuclei up to 400~MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying $\\bar pN$ scattering amplitudes are derived from the Paris $\\bar NN$ potential, including modifications in the medium. Emphasis is placed on the role of the $P$-wave amplitudes with respect to the repulsive $S$-wave amplitudes.

  10. Nuclear dynamics induced by antiprotons

    CERN Document Server

    Feng, Zhao-Qing

    2015-01-01

    Reaction dynamics in collisions of antiprotons on nuclei is investigated within the Lanzhou quantum molecular dynamics model. The reaction channels of elastic scattering, annihilation, charge exchange and inelastic collisions of antiprotons on nucleons have been included in the model. Dynamics on particle production, in particular pions, kaons, antikaons and hyperons, is investigated in collisions of $\\overline{p}$ on $^{12}$C, $^{20}$Ne, $^{40}$Ca and $^{181}$Ta from a low to high incident momenta. It is found that the annihilations of $\\overline{p}$ on nucleons are of importance on the dynamics of particle production in phase space. Hyperons are mainly produced via meson induced reactions on nucleons and strangeness exchange collisions, which lead to the delayed emission in antiproton-nucleus collisions.

  11. Benchmark for a quasi-bound state of the $\\overset{\\_}{K}pp$ system

    CERN Document Server

    Kezerashvili, Roman Ya; Filikhin, Igor N; Suslov, Vladimir M; Vlahovic, Branislav

    2015-01-01

    We present three-body nonrelativistic calculations within the framework of a potential model for the kaonic cluster $\\overset{\\_}{K}pp$ using two completely different methods: the method of hyperspherical harmonics in the momentum representation and the method of Faddeev equations in configuration space. To perform a numerical benchmark, different $NN$ and antikaon-nucleon interactions are applied. The results of the calculations for the ground state energy for the $\\overset{\\_}{K}pp$ system obtained by both methods are in reasonable agreement. Although the ground state energy is not sensitive to the $NN$ interaction, it shows very strong dependence on the $\\overset{\\_}%{K}N$ potential. We show that the dominant clustering of the $\\overset{\\_}{K}pp$ \\ system in the configuration $\\Lambda (1405)+p$ allows us to calculate the binding energy to good accuracy within a simple cluster approach for the differential Faddeev equations. The theoretical discrepancies in the binding energy and width for the $\\overset{\\_}...

  12. In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions

    CERN Document Server

    Feng, Zhao-Qing; Chen, Peng-Hui; Chen, Jie; Jin, Gen-Ming

    2015-01-01

    Dynamics of pseudoscalar mesons ($\\pi$, $\\eta$, $K$ and $\\overline{K}$ ) and hyperons ($\\Lambda$ and $\\Sigma$) produced in heavy-ion collisions near threshold energies has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport model. The in-medium modifications on particle production in dense nuclear matter are implemented in the model through corrections on the elementary cross sections and by inclusion of the meson (hyperon)-nucleon potentials, in which the isospin effects are considered. It is found that the transportation of particles are influenced with the in-medium corrections. The total number of pions is reduced with an isospin, density and momentum dependent pion-nucleon potential. However, the ratios of charged pions is enhanced with inclusion of the potential. The production of eta in the domain of mid-rapidities and high momenta is sensitive to the $\\eta$-nucleon potential, but weakly depends on symmetry energy. The attractive antikaon-nucleon potential enhances the subt...

  13. Nuclear in-medium effects of strange particles in proton-nucleus collisions

    CERN Document Server

    Feng, Zhao-Qing

    2014-01-01

    Dynamics of strange particles produced in proton induced nuclear reactions near threshold energies has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport model. The in-medium modifications on particle production in dense nuclear matter are considered through corrections on the elementary cross sections via the effective mass and the mean-field potentials. It is found that the attractive antikaon-nucleon potential enhances the subthreshold $\\overline{K}$ production and also influences the structure of inclusive spectra. The strangeness production is strongly suppressed in proton induced reactions in comparison to heavy-ion collisions. The measured K$^{-}$/K$^{+}$ ratios in the $^{12}$C+$^{12}$C and p+$^{12}$C collisions from KaoS collaboration have been well explained with inclusion of the in-medium potentials.

  14. Kaon production in heavy ion reactions at intermediate energies

    CERN Document Server

    Fuchs, C

    2006-01-01

    The article reviews the physics related to kaon and antikaon production in heavy ion reactions at intermediate energies. Chiral dynamics predicts substantial modifications of the kaon properties in a dense nuclear environment. The status of the theoretical predictions as well as experimental evidences for medium effects such as repulsive/attractive mass shifts for $K^+/K^-$ are reviewed. In the vicinity of the thresholds, and even more pronounced below threshold, the production of strangeness is a highly collective process. Starting from elementary reaction channels the phenomenology of $K^+$ and $K^-$ production, i.e. freeze-out densities, time scales etc. as derived from experiment and theoretical transport calculations is presented. Below threshold kaon production shows a high sensitivity on the nuclear compression reached in heavy ion reactions. This allows to put constraints on the nuclear equation-of-state which are finally discussed.

  15. On the pole content of coupled channels chiral approaches used for the $\\bar{K}N$ system

    CERN Document Server

    Cieplý, A; Meißner, Ulf-G; Smejkal, J

    2016-01-01

    Several theoretical groups describe the antikaon-nucleon interaction at low energies within approaches based on the chiral SU(3) dynamics and including next-to-leading order contributions. We present a comparative analysis of the pertinent models and discuss in detail their pole contents. It is demonstrated that the approaches lead to very different predictions for the $K^{-}p$ amplitude extrapolated to subthreshold energies as well as for the $K^{-}n$ amplitude. The origin of the poles generated by the models is traced to the so-called zero coupling limit, in which the inter-channel couplings are switched off. This provides new insights into the pole contents of the various approaches. In particular, different concepts of forming the $\\Lambda(1405)$ resonance are revealed and constraints related to the appearance of such poles in a given approach are discussed.

  16. Golden Jubilee photos: LEAR

    CERN Multimedia

    2004-01-01

    Extraction lines that carried the antiprotons from LEAR to the experiments. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously. Particle physicists don't always need ever more powerful accelerators to study interesting physics. LEAR, the Low Energy Antiproton Ring, was designed to help explore the properties of antimatter, with the annihilation of protons and antiprotons becoming the main theme. LEAR was commissioned in 1983 and contributed to more than 30 experiments with great success. LEAR took part in the discovery of a 'glueball', a particle composed entirely of gluons, the carriers of the strong nuclear force. LEAR also observed that neutral kaons and antikaons decay at a slightly different rate, offering physicists another insight into the mystery about why matter prevails over antimatter in the Universe. Uniquely, LEAR combined both the electron and stochastic beam cooling techniques, used to control and refine the beams. It also pioneered a technique usin...

  17. Kaonic atoms measurements at the DA{Phi}NE accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Curceanu, C., E-mail: petrascu@lnf.infn.it; Bazzi, M. [Laboratori Nazionali di Frascati, INFN (Italy); Beer, G. [University of Victoria, Department of Physics and Astronomy (Canada); Bombelli, L. [Politecnico di Milano, Dip. di Elettronica (Italy); Bragadireanu, A. M. [Laboratori Nazionali di Frascati, INFN (Italy); Cargnelli, M. [Stefan Meyer Institut fuer subatomare Physik (Austria); Fiorini, C.; Frizzi, T. [Politecnico di Milano, Dip. di Elettronica (Italy); Ghio, F.; Girolami, B. [INFN Sezione di Roma I and Istituto Superiore di Sanita (Italy); Guaraldo, C. [Laboratori Nazionali di Frascati, INFN (Italy); Hayano, R. [University of Tokyo (Japan); Iliescu, M. [Laboratori Nazionali di Frascati, INFN (Italy); Ishiwatari, T. [Stefan Meyer Institut fuer subatomare Physik (Austria); Iwasaki, M. [The Institute of Physical and Chemical Research, RIKEN, Muon Science Laboratory (Japan); Kienle, P. [Stefan Meyer Institut fuer subatomare Physik (Austria); Lechner, P. [PNSensors GmbH (Germany); Levi Sandri, P. [Laboratori Nazionali di Frascati, INFN (Italy); Longoni, A. [Politecnico di Milano, Dip. di Elettronica (Italy); Lucherini, V. [Laboratori Nazionali di Frascati, INFN (Italy)

    2009-09-15

    The DA{Phi}NE electron-positron collider at the Frascati National Laboratories has made available a unique 'beam' of negative kaons. The SIDDHARTA (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) experiment, successor of DEAR (DA{Phi}NE Exotic Atom Research), aims at a precision measurement of the strong interaction shift and width of the fundamental 1s level, via the measurement of the x-ray transitions to this level, for kaonic hydrogen and kaonic deuterium. The final goal is to extract the isospin dependent antikaon-nucleon scattering lengths which contribute to the understanding of aspects of non-perturbative QCD in the strangeness sector. Other possible hadronic atoms measurements at DA{Phi}NE are under study.

  18. Measurement of kaonic atoms at DAΦNE

    International Nuclear Information System (INIS)

    The DAΦNE electron-positron collider at the Frascati National Laboratories has made available a unique 'beam' of negative kaons providing unprecedented conditions for the study of the low-energy kaon-nucleon interaction, a field still largely unexplored. The DEAR (DAΦNE Exotic Atom Research) experiment at DAΦNE and its successor SIDDHARTA (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) aim at a precision measurement of the strong interaction shift and width of the fundamental 1s level, via the measurement of the x-ray transitions to this level, for kaonic hydrogen and kaonic deuterium. The final aim is to extract the isospin dependent antikaon-nucleon scattering lengths which contribute to the understanding of aspects of chiral symmetry breaking in the strangeness sector. Other kaonic atoms transition measurements possible at DAΦNE are under study. (authors)

  19. Shedding New Light on Kaon-Nucleon/Nuclei Interaction and Its Astrophysical Implications with the AMADEUS Experiment at DAFNE

    CERN Document Server

    Scordo, A; Bellotti, G; Berucci, C; Bosnar, D; Bragadireanu, A M; Clozza, A; Cargnelli, M; Curceanu, C; Butt, A Dawood; Del Grande, R; Fabbietti, L; Fiorini, C; Ghio, F; Guaraldo, C; Iliescu, M; Sandri, P Levi; Marton, J; Pietreanu, D; Piscicchia, K; Shi, H; Sirghi, D; Sirghi, F; Tucakovic, I; Doce, O Vazquez; Wiedmann, W; Zmeskal, J

    2015-01-01

    The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DA{\\Phi}NE collider at LNF-INFN, which is fundamental to respond longstanding questions in the non-perturbative QCD strangeness sector. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would open the possibility for the formation of cold dense baryonic matter. The confirmation of this scenario may imply a fundamental role of strangeness in astrophysics. AMADEUS step 0 consisted in the reanalysis of 2004/2005 KLOE dataset, exploiting K- absorptions in H, 4He, 9Be and 12C in the setup materials. In this paper, together with a review on the multi-nucleon K- absorption and the particle identification procedure, the first results on the {\\Sigma}0-p channel will be presented including a statistical analysis on the possible accomodation of a deeply bound state

  20. Kaonic atoms measurements at the DAΦNE accelerator

    International Nuclear Information System (INIS)

    The DAΦNE electron-positron collider at the Frascati National Laboratories has made available a unique 'beam' of negative kaons. The SIDDHARTA (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) experiment, successor of DEAR (DAΦNE Exotic Atom Research), aims at a precision measurement of the strong interaction shift and width of the fundamental 1s level, via the measurement of the x-ray transitions to this level, for kaonic hydrogen and kaonic deuterium. The final goal is to extract the isospin dependent antikaon-nucleon scattering lengths which contribute to the understanding of aspects of non-perturbative QCD in the strangeness sector. Other possible hadronic atoms measurements at DAΦNE are under study.

  1. Precision measurements of kaonic atoms at DAΦNE and future perspectives

    International Nuclear Information System (INIS)

    The DAΦNE electron-positron collider at the Frascati National Laboratories has made available a unique ''beam'' of negative kaons providing unprecedented conditions for the study of the low-energy kaon-nucleon interaction, a field still largely unexplored. The DEAR (DAΦNE Exotic Atom Research) experiment at DAΦNE and its successor SIDDHARTA (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) aim at a precision measurement of the strong-interaction shift and width of the fundamental 1s level, via the measurement of the X-ray transitions to this level, for kaonic hydrogen and kaonic deuterium. The aim is to extract the isospin-dependent antikaon-nucleon scattering lengths and to contribute to the understanding of aspects of chiral symmetry breaking in the strangeness sector. (orig.)

  2. Shedding new light on kaon-nucleon/nuclei interaction and its astrophysical implications with the AMADEUS experiment at DAΦNE

    Science.gov (United States)

    Scordo, A.; Bazzi, M.; Bellotti, G.; Berucci, C.; Bosnar, D.; Bragadireanu, A. M.; Clozza, A.; Cargnelli, M.; Curceanu, C.; Butt, A. Dawood; Grande, R. Del; Fabbietti, L.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Iliescu, M.; Sandri, P. Levi; Marton, J.; Pietreanu, D.; Piscicchia, K.; Shi, H.; Sirghi, D.; Sirghi, F.; Tucakovic, I.; Doce, O. Vazquez; Wiedmann, W.; Zmeskal, J.

    2016-05-01

    The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN. The aim is to answer fundamental longstanding questions in the non-perturbative QCD strangeness sector. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would open the possibility for the formation of cold dense baryonic matter. The confirmation of this scenario may imply a fundamental role of strangeness in astrophysics. AMADEUS step 0 consisted in the reanalysis of 2004/2005 KLOE dataset, exploiting K- absorptions in H, 4He, 9Be and 12C in the setup materials. In this paper, together with a review on the multi-nucleon K- absorption and the particle identification procedure, the first results on the Σ0p channel will be presented including a statistical analysis on the possible accomodation of a deeply bound state.

  3. New precision measurements of the strong interaction in kaonic hydrogen

    International Nuclear Information System (INIS)

    The DEAR experiment performed at the DAΦNE electron-positron collider (Frascati, Italy) studied the strong interaction shift and width of the 1s state in kaonic hydrogen using x-ray spectroscopy. The repulsive character of the kaon-proton interaction at threshold was confirmed and the most precise values of the shift and width were obtained. However, high precision data at the percent level are highly requested to further develop the theories and thus our understanding of the low-energy antikaon-nucleon interaction. Therefore, a new series of precision experiments on kaonic hydrogen and kaonic deuterium are planned at LNF. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

  4. Precision measurements of kaonic atoms at DA{phi}NE and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Curceanu, C.; Bazzi, M.; Catitti, M.; Guaraldo, C.; Iliescu, M.; Levi Sandri, P.; Lucherini, V.; Pietreanu, D.; Sirghi, F. [INFN, Laboratori Nazionali di Frascati (Roma) (Italy); Beer, G. [University of Victoria, Department of Physics and Astronomy, Victoria B.C. (Canada); Bombelli, L.; Fiorini, C.; Frizzi, T.; Longoni, A. [Sezione di Elettronica, Politecnico di Milano, Milano (Italy); Bragadireanu, A.M.; Sirghi, D.L. [INFN, Frascati (Italy); IFIN-HH, Bucharest (Romania); Cargnelli, M.; Ishiwatari, T.; Marton, J.; Widmann, E.; Zmeskal, J. [Stefan Meyer Institut fuer Subatomare Physik, Vienna (Austria); Ghio, F.; Girolami, B. [INFN Sezione di Roma I (Italy); Istituto Superiore di Sanita, Roma (Italy); Kienle, P. [Stefan Meyer Inst. fuer Subatomare Physik, Vienna (Austria); Technische Univ., Muenchen (Germany); Lechner, P.; Soltau, H. [PNSensors GmbH, Muenchen (Germany); Ponta, T. [IFIN-HH, Magurele, Bucharest (Romania); Struder, L. [MPI for Extraterrestrial Physics, Garching (Germany)

    2007-03-15

    The DA{phi}NE electron-positron collider at the Frascati National Laboratories has made available a unique ''beam'' of negative kaons providing unprecedented conditions for the study of the low-energy kaon-nucleon interaction, a field still largely unexplored. The DEAR (DA{phi}NE Exotic Atom Research) experiment at DA{phi}NE and its successor SIDDHARTA (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) aim at a precision measurement of the strong-interaction shift and width of the fundamental 1s level, via the measurement of the X-ray transitions to this level, for kaonic hydrogen and kaonic deuterium. The aim is to extract the isospin-dependent antikaon-nucleon scattering lengths and to contribute to the understanding of aspects of chiral symmetry breaking in the strangeness sector. (orig.)

  5. First results on kaonic hydrogen from the DEAR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Guaraldo, C.; Lucherini, V. [INFN-Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Beer, G. [University of Victoria, Department of Physics and Astronomy, Victoria, BC (Canada); Bragadireanu, A.M.; Curceanu, C.; Iliescu, M.; Ponta, T.; Sirghi, D. [INFN-Laboratori Nazionali di Frascati, C.P. 13, Via E. Fermi 40, I-00044 Frascati (Italy); Institute of Physics and Nuclear Engineering ' ' Horia Hulubei' ' , P.O. Box MG - 6, R-76900, Bucharest (Romania); Cargnelli, M.; Fuhrman, H.; Ishiwatari, T.; Marton, J. [Institute for Medium Energy Physics, Boltzmanngasse 3, A-1090 Vienna (Austria); Egger, J.P. [Universite de Fribourg, Institut de Physique, Bd. de Perolles, CH-1700 Fribourg (Switzerland); Universite de Neuchatel, Institut de Physique, 1 rue A.-L. Breguet, CH-2000 Neuchatel (Switzerland); Itahashi, K. [Tokyo Institute of Technology, 2-12-1 Ookoyana Meguro, Tokyo 152 (Japan); Iwasaki, M. [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-01 (Japan); Lauss, B. [Physics Department, University of California and Berkeley, Berkeley CA 94720 (United States); Ludhova, L.; Mulhauser, F.; Schaller, L.A. [Universite de Fribourg, Institut de Physique, Bd. de Perolles, CH-1700 Fribourg (Switzerland); Seki, R. [W.E. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Department of Physics and Astrophysics, California State University, Northridge, CA 91330 (United States); Sirghi, F.; Strasser, P.; Zmeskal, J.

    2004-02-01

    The objective of DEAR (DA{phi}NE Exotic Atom Research) is the measurement of the K{sub {alpha}} line shift and width, due to the strong interaction, in kaonic hydrogen and a similar measurement - the first one - in kaonic deuterium. The aim is a precision determination of the antikaon-nucleon isospin dependent scattering lengths in order to obtain the kaon nucleon sigma terms. In a first phase, dedicated to the calibration and optimization of the setup, the experiment collected data on kaonic nitrogen: for the first time a complex of three transitions (7{yields}6 at 4.6 keV, 6{yields}5 at 7.6 keV and 5{yields}4 at 14 keV) was measured, and the corresponding yields obtained. The kaonic hydrogen measurement was performed for a total integrated luminosity of about 60 pb{sup -1} in the last months of the 2002 year. Data analyses are in progress, preliminary results being hereby presented, together with those on kaonic nitrogen. (orig.)

  6. First results on kaonic hydrogen from the DEAR experiment

    International Nuclear Information System (INIS)

    The objective of DEAR (DAΦNE Exotic Atom Research) is the measurement of the Kα line shift and width, due to the strong interaction, in kaonic hydrogen and a similar measurement - the first one - in kaonic deuterium. The aim is a precision determination of the antikaon-nucleon isospin dependent scattering lengths in order to obtain the kaon nucleon sigma terms. In a first phase, dedicated to the calibration and optimization of the setup, the experiment collected data on kaonic nitrogen: for the first time a complex of three transitions (7→6 at 4.6 keV, 6→5 at 7.6 keV and 5→4 at 14 keV) was measured, and the corresponding yields obtained. The kaonic hydrogen measurement was performed for a total integrated luminosity of about 60 pb-1 in the last months of the 2002 year. Data analyses are in progress, preliminary results being hereby presented, together with those on kaonic nitrogen. (orig.)

  7. Azimuthal angular distributions of K{sup +} and K{sup -} mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV

    Energy Technology Data Exchange (ETDEWEB)

    Ploskon, M.

    2005-07-01

    The Kaon-Spectrometer (KaoS) at the heavy-ion synchrotron (SIS) at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt has been used to study production and propagation of K{sup +} and K{sup -} mesons from Au+Au collisions at a kinetic beam energy of 1.5 AGeV. The azimuthal angular distributions of particles as a function of the collision centrality and particle transverse momenta have been measured. We found a dependence of the K{sup -} meson azimuthal emission pattern on the transverse momentum. The antikaons registered with p{sub t}<0.5 GeV/c are preferentially emitted in the reaction plane and the particles with p{sub t} > 0.5 GeV/c show strong out-of-plane enhancement. The emission patterns of K{sup -} can be explained in terms of two competing phenomena: one of them is indeed the influence of the attractive K{sup -}N potential, however, the second one originates from the strangeness-exchange process. (orig.)

  8. Predictions for the Λ{sub b} → J/ψ Λ(1405) decay

    Energy Technology Data Exchange (ETDEWEB)

    Roca, L. [Universidad de Murcia, Departamento de Fisica, Murcia (Spain); Mai, M. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn and Bethe Center for Theoretical Physics, Bonn (Germany); Oset, E. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Meissner, Ulf G. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany)

    2015-05-15

    We calculate the shape of the πΣ and anti KN invariant mass distributions in the Λ{sub b} → J/ψπΣ and Λ{sub b} → J/ψ anti KN decays that are dominated by the Λ(1405) resonance. The weak interaction part is the same for both processes and the hadronization into the different meson-baryon channels in the final state is given by symmetry arguments. The most important feature is the implementation of the meson-baryon final-state interaction using two chiral unitary models from different theoretical groups. Both approaches give a good description of antikaon-nucleon scattering data, the complex energy shift in kaonic hydrogen and the line shapes of πΣK in photoproduction, based on the two-pole scenario for the Λ(1405). We find that this reaction reflects more the higher mass pole and we make predictions of the line shapes and relative strength of the meson-baryon distributions in the final state. (orig.)

  9. Breaking of flavor permutational symmetry and the CKM matrix

    International Nuclear Information System (INIS)

    Different ansaetze for the breaking of the flavor permutational symmetry according to SL(3) x SR(3) superset of SL(2) x SR(2) give different Hermitian mass matrices which differ in the symmetry breaking pattern. In this work we obtain a clear and precise indication on the preferred symmetry breaking pattern. The preferred pattern allows us to compute the CKM mixing matrix, the Jarlskog invariant J, and the three inner angles of the unitarity triangle in terms of four quark mass ratios and the CP violating phase Φ. Excellent agreement with the experimentally determined absolute values of the entries in the CKM matrix is obtained for Φ=90 deg. The corresponding computed values of the Jarlskog invariant and the inner angles are J=3.00x10-5, α=84 deg., β=24 deg. and γ=72 deg. in very good agreement with current data on CP violation in the neutral kaon-antikaon system and oscillations in the Bs deg.-B-bars deg. system

  10. The breaking of the flavour permutational symmetry Mass textures and the CKM matrix

    CERN Document Server

    Mondragón, A

    1998-01-01

    Different ansaetze for the breaking of the flavour permutational symmetry according to S(3)L X S(3)R in S(2)L X S(2)R give different Hermitian mass matrices of the same modified Fritzsch type which are classified in terms of an auxiliary S(2) which is not a subgroup of S(3)L X S(3)R. A fit of the predicted theoretical Vckm to the experimentally determined absolute values of the elements of the CKM matrix gives a clear and precise indication on the preferred symmetry breaking scheme. The preferred scheme leads to simple mass textures and allows us to compute the CKM mixing matrix in terms of four quark mass ratios and only one free parameter: the CP violating phase Phi. Excellent agreement with the experimentally determined absolute values of the entries in the CKM matrix is obtained for Phi = 76.8 deg. The corresponding computed value of the Jarlskog invariant is J = -2.18 10^-5 in very good agreement with current data on CP violation in the neutral kaon-antikaon system.

  11. Parton/hadron dynamics in heavy-ion collisions at FAIR energies

    Directory of Open Access Journals (Sweden)

    Cassing W.

    2015-01-01

    Full Text Available Recent STAR data for the directed flow of protons, antiprotons and charged pions obtained within the beam energy scan program are analyzed within the Parton-Hadron-String-Dynamics (PHSD/HSD transport models. Both versions of the kinetic approach are used to clarify the role of partonic degrees of freedom. The PHSD results, simulating a partonic phase and its coexistence with a hadronic one, are roughly consistent with the STAR data. Generally, the semi-qualitative agreement between the measured data and model results supports the idea of a crossover type of quark-hadron transition which softens the nuclear EoS but shows no indication of a first-order phase transition. Furthermore, the directed flow of kaons and antikaons is evaluated in the PHSD/HSD approachesfrom √sNN ≈ 3 - 200 GeV which shows a high sensitivity to hadronic potentials in the FAIR/NICA energy regime √sNN ≤ 8 GeV.

  12. Progress and perspectives in the low-energy kaon-nucleon/nuclei interaction studies at the DAΦNE collider

    International Nuclear Information System (INIS)

    Low-energy QCD is still lacking experimental results, fundamental for reaching a good understanding of the strangeness sector. The information provided by the low energy kaon- nucleon/nuclei interaction is accessible through the study of kaonic atoms and kaonic nuclear processes. The lightest atomic systems, namely the kaonic hydrogen and the kaonic deuterium, provide the isospin dependent kaon-nucleon scattering lengths by measuring the X-rays emitted during their de-excitation to the 1s level. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium and of upper-level transitions in kaonic helium 3 and kaonic helium 4 were carried out at the DAΦNE collider by the SIDDHARTA collaboration. Presently, a significantly upgraded setup developped by the SIDDHARTA-2 collaboration is ready to perform a precise measurement of kaonic deuterium and, afterwards, of heavier exotic atoms. In parallel, the kaon-nuclei interaction at momenta below 130 MeV/c is studied by the AMADEUS collaboration, using the KLOE detector and a dedicated setup inserted in the central region, near the interaction point. Preliminary results of the study of charged antikaons interacting with nuclei are shown, including an analysis of the controversial Λ(1405)

  13. Revisiting RG Flow for Kaon Condensation

    CERN Document Server

    Paeng, Won-Gi

    2014-01-01

    Kaon condensation in compact-star matter can be considered as a quantum critical phenomenon with the kaon mass tuned to zero by the baryon density plus the electron chemical potential that increases at the increase of the density. We approach this problem with a renormalization group flow at one loop of the system of anti-kaons considered as pseudo-Goldstone bosons coupled to nucleonic matter described as a Fermi liquid near its fixed point. While the Weinberg-Tomozawa term in chiral Lagrangians is of leading order in describing kaon-nucleon interactions in chiral perturbation theory, hence widely employed in the literature, it is irrelevant in the RG sense, therefore plays, if any, a less important role in the condensation process. The consequence is that the $\\Lambda (1405)$ resonance which is driven by the Weinberg-Tomozawa term is irrelevant for triggering kaon condensation. On the contrary, the $KN$ sigma term $\\Sigma_{KN}$, subleading in chiral counting, can play a more crucial role in renormalization g...

  14. Predictions for the $\\Lambda_b \\to J/\\psi ~ \\Lambda(1405)$ decay

    CERN Document Server

    Roca, Luis; Oset, Eulogio; Meißner, Ulf-G

    2015-01-01

    We calculate the shape of the $\\pi\\Sigma$ and $\\bar K N$ invariant mass distributions in the $\\Lambda_b \\to J/\\psi\\, \\pi\\Sigma$ and $\\Lambda_b \\to J/\\psi \\,\\bar K N$ decays that are dominated by the $\\Lambda(1405)$ resonance. The weak interaction part is the same for both processes and the hadronization into the different meson-baryon channels in the final state is related by SU(3) symmetry. The most important feature is the implementation of the meson-baryon final-state interaction using two chiral unitary models from different theoretical groups. Both approaches give a good description of antikaon-nucleon scattering data, the complex energy shift in kaonic hydrogen and the line shapes of $\\pi \\Sigma K$ in photoproduction, based on the two-pole scenario for the $\\Lambda (1405)$. We find that this reaction reflects more the higher mass pole and we make predictions of the line shapes and relative strength of the meson-baryon distributions in the final state.

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

    CERN Document Server

    Curceanu, C; Bazzi, M; Berucci, C; Bosnar, D; Bragadireanu, A M; Clozza, A; Cargnelli, M; D'uffizi, A; Fabbietti, L; Fiorini, C; Ghio, F; Guaraldo, C; Iliescu, M; Sandri, P Levi; Marton, J; Pietreanu, D; Lener, M Poli; Quaglia, R; Vidal, A Romero; Sbardella, E; Scordo, A; Shi, H; Sirghi, D; Sirghi, F; Skurzok, M; Tucakovic, I; Doce, O Vazquez; Widmann, E; Zmeskal, J

    2015-01-01

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

  16. Kaon Condensation and Lambda-Nucleon Loop in the Relativistic Mean-Field Approach

    CERN Document Server

    Maruyama, T; Tatsumi, T; Tsushima, K; Thomas, A W; Maruyama, Tomoyuki; Muto, Takumi; Tatsumi, Toshitaka; Tsushima, Kazuo; Thomas, Anthony W.

    2005-01-01

    The possibility of kaon condensation in high-density symmetric nuclear matter is investigated including both s- and p-wave kaon-baryon interactions within the relativistic mean-field (RMF) theory. Above a certain density, we have a collective ${\\bar K}_s$ state carrying the same quantum numbers as the antikaon. The appearance of the ${\\bar K}_s$ state is caused by the time component of the axial-vector interaction between kaons and baryons. It is shown that the system becomes unstable with respect to condensation of $K$-${\\bar K}_s$ pairs. We consider how the effective baryon masses affect the kaon self-energy coming from the time component of the axial-vector interaction. Also, the role of the spatial component of the axial-vector interaction on the possible existence of the collective kaonic states is discussed in connection with $\\Lambda$-mixing effects in the ground state of high-density matter. Implications of $K{\\bar K}_s$ condensation for high-energy heavy-ion collisions are briefly mentioned.

  17. Directed flow in heavy-ion collisions from the PHSD transport approach

    Science.gov (United States)

    Palmese, A.; Cassing, W.

    2016-01-01

    Recent STAR data for the directed flow of protons, antiprotons, charged pions and kaons obtained within the beam energy scan (BES) program are analyzed within the Parton- Hadron-String-Dynamics (PHSD/HSD) transport models. Both versions of the kinetic approach are used to clarify the role of partonic degrees of freedom. The PHSD results, simulating a partonic phase and its coexistence with a hadronic one, are roughly consistent with the STAR data. Generally, the semi-qualitative agreement between the measured data and model results supports the idea of a crossover type of quark-hadron transition which softens the nuclear EoS but shows no indication of a first-order phase transition. Furthermore, the directed flow of kaons and antikaons is evaluated in the PHSD approach from √sNN ≈ 5-12 GeV which shows a high sensitivity to the hadronic potentials in the FAIR/NICA energy regime √sNN ≤⃒ 8 GeV.

  18. Kaon Condensation and Lambda-Nucleon Loop in the Relativistic Mean-Field Approach

    Energy Technology Data Exchange (ETDEWEB)

    Tomoyuki Maruyama; Takumi Muto; Toshitaka Tatsumi; Kazuo Tsushima; Anthony W. Thomas

    2005-02-24

    The possibility of kaon condensation in high-density symmetric nuclear matter is investigated including both s- and p-wave kaon-baryon interactions within the relativistic mean-field (RMF) theory. Above a certain density, we have a collective K{sub s} state carrying the same quantum numbers as the antikaon. The appearance of the K{sub s} state is caused by the time component of the axial-vector interaction between kaons and baryons. It is shown that the system becomes unstable with respect to condensation of K-Kbar{sub s} pairs. We consider how the effective baryon masses affect the kaon self-energy coming from the time component of the axial-vector interaction. Also, the role of the spatial component of the axial-vector interaction on the possible existence of the collective kaonic states is discussed in connection with Lambda-mixing effects in the ground state of high-density matter. Implications of K-Kbar{sub s} condensation for high-energy heavy-ion collisions are briefly mentioned.

  19. Unprecedented Studies of the Low-energy Negatively Charged Kaons Interactions in Nuclear Matter by AMADEUS

    Science.gov (United States)

    Curceanu, C.; Piscicchia, K.; Bazzi, M.; Berucci, C.; Bosnar, D.; Bragadireanu, A. M.; Clozza, A.; Cargnelli, M.; D'Uffizi, A.; Fabbietti, L.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Iliescu, M.; Levi Sandri, P.; Marton, J.; Pietreanu, D.; Poli Lener, M.; Quaglia, R.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D.; Sirghi, F.; Skurzok, M.; Tucakovic, I.; Vazquez Doce, O.; Widmann, E.; Zmeskal, J.

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

  20. Precision spectroscopy of Kaonic helium-3 and helium-4 3d-->2p X-rays

    Science.gov (United States)

    Ishiwatari, T.; Bazzi, M.; Bhang, H.; Beer, G.; Bombelli, L.; Bragadireanu, A. M.; Cargnelli, M.; Choi, S.; Corradi, G.; Curceanu, C.; d'Uffizi, A.; Enomoto, S.; Fiorini, C.; Frizzi, T.; Fujioka, H.; Fujiwara, Y.; Ghio, F.; Girolami, B.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Ishimoto, S.; Itahashi, K.; Iwasaki, M.; Kienle, P.; Kou, H.; Levi Sandri, P.; Longoni, A.; Lucherini, V.; Marton, J.; Matsuda, Y.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Pietreanu, D.; Ponta, T.; Rizzo, A.; Romero Vidal, A.; Sakuma, F.; Sato, M.; Scordo, A.; Sekimoto, M.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Suzuki, T.; Tanida, K.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Tudorache, A.; Tudorache, V.; Vazquez Doce, O.; Widmann, E.; Wünschek, B.; Yamazaki, T.; Zmeskal, J.

    2010-08-01

    Recently, the shift of the kaonic helium-4 2p state was precisely determined by the E570 and SIDDHARTA experiments. Prior to the experiment by E570, the average of three earlier experimental results showed -43±8 eV, while most of the theoretical calculations give ˜0 eV. This five-sigma discrepancy between theory and experiment was known as the "kaonic helium puzzle". A recent theoretical model showed a possible resonance-like shift of maximum 10 eV for a certain value of a deep antikaon-nucleon interaction potential, which is different in helium 3 and helium 4. The E570 experiment determined the shift of the kaonic helium-4 2p state as +2±2 (stat)±2 (sys) eV in 2007. The SIDDHARTA experiment determined the shift as 0±6(stat)±2(sys) eV in 2009. The results of these experiments resolved the long-standing puzzle. A new experiment of the kaonic helium-3 X-ray measurement is being prepared by the J-PARC E17 collaborators, and the kaonic helium-3 X-ray data taken very recently by the SIDDHARTA experiment are on the way to be analyzed. The results of the E570, E17 and SIDDHARTA experiments examine the strong interaction for light nuclei with different isospin, and test furthermore recent theoretical predictions.

  1. Experimental studies on kaonic atoms at DA{phi}NE

    Energy Technology Data Exchange (ETDEWEB)

    Zmeskal, J. [Stefan Meyer Insitut fuer subatomare Physik, Vienna (Austria); Bazzi, M. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy); Beer, G. [Department of Physics and Astronomy, Univ. of Victoria, Victoria B.C. (Canada); Bombelli, L. [Politecnico di Milano, Sez. Di Elettronica, Milan (Italy); Bragadirean, A.M. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy)]|[IFIN-HH, Bucharest (Romania); Cargnelli, M. [Stefan Meyer Insitut fuer subatomare Physik, Vienna (Austria); Catitti, M. [INFN, Laboratori Nazionali di Frascati, Frascati (Roma) (Italy); Curceanu Petrascu, C. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy)]|[IFIN-HH, Bucharest (Romania); Fiorini, C. [Politecnico di Milano, Sez. Di Elettronica, Milan (Italy); Frizzi, T. [Politecnico di Milano, Sez. Di Elettronica, Milan (Italy); Ghio, F. [INFN, Sez. Di RomaI and Istituto Superiore di Sanita, Rome (Italy); Girolami, B. [INFN, Sez. Di RomaI and Istituto Superiore di Sanita, Rome (Italy); Guaraldo, C.; Iliescu, M. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy); Ishiwatari, T.; Kienle, P. [Stefan Meyer Insitut fuer subatomare Physik, Vienna (Austria); Lechner, P. [PNSensor GmbH, Munich (Germany); Levi Sandri, P.; Lucherini, V. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy); Longoni, A. [Politecnico di Milano, Sez. Di Elettronica, Milan (Italy); Marton, J. [Stefan Meyer Insitut fuer subatomare Physik, Vienna (Austria); Pietreanu, D.; Sirghi, F. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy); Ponta, T. [IFIN-HH, Bucharest (Romania); Sirghi, D.L. [INFN, Laboratori Nazionali di Frascati, Frascati (Rome) (Italy)]|[IFIN-HH, Bucharest (Romania); Soltau, H. [PNSensor GmbH, Munich (Germany); Strueder, L. [MPI for Extraterrestrial Physics, Garching (Germany); Widmann, E. [Stefan Meyer Insitut fuer subatomare Physik, Vienna (Austria)

    2007-06-15

    With precise X-ray spectroscopy on kaonic hydrogen at the DA{phi}NE electron-positron collider at Laboratori Natzionali di Frascati the chiral symmetry breaking scenario in the strangeness sector will be investigated by studying the K{sup -}p and K{sup -}d s-wave interaction at threshold. The strong interaction induced shift and width of the kaonic hydrogen 1s atomic state was measured with DEAR (DA{phi}NE Exotic Atom Research) and in future with SIDDHARTA (Silicon Drift Detector for Hadronic Atom Research with Timing Application) the kaonic hydrogen system will be measured with utmost precision. In addition, data for the K{sup -}d system will become available for the first time. Kaonic hydrogen together with precision measurements of kaonic helium will allow the study of the sub-threshold {lambda}(1405) resonance, which might act as a doorway for the formation of antikaon-mediated deeply bound nuclear states in light nuclei. Therefore, these precision measurements are a powerful tool to test chiral symmetry breaking in systems with strangeness.

  2. Experimental studies on kaonic atoms at DAΦNE

    International Nuclear Information System (INIS)

    With precise X-ray spectroscopy on kaonic hydrogen at the DAΦNE electron-positron collider at Laboratori Natzionali di Frascati the chiral symmetry breaking scenario in the strangeness sector will be investigated by studying the K-p and K-d s-wave interaction at threshold. The strong interaction induced shift and width of the kaonic hydrogen 1s atomic state was measured with DEAR (DAΦNE Exotic Atom Research) and in future with SIDDHARTA (Silicon Drift Detector for Hadronic Atom Research with Timing Application) the kaonic hydrogen system will be measured with utmost precision. In addition, data for the K-d system will become available for the first time. Kaonic hydrogen together with precision measurements of kaonic helium will allow the study of the sub-threshold Λ(1405) resonance, which might act as a doorway for the formation of antikaon-mediated deeply bound nuclear states in light nuclei. Therefore, these precision measurements are a powerful tool to test chiral symmetry breaking in systems with strangeness

  3. Progress and perspectives in the low-energy kaon-nucleon/nuclei interaction studies at the DAΦNE collider

    Science.gov (United States)

    Iliescu, M.; Bazzi, M.; Beer, G.; Berucci, C.; Bosnar, D.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu, C.; d'Uffizi, A.; Fabietti, L.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R. S.; Ishiwatari, T.; Iwasaki, M.; Marton, J.; Okada, S.; Pietreanu, D.; Piscicchia, K.; Poli Lener, M.; Ponta, T.; Quaglia, R.; Romero Vidal, A.; Levi Sandri, P.; Sbardella, E.; Schembari, F.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Tucakovic, I.; Vazquez Doce, O.; Widmann, E.; Wünschek, B.; Zmeskal, J.; Siddharta; Siddharta-2; Amadeus Collaborations

    2014-11-01

    Low-energy QCD is still lacking experimental results, fundamental for reaching a good understanding of the strangeness sector. The information provided by the low energy kaon- nucleon/nuclei interaction is accessible through the study of kaonic atoms and kaonic nuclear processes. The lightest atomic systems, namely the kaonic hydrogen and the kaonic deuterium, provide the isospin dependent kaon-nucleon scattering lengths by measuring the X-rays emitted during their de-excitation to the 1s level. The most precise kaonic hydrogen measurement to date, together with an exploratory measurement of kaonic deuterium and of upper-level transitions in kaonic helium 3 and kaonic helium 4 were carried out at the DAΦNE collider by the SIDDHARTA collaboration. Presently, a significantly upgraded setup developped by the SIDDHARTA-2 collaboration is ready to perform a precise measurement of kaonic deuterium and, afterwards, of heavier exotic atoms. In parallel, the kaon-nuclei interaction at momenta below 130 MeV/c is studied by the AMADEUS collaboration, using the KLOE detector and a dedicated setup inserted in the central region, near the interaction point. Preliminary results of the study of charged antikaons interacting with nuclei are shown, including an analysis of the controversial Λ(1405).

  4. Study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE

    CERN Document Server

    Bazzi, M; Berucci, C; Bombelli, L; Bragadireanu, A M; Cargnelli, M; Curceanu, C; d'Uffizi, A; Fiorini, C; Frizzi, T; Ghio, F; Guaraldo, C; Hayano, R; Iliescu, M; Ishiwatari, T; Iwasaki, M; Kienle, P; Sandri, P Levi; Longoni, A; Marton, J; Okada, S; Pietreanu, D; Ponta, T; Vidal, A Romero; Sbardella, E; Scordo, A; Shi, H; Sirghi, D L; Sirghi, F; Tatsuno, H; Tudorache, A; Tudorache, V; Doce, O Vazquez; Widmann, E; Zmeskal, J

    2013-01-01

    The study of the KbarN system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA experiment used X-ray spectroscopy of the kaonic atoms to determine the transition yields and the strong interaction induced shift and width of the lowest experimentally accessible level (1s for H and D and 2p for He). Shift and width are connected to the real and imaginary part of the scattering length. To disentangle the isospin dependent scattering lengths of the antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We report here on an exploratory deuterium measurement, from which a limit for the yield of the K-series transitions was derived: Y(K_tot)<0.0143 and Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming ...

  5. Kaon Condensation and Lambda-Nucleon Loop in the Relativistic Mean-Field Approach

    International Nuclear Information System (INIS)

    The possibility of kaon condensation in high-density symmetric nuclear matter is investigated including both s- and p-wave kaon-baryon interactions within the relativistic mean-field (RMF) theory. Above a certain density, we have a collective Ks state carrying the same quantum numbers as the antikaon. The appearance of the Ks state is caused by the time component of the axial-vector interaction between kaons and baryons. It is shown that the system becomes unstable with respect to condensation of K-Kbars pairs. We consider how the effective baryon masses affect the kaon self-energy coming from the time component of the axial-vector interaction. Also, the role of the spatial component of the axial-vector interaction on the possible existence of the collective kaonic states is discussed in connection with Lambda-mixing effects in the ground state of high-density matter. Implications of K-Kbars condensation for high-energy heavy-ion collisions are briefly mentioned

  6. Kaon condensation and lambda-nucleon loop in the relativistic mean-field approach

    International Nuclear Information System (INIS)

    The possibility of kaon condensation in high-density symmetric nuclear matter is investigated including both s- and p-wave kaon-baryon interactions within the relativistic mean-field (RMF) theory. Above a certain density, we have a collective K-bar s state carrying the same quantum numbers as the antikaon. The appearance of the K-bar s state is caused by the time component of the axial-vector interaction between kaons and baryons. It is shown that the system becomes unstable with respect to condensation of K-K-bar s pairs. We consider how the effective baryon masses affect the kaon self-energy coming from the time component of the axial-vector interaction. Also, the role of the spatial component of the axial-vector interaction on the possible existence of the collective kaonic states is discussed in connection with Λ-mixing effects in the ground state of high-density matter. Implications of KK-bar s condensation for high-energy heavy-ion collisions are briefly mentioned

  7. Double-pole nature of Λ(1405) studied with coupled-channel complex scaling method using complex-range Gaussian basis

    International Nuclear Information System (INIS)

    The excited hyperon Λ(1405) is the important building block for kaonic nuclei which are a nuclear many-body system with anti-kaons. We have been investigating the Λ(1405) resonance with the coupled-channel Complex Scaling Method (ccCSM) in which the Λ(1405) is treated as a hadron-molecular state of a K¯N–πΣ coupled system. We use a K¯N(–πY) potential based on the chiral SU(3) theory. In this article, we report the double-pole nature of the Λ(1405), which is a characteristic property predicted by many studies with chiral SU(3)-based models. With the help of the complex-range Gaussian basis in ccCSM, we have found successfully another pole besides a pole near the K¯N threshold (called higher pole) which was found in our previous work with the real-range Gaussian basis. The new pole (called lower pole) is found far below K¯N threshold: (M,−Γ/2)=(1395,−138) MeV when fπ=110 MeV. In spite of so broad width of the lower-pole state, the state is clearly identified with good separation from continuum states, since the oscillatory behavior of the continuum states is improved owing to the complex-range Gaussian basis. Analyzing the ccCSM wave function of the lower pole, we have revealed explicitly that the lower-pole state is dominated by the πΣ component rather than the K¯N component. We have confirmed that the ccCSM wave function is correctly connected to the asymptotic form of the resonance wave function. Estimating the meson–baryon mean distance for the lower-pole state which involves a large decay width, the obtained value has a large imaginary part comparable to a real part. Therefore, the mean-distance of the lower-pole state is difficult to be interpreted intuitively. Such a nature of the lower pole is different from that of the higher pole. In addition, we have investigated the origin of the appearance of the lower pole. The lower pole is confirmed to be generated by the energy dependence attributed to the chiral dynamics, by comparing the

  8. Measurable consequences of an attractive anti KN interaction

    Energy Technology Data Exchange (ETDEWEB)

    Epple, Eliane Melanie Franziska

    2014-07-07

    In the field of low energy QCD the effective description of interactions between ground state hadrons plays a major role in nuclear physics. One of these interactions occurs between anti-kaons and nucleons, and is a topic of a long standing interest. A specific attention is lately drawn to the possible existence of bound states between anti Ks and nucleons. This old concept is based on the idea that the attractive interaction between anti-kaons and nucleons, that already manifests itself as the anti KN-pole of the Λ(1405)-resonance, is strong enough to bind further nucleons by the help of a anti K. The simplest form of these clusters is the anti KNN which consists of a anti K bound to two nucleons. This state might decay into pΛ and is, thus, accessible via open strangeness production in p+p collisions. This work continues the investigations in this field, as a rather puzzling impression is left behind from previous experiments, and further conclusions are needed. The work contains two major data analyses. The first one is dedicated to the anti KN bound state, and selects the semi-exclusive reaction p+p→p+K{sup +}+Λ+X. This was done to investigate the strange resonances Λ(1405) and Σ(1385){sup 0} in their neutral decay channels Σ{sup 0}π{sup 0} and Λπ{sup 0}, respectively. Besides resonance production, several other states contribute to this final state. Their relative strengths have been determined and the obtained production cross sections were in agreement with the results from an independent analysis of the Λ(1405) decay into Σ{sup ±}π{sup -+}, done in a parallel work. To set reasonable constraints for coupled channels calculations in the anti KN sector, a high-precision Λ(1405)-mass spectrum is needed. The obtained yield and uncertainty of the Λ(1405) contribution to the final spectra, however, showed that the required precision is not given in the neutral decay channel. Nonetheless, the extracted production cross section of the Σ(1385){sup 0

  9. Measurable consequences of an attractive anti KN interaction

    International Nuclear Information System (INIS)

    In the field of low energy QCD the effective description of interactions between ground state hadrons plays a major role in nuclear physics. One of these interactions occurs between anti-kaons and nucleons, and is a topic of a long standing interest. A specific attention is lately drawn to the possible existence of bound states between anti Ks and nucleons. This old concept is based on the idea that the attractive interaction between anti-kaons and nucleons, that already manifests itself as the anti KN-pole of the Λ(1405)-resonance, is strong enough to bind further nucleons by the help of a anti K. The simplest form of these clusters is the anti KNN which consists of a anti K bound to two nucleons. This state might decay into pΛ and is, thus, accessible via open strangeness production in p+p collisions. This work continues the investigations in this field, as a rather puzzling impression is left behind from previous experiments, and further conclusions are needed. The work contains two major data analyses. The first one is dedicated to the anti KN bound state, and selects the semi-exclusive reaction p+p→p+K++Λ+X. This was done to investigate the strange resonances Λ(1405) and Σ(1385)0 in their neutral decay channels Σ0π0 and Λπ0, respectively. Besides resonance production, several other states contribute to this final state. Their relative strengths have been determined and the obtained production cross sections were in agreement with the results from an independent analysis of the Λ(1405) decay into Σ±π-+, done in a parallel work. To set reasonable constraints for coupled channels calculations in the anti KN sector, a high-precision Λ(1405)-mass spectrum is needed. The obtained yield and uncertainty of the Λ(1405) contribution to the final spectra, however, showed that the required precision is not given in the neutral decay channel. Nonetheless, the extracted production cross section of the Σ(1385)0-resonance provided a crucial constraint for