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113 results on '"K, Siwek"'

1. Azimuthal Emission Patterns of $K^{+}$ and of $ K^{-} $ Mesons in Ni + Ni Collisions near the Strangeness Production Threshold

Author

Zinyuk, V., Kang, T. I., Leifels, Y., Herrmann, N., Hong, B., Averbeck, R., Andronic, A., Barret, V., Basrak, Z., Bastid, N., Benabderrahmane, M. L., Berger, M., Buehler, P., Cargnelli, M., Čaplar, R., Carevic, I., Crochet, P., Deppner, I., Dupieux, P., Dželalija, M., Fabbietti, L., Fodor, Z., Gasik, P., Gašparić, I., Grishkin, Y., Hartmann, O. N., Hildenbrand, K. D., Kecskemeti, J., Kim, Y. J., Kirejczyk, M., Kiš, M., Koczon, P., Kotte, R., Lebedev, A., Fèvre, A. Le, Liu, J. L., Lopez, X., Manko, V., Marton, J., Matulewicz, T., Münzer, R., Petrovici, M., Piasecki, K., Rami, F., Reischl, A., Reisdorf, W., Ryu, M. S., Schmidt, P., Schüttauf, A., Seres, Z., Sikora, B., Sim, K. S., Simion, V., ilczyńska, K. Siwek, Smolyankin, V., Suzuki, K., Tyminski, Z., Wagner, P., Widmann, E., Wiśniewski, K., Xiao, Z. G., Yushmanov, I., Zhang, Y., Zhilin, A., and Zmeskal, J.

Subjects
Nuclear Experiment
Abstract

Azimuthal emission patterns of $K^\pm$ mesons have been measured in Ni + Ni collisions with the FOPI spectrometer at a beam kinetic energy of 1.91 A GeV. The transverse momentum $p_{T}$ integrated directed and elliptic flow of $K^{+}$ and $K^{-}$ mesons as well as the centrality dependence of $p_{T}$ - differential directed flow of $K^{+}$ mesons are compared to the predictions of HSD and IQMD transport models. The data exhibits different propagation patterns of $K^{+}$ and $K^{-}$ mesons in the compressed and heated nuclear medium and favor the existence of a kaon-nucleon in-medium potential, repulsive for $K^{+}$ mesons and attractive for $K^{-}$ mesons.

Published
2014
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2. Dynamical versus statistical production of Intermediate Mass Fragments at Fermi Energies

Author

G. Lanzalone, E. De Filippo, N. S. Martorana, Luis Acosta, E. Piasecki, K. Siwek-Wilczyńska, Triestino Minniti, F. Porto, Giuseppe Verde, B. Gnoffo, Lucrezia Auditore, E. V. Pagano, S. Pirrone, S. De Luca, Elio Rosato, Angelo Pagano, G. Politi, E. Geraci, C. Maiolino, T. Cap, Ivano Lombardo, M. Trimarchi, Antonio Trifiro, L. Quattrocchi, G. Cardella, Michele Papa, S. Norella, F. Rizzo, P. Russotto, J. Wilczynski, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hadron, Nuclear Theory, Order (ring theory), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Isospin, 0103 physical sciences, Content (measure theory), Production (computer science), Neutron, Atomic number, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

International audience; The emission probability of Intermediate Mass Fragments (IMFs) in non-central reactions has been investigated in collisions of heavy $^{124}\hbox {Xe}$ projectiles with the two different medium-mass targets of $^{64}\hbox {Ni}$ and $^{64}\hbox {Zn}$ at the laboratory energy of 35 A MeV. The two colliding systems differ only for the target atomic number Z and, consequently, for the isospin N/Z ratio. The probability of IMFs emission from the projectile-like fragment has been measured, showing an enhancement of the IMFs emission for the neutron rich $^{64}\hbox {Ni}$ target. Most of the observed projectile break-up yield is associated with the production of only one IMF, that is, a quasi-binary splitting of projectile in two fragments in a broad range of charge asymmetry. For the events with one IMF, the relative contributions of the dynamical and statistical emissions have been evaluated. We find an enhancement of dynamical break-up probability for the neutron rich target with respect to the neutron poor one. The analysis suggests influence of the target isospin in inducing the dynamical break-up of projectile-like fragments. The new data have been also compared with previous published results of $^{112,124}\hbox {Sn}$ + $^{58,64}\hbox {Ni}$ systems, in order to disentangle between isospin effects against system-size effects on the emission probability. The comparisons between previous and new data suggest that the dynamical break-up is determined by the N/Z content of both projectile and target; for the cases here investigated, the influence of the system size on the dynamical emission probability can be excluded.

Published
2020

3. Nuclear neck-density determination at Fermi energy with CHIMERA detector

Author

Angelo Pagano, S. Pirrone, E. V. Pagano, Lucrezia Auditore, Michele Papa, P. Russotto, T. Cap, C. Maiolino, Antonio Trifiro, L. Quattrocchi, G. Politi, F. Rizzo, E. Piasecki, Luis Acosta, K. Siwek-Wilczyńska, B. Gnoffo, F. Favela, Maria Colonna, Marina Trimarchi, E. Geraci, G. Cardella, E. De Filippo, N. S. Martorana, M. B. Chatterjee, and G. Lanzalone

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, Fermi energy, Nuclear matter, 01 natural sciences, Asymmetry, Nuclear physics, Isospin, 0103 physical sciences, Nuclear fusion, Nuclear Experiment, 010306 general physics, Nucleon, Nuclear density, media_common
Abstract

Binary collisions of either stable or radioactive heavy ions at Fermi energies allow to study the nuclear reaction mechanisms under dynamical conditions of non-equilibrium and the formation of transient pieces of nuclear matter of very short mean life times at sub-normal density. An important role in the evolutionary phase of the collision is played by the gradient of the nuclear density affecting the isospin asymmetry of the reaction products by typical transport phenomena such as the isospin diffusion and drift. Experimental determination of the value of the nuclear matter density in the early phase of the collision is a crucial step towards understanding the underlying mechanism responsible for the production of clusters. In this paper a method for evaluating the nuclear density in semi-peripheral collisions in the reaction $$^{124}Sn + ^{64}Ni$$ at 35 MeV/nucleon as studied with the CHIMERA multi-particle detector is described.

Published
2020

4. Exploring the production of new superheavy nuclei with proton and α -particle evaporation channels

Author

M. Kowal, T. Cap, and K. Siwek-Wilczyńska

Subjects
Physics, Range (particle radiation), Proton, 010308 nuclear & particles physics, Fission, Nuclear Theory, Alpha particle, 01 natural sciences, Nuclear physics, Cross section (physics), 0103 physical sciences, Nuclide, Atomic number, Nuclear Experiment, 010306 general physics, Excitation
Abstract

Excitation functions for fusion-$xn$ evaporation reaction channels induced by $^{48}\mathrm{Ca}$ as well as by heavier projectiles (usually leading to smaller cross sections) on actinide targets were calculated in the framework of the fusion-by-diffusion (FBD) model. For the first time, in this approach, channels in which a proton ($pxn$) or alpha particle ($\ensuremath{\alpha}xn$) is evaporated have been included in the first step of the de-excitation cascade. To calculate the synthesis cross sections entry data such as fission barriers, ground-state masses, deformations, and shell effects of the superheavy nuclei calculated in a consistent way within the Warsaw macroscopic-microscopic model were used. The only adjustable parameter of the FBD model is the injection point distance ${s}_{inj}$. The systematics determined in our previous analysis of experimental cross sections for the synthesis of superheavy nuclei of $Z=114--118$ has been used. Excitation functions for the synthesis of selected (cross section above a few fb) new superheavy nuclides in the range of atomic numbers 112--120 are presented. Observation of 21 new heaviest isotopes is also predicted. A realistic discussion of the FBD model uncertainties is presented for the first time.

Published
2019

5. Wide-acceptance measurement of the K−/K+ ratio from Ni+Ni collisions at 1.91A GeV

Author

Mile Dželalija, M. Korolija, A. Lebedev, Xavier Bernard Lopez, P. Koczon, Ivana Weber, A. Mangiarotti, Ralf Peter Averbeck, M. Merschmeyer, M. Kirejczyk, Anton Andronic, Johann Marton, Valerie Ramillien Barret, K. Wiśniewski, R. Kotte, Pascal Dupieux, A. Reischl, N. Herrmann, K. D. Hildenbrand, Laura Fabbietti, R. H. Munzer, Nicole Bastid, D. Pelte, H. S. Xu, I. E. Yushmanov, V. Simion, A. Le Fèvre, I. M. Deppner, Y. Leifels, Mladen Kiš, K. Suzuki, Jianli Liu, T. I. Kang, M. Berger, W. Reisdorf, Peter Wagner, Piotr Jan Gasik, Paul Buehler, T. Matulewicz, Z. Fodor, Vladislav Manko, Krzysztof Piasecki, Z. Seres, E. Widmann, K. Siwek-Wilczyńska, Mihai Petrovici, Igor Gašparić, O. Czerwiakowa, P. Crochet, Z. Basrak, Fouad Rami, P. Schmidt, J. Kecskemeti, K. S. Sim, A. Zhilin, B. Sikora, Roman Čaplar, Y. Grishkin, Johann Zmeskal, O. N. Hartmann, Byung-Sik Hong, V. Zinyuk, Zhigang Xiao, Michael Cargnelli, Yongsun Kim, M. L. Benabderrahmane, V. T. Smolyankin, M. S. Ryu, A. Schüttauf, Y. H. Zhang, E. Cordier, Gabriel Stoicea, and Z. Tyminski

Subjects
Physics, Meson, 010308 nuclear & particles physics, Plane (geometry), Nuclear Theory, Kinetic energy, 7. Clean energy, 01 natural sciences, Synchrotron, Spectral line, law.invention, Nuclear physics, Distribution (mathematics), law, Yield (chemistry), 0103 physical sciences, High Energy Physics::Experiment, Polar coordinate system, Nuclear Experiment, 010306 general physics
Abstract

The FOPI Collaboration at the GSI SIS-18 synchrotron measured charged kaons from central and semicentral collisions of Ni+Ni at a beam energy of 1.91A GeV. We present the distribution of the K−/K+ ratio on the energy vs polar angle plane in the nucleon-nucleon center-of-mass frame, with and without subtraction of the contribution of ϕ(1020) meson decays to the K− yield. The acceptance of the current experiment is substantially wider compared to the previous measurement of the same colliding system. The ratio of K− to K+ energy spectra is expected to be sensitive to the in-medium modifications of basic kaon properties like mass. Recent results obtained by the HADES Collaboration at 1.23A and 1.76A GeV indicate that after inclusion of the ϕ meson decay contribution to the K− production no difference between the slopes of the K− and K+ energy spectra is observed within uncertainties. For our data a linear fit to this ratio obtained after subtraction of the ϕ meson contribution still shows a decrease with kinetic energy, although a constant value cannot be rejected. The contribution of Λ(1520)→pK− decays estimated from fitting the thermal model to the experimental yields appears to be another factor of moderate relevance.

Published
2019

6. Isospin effects on reaction dynamics at Fermi energies

Author

G. Lanzalone, Paolo Russotto, Erik Piasecki, F. Catara, Marina Trimarchi, S. Pirrone, E. G. Lanza, Marco La Commara, M.V. Andrés, E. V. Pagano, Giuseppe Politi, Lucia Quattrocchi, K. Siwek-Wilczyńska, Andrea Vitturi, A. Pagano, M. Papa, B. Gnoffo, G. Cardella, Shuhrat Kalandarov, N. S. Martorana, E. Geraci, Antonio D'Onofrio, Domenico Santonocito, Enrico De Filippo, C. Maiolino, Lucrezia Auditore, Maria Colonna, F. Rizzo, T. Cap, Antonio Trifiro, Luis Acosta, C. Beck, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, and Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Field (physics), 010308 nuclear & particles physics, QC1-999, Nuclear structure, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear matter, 01 natural sciences, 7. Clean energy, Symmetry (physics), Nuclear physics, Physics and Astronomy (all), Reaction dynamics, Isospin, 0103 physical sciences, Neutron, 010306 general physics, Nuclear Experiment, Fermi Gamma-ray Space Telescope
Abstract

International audience; The study of nuclei properties and of collision dynamics is a very active research field whose result have implications in different domains as for example astrophysics. The present and future facilities delivering radioactive ion beams with high intensity allow to extend these studies in the region far from the stability valley. New insight has thus been found on the effects of neutron richness on reaction mechanisms as well as on nuclear structure and nuclear matter properties, as for instance, the role of symmetry energy term of the nuclear Equation of State. The presence of diverse reaction products demands for highly performing and very specialized devices, also able to disentangle among different mechanisms, from fast dynamical processes to statistical emission from equilibrated sources. Numerous studies of the effects of N/Z ratio on fusion and associated processes can be found at different energies, together with many examples of the influence of neutron richness on the reaction time scale and the competition between equilibrated and prompt processes. A survey of very recent findings obtained with the CHIMERA and FARCOS devices is presented.

Published
2018

7. Statistical against dynamical PLF fission as seen by the IMF-IMF correlation functions and comparisons with CoMD model

Author

M. Trimarchi, Luis Acosta, K. Siwek-Wilczyńska, Lucrezia Auditore, L. Quattrocchi, B. Gnoffo, P. Russotto, G. Cardella, A. Pagano, Maria Colonna, G. Politi, E. Geraci, F. Rizzo, E. De Filippo, N. S. Martorana, E. V. Pagano, A. Trifirò, S. Pirrone, G. Lanzalone, F. Porto, E. Piasecki, T. Cap, Michele Papa, and C. Maiolino

Subjects
Nuclear reaction, Physics, History, 010308 nuclear & particles physics, Fission, media_common.quotation_subject, Binary number, Charge (physics), Function (mathematics), 01 natural sciences, Asymmetry, Computer Science Applications, Education, Nuclear physics, Correlation function (statistical mechanics), Physics and Astronomy (all), 0103 physical sciences, Nuclear Experiment, 010306 general physics, Fermi Gamma-ray Space Telescope, media_common
Abstract

In nuclear reactions at Fermi energies two and multi particles intensity interferometry correlation methods are powerful tools in order to pin down the characteristic time scale of the emission processes. In this paper we summarize an improved application of the fragment-fragment correlation function in the specific physics case of heavy projectile-like (PLF) binary massive splitting in two fragments of intermediate mass(IMF). Results are shown for the reverse kinematics reaction 124 Sn+64 Ni at 35 AMeV that has been investigated by using the forward part of CHIMERA multi-detector. The analysis was performed as a function of the charge asymmetry of the observed couples of IMF. We show a coexistence of dynamical and statistical components as a function of the charge asymmetry. Transport CoMD simulations are compared with the data in order to pin down the timescale of the fragments production and the relevant ingredients of the in medium effective interaction used in the transport calculations.

Published
2018

8. Signals for dynamical process from IMF-IMF correlation function

Author

S. Pirrone, K. Siwek Wilczyńska, G. Lanzalone, M. Trimarchi, E. Piasecki, E. De Filippo, Michele Papa, N. S. Martorana, F. Porto, C. Maiolino, M. Casolino, A. Pagano, E. Geraci, Lucrezia Auditore, P. Russotto, T. Cap, Antonio Trifiro, G. Politi, L. Quattrocchi, F. Rizzo, B. Gnoffo, L. Acosta, E. V. Pagano, and G. Cardella

Subjects
Physics, Correlation function (statistical mechanics), Inverse kinematics, media_common.quotation_subject, Binary number, Fermi energy, Charge (physics), Function (mathematics), Statistical physics, Nuclear Experiment, Breakup, Asymmetry, media_common
Abstract

In this paper we briefly discuss about a novel application of the IMF- IMF correlation function in the physics case of heavy projectile-like (PLF) binary fission-like massive splitting in heavy ion collisions at Fermi energy. In particular, results are shown for the reverse kinematics reaction 124Sn+64Ni at 35 AMeV that has been investigated by using the forward part of CHIMERA multi-detector. Transport CoMD simulations are compared with the data. The main analysis was performed as a function of the charge asymmetry of the decay channel. The coexistence of dynamical and statistical components as a function of the charge asymmetry of the binary breakup is clearly evidenced. We show that the IMF-IMF correlation functions, when coupled with transport calculations, can be used to pin down the timescale of the fragments production and consequently the relevant ingredients of the in medium effective interaction. Efforts are being planned to extend the method to different reaction mechanisms and nuclear systems and, also, to compare the data with different transport theory simulations.

Published
2017

9. Challenges in QCD matter physics --The scientific programme of the Compressed Baryonic Matter experiment at FAIR

Author

V. Jakovlev, R. Talukdar, Alberica Toia, V.M. Golovatyuk, P. Ivanov, Abhijit Bhattacharyya, M. Kohn, Yu. Onishchuk, M. Tanha, Suman Sau, E. Friske, L. Kumar, A. Roy, Valerica Baban, Yaping Wang, V. Blinov, D. Svirida, Pradip Kumar Sahu, D. Dementiev, A. Gomez Ramirez, M. Petris, Ming Shao, D. Blau, Yu. P. Tsyupa, A. Rost, D. P. Mahapatra, Y. F. Ryabov, D. Wielanek, Anju Bhasin, C. Lara, Saikat Biswas, Shusu Shi, E. P. Akishina, F. Seck, V. Jain, Hongfang Chen, O. Malyatina, B. Komkov, I. Carevic, V. Baublis, Raghunath Sahoo, D. Normanov, Tetyana Galatyuk, S. Amar-Youcef, Cristian Andrei, Yu. I. Bocharov, A. Vorobiev, M. Strikhanov, Y. Leifels, O. Petukhov, A. Petrovici, Dezso Varga, Oana Ristea, W. Verhoeven, J. Sánchez Rosado, Victor Golovtsov, S. Belogurov, E. Kryshen, M. Dey, Johannes Lehrbach, Y. P. Viyogi, A. V. Kazantsev, A. Himmi, M. Anđelić, Oleg Bezshyyko, Cheng Li, A. Raportirenko, Xu Cai, C. Kreidl, Daniela Bartos, T. Balog, Volker Lindenstruth, A. Chaus, M. Mohisin Khan, Mate Csanad, J. Pluta, A. Senger, Matthias Balzer, Christoph Blume, H. Appelshäuser, Di Jiang, B. Kämpfer, A. Lymanets, I. Berceanu, S. Gorbunov, S. Sarangi, V. Pospíšil, N. Heine, A. Veshikov, Yuanjing Li, V. Kushpil, Ch. Klein-Bösing, I. Selyuzhenkov, S. Razin, Guofeng Song, D. Belyakov, G. Berezin, V. Kyva, Andrei Ionut Herghelegiu, Heiko Engel, K. Schmidt, V. Klochkov, Alla Maevskaya, P.-A. Loizeau, L. Golinka-Bezshyyko, V.A. Karnaukhov, J. Bendarouach, C. Xiang, A.D. Sheremetiev, V. F. Chepurnov, Hr Schmidt, Zbigniew Sosin, M. Singla, I. Momot, O. Andreeva, I. Alexandrov, R. N. Singaraju, S. Avdeev, Evgeny Alexandrov, R. Płaneta, Gennady Ososkov, D. Hutter, A. Reinefeld, C.J. Schmidt, Andrei Dorokhov, Vikram Patel, K.-H. Becker, N. Kurepin, E. Lebedeva, C. P. Singh, Y. K. Sun, K. Jaaskelainen, Andras Szabo, J. Rożynek, Sanjeev Singh Sambyal, V. S. Negi, Krzysztof Piasecki, W. F. J. Müller, M. Baznat, N. Miftakhov, Feng Liu, N. Ahmad, L. Skoda, G. D. Kekelidze, Vladimir Ivanov, Krzysztof Kasinski, Xi-Wei Wang, D. Miskowiec, Serguei Volkov, Sudhir Raniwala, I. Tsakov, A. Nedosekin, Peter Senger, T. Barczyk, S. Dubnichka, C. Ristea, N.G. Tuturas, E. V. Atkin, D. Karmanov, W. Zabolotny, Tatiana Karavicheva, Subhasis Samanta, Yu.V. Zanevsky, S. Bähr, O. Batenkov, M. Petrovici, B. Milanovic, Muhammad Farooq, R. Karabowicz, I. Vassiliev, P. Staszel, Sheng Dong, Udo Wolfgang Kebschull, P. Koczon, Goutam Gangopadhyay, P. Zumbruch, Vladimir Plujko, Y. Berdnikov, Shue He, Volodymyr Vovchenko, V. Mialkovski, W. Zipper, T. Bus, O. Tarassenkova, S. K. Sahu, V. Militsija, Yu. Zaitsev, C. Müntz, S. K. Ghosh, Sushanta Tripathy, E. Rostchin, V. Shumikhin, I. Fröhlich, I. Panasenko, A. Laso Garcia, L. Dutka, Yu.S. Anisimov, B. Linnik, T. Tischler, A. Ivashkin, R. Kotte, Calin Besliu, T. Akishina, Rashmi Raniwala, Sheng Zheng, K. Koch, J. Kunkel, A. Shabunov, E. Lobanova, Wojciech Kucewicz, T. Breitner, M. Al-Turany, R. P. Adak, Claudiu Cornel Schiaua, S. Masciocchi, Zhongbao Yin, Xinjie Huang, Jens Wiechula, Nu Xu, I. Kisel, Christian Sturm, T. Mahmoud, V. Kalinin, A. Abuhoza, Mohd Danish Azmi, P. Zrelov, Jing Zhou, M. Dželalija, C. Deveaux, M. Goffe, Ke-Jun Wu, S. Strohauer, S. Bashir, D. Argintaru, B. Heß, A. Turowiecki, M. B. Golubeva, F. Ahmad, S. Gläßel, V. Plotnikov, Manuel Penschuck, Supriya Das, Grzegorz Kasprowicz, Vladislav Manko, O. Vasylyev, D. Kresan, L. Kudin, Yu. V. Gusakov, Dongdong Hu, Vladimir Nikulin, M. Ivanov, D. Gottschalk, Karl-Heinz Kampert, A. Kolosova, G. Caragheorgheopol, K. Dey, K. Mikhailov, Anand Kumar Dubey, J. Scholten, S. P. D. Figuli, T. Blank, Ajit Kumar, Vladimir Peshekhonov, Igor Pshenichnov, E. Badura, Michael Deveaux, I. Rostovtseva, M. Kiš, Jürgen Becker, Evgeny Karpechev, B. W. Kolb, Valery Pugatch, Xiaofeng Luo, I. Som, E. Ovcharenko, F.F. Guber, H. Büsching, H. Cherif, N. R. Panda, Zubayer Ahammed, R. Najman, Fouad Rami, M. Gumiński, J. Pieper, Jerzy Gajda, G. Kozlov, H. Jahan, A. Drozd, V. Butuzov, Joachim Stroth, I. K. Yoo, Thomas Janson, M. Petri, R. Holzmann, D. Finogeev, S. Golovnya, Ping Cao, E. Malankin, Buddhadeb Bhattacharjee, L. Meder, Junfeng Yang, Lei Zhao, C. Simon, S. Kuznetsov, I. Valin, M. Zyzak, H. Hartmann, T. Satława, Yi Wang, Anton Andronic, Daicui Zhou, Zebo Tang, M. Prokudin, V. Saveliev, Qiyan Li, I. M. Deppner, Mahitosh Mandal, F. Uhlig, J. A. Lucio Martínez, J. Book, L. Mik, S. Schatral, S. K. Pal, A. Petrovskiy, J. Pietraszko, B. Debnath, E. Usenko, O. Svoboda, Gy. Wolf, V.V. Elsha, J. Lehnert, Pengfei Lyu, S. Seddiki, Peter Fischer, Huanhuan Fan, D. Doering, J. Frühauf, C. Wendisch, Yu Zhang, V. Kozlov, P. Tlustý, Piotr Otfinowski, N. Baranova, Sergey Kiselev, J. Rautenberg, Dmitry Mal'kevich, I. Kadenko, I. Lobanov, Mikhail Zhalov, A. Rodriguez Rodriguez, D. Emschermann, Vikas Singhal, Pavel Akishin, M. Bach, P. Kravtsov, X. Zhu, C. Nandi, I. Korolko, Rongxing Yang, E. Nandy, D. Ivanischev, Anil Prakash, A. Semennikov, I. E. Yushmanov, S. Parzhitskiy, M. Vznuzdaev, A. Khvorostukhin, A. Kiryakov, Soma Mukherjee, LuYao Chen, M. Pugach, Piotr Kmon, J. Gebelein, V. Kleipa, C. Bergmann, Kai Schweda, S. Rabtsun, Victor Ivanov, Tivadar Kiss, M. Dreschmann, I. G. Alekseev, A. K. Kurilkin, A. Volochniuk, E. Krebs, A. Lebedev, V. Kramarenko, N. Topil'skaya, S. Das, S. Lebedev, S. Querchfeld, Madan M. Aggarwal, N.I. Zamiatin, Amrendra K. Singh, Swagata Mandal, A. Khanzadeev, C. Simons, Gilles Claus, U. Frankenfeld, V.V. Ivanov, A. Chernogorov, Pascal Dillenseger, V. Dobyrn, Z. Dubnichkova, S. Löchner, Bhartendu K. Singh, S. Ahmad, Rishat Sultanov, J. Kallunkathariyil, A. Wieloch, T. Matulewicz, R. Berendes, A. Shabanov, Saniya Khan, V. Friese, Anik Gupta, L. Kochenda, M. Kirejczyk, Pavel Kisel, Amlan Chakrabarti, Ashwini Kumar, Michal Koziel, A. Berdnikov, A. Sadovsky, T. O. Ablyazimov, S. Mahajan, M. Merkin, Robert Szczygiel, C. Pauly, Krzysztof Poźniak, F. Roether, Alexey Kurepin, Alexander Voronin, A. Bubak, Nikolai Shumeiko, Nicolas Winckler, A. V. Kryanev, Andrey Reshetin, A. Simakov, Sukalyan Chattopadhyay, E. M. Ilgenfritz, B. Sikora, Jihye Song, J. Hehner, Zhi Deng, M. Irfan, J. Saini, S. A. Lone, L. Naumann, D. Eschweiler, A. M. Marin Garcia, P. Kähler, O. Derenovskaya, A.P. Ierusalimov, Alexandru Jipa, K. Agarwal, T. Tolyhi, H. Malygina, Xingming Fan, Amalia Pop, Dmitry Golubkov, E. M. Verbitskaya, L. Radulescu, Ryszard S. Romaniuk, D. Pfeifer, Yifei Zhang, Rajarshi Ray, V. Zryuev, M. Teklishyn, M. Träger, S. Morozov, H. Flemming, A. Oancea, A. Wilms, P. Ghosh, A. Grzeszczuk, V. Mikhaylov, Patrick Simon Reichelt, Ankhi Roy, Sanguk Won, Vladimir Samsonov, T. Esanu, V. Akishina, D.V. Peshekhonov, A.I. Zinchenko, M. Żoładź, Xin Li, I. Sibiryak, J. Wüstenfeld, Aleksey Voronin, M. Korolev, Guangming Huang, A. Kugler, E. Kaptur, J. Michel, J. Tarasiuk, Manjit Kaur, A. Bychkov, F. Lemke, Bekhzod S Yuldashev, T. K. Bhattacharyya, S. Gorokhov, F. Schintke, P. Klaus, Adrian Byszuk, Ionel Lazanu, Dong Wang, Michael Dürr, M. Krieger, H. Deppe, Sibaji Raha, O. Sander, S. Kowalski, K. Wiśniewski, Alexander Malakhov, I. Filozova, Shengqin Feng, M. Calin, S. Reinecke, V. Kucher, M. Weber, A. Kovalchuk, V. Petráček, M. Adamczyk, K.K. Gudima, Johannes Peter Wessels, P. Sitzmann, J. Markert, V. K. Eremin, Alexandru Bercuci, Marc Winter, Mateusz Baszczyk, M.I. Ciobanu, E. Bao, M. Kuc, U. Brüning, O. V. Fateev, Piotr Maj, J. de Cuveland, M. G. Târzilă, Pavel Larionov, R. Averbeck, Jianping Cheng, Jacek Rauza, C. E. Muñoz Castillo, N. D'Ascenzo, O. Bertini, Wendi Deng, G. Kretschmar, I. Skwira-Chalot, W. Niebur, K. Oh, V. P. Ladygin, T. Morhardt, C. Höhne, M. G. Wiebusch, Partha Pratim Bhaduri, Dong Han, Oleg Karavichev, N. Herrmann, R. Visinka, F. Constantin, C. García Chávez, J. Brzychczyk, Sidharth Kumar Prasad, D. Soyk, V. V. Kirakosyan, W. Koenig, D. Bertini, Z. Majka, F. Khasanov, J. Eschke, P. Gryboś, E. Lavrik, V. Cătănescu, K. Siwek-Wilczyńska, P. K. Kurilkin, J.M. Heuser, Adeel Akram, Yu. Murin, Alexander Akindinov, A. K. Bhati, I. Kres, J. Förtsch, Rafal Kleczek, Jiajun Zheng, S. Manz, T. K. Nayak, Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), CBM, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), and Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
J/psi(3100), Phase transition, matter: interaction, Hadron, Nuclear Theory, hypernucleus, 7. Clean energy, 01 natural sciences, Critical point (thermodynamics), transport theory, hadron: gas, Nuclear Experiment, neutron star, QCD matter, Brookhaven RHIC Coll, quark gluon: plasma, Physics, Large Hadron Collider, fireball, elliptic flow, strong interaction, Observable, heavy ion, CERN LHC Coll, QCD matter, Quark-Gluon-Plasma (QGP), QCD phase diagram, strong interaction, hadronic matter, partonic matte, heavy-ion, 2-4.9 GeV/nucleon, Nuclear and High Energy Physics, Particle physics, CBM, charmonium, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Strong interaction, review, nonperturbative, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], symmetry: chiral, quantum chromodynamics: critical phenomena, strangeness, 0103 physical sciences, density: high, Darmstadt GSI FAIR, structure, 010306 general physics, equation of state, quantum chromodynamics: matter, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, nucleus, temperature: high, baryon, Neutron star, Automatic Keywords, HADES, charm
Abstract

International audience; Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 ( $\sqrt{s_{NN}}=$ 2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials ( $\mu_B > 500$ MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.

Published
2017

10. Fragmentation studies with the CHIMERA detector at LNS in Catania: recent progress

Author

H. Wu, L. Auditore, J. Blicharska, M. Papa, G. Vannini, M. Trimarchi, S. M. Li, L. Zetta, Z. Majka, Angelo Pagano, S. Lo Nigro, M. L. Sperduto, T. Paduszynski, G. Lanzalone, G. Lanzanó, A. Chbihi, I. Skwira, M. Iacono-Manno, E. La Guidara, M.F Rivet, M. Bruno, J.P. Wieleczko, K. Siwek-Wilczyńska, Maria Colonna, R. Bougault, G.R. Sechi, E. Rosato, Monica Alderighi, Amalia Pop, V. Simion, J. Cibor, N. Le Neindre, J.C. Steckmeyer, F. Rizzo, F. Porto, E. De Filippo, L. Swiderski, P. Russotto, A. Anzalone, V. Baran, Zhigang Xiao, M. Bartolucci, R. Planeta, M. D'Agostino, J. Wilczynski, M. Di Toro, A. Bonasera, P. Guazzoni, A. Grzeszczuk, R. Dayras, S. Cavallaro, I. Berceanu, S. Russo, E. Geraci, F. Giustolisi, B. Borderie, J. Brzychczyk, M. Sassi, S. Kowalski, W. Gawlikowicz, E. Piasecki, A. Trifiro, Mariano Vigilante, G. Politi, L. Arena, S. Pirrone, W. Zipper, D. Guinet, G. Cardella, G. Manfredi, F. Amorini, C. Maiolino, M. Petrovici, M. B. Chatterjee, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), A. Pagano, M. Alderighi, F. Amorini, A. Anzalone, L. Arena, L. Auditore, V. Baran, M. Bartolucci, I. Berceanu, J. Blicharska, J.Brzychczyk, A. Bonasera, B. Borderie, R. Bougault, M. Bruno, G.Cardella, S. Cavallaro, M.B. Chatterjee, A. Chbihi, J. Cibor, M.Colonna, M. D'Agostino, R. Dayra, E. De Filippo, M. Di Toro, W.Gawlikowicz, E. Geraci, F. Giustolisi, A. Grzeszczuk, P. Guazzoni, D.Guinet, M. Iacono-Manno, S. Kowalski, E. La Guidara, G. Lanzano', G.Lanzalone, N.Le Neindre, S. Li, S. Lo Nigro, C. Maiolino, Z. Majka, G. Manfredi, T. Paduszynski, M. Papa, M. Petrovici, E. Piasecki, S.Pirrone, R. Planeta, G. Politi, A. Pop, F. Porto, M.F. Rivet, E. Rosato, F. Rizzo, S. Russo, P. Russotto, M. Sassi, G. Sechi, V. Simion, K. Siwek-Wilczynska, I. Skwira, M.L. Sperduto, J.C. Steckmeyer, L. Swiderski, A. Trifiro`, M. Trimarchi, G. Vannini, M. Vigilante, J.P. Wieleczko, J. Wilczynski, H. Wu, Z. Xiao, L. Zetta, W. Zipper, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Nuclear reaction, Nuclear and High Energy Physics, APPARATO DI RIVELAZIONE, TECNICHE DI IDENTIFICAZIONE, REAZIONI NUCLEARI SEMI-PERIFERICHE, PRODUZIONE DI FRAMMENTI DI MASSA INTERMEDIA, TEMPI DI PRODUZIONE DEI FRAMMENTI, Cyclotron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, 01 natural sciences, Particle identification, law.invention, Ion, Nuclear physics, law, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Physics, 010308 nuclear & particles physics, Detector, Charged particle, Time of flight, Nucleon
Abstract

The new detector CHIMERA, in its final 4π configuration, has been installed at Laboratori Nazionali del Sud (LNS) in Catania in January 2003. Beams of different energies ranging from protons to Au ions were delivered by the Tandem and the Super Conducting Cyclotron for nuclear reaction studies, in agreement with the approval of the Scientific Advisory Committee of LNS. Recent experimental results confirm very low energy thresholds of the trigger (below 0.5 MeV/nucleon), ensured within a wide dynamical range. Good characteristics of identification of light charged particles and heavy fragments have been obtained by using three detection techniques: Δ E-E , Δ E -time of flight, and the Pulse-Shape discrimination method. We present results of recent analysis concerning the production of intermediate mass fragments (IMF) in semi-peripheral collisions. Our results combined with theoretical Boltzmann-Nordheim-Vlasov simulations clearly demonstrate the presence of very fast processes of IMF production in the overlapping region of the target and projectile nuclei during re-separation, i.e. in the time scale comparable with the collision time. Evidence for slower, sequential-like production of IMF's is also shown.

Published
2004

11. Correlations between emission timescale of fragments and isospin dynamics in ^{124}Sn+^{64}Ni and ^{112}Sn+^{58}Ni reactions at 35A MeV

Author

E. De Filippo, A. Pagano, P. Russotto, F. Amorini, A. Anzalone, L. Auditore, V. Baran, I. Berceanu, B. Borderie, R. Bougault, M. Bruno, T. Cap, G. Cardella, S. Cavallaro, M. B. Chatterjee, A. Chbihi, M. Colonna, M. D'Agostino, R. Dayras, M. Di Toro, J. Frankland, E. Galichet, W. Gawlikowicz, E. Geraci, A. Grzeszczuk, P. Guazzoni, S. Kowalski, E. La Guidara, G. Lanzalone, G. Lanzanò, N. Le Neindre, C. Maiolino, M. Papa, E. Piasecki, S. Pirrone, R. Płaneta, G. Politi, A. Pop, F. Porto, M. F. Rivet, F. Rizzo, K. Schmidt, K. Siwek Wilczyńska, I. Skwira Chalot, A. Trifirò, M. Trimarchi, G. Verde, J. P. Wieleczko, J. Wilczyński, L. Zetta, W. Zipper, LOMBARDO, IVANO, ROSATO, ELIO, VIGILANTE, MARIANO, E. De Filippo, A. Pagano, P. Russotto, F. Amorini, A. Anzalone, L. Auditore, V. Baran, I. Berceanu, B. Borderie, R. Bougault, M. Bruno, T. Cap, G. Cardella, S. Cavallaro, M. B. Chatterjee, A. Chbihi, M. Colonna, M. D'Agostino, R. Dayra, M. Di Toro, J. Frankland, E. Galichet, W. Gawlikowicz, E. Geraci, A. Grzeszczuk, P. Guazzoni, S. Kowalski, E. La Guidara, G. Lanzalone, G. Lanzanò, N. Le Neindre, I. Lombardo, C. Maiolino, M. Papa, E. Piasecki, S. Pirrone, R. Płaneta, G. Politi, A. Pop, F. Porto, M. F. Rivet, F. Rizzo, E. Rosato, K. Schmidt, K. Siwek-Wilczyńska, I. Skwira-Chalot, A. Trifirò, M. Trimarchi, G. Verde, M. Vigilante, J. P. Wieleczko, J. Wilczyński, L. Zetta, W. Zipper, E., De Filippo, A., Pagano, P., Russotto, F., Amorini, A., Anzalone, L., Auditore, V., Baran, I., Berceanu, B., Borderie, R., Bougault, M., Bruno, T., Cap, G., Cardella, S., Cavallaro, M. B., Chatterjee, A., Chbihi, M., Colonna, M., D'Agostino, R., Dayra, M., Di Toro, J., Frankland, E., Galichet, W., Gawlikowicz, E., Geraci, A., Grzeszczuk, P., Guazzoni, S., Kowalski, E., La Guidara, G., Lanzalone, G., Lanzanò, N., Le Neindre, Lombardo, Ivano, C., Maiolino, M., Papa, E., Piasecki, S., Pirrone, R., Płaneta, G., Politi, A., Pop, F., Porto, M. F., Rivet, F., Rizzo, Rosato, Elio, K., Schmidt, K., Siwek Wilczyńska, I., Skwira Chalot, A., Trifirò, M., Trimarchi, G., Verde, Vigilante, Mariano, J. P., Wieleczko, J., Wilczyński, L., Zetta, and W., Zipper

Subjects
timescale, isospin, semiperipheral collisions, intermediate mass fragment, isospin migration, HEAVY ION REACTIONS, emission timescale, Nuclear Theory, Nuclear Experiment, fragment emission
Abstract

We present a new experimental method to correlate the isotopic composition of intermediate mass fragments (IMF) emitted at midrapidity in semiperipheral collisions with the emission timescale: IMFs emitted in the early stage of the reaction show larger values of (N/Z) isospin asymmetry, stronger angular anisotropies, and reduced odd-even staggering effects in neutron to proton ratio (N/Z) distributions than those produced in sequential statistical emission. All these effects support the concept of isospin “migration”, that is sensitive to the density gradient between participant and quasispectator nuclear matter, in the so called neck fragmentation mechanism. By comparing the data to a stochastic mean field (SMF) simulation we show that this method gives valuable constraints on the symmetry energy term of nuclear equation of state at subsaturation densities. An indication emerges for a linear density dependence of the symmetry energy.

Published
2012

12. Probing the symmetry energy at low density using observables from neck fragmentation

Author

G. Cardella, Lucrezia Auditore, M. Trimarchi, Michele Papa, R. Planeta, A. Trifirò, A. Grzeszczuk, L. Zetta, Maria Colonna, E. La Guidara, Mariano Vigilante, G. Politi, F. Porto, Giuseppe Verde, F. Rizzo, L. Acosta, S. Pirrone, C. Maiolino, K. Siwek-Wilczyńska, E. V. Pagano, I. Skwira-Chalot, F. Amorini, Ji-Youn Han, C. Agodi, J. Wilczyński, E. Piasecki, Triestino Minniti, G. Lanzalone, A. Pagano, P. Guazzoni, R. Gianì, I. Berceanu, E. Geraci, Ivano Lombardo, Amalia Pop, V. Baran, T. Cap, L. Quattrocchi, L. Grassi, P. Russotto, Elio Rosato, E. De Filippo, L. Francalanza, S. Lunardi, P.G. Bizzeti, C. Bucci, M. Chiari, A. Dainese, P. Di Nezza, R. Menegazzo, A. Nannini, C. Signorini, J.J. Valiente-Dobon, E., Defilippo, L., Acosta, C., Agodi, F., Amorini, A., Anzalone, L., Auditore, V. Baran I., Berceanu, T., Cap, G., Cardella, M., Colonna, L., Francalanza, E., Geraci, R., Gianì, L., Grassi, A., Grzeszcuk, P., Guazzoni, J., Han, E., La Guidara, G., Lanzalone, Lombardo, Ivano, C., Maiolino, T., Minniti, A., Pagano, E. V., Pagano, M., Papa, E., Piasecki, R., Planeta, S., Pirrone, G., Politi, A., Pop, F., Porto, L., Quattrocchi, F., Rizzo, Rosato, Elio, P., Russotto, K., Siwek Wilczynska, I., Skwira Chalot, A., Trifiró, M., Trimarchi, G., Verde, Vigilante, Mariano, J., Wilczynski, and L., Zetta

Subjects
Physics, Projectile, QC1-999, Observable, ionic collisions, isospin-dependent quantum, Fragmentation (mass spectrometry), fragmentation, fragments, Low density, Incident energy, NUCLEAR COLLISIONS, Atomic physics, Nuclear Experiment
Abstract

Semi-peripheral collisions of ^{64}Ni + ^{124}Sn in direct and inverse kinematics, at 35 A MeV incident energy, are studied to characterize the dynamical origin and align-ments properties of fragments emission at midrapidity. This emission is partly due to the fragmentation of a transient neck joining the projectile and target in the early stages of the reaction. Recently we exploited observable from neck fragmentation to constraint the density dependence of the symmetry energy. In this contribution we focus on the density evolution of the mid-rapidity source. An experimental survey is suggested to check if data are consistent with the formation of neck fragments in a dilute density region in contact with the projectile-like and target-like spectators at normal saturation density.

Published
2014

13. Sensitivity of N/Z ratio in projectile break-up of isobaric systems

Author

T. Cap, L. Quattrocchi, Giuseppe Verde, E. V. Pagano, S. Pirrone, E. Piasecki, K. Siwek-Wilczyńska, G. Lanzalone, M. Trimarchi, G. Marquínez-Durán, Michele Papa, L. Acosta, Maria Colonna, F. Porto, A. Pagano, C. Maiolino, Lucrezia Auditore, B. Gnoffo, F. Rizzo, V. Baran, Mariano Vigilante, A. Trifirò, Ivano Lombardo, P. Russotto, J. Wilczyński, G. Politi, Triestino Minniti, S. Norella, G. Cardella, L. Francalanza, Elio Rosato, E. De Filippo, Greco, V., De Filippo, E., Pagano, A., Russotto, P., Acosta, L., Auditore, L., Baran, V., Cap, T., Cardella, G., Colonna, M., Francalanza, L., Gnoffo, B., Lanzalone, G., Lombardo, I., Marquínez-Durán, G., Maiolino, C., Minniti, T., Norella, S., Pagano, E. V., Papa, M., Piasecki, E., Pirrone, S., Politi, G., Porto, F., Quattrocchi, L., Rizzo, F., Rosato, E., Trifirò, A., Trimarchi, M., Verde, G., Vigilante, M., Siwek-Wilczyńska, K., and Wilczyński, J.

Subjects
Nuclear reaction, Fission, Chemistry, Physics, QC1-999, Nuclear Theory, Physics and Astronomy (all), Isotopes of tin, Isotopes of xenon, Isobaric process, Neutron, Atomic physics, Nucleon, Nuclear Experiment, Radioactive decay
Abstract

The binary break-up of projectile-like fragments in non central heavy-ion collisions follows different decay patterns, from equilibrated emission towards dynamical (prompt) fission. Recently, comparing two systems with different N/Z in the entrance channel, it has been shown that the dynamical emission cross-section is enhanced for the most neutron rich system while the statistical emission cross-section is independent from the isotopic composition. In order to understand this dependence and disentangle it from the initial size of the nuclei, we have studied the two isobaric systems 124 Xe +64 Zn and 124 Xe +64 Ni at 35 A MeV (InKiIsSy experiment), in comparison with the previous studied reactions (124 Sn +64 Ni and 112 Sn +58 Ni ) at the same bombarding energy. We present the first results evidencing a striking similar effect in the dynamical decay as a function of the N/Z of the target for equal size systems.

Published
2016

14. Strange meson production in Al plus Al collisions at 1.9 AGeV

Author

K. S. Sim, Michael Cargnelli, Fouad Rami, Jianli Liu, I. M. Deppner, J. Zmeskal, Xavier Bernard Lopez, P. Koczon, K. Wiśniewski, Byung-Sik Hong, Anton Andronic, R. Čaplar, Y. Leifels, I. Weber, Vladislav Manko, Peter Wagner, Paul Buehler, I. E. Yushmanov, V. Simion, Pascal Dupieux, O. Czerwiakowa, Mihai Petrovici, Ralf Peter Averbeck, A. Lebedev, Z. Basrak, A. Zhilin, P. Crochet, V. T. Smolyankin, K. Suzuki, T. I. Kang, Johann Marton, T. Matulewicz, M. Berger, M. S. Ryu, E. Widmann, Laura Fabbietti, Z. Fodor, R. Kotte, Z. Seres, M. L. Benabderrahmane, N. Herrmann, K. D. Hildenbrand, A. Le Fèvre, P. Schmidt, O. N. Hartmann, A. Schüttauf, V. Zinyuk, Y. Grishkin, B. Sikora, M. Kirejczyk, M. Kiš, R. H. Munzer, Nicole Bastid, Zhigang Xiao, Yongsun Kim, Krzysztof Piasecki, K. Siwek-Wilczyńska, W. Reisdorf, Piotr Jan Gasik, Y. H. Zhang, Z. Tyminski, M. Dželalija, Igor Gašparić, J. Kecskemeti, Valerie Ramillien Barret, A. Reischl, Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), FOPI, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de Clermont ( LPC ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Pluridisciplinaire Hubert Curien ( IPHC ), and Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA )

Subjects
Nuclear and High Energy Physics, Meson production, Meson, Nuclear Theory, FOS: Physical sciences, Inverse, threshold: production, heavy-ion collisions, sis energies, antikaon production, kaon production, detector, matter, fopi, anisotropy, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Kinetic energy, K+, 01 natural sciences, 7. Clean energy, K: yield, K, beam: energy, Nuclear physics, 0103 physical sciences, transport theory, Nuclear Experiment (nucl-ex), [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Anisotropy, Nuclear Experiment, Line (formation), Physics, energy: kinetic, 010308 nuclear & particles physics, Phi(1020), nucleus nucleus: scattering, meson: decay, Yield (chemistry), K: production, aluminum, slope, Production (computer science), High Energy Physics::Experiment, strange meson: production
Abstract

The production of K$^+$, K$^-$ and $\varphi$(1020) mesons is studied in Al+Al collisions at a beam energy of 1.9A GeV which is close or below the production threshold in NN reactions. Inverse slopes, anisotropy parameters, and total emission yields of K$^{\pm}$ mesons are obtained. A comparison of the ratio of kinetic energy distributions of K$^-$ and K$^+$ mesons to the HSD transport model calculations suggests that the inclusion of the in-medium modifications of kaon properties is necessary to reproduce the ratio. The inverse slope and total yield of $\phi$ mesons are deduced. The contribution to K$^-$ production from $\phi$ meson decays is found to be [17 $\pm$ 3 (stat) $^{+2}_{-7}$ (syst)] %. The results are in line with previous K$^{\pm}$ and $\phi$ data obtained for different colliding systems at similar incident beam energies., Comment: 16 pages, 11 figures

Published
2016

15. Determination of impact parameters in aligned breakup of projectile-like fragments in 197Au + 197Au collisions at 23AMeV

Author

R. Najman, L. Grassi, Giuseppe Verde, G. Lanzalone, W. Zipper, F. Rizzo, S. Pirrone, A. Grzeszczuk, Tomasz Kozik, E. Geraci, G. Cardella, Lucrezia Auditore, Ivano Lombardo, T. Cap, E. La Guidara, M. Trimarchi, Michele Papa, F. Amorini, Antonio Trifiro, P. Russotto, E. Piasecki, G. Politi, R. Płaneta, A. Pagano, K. Siwek-Wilczyńska, N. G. Nicolis, J. Wilczyński, Ji-Youn Han, E. De Filippo, and I. Skwira-Chalot

Subjects
Physics, Reaction yields, Projectile, Nuclear Theory, General Physics and Astronomy, Breakup, Nuclear & Particles Physics, Mathematical Sciences, Nuclear physics, Physics and Astronomy (all), Physical Sciences, zderzenia ciężkich jonów, reakcje jądrowe, Nuclear Experiment
Abstract

Author(s): Cap, T; Siwek-Wilczynska, K; Wilczynski, J; Amorini, F; Auditore, L; Cardella, G; De Filippo, E; Geraci, E; Grassi, L; Grzeszczuk, A; La Guidara, E; Han, J; Kozik, T; Lanzalone, G; Lombardo, I; Najman, R; Nicolis, NG; Pagano, A; Papa, M; Piasecki, E; Pirrone, S; Planeta, R; Politi, G; Rizzo, F; Russotto, P; Skwira-Chalot, I; Trifiro, A; Trimarchi, M; Verde, G; Zipper, W

Published
2016

16. Investigation of the freeze-out configuration in the 197Au + 197Au reaction at 23 AMeV

Author

A. Pagano, G. Lanzalone, I. Skwira-Chalot, S. Pirrone, Tomasz Kozik, Lucrezia Auditore, E. Geraci, E. Piasecki, G. Politi, P. Russotto, R. Płaneta, J. Wilczynski, E. De Filippo, S. Kowalski, Ivano Lombardo, A. Grzeszczuk, M. Trimarchi, T. Cap, R. Najman, Antonio Trifiro, F. Rizzo, F. Amorini, G. Cardella, W. Zipper, Z. Majka, A. Sochocka, N. G. Nicolis, and K. Siwek-Wilczyńska

Subjects
Physics, Nuclear physics, Physics and Astronomy (all), Physics::Plasma Physics, General Physics and Astronomy, Astrophysics, reakcje jądrowe, Nuclear Experiment, struktura jądra atomowego
Abstract

According to the model predictions, observation of toroidal objects is expected in collisions of heavy ion at low incident energies. Comparison between experimental data and model predictions which may indicate the formation of flat/toroidal nuclear systems is shown.

Published
2016

17. Centrality dependence of subthreshold $\phi$ meson production in Ni + Ni collisions at 1.9A GeV

Author

Xavier Bernard Lopez, P. Koczon, Byung-Sik Hong, Anton Andronic, Fouad Rami, Johann Marton, R. Kotte, D. Pelte, O. N. Hartmann, Piotr Jan Gasik, A. Mangiarotti, N. Herrmann, Igor Gašparić, A. Le Fèvre, K. D. Hildenbrand, Y. Leifels, J. Kecskemeti, K. S. Sim, Y. H. Zhang, E. Cordier, Michael Cargnelli, M. Merschmeyer, M. L. Benabderrahmane, E. Widmann, V. Zinyuk, Valerie Ramillien Barret, M. Berger, J. Zmeskal, Gabriel Stoicea, Z. Fodor, I. Weber, B. Sikora, Zhigang Xiao, Z. Seres, A. Reischl, Mihai Petrovici, Laura Fabbietti, Yongsun Kim, Ralf Peter Averbeck, W. Reisdorf, Peter Wagner, Paul Buehler, P. Schmidt, Z. Tyminski, M. Kiš, K. Suzuki, M. Dželalija, P. Crochet, K. Wiśniewski, Pascal Dupieux, T. I. Kang, O. Czerwiakowa, Z. Basrak, Jianli Liu, M. Korolija, I. M. Deppner, A. Lebedev, R. H. Munzer, Nicole Bastid, V. Simion, T. Matulewicz, Krzysztof Piasecki, K. Siwek-Wilczyńska, I. E. Yushmanov, A. Schüttauf, R. Čaplar, M. Kirejczyk, H. S. Xu, Y. Grishkin, V. T. Smolyankin, M. S. Ryu, Vladislav Manko, A. Zhilin, Laboratoire de Physique de Clermont ( LPC ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Pluridisciplinaire Hubert Curien ( IPHC ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA ), FOPI, Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Particle physics, heavy ion: scattering, Meson, Strangeness, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Kinetic energy, 01 natural sciences, K-: production, beam: energy, Nuclear physics, 25.75.Dw, 0103 physical sciences, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], 010306 general physics, Power function, Nuclear Experiment, impact parameter, Physics, energy: kinetic, 010308 nuclear & particles physics, Phi meson, Phi(1020): multiplicity, Phi(1020): production, Exponent, FOPI, High Energy Physics::Experiment, spectrometer, Impact parameter, Centrality, 13.60.Le
Abstract

We analysed the $\phi$ meson production in central Ni+Ni collisions at the beam kinetic energy of 1.93A GeV with the FOPI spectrometer and found the production probability per event of $[8.6 ~\pm~ 1.6 ~(\text{stat}) \pm 1.5 ~(\text{syst})] \times 10^{-4}$. This new data point allows for the first time to inspect the centrality dependence of the subthreshold $\phi$ meson production in heavy-ion collisions. The rise of $\phi$ meson multiplicity per event with mean number of participants can be parameterized by the power function with exponent $\alpha = 1.8 \pm 0.6$. The ratio of $\phi$ to $\text{K}^-$ production yields seems not to depend within the experimental uncertainties on the collision centrality, and the average of measured values was found to be $0.36 \pm 0.05$., Comment: 9 pages, 5 figures

Published
2016

18. Freeze-out configuration properties in theAu197+Au197reaction at23AMeV

Author

S. Pirrone, Lucrezia Auditore, J. Wilczyński, P. Russotto, I. Skwira-Chalot, G. Politi, R. Płaneta, W. Zipper, F. Rizzo, Ivano Lombardo, M. Trimarchi, E. Piasecki, R. Najman, G. Cardella, A. Pagano, T. Cap, Antonio Trifiro, A. Sochocka, K. Siwek-Wilczyńska, G. Lanzalone, N. G. Nicolis, Tomasz Kozik, A. Grzeszczuk, E. Geraci, F. Amorini, E. De Filippo, S. Kowalski, and Z. Majka

Subjects
Physics, Nuclear physics, Efficiency factor, Nuclear and High Energy Physics, Toroid, Nuclear Theory, Code (cryptography), Experimental data, Nuclear Experiment
Abstract

Data from the experiment on the 197Au + 197Au reaction at 23 AMeV are analyzed with an aim to find signatures of exotic nuclear configurations such as toroid-shaped objects. The experimental data are compared with predictions of the ETNA code dedicated to look for such configurations and with the QMD model. A novel criterion of selecting events possibly resulting from the formation of exotic freeze-out configurations, "the efficiency factor", is tested. Comparison between experimental data and model predictions may indicate for the formation of flat/toroidal nuclear systems.

Published
2015

19. ISOTOPIC EFFECTS IN EMISSION OF INTERMEDIATE MASS FRAGMENTS IN THE 124<font>Sn</font> + 64<font>Ni</font> REACTION AT 35 MeV/NUCLEON

Author

T. Cap, K. Siwek-Wilczyńska, J. Wilczyński, and I. Skwira-Chalot

Subjects
Physics, Nuclear and High Energy Physics, Isotope, Nuclear Theory, General Physics and Astronomy, Rest frame, Nuclear physics, Mass, Fragmentation (mass spectrometry), Neutron, Angular dependence, Atomic physics, Nuclear Experiment, Nucleon
Abstract

We present results of a new analysis of the experiment carried out by the REVERSE-ISOSPIN collaboration on the 124 Sn + 64 Ni reaction at the bombarding energy of 35 MeV/nucleon. The mass numbers of the intermediate mass fragments (isotopes of Be , B and C ) could be resolved in this experiment. Angular distributions of the neck fragmentation products in the rest frame of the primary projectile-like fragment were studied. The angular dependence of the isotopic ratios of the intermediate mass fragments proves the effect of neutron enrichment of the neck region.

Published
2011

20. The Physics of Nucleus - Nucleus Fusion and Synthesis of Super Heavy Nuclei

Author

K. Siwek-Wilczyńska, Janusz Wilczyński, and Władysław J. Świαtecki

Subjects
Flexibility (engineering), Physics, Fusion, Theoretical physics, medicine.anatomical_structure, Conceptual framework, Nuclear Theory, medicine, General Physics and Astronomy, Nuclear Experiment, Nucleus
Abstract

A descriptive account is given of the “Fusion by Diffusion” theory of nucleus-nucleus amalgamation. The stress is on explaining the physical elements that go into a theory that provides a general conceptual framework for describing nucleus-nucleus fusion, but whose detailed implementation is subject to some flexibility. Despite notable successes, the theory is in need of improvements both as regards the inclusion of important physical refinements and the optimal choice of its adjustable parameter(s).

Published
2008

21. In-beam γ-ray spectroscopy at the proton dripline: 23Al

Author

P. Adrich, Alexandra Gade, M. D. Bowen, D. Bazin, A. Obertelli, L. A. Riley, D. Weisshaar, C. M. Campbell, T. Glasmacher, S. McDaniel, J. M. Cook, D. McGlinchery, K. Siwek, K. E. Hosier, B. A. Brown, and J. A. Tostevin

Subjects
Physics, Nuclear and High Energy Physics, Proton, 010308 nuclear & particles physics, Proton decay, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Gamma ray, FOS: Physical sciences, 01 natural sciences, 7. Clean energy, Physics::Geophysics, Excited state, 0103 physical sciences, Physics::Space Physics, Physics::Accelerator Physics, Neutron, Atomic physics, Proton emission, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Spectroscopy, Nuclear Experiment
Abstract

We report on the first in-beam $\gamma$-ray spectroscopy of \nuc{23}{Al} using two different reactions at intermediate beam energies: inelastic scattering off \nuc{9}{Be} and heavy-ion induced one-proton pickup, \nuc{9}{Be}(\nuc{22}{Mg},\nuc{23}{Al}$+\gamma$)X, at 75.1 MeV/nucleon. A $\gamma$-ray transition at 1616(8) keV -- exceeding the proton separation energy by 1494 keV -- was observed in both reactions. From shell model and proton decay calculations we argue that this $\gamma$-ray decay proceeds from the core-excited $7/2^+$ state to the $5/2^+$ ground state of \nuc{23}{Al}. The proposed nature of this state, $[\nuc{22}{Mg}(2^+_1) \otimes \pi d_{5/2}]_{7/2+}$, is consistent with the presence of a gamma-branch and with the population of this state in the two reactions., Comment: Physics Letters B, accepted

Published
2008
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22. Isospin against size effects in projectile dynamical fission for 112,124Sn+58,64Ni and 124Xe+64Zn reactions at 35 A.MeV

Author

A. Grzeszczuk, Lucrezia Auditore, W. Zipper, L. Francalanza, N. Giudice, M. D'Andrea, J. Wilczyński, E. De Filippo, F. Fichera, G. Politi, M. Bruno, L. Quattrocchi, Chiara Guazzoni, I. Berceanu, G. Sacca, Maria Colonna, J.P. Wieleczko, E. La Guidara, S. Kowalski, Michele Papa, F. Porto, L. Zetta, P. Russotto, Triestino Minniti, T. Cap, Giuseppe Verde, M. Di Toro, A. Chbihi, S. Cavallaro, I. Skwira-Chalot, M.F Rivet, A. Anzalone, S. Pirrone, Ivano Lombardo, Antonio Trifiro, G. Marquínez-Durán, L. Acosta, V. Baran, E. V. Pagano, Katarzyna Schmidt, E. Geraci, P. Zambon, M. Trimarchi, F. Amorini, G. Lanzano, F. Riccio, K. Siwek-Wilczyńska, G. Cardella, Mariano Vigilante, M. D'Agostino, M. B. Chatterjee, G. Lanzalone, A. Grimaldi, E. Piasecki, F. Rizzo, R. Giani, G. Passaro, Elio Rosato, R. Płaneta, A. Castoldi, C. Maiolino, A. Pagano, P. Guazzoni, B. Borderie, C. Boiano, B. Gnoffo, Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Giorgio Giardina, Avazbek K. Nasirov, Giuseppe Mandaglio, G.Giardina, A.K.Nasirov, G.Mandaglio, P., Russotto, E., De Filippo, A., Pagano, E., Piasecki, L., Acosta, F., Amorini, A., Anzalone, L., Auditore, V., Baran, I., Berceanu, C., Boiano, B., Borderie, M., Bruno, T., Cap, G., Cardella, A., Castoldi, S., Cavallaro, M. B., Chatterjee, A., Chbihi, M., Colonna, M., D’Agostino, M., D’Andrea, M., Di Toro, F., Fichera, L., Francalanza, E., Geraci, R., Gianì, B., Gnoffo, A., Grimaldi, A., Grzeszczuk, C., Guazzoni, P., Guazzoni, N., Giudice1, S., Kowalski, E., La Guidara, G., Lanzalone4, G., Lanzanò, Lombardo, Ivano, C., Maiolino, G., Marquínez Durán, T., Minniti, M., Papa, E. V., Pagano, G., Passaro, S., Pirrone, R., Planeta, G., Politi, F., Porto, L., Quattrocchi, M. F., Rivet, Rosato, Elio, F., Riccio, F., Rizzo, G., Saccà, K., Schmidt, K., Siwek Wilczyska, I., Skwira Chalot, A., Trifirò, M., Trimarchi, G., Verde, Vigilante, Mariano, J. P., Wieleczko, J., Wilczyński, P., Zambon, L., Zetta, W., Zipper, and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
History, Fission, Nuclear Theory, Nuclear physics, Physics and Astronomy (all), sezele, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Thermal and statistical models, Education, Physics and Astronomy (all), Spin, isospin effects, statistical and dynamical fission, Neutron, Nucleon distributions and halo features, Spin (physics), Nuclear reactioon, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS, Spin, parity, and isobaric spin, General properties of fission, Physics, 21.10.Hw, 27.60.+j, 24.75.+i, 25.85.-w, 21.10.Gv, 24.10.Pa, sezele, Projectile, Nuclear fission, Parity (physics), and isobaric spin, Computer Science Applications, Entrance channel, parity, Isospin, Fission reactions, Atomic physics, Beam energy
Abstract

In past experiments, mass asymmetric projectile-target combinations 124Sn+64Ni and 112Sn+58Ni were investigated at ELab(112,124Sn)=35 A.MeV beam energy by using the 4π multi-detector CHIMERA. From a quantitative comparison of cross sections associated to Statistical and Dynamical Fission of the Projectile-Like Fragments, it resulted that Dynamical Fission process is about two times more probable in the neutron rich 124Sn+64Ni system than in the 112Sn +58 Ni neutron poor one. In contrast, no sizable difference was found for Statistical Fission mechanism. The observed difference in the strength of the Dynamical effects could arise from the difference in entrance channel Isospin (N/Z) content. In order to disentangle Isospin effects from effects due to the different masses of the two systems, a new experiment 124Xe+64Zn at 35 A.MeV beam energy has been recently carried out.

Published
2013

23. Influence ofϕmesons on negative kaons in Ni + Ni collisions at1.91A GeV beam energy

Author

M. Kiš, Philippe Crochet, Ken Suzuki, Byung-Sik Hong, Laura Fabbietti, Krzysztof Piasecki, Y. Leifels, Xavier Bernard Lopez, Zhigang Xiao, K. D. Hildenbrand, Fouad Rami, Ya-Peng Zhang, R. Čaplar, P. Wagner, Anton Andronic, Y. Grishkin, M. Dželalija, Paul Buehler, R. Kotte, J. L. Liu, Y. J. Kim, K. S. Sim, P. Gasik, I. E. Yushmanov, K. Siwek-Wilczyńska, W. Reisdorf, A. Le Fèvre, M. L. Benabderrahmane, Johann Marton, V. Simion, Mihai Petrovici, Vladislav Manko, O. N. Hartmann, V. T. Smolyankin, M. S. Ryu, T. Matulewicz, Michael Cargnelli, J. Zmeskal, V. Zinyuk, A. Zhilin, B. Sikora, N. Herrmann, A. Schüttauf, M. Berger, Z. Seres, T. I. Kang, I. Weber, Ralf Peter Averbeck, Z. Tyminski, Z. Fodor, Pascal Dupieux, O. Czerwiakowa, Z. Basrak, Eberhard Widmann, P. Schmidt, A. Lebedev, K. Wis̈niewski, P. Koczon, I. M. Deppner, Valerie Ramillien Barret, A. Reischl, M. Kirejczyk, Igor Gašparić, J. Kecskemeti, R. H. Munzer, and Nicole Bastid

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Meson production, Meson, Nuclear Theory, Inverse, High Energy Physics::Experiment, Nuclear Experiment, Kinetic energy, Beam energy
Abstract

$\ensuremath{\phi}$ and ${\mathrm{K}}^{\ensuremath{-}}$ mesons from Ni+Ni collisions at the beam energy of $1.91A$ GeV have been measured by the FOPI spectrometer, with a trigger selecting central and semicentral events amounting to 52% of the total cross section. The phase-space distributions, and the total yield of ${\mathrm{K}}^{\ensuremath{-}}$, as well as the kinetic energy distribution and the total yield of $\ensuremath{\phi}$ mesons are presented. The $\ensuremath{\phi}/$ ${\mathrm{K}}^{\ensuremath{-}}$ ratio is found to be $0.44\ifmmode\pm\else\textpm\fi{}0.07{(\text{stat})}_{\ensuremath{-}0.10}^{+0.16}(\text{syst})$, meaning that about 22% of ${\mathrm{K}}^{\ensuremath{-}}$ mesons originate from the decays of $\ensuremath{\phi}$ mesons, occurring mostly in vacuum. The inverse slopes of direct kaons are up to about 15 MeV larger than the ones extracted within the one-source model, signaling that a considerable share of gap between the slopes of ${\mathrm{K}}^{+}$ and ${\mathrm{K}}^{\ensuremath{-}}$ could be explained by the contribution of $\ensuremath{\phi}$ mesons to negative kaons.

Published
2015

24. Production cross sections for intermediate mass fragments from dynamical and statistical decay of projectile-like fragments inSn124+Ni64andSn112+Ni58collisions at35AMeV

Author

J.D. Frankland, M. Trimarchi, P. Russotto, E. V. Pagano, M. D'Agostino, M. B. Chatterjee, S. Pirrone, A. Chbihi, R. Bougault, K. Siwek-Wilczyńska, C. Maiolino, E. Galichet, E. De Filippo, G. Politi, S. Kowalski, F. Porto, W. Zipper, Giuseppe Verde, N. Le Neindre, I. Berceanu, W. Gawlikowicz, G. Lanzalone, J. Wilczynski, L. Acosta, M. Bruno, L. Quattrocchi, G. Lanzano, L. Zetta, G. Cardella, A. Grzeszczuk, Mariano Vigilante, P. Guazzoni, Maria Colonna, Angelo Pagano, M. Papa, E. Piasecki, Triestino Minniti, T. Cap, Elio Rosato, M. Di Toro, F. Rizzo, Ivano Lombardo, V. Baran, B. Gnoffo, I. Skwira-Chalot, B. Borderie, M.F. Rivet, Antonio Trifiro, L. Francalanza, S. Cavallaro, Lucrezia Auditore, K. Schmidt, R. Płaneta, E. Geraci, and J.P. Wieleczko

Subjects
Physics, Nuclear and High Energy Physics, Reaction mechanism, Astrophysics::High Energy Astrophysical Phenomena, Production (computer science), Astrophysics::Cosmology and Extragalactic Astrophysics, Sensitivity (control systems), Atomic physics, Nuclear Experiment, 7. Clean energy, Astrophysics::Galaxy Astrophysics, Energy (signal processing), Charged particle
Abstract

Background: In heavy-ion collisions at intermediate energies the production of light charged particles and intermediate mass fragments (IMFs) is due to different reaction mechanisms and different time scales, ranging from fast dynamical processes to statistical emission from the equilibrated system.Purpose: We compare the IMF statistical and dynamical emission probabilities in collisions of a neutron-rich $^{124}\mathrm{Sn}+^{64}\mathrm{Ni}$ system and a neutron-poor $^{112}\mathrm{Sn}+^{58}\mathrm{Ni}$ system at the laboratory energy of 35 $A$ MeV.Method: The IMFs production mechanism in semiperipheral reactions has been investigated in our previous works. In this paper, the analysis is expanded for the same set of data and production cross sections have been evaluated for dynamical and statistical emission in a coherent way for light and heavy fragments.Results: The data analysis has evidenced a strong competition between dynamical and statistical emission mechanisms. Probability of the dynamical emission of IMFs is strongly influenced by the ($N/Z$) ratio of the colliding system.Conclusions: It is demonstrated that the statistical emission is equally probable for the two systems, while the dynamical emission is enhanced for the neutron-rich system, especially for heavy fragments ($Z\ensuremath{\ge}6$). The observed effect points at a high sensitivity of the prompt-dynamical emission to the ($N/Z$) ratio of a given system.

Published
2015

25. DYNAMICAL EVOLUTION OF THE 197<font>Au</font> + 197<font>Au</font> SYSTEM AT 15 MeV/NUCLEON

Author

R. Płaneta, G. Cardella, K. Siwek-Wilczyńska, A. Anzalone, J. Wilczyński, I. Skwira-Chalot, S. Pirrone, W. Zipper, Angelo Pagano, E. Piasecki, A. Grzeszczuk, P. Guazzoni, Maria Colonna, A. Sochocka, S. Cavallaro, G. Lanzano, F. Amorini, E. De Filippo, C. Maiolino, M. Di Toro, M. Papa, F. Rizzo, V. Baran, Ł. Świderski, S. Kowalski, M. B. Chatterjee, E. La Guidara, Marina Trimarchi, F. Porto, G. Lanzalone, N. G. Nicolis, L. Zetta, Z. Majka, Lucrezia Auditore, J. Brzychczyk, G. Politi, Antonio Trifiro, K. Schmidt, and P. Russotto

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, General Physics and Astronomy, Dissipation, Nuclear Experiment, Ternary operation, Nucleon, Excitation
Abstract

Collisions of a very heavy 197 Au + 197 Au system have been studied at an energy of 15 MeV/nucleon with the aim to investigate a possible change of the energy dissipation mechanism from one-body dissipation (presumably dominating at low excitation energies) to two-body dissipation. The experiment was carried out in 4π geometry using the CHIMERA multidetector array. A class of ternary events satisfying nearly complete balance of mass numbers was selected. Preliminary results suggest that the selected ternary events represent mostly prompt ternary partitions of the colliding system, in which the lightest fragment is quite massive. In the light of theoretical predictions of Cârjan, Sierk and Nix this result may imply that the observed ternary reactions are driven by the two-body dissipation mechanism already at 15 MeV/nucleon.

Published
2006

26. Shape parameters of the participant source in Ru + Ru collisions at

Author

V. Simion, M. Dželalija, E. Cordier, K. D. Hildenbrand, A. Schuettauf, Gabriel Stoicea, N. Herrmann, V. T. Smolyankin, Philippe Crochet, Z. Tyminski, M. L. Benabderrahmane, Z. Fodor, P. Wagner, A. Gobbi, B. de Schauenburg, Fouad Rami, Igor Gašparić, Y. Leifels, J. Kecskemeti, M. Merschmeyer, Valerie Ramillien Barret, Z. Basrak, I. E. Yushmanov, R. Kotte, D. Pelte, M. R. Stockmeier, D. Wohlfarth, Z. Seres, A. Bendarag, M. Kirejczyk, Nicole Bastid, R. Čaplar, M. M. Smolarkiewicz, Y. Grishkin, Zhigang Xiao, Yongsun Kim, Mihai Petrovici, Byung-Sik Hong, O. N. Hartmann, T. Kress, Alexandre Lebedev, W. Neubert, J. P. Alard, Vladislav Manko, W. Reisdorf, I. J. Soliwoda, A. Mangiarotti, A. Zhilin, Pascal Dupieux, M. Korolija, K. Wiśniewski, P. Koczon, B. Sikora, Xavier Bernard Lopez, Anton Andronic, K. S. Sim, D. Moisa, and K. Siwek-Wilczyńska

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Gaussian, Nuclear Theory, Nuclear physics, Momentum, symbols.namesake, Cross section (physics), Flow (mathematics), Phase space, Isospin, symbols, Impact parameter, Nuclear Experiment
Abstract

New results on nuclear collective flow are presented for central and semi-central Ru + Ru collisions at 400 A MeV measured with the FOPI detector at GSI-Darmstadt. The source shape parameters, flow angle and aspect ratios, are extracted from Gaussian fits to in-plane and out-of-plane momentum distributions. The orientation and the shape of the source exhibit different trends according to the investigated phase space region. The shape parameters of the participant source are studied as a function of the particle mass and collision centrality. The flow angle is found to be independent of the particle mass. Both the flow angle and the aspect ratios depend sensitively on the impact parameter. Detailed comparisons with the predictions of the isospin quantum molecular dynamics model are performed. It is shown in particular that the source shape parameters permit to extract information on the in-medium nucleon–nucleon cross section.

Published
2004

27. Sub-threshold φ-meson yield in central collisions

Author

A. Mangiarotti, N. Herrmann, P.R. Maurenzig, A. Gobbi, R. Kotte, J. Kecskemeti, Y. Leifels, J.P. Alard, A. Andronic, R. Averbeck, V. Barret, Z. Basrak, N. Bastid, I. Belyaev, A. Bendarag, G. Berek, R. Čaplar, P. Crochet, A. Devismes, P. Dupieux, M. Dž, Ch. Finck, Z. Fodor, Y. Grishkin, O. Hartmann, K.D. Hildenbrand, B. Hong, Y.J. Kim, M. Kirejczyk, P. Koczoń, M. Korolija, T. Kress, R. Kutsche, A. Lebedev, V. Manko, M. Merschmeyer, D. Moisa, A. Nianine, W. Neubert, D. Pelte, M. Petrovici, C. Plettner, F. Rami, W. Reisdorf, B. de Schauenburg, D. Schü, Z. Seres, B. Sikora, K.S. Sim, V. Simion, K. Siwek-Wilczyń, V. Smolyankin, M. Stockmeier, G. Stoicea, M. Vasiliev, P. Wagner, K. Wiś, D. Wohlfarth, I. Yushmanov, and A. Zhilin

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Cross section (physics), Background subtraction, Meson, Yield (chemistry), Detector, Production (computer science), Nuclear Experiment, Phi meson, Energy (signal processing)
Abstract

The $\phi$-meson production cross section is measured for the first time at a sub-threshold energy of 1.93 AGeV in \nuc{58}{Ni}+\nuc{58}{Ni} central collisions. The $\phi$ data were obtained within the acceptance of the CDC/Barrel subsystem of FOPI. For a sample of $4.7\cdot 10^6$ central events, after background subtraction, 23 candidates were observed. Extensive GEANT simulations of the detector performance are shown in a thorough comparison to the real response, aiming at a good understanding of the apparatus and at a trustable determination of the efficiencies, production probability and possible systematic errors. A filter procedure is elaborated, which is meant to facilitate the comparison of any theoretical calculation or new data with the current ones. How to extrapolate the present value to a $\phi$-meson cross section in $4\pi$ is also discussed. This result on pseudo-vector mesons can now be compared to existing experimental knowledge for the same reaction at the same incident energy for various outgoing channels, $K^+$ and $K^-$ included. A significant fraction (at least 20%) of the $K^-$-mesons is originating in the decay of the $\phi$, supporting the statement that the two channels are strongly correlated.

Published
2003

28. Isospin Effects in Heavy-Ion Collisions: Some Results From CHIMERA Experiments At LNS And Perspectives With Radioactive Beams

Author

G. Cardella, F. Amorini, A. Anzalone, N. Arena, L. Auditore, R. Barnà, A. Benisz, I. Berceanu, M. B. Chatterjee, S. Cavallaro, E. De Filippo, U. Emanuele, W. Gawlikowicz, E. Geraci, L. Grassi, G. Giuliani, A. Grzeszczuk, P. Guazzoni, S. Kowalski, E. La Guidara, G. Lanzalone, I. Lombardo, S. Lo Nigro, D. Loria, C. Maiolino, N. G. Nicolis, A. Pagano, M. Papa, I. Pawelczak, M. Petrovici, S. Pirrone, R. Planeta, G. Politi, A. Pop, F. Porto, F. Previdi, M. Quinlan, F. Rizzo, E. Rosato, P. Russotto, W. U. Schrőder, I. Skwira-Chalot, K. Siwek-Wilczynska, K. Schmidt, A. Sochocka, L. Swiderski, A. Trifirò, M. Trimarchi, J. Tõke, G. Verde, M. Vigilante, J. Wilczynski, L. Zetta, W. Zipper, Sun-Chan Jeong, Yutaka Utsuno, Tohru Motobayashi, Angela Bracco, S.C.Jeong,Y.Utsuno, T.Motobayashi, A.Bracco, G., Cardella, F., Amorini, A., Anzalone, N., Arena, L., Auditore, R., Barnà, A., Benisz, I., Berceanu, M. B., Chatterjee, S., Cavallaro, E., De Filippo, U., Emanuele, W., Gawlikowicz, E., Geraci, L., Grassi, G., Giuliani, A., Grzeszczuk, P., Guazzoni, S., Kowalski, E., La Guidara, G., Lanzalone, I., Lombardo, S., Lo Nigro, D., Loria, C., Maiolino, N. G., Nicoli, A., Pagano, M., Papa, I., Pawelczak, M., Petrovici, S., Pirrone, R., Planeta, G., Politi, A., Pop, F., Porto, F., Previdi, M., Quinlan, F., Rizzo, Rosato, Elio, P., Russotto, W. U., Schr?der, I., Skwira Chalot, K., Siwek Wilczynska, K., Schmidt, A., Sochocka, L., Swiderski, A., Trifirò, M., Trimarchi, J., Toke, G., Verde, Vigilante, Mariano, J., Wilczynski, L., Zetta, and W., Zipper

Subjects
Physics, Particle physics, Field (physics), Nuclear Theory, Physics::Medical Physics, Detector, Nuclear structure, Scintillator, Charged particle, Nuclear physics, Settore ING-INF/04 - Automatica, Isospin, Heavy ion, Nuclear Experiment, Spin (physics)
Abstract

CHIMERA is a 4π multidetector for charged particles available at Laboratori Nazionali del Sud (INFN‐LNS). A new method to measure the time scale of the emission of nuclear fragments is described, together with some applications in the field of the isospin dynamics of heavy‐ion collisions. Competition between fusion‐like and binary reactions near the energy threshold for nuclear multifragmentation is discussed. Opportunities are pointed out to use the detector at low and intermediate energies using the kinematical‐coincidence method.

Published
2009

29. Azimuthal emission patterns ofK+and ofK−mesons in Ni + Ni collisions near the strangeness production threshold

Author

Philippe Crochet, M. S. Ryu, Paul Buehler, W. Reisdorf, Johann Zmeskal, Y. Leifels, P. Wagner, Michael Cargnelli, R. Kotte, Elena Bratkovskaya, Zhigang Xiao, Igor Gašparić, A. Lebedev, Xavier Bernard Lopez, Y. J. Kim, K. S. Sim, A. Le Fèvre, J. Kecskemeti, A. Reischl, Anton Andronic, P. Gasik, Vladislav Manko, K. Wiśniewski, M. Kiš, Valerie Ramillien Barret, Pascal Dupieux, Fouad Rami, Johann Marton, K. Siwek-Wilczyńska, R. Čaplar, P. Koczon, M. Dželalija, I. Deppner, I. E. Yushmanov, Byung-Sik Hong, Ken Suzuki, N. Herrmann, R. H. Munzer, V. T. Smolyankin, Z. Basrak, V. Simion, Nicole Bastid, A. Zhilin, Mihai Petrovici, O. N. Hartmann, Z. Fodor, A. Schüttauf, M. Berger, B. Sikora, M. L. Benabderrahmane, Z. Seres, T. I. Kang, Laura Fabbietti, T. Matulewicz, K. D. Hildenbrand, V. Zinyuk, Eberhard Widmann, Krzysztof Piasecki, Ralf Peter Averbeck, Z. Tyminski, C. Hartnack, P. Schmidt, M. Kirejczyk, Ya-Peng Zhang, J. L. Liu, I. Carevic, and Y. Grishkin

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, Elliptic flow, Strangeness production, Kinetic energy, Nuclear matter, 7. Clean energy, Azimuth, Nuclear physics, Transverse momentum, High Energy Physics::Experiment, Nuclear Experiment, Beam (structure)
Abstract

Azimuthal emission patterns of $K^\pm$ mesons have been measured in Ni + Ni collisions with the FOPI spectrometer at a beam kinetic energy of 1.91 A GeV. The transverse momentum $p_{T}$ integrated directed and elliptic flow of $K^{+}$ and $K^{-}$ mesons as well as the centrality dependence of $p_{T}$ - differential directed flow of $K^{+}$ mesons are compared to the predictions of HSD and IQMD transport models. The data exhibits different propagation patterns of $K^{+}$ and $K^{-}$ mesons in the compressed and heated nuclear medium and favor the existence of a kaon-nucleon in-medium potential, repulsive for $K^{+}$ mesons and attractive for $K^{-}$ mesons.

Published
2014

30. Aligned ternary partitioning of the 197Au+197Au system at 23 A MeV beam energy

Author

L. Grassi, Ji-Youn Han, Marina Trimarchi, Michele Papa, A. Pagano, R. Najman, T. Cap, K. Siwek-Wilczyńska, F. Amorini, Antonio Trifiro, Tomasz Kozik, Ivano Lombardo, E. Geraci, E. De Filippo, G. Cardella, P. Russotto, G. Lanzalone, N. G. Nicolis, J. Wilczyński, A. Grzeszczuk, Lucrezia Auditore, W. Zipper, G. Politi, I. Skwira-Chalot, F. Rizzo, E. La Guidara, E. Piasecki, Giuseppe Verde, S. Pirrone, and R. Płaneta

Subjects
Physics, Mass number, projectile breakup, nucleus–nucleus collisions, Astrophysics::Cosmology and Extragalactic Astrophysics, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, polar-side emission, aligned ternary partitioning, Primary (astronomy), Polar, Atomic physics, Ternary operation, Nuclear Experiment, Beam energy, Mathematical Physics, Astrophysics::Galaxy Astrophysics, neck-side emission
Abstract

Ternary partitions of the ^{197}Au+^{197}Au system in collisions at 23 A MeV beam energy have been studied. It is observed that the mass number distribution of the lightest fragments, called intermediate mass fragments (IMF), extends up to mass numbers corresponding to partitions into three comparable fragments. The lightest IMFs of A_{IFM} < 20 show well known features of prompt emission originating from the interaction zone (neck) during reseparation. Heavier IMFs (of A_{IFM} > 30) definitely originate from sequential (but not equilibrated) decay of the primary projectile-like fragments (PLF*) (or target-like fragments (TLF*)). The decaying system evidently keeps memory of the neck configuration and consequently the IMFs are emitted collinearly either from the neck side or from the opposite side along the separation axis (polar emission). The new intriguing process of the polar emission dominates for IMFs of A_{IMF} > 50.

Published
2014

31. Results from FOPI on strangeness in nuclear matter at SIS energies

Author

M. R. Stockmeier, W. Reisdorf, Kin Sing Stephen Lee, T. Kress, M. Dželalija, A. Somov, V. T. Smolyankin, M. Korolija, R. Kotte, B. de Schauenburg, D. Pelte, G. Berek, A. Devismes, A. Bendarag, K. Siwek-Wilczyńska, R. Čaplar, A. Gobbi, A. Nianine, P. Wagner, Valerie Ramillien Barret, R. Averbeck, D. Moisa, Byung-Sik Hong, K. Wiśniewski, Anton Andronic, Y. Leifels, I. E. Yushmanov, Y. Grishkin, N. Cindro, P. Crochet, Alexandre Lebedev, V. Simion, M. Eskef, W. Neubert, Nicole Bastid, Z. Fodor, N. Herrmann, R. Kutsche, J. P. Alard, D. Schüll, O. Hartmann, Kwang Souk Sim, Pascal Dupieux, B. Sikora, H. Merlitz, F. Rami, M. A. Vasiliev, Z. Basrak, M. Kowalczyk, J. Kecskemeti, I. Belyaev, J. T. Yang, Ch. Finck, Gabriel Stoicea, C. Plettner, Vladislav Manko, M. Kirejczyk, S. Mohren, D. Wohlfarth, A. Zhilin, Yongsun Kim, P Koczon, Z. Seres, Mihai Petrovici, and K.D. Hildenbrand

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Flow (mathematics), Phase space, Nuclear Theory, Detector, High Energy Physics::Experiment, Strangeness, Nuclear Experiment, Nuclear matter
Abstract

Experimental data on charged kaon phase space distributions and strangeness sideward flow measured with the FOPI detector at SIS/GSI are presented. Comparisons are made with the predictions of transport models investigating the in-medium kaon-nucleon potential.

Published
2001

32. Dynamical multi-breakup processes in the 124Sn+64Ni system at 35 MeV/nucleon

Author

M. Papa, F. Amorini, A. Anzalone, L. Auditore, V. Baran, I. Berceanu, J. Blicharska, J. Brzychczyk, A. Bonasera, B. Borderie, R. Bougault, G. Cardella, S. Cavallaro, M. B. Chatterjee, A. Chbihi, M. Colonna, R. Dayras, E. De Filippo, M. Di Toro, J. Frankland, E. Galichet, W. Gawlikowicz, G. Giuliani, F. Giustolisi, A. Grzeszczuk, P. Guazzoni, D. Guinet, M. Iacono Manno, S. Kowalski, E. La Guidara, G. Lanzalone, G. Lanzano', C. Maiolino, Z. Majka, N. Le Neindre, A. Pagano, M. Petrovici, E. Piasecki, S. Pirrone, R. Płaneta, G. Politi, A. Pop, F. Porto, F. Rizzo, E. Rosato, S. Russo, P. Russotto, M. Sassi, K. Schmidt, K. Siwek Wilczynska, I. Skwira, A. Sochocka, L. Swiderski, A. Trifiro', M. Trimarchi, G. Verde, M. Vigilante, J. P. Wieleczko, J. Wilczynski, L. Zetta, W. Zipper, GERACI, ELENA IRENE, VANNINI, GIANNI, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Istituto Nazionale di Fisica Nucleare, Sezione di Catania (INFN), Università degli studi di Catania [Catania], Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Catania = University of Catania (Unict), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), M. Papa, F. Amorini, A. Anzalone, L. Auditore, V. Baran, I. Berceanu, J. Blicharska, J. Brzychczyk, A. Bonasera, B. Borderie, R. Bougault, G. Cardella, S. Cavallaro, M. B. Chatterjee, A. Chbihi, M. Colonna, R. Dayra, E. De Filippo, M. Di Toro, J. Frankland, E. Galichet, W. Gawlikowicz, E. Geraci, G. Giuliani, F. Giustolisi, A. Grzeszczuk, P. Guazzoni, D. Guinet, M. Iacono-Manno, S. Kowalski, E. La Guidara, G. Lanzalone, G. Lanzano', C. Maiolino, Z. Majka, N. Le Neindre, A. Pagano, M. Petrovici, E. Piasecki, S. Pirrone, R. Płaneta, G. Politi, A. Pop, F. Porto, F. Rizzo, E. Rosato, S. Russo, P. Russotto, M. Sassi, K. Schmidt, K. Siwek-Wilczynska, I. Skwira, A. Sochocka, L. Swiderski, A. Trifiro', M. Trimarchi, G. Vannini, G. Verde, M. Vigilante, J. P. Wieleczko, J. Wilczynski, L. Zetta, and W. Zipper

Subjects
BREAK-UP, 25.70.Mn, 24.10.Cn, 25.70.Pq, MOLECULAR DYNAMICS, EXPERIMENT, HEAVY-ION COLLISIONS, FISSION, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

International audience; Multi-breakup processes for the $^{124}$Sn+$^{64}$Ni system at 35 MeV/nucleon have been studied with the forward part of the CHIMERA detector. An extensive comparison between experimental data corresponding to almost complete ternary events and constrained molecular dynamics (CoMD-II) calculations suggests different characteristic times in the selected processes. This is in agreement with previous studies of the same reaction already published concerning the prompt intermediate-mass-fragment emission. Stimulated by CoMD-II calculations, we investigate the existence of more complex dynamical multi-breakup processes occurring on the same time scale. A detailed study of the rotational dynamics leading to slower dynamical fission processes is also presented.

Published
2007

33. Identification of baryon resonances in central heavy-ion collisions at energies between 1 and 2 AGeV

Author

M. Eskef, D. Pelte, G. Goebels, E. Häfele, N. Herrmann, M. Korolija, Y. Leifels, H. Merlitz, S. Mohren, M.R. Stockmeier, M. Trzaska, J.P. Alard, A. Andronic, R. Averbeck, Z. Basrak, N. Bastid, I. Belyaev, D. Best, A. Buta, R. Čaplar, N. Cindro, J.P. Coffin, P. Crochet, P. Dupieux, M. Dželalija, L. Fraysse, Z. Fodor, A. Genoux-Lubain, A. Gobbi, K.D. Hildenbrand, B. Hong, F. Jundt, J. Kecskemeti, M. Kirejczyk, R. Kotte, R. Kutsche, A. Lebedev, V. Manko, J. Mösner, D. Moisa, W. Neubert, M. Petrovici, C. Pinkenburg, C. Plettner, P. Pras, F. Rami, V. Ramillien, W. Reisdorf, J.L. Ritman, B. de Schauenburg, D. Schüll, Z. Seres, B. Sikora, V. Simion, K. Siwek-Wilczynska, V. Smolyankin, M.A. Vasiliev, P. Wagner, G.S. Wang, K. Wisniewski, D. Wohlfarth, and A. Zhilin

Subjects
Physics, Nuclear and High Energy Physics, Mass distribution, 010308 nuclear & particles physics, Resonance, Kinetic energy, 7. Clean energy, 01 natural sciences, Spectral line, Baryon, Nuclear physics, Pion, Isospin, 0103 physical sciences, Invariant (mathematics), Nuclear Experiment, 010306 general physics
Abstract

The mass distributions of baryon resonances populated in near-central collisions of Au on Au and Ni on Ni are deduced by defolding the $p_t$ spectra of charged pions by a method which does not depend on a specific resonance shape. In addition the mass distributions of resonances are obtained from the invariant masses of $(p, \pi^{\pm})$ pairs. With both methods the deduced mass distributions are shifted by an average value of -60 MeV/c$^2$ relative to the mass distribution of the free $\Delta(1232)$ resonance, the distributions descent almost exponentially towards mass values of 2000 MeV/c^2. The observed differences between $(p, \pi^-)$ and $(p, \pi^+)$ pairs indicate a contribution of isospin $I = 1/2$ resonances. The attempt to consistently describe the deduced mass distributions and the reconstructed kinetic energy spectra of the resonances leads to new insights about the freeze out conditions, i.e. to rather low temperatures and large expansion velocities.

Published
1998

34. Stopping and radial flow in central58Ni+58Nicollisions between1Aand2AGeV

Author

C. Roy, J. Mösner, D. Wohlfarth, A. Genoux-Lubain, Vladislav Manko, C. Pinkenburg, A. Buta, Christian Claude Kuhn, G. Guillaume, Byung-Sik Hong, E. Häfele, James Ritman, B. Sikora, D. Best, W. Reisdorf, F. Jundt, V. Simion, P. Crochet, W. Neubert, S. Mohren, Mihai Petrovici, U. Sodan, Peter Wagner, J. Biegansky, B. de Schauenburg, A. Somov, Y. Leifels, A. Lebedev, T. Wienold, C. Maazouzi, V. Amouroux, Vasilev, A. Zhilin, R. Kotte, I. Belyaev, Fouad Rami, G.S. Wang, D. Pelte, L. Fraysse, Z. Seres, N. Herrmann, K. D. Hildenbrand, M. Eskef, J. P. Coffin, J. Kecskemeti, J. P. Alard, Pascal Dupieux, D. Schüll, P. Fintz, I. Legrand, M. Trzaska, M. Kirejczyk, L. Tizniti, G. Berek, K. Siwek-Wilczyńska, Nicole Bastid, G. Goebels, R. Dona, P. Pras, M. Korolija, Z. Fodor, and A. Gobbi

Subjects
Physics, Nuclear and High Energy Physics, Energy loss, 010308 nuclear & particles physics, Nuclear Theory, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Quantum molecular dynamics, Nuclear physics, Nickel, chemistry, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Radial flow, Nuclear Experiment, 010306 general physics
Published
1998

35. Out-of-plane emission of nuclear matter in Au+Au collisions between 100 and 800 AMeV

Author

D. Best, L. Fraysse, D. Wohlfarth, W. Neubert, U. Sodan, J. P. Wessels, M. Trzaska, N. Cindro, N. Herrmann, Z. Basrak, P. Fintz, C. Maazouzi, R. Čaplar, F. Jundt, P. Crochet, Y. Leifels, C. Pinkenburg, D. Moisa, Th. Blaich, S. C. Jeong, S. Hölbling, G. Guillaume, M. Dželalija, C. Cerruti, T. Wienold, Pascal Dupieux, B. Sikora, R. Dona, G. S. Wang, James Ritman, Mihai Petrovici, M. A. Vasiliev, J. Biegansky, G. Mgebrishvili, V. T. Smolyankin, P. Koncz, P. Pras, Y. Korchagin, Z. Seres, Z. G. Fan, Christian Claude Kuhn, Fouad Rami, K. M. Teh, V. Simion, J. P. Coffin, I. Belyaev, K. Siwek-Wilczyńska, C. Roy, J. Keczkemeti, M. Kirejczyk, Nicole Bastid, L. Tizniti, M. Krämer, D. Schüll, K. Wisniewski, A. Sadchikov, I. Legrand, B. Hong, P. Wagner, R. Kotte, D. Pelte, J. Mösner, W. Reisdorf, Vladislav Manko, A. Buta, R. P. Freifelder, A. Zhilin, V. Amouroux, K. D. Hildenbrand, E. Erö, A.L. Lebedev, J. P. Alard, Z. Fodor, and A. Gobbi

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Phase (waves), Charge (physics), Nuclear matter, Azimuth, Nuclear physics, Nuclear Reactions, Au-197 (Au-197, X), E=100-800 MeV/nucleon, Azimuthal anisotropy, Out-of-plane emission, Atomic physics, Nuclear Experiment, Anisotropy, Saturation (magnetic), Beam (structure)
Abstract

We present new experimental results concerning the azimuthal distributions of proton-likes, light and intermediate mass fragments at midrapidity for Au(100-800 AMeV)+Au collisions measured with the FOPI phase-I detector at GSI in Darmstadt. The azimuthal distributions are investigated as a function of the collision centrality, the incident energy, the fragment charge and transverse momentum. The azimuthal anisotropy is maximum for impact parameters around 7 fm. Intermediate mass fragments present a stronger out-of-plane emission signal than light fragments and a saturation is reached for Z greater than or equal to 4. The azimuthal anisotropy increases with the fragment transverse momentum and decreases as the incident energy increases. The azimuthal anisotropy of Z = 2 particles investigated as a function of the scaled fragment transverse momentum follows an universal curve for bombarding energies between 250-800 AMeV. A signature for a transition from in-plane to out-of-plane emission is evidenced at the lowest beam energies.

Published
1997

36. Charged pion production in Au on Au collisions at 1 AGeV The FOPI Collaboration

Author

Y. Leifels, Christian Claude Kuhn, E. Häfele, D. Best, Mihai Petrovici, U. Sodan, G. Goebels, James Ritman, A. Gobbi, Peter Wagner, Z. Seres, R. Čaplar, J. Mösner, W. Reisdorf, Vladislav Manko, Y. Korchagin, V. T. Smolyankin, P. Pras, I. Belyaev, J. P. Coffin, A. Buta, D. Moisa, D. Wohlfarth, A. Genoux-Lubain, V. Ramillien, G. Guillaume, G.S. Wang, F. Jundt, P. Crochet, V. Simion, D. Lambrecht, A. Zhilin, C. Roy, M. Eskef, Z. Fodor, P. Koncz, V. Amouroux, R. Kotte, M. Kirejczyk, J. P. Alard, T. Wienold, D. Pelte, J. Biegansky, M. A. Vasiliev, Anton Andronic, D. Schüll, I. Legrand, J. Kecskemeti, Nicole Bastid, P. Fintz, Fouad Rami, N. Herrmann, C. Pinkenburg, M. Korolija, Byung-Sik Hong, Alexandre Lebedev, B. Sikora, W. Neubert, M. Trzaska, N. Cindro, Pascal Dupieux, H. Merlitz, S. Mohren, J. Erö, K. D. Hildenbrand, K. Siwek-Wilczyńska, Z. Basrak, and M. Dzelalija

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Equation of state, Nuclear Theory, Kinetic energy, Spectral line, Momentum, Nuclear physics, Pion, Nuclear fusion, Hermetic detector, High Energy Physics::Experiment, Rapidity, Nuclear Experiment
Abstract

Charged pions are measured with the 4π detector FOPI at GSI using the Au on Au reaction at 1.06 AGeV bombarding energy. The pion multiplicities ngp increase with the number of participants Apart. The average pion multiplicities per participant are #### and #### These values are only half as large as extrapolated from the low-mass systems studied by Harris et al. The ratio #### increases with Apart and decreases with the pion kinetic energies. The pion kinetic energy spectra have concave shapes, their parametrization in terms of thermal Boltzmann distributions yields a low (T l,π) and high (Th,π) temperature which change with the cm emission angle Θ of the pions. In the angular range 45dg is larger than , the high temperatures , are, within experimental uncertainties, the same. The inclusive polar angular distributions of pions are anisotropic, dσ/dΩ increases for forward and backward angles. The forward — backward enhancements are independent of the pion kinetic energies or the number of participants. In addition to the preferred forward — backward emission, also the enhanced emission into the transverse direction Θ = 90° is observed for pions with high energies or for pions from near-central collisions. These observations and the shape of the rapidity spectra suggest that pions, emitted from the central rapidity region, are partly rescattered by spectator matter. The strength of the rescattering process depends only weakly on the number of participants. The experimental data are compared to the results of IQMD/GEANT calculations using momentum dependent NN interactions and a hard equation of state. The calculated pion multiplicities are approximately 50% larger than experimentally determined; the existence of secondary pion sources is reproduced by the calculation, but their predicted strengths are larger than experimentally observed.

Published
1997

37. Central collisions of Au on Au at 150, 250 and 400 A·MeV

Author

W. Reisdorf, D. Best, A. Gobbi, N. Herrmann, K.D. Hildenbrand, B. Hong, S.C. Jeong, Y. Leifels, C. Pinkenburg, J.L. Ritman, D. Schüll, U. Sodan, K. Teh, G.S. Wang, J.P. Wessels, T. Wienold, J.P. Alard, V. Amouroux, Z. Basrak, N. Bastid, I. Belyaev, L. Berger, J. Biegansky, M. Bini, S. Boussange, A. Buta, R. Čaplar, N. Cindro, J.P. Coffin, P. Crochet, R. Dona, P. Dupieux, M. Dželalija, J. Erö, M. Eskef, P. Fintz, Z. Fodor, L. Fraysse, A. Genoux-Lubain, G. Goebels, G. Guillaume, Y. Grigorian, E. Häfele, S. Hölbling, A. Houari, M. Ibnouzahir, M. Joriot, F. Jundt, J. Kecskemeti, M. Kirejczyk, P. Koncz, Y. Korchagin, M. Korolija, R. Kotte, C. Kuhn, D. Lambrecht, A. Lebedev, I. Legrand, C. Maazouzi, V. Manko, T. Matulewicz, P.R. Maurenzig, H. Merlitz, G. Mgebrishvili, J. Mösner, S. Mohren, D. Moisa, G. Montarou, I. Montbel, P. Morel, W. Neubert, A. Olmi, G. Pasquali, D. Pelte, M. Petrovici, G. Poggi, P. Pras, F. Rami, V. Ramillien, C. Roy, A. Sadchikov, Z. Seres, B. Sikora, V. Simion, K. Siwek-Wilczyńska, V. Smolyankin, N. Taccetti, R. Tezkratt, L. Tizniti, M. Trzaska, M.A. Vasiliev, P. Wagner, K. Wisniewski, D. Wohlfarth, and A. Zhilin

Subjects
Physics, selected central collisions, Nuclear and High Energy Physics, Angular range, E=150 and 250 and 400 MeV/nucleon, Isotope, charges and yields, comparison to statistical multifragmentation models, FOS: Physical sciences, deduced radial flow, measured fragment velocity vectors, Effective nuclear charge, Charged particle, Azimuth, Nuclear physics, Transverse plane, Cross section (physics), NUCLEAR REACTIONS Au(Au,X), chemical composition, Nuclear Experiment (nucl-ex), Nuclear Experiment, Quantum, quantum molecular dynamics model
Abstract

Collisions of Au on Au at incident energies of 150, 250 and 400 A MeV were studied with the FOPI-facility at GSI Darmstadt. Nuclear charge (Z < 16) and velocity of the products were detected with full azimuthal acceptance at laboratory angles of 1-30 degrees. Isotope separated light charged particles were measured with movable multiple telescopes in an angular range of 6-90 degrees. Central collisions representing about 1 % of the reaction cross section were selected by requiring high total transverse energy, but vanishing sideflow. The velocity space distributions and yields of the emitted fragments are reported. The data are analysed in terms of a thermal model including radial flow. A comparison with predictions of the Quantum Molecular Model is presented., LateX text 62 pages, plus six Postscript files with a total of 34 figures, accepted by Nucl.Phys.A

Published
1997

38. Determination of nuclear friction in strongly damped reactions from prescission neutron multiplicities

Author

Hans Wilschut, J. Wilczyński, K. Siwek-Wilczyńska, and KVI - Center for Advanced Radiation Technology

Subjects
DYNAMICS, Physics, Nuclear and High Energy Physics, QUASI-FISSION, Order (ring theory), Resonance, Multiplicity (mathematics), Dissipation, DIFFUSION, Dipole, ONE-BODY DISSIPATION, Giant resonance, Neutron, FUSION-FISSION, Atomic physics, EMISSION, Nuclear Experiment, Energy (signal processing)
Abstract

Nonfusion, fissionlike reactions in collisions of four heavy systems (well below the fusion extra-push energy threshold), for which Hinde and co-workers had measured the prescission neutron multiplicities, have been analyzed in terms of the deterministic dynamic model of Feldmeier coupled to a time-dependent statistical cascade calculation. In order to reproduce the measured prescission multiplicities and the observed (nearly symmetric) mass divisions, the energy dissipation must be dramatically changed with regard to the standard one-body dissipation: In the entrance channel, in the process of forming a composite system, the energy dissipation has to be reduced to at least half of the one-body dissipation strength (${\mathit{k}}_{\mathit{s}}^{\mathrm{in}}$\ensuremath{\le}0.5), and in the exit channel (from a mononucleus shape to scission) it must be increased by a factor ranging for the studied reactions from ${\mathit{k}}_{\mathit{s}}^{\mathrm{out}}$=4 to ${\mathit{k}}_{\mathit{s}}^{\mathrm{out}}$=12. These results are compared with the temperature dependence of the friction coefficient, recently deduced by Hofman, Back, and Paul from data on the prescission giant dipole resonance emission in fusion-fission reactions. The combined picture of the temperature dependence of the friction coefficient, for both fusion-fission and nonfusion reactions, may indicate the onset of strong two-body dissipation already at a nuclear temperature of about 2 MeV. \textcopyright{} 1996 The American Physical Society.

Published
1996

39. Time scales of fusion-fission reactions calculated from prescission neutron multiplicities

Author

J. Wilczyński, H. W. Wilschut, R.H. Siemssen, K. Siwek-Wilczyński, and KVI - Center for Advanced Radiation Technology

Subjects
DYNAMICS, Physics, Nuclear and High Energy Physics, Range (particle radiation), NUCLEI, QUASI-FISSION, Nuclear Theory, Fusion fission, Nuclear physics, ONE-BODY DISSIPATION, Nuclear dynamics, Cascade, Neutron, Atomic physics, Nuclear Experiment, EMISSION, PROBE
Abstract

The time scale of fusion-fission reactions was found to be in the range from τ f = 5 · 10 −20 to 5 · 10 −19 s. This result was obtained from the analysis of the prescission neutron multiplicities with a new method combining the time-dependent statistical cascade calculations with the nuclear dynamics model of Feldmeier.

Published
1995

40. Missing momentum vector in the 197Au(20Ne;F1,F2PLF) reaction at 15 MeV/u

Author

R.H. Siemssen, K. Grotowski, Z. Sosin, J. Wilczyński, H.K.W. Leegte, J. Brzychczyk, R. Płaneta, Piotr Pawłowski, S. Micek, A. Wieloch, K. Siwek-Wilczyńska, and H. W. Wilschut

Subjects
Nuclear reaction, Nuclear physics, Physics, Momentum, Nuclear and High Energy Physics, Fission, Systematic deviation, Beam direction, Atomic physics, Nuclear Experiment, Coincidence, Analysis method, Ion
Abstract

Projectile-like fragments (PLF's) emitted in damped collisions of 15 MeV/u 20Ne ions with 197Au were observed in coincidence with two fission fragments. For given detection angles of the PLF's differential and energy-integrated fission probabilities were obtained and the average missing momentum vectors were deduced by using improved analysis methods of the fission fragment angular correlation. The average missing momentum vectors were found to point in the direction of the observed PLF, with a systematic deviation towards beam direction for larger mass transfers. The missing momentum thus appears to mainly originate from the sequential decay of the PLF's.

Published
1995

41. Systematic study ofp-shell nuclei via single-nucleon knockout reactions

Author

P. Adrich, J. R. Terry, S. McDaniel, J. A. Tostevin, K. Siwek, D. Weisshaar, C. M. Campbell, A. Obertelli, Robert B. Wiringa, G. F. Grinyer, B. A. Brown, D. Bazin, T. Glasmacher, J. M. Cook, Alexandra Gade, M. D. Bowen, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Proton, 010308 nuclear & particles physics, Projectile, Nuclear Theory, Shell (structure), Nuclear structure, 21.10.Jx, 21.60.De, 24.50.+g, 25.10.+s, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Nuclear physics, 0103 physical sciences, Neutron, Variational Monte Carlo, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Expérience au NSCL; A systematic investigation of the inclusive cross sections for single-nucleon knockout reactions from p-shell nuclei has been performed. A total of seven reactions were studied for projectiles with masses between A = 7 and 10, having a wide range of nucleon separation energies. Results were obtained for a range of incident beam energies and targets. These differences were found to have a minimal impact on the deduced cross sections. Experimental results were compared to theoretical predictions based on variational Monte Carlo (VMC) nuclear structure calculations, whose radial overlap functions and neutron and proton densities were included in the reaction description. These results are compared with the conventional model, developed for heavier nuclei, that uses shell-model and Hartree-Fock structure inputs. The VMC-based calculations agreed with the experimental data for several reactions where deeply bound nucleons are removed but does not describe some of the more weakly bound nucleon removal cases with comparable accuracy.

Published
2012

42. Correlations between emission timescale of fragments and isospin dynamics in124Sn+64Ni and112Sn+58Ni reactions at 35AMeV

Author

E. Geraci, M. Bruno, L. Zetta, K. Schmidt, R. Płaneta, Ivano Lombardo, M. Trimarchi, B. Borderie, Maria Colonna, S. Cavallaro, E. La Guidara, Giuseppe Verde, G. Lanzano, S. Pirrone, T. Cap, M. D'Agostino, M. B. Chatterjee, R. Bougault, A. Pagano, P. Guazzoni, E. De Filippo, J.P. Wieleczko, A. Anzalone, I. Berceanu, S. Kowalski, W. Gawlikowicz, E. Piasecki, Lucrezia Auditore, E. Galichet, C. Maiolino, M. Papa, J.D. Frankland, G. Politi, F. Rizzo, M.F. Rivet, Antonio Trifiro, F. Porto, P. Russotto, Amalia Pop, J. Wilczynski, M. Di Toro, V. Baran, Elio Rosato, K. Siwek-Wilczyńska, I. Skwira-Chalot, A. Chbihi, W. Zipper, N. Le Neindre, G. Cardella, F. Amorini, A. Grzeszczuk, Mariano Vigilante, G. Lanzalone, and R. Dayras

Subjects
Physics, Nuclear and High Energy Physics, Density gradient, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear matter, 01 natural sciences, Asymmetry, Nuclear physics, Mean field theory, Fragmentation (mass spectrometry), Isospin, 0103 physical sciences, Neutron, Atomic physics, Nuclear Experiment, 010306 general physics, Anisotropy, media_common
Abstract

We present a new experimental method to correlate the isotopic composition of intermediate mass fragments (IMF) emitted at midrapidity in semiperipheral collisions with the emission timescale: IMFs emitted in the early stage of the reaction show larger values of $\ensuremath{\langle}N/Z\ensuremath{\rangle}$ isospin asymmetry, stronger angular anisotropies, and reduced odd-even staggering effects in neutron to proton ratio $\ensuremath{\langle}N/Z\ensuremath{\rangle}$ distributions than those produced in sequential statistical emission. All these effects support the concept of isospin ``migration'', that is sensitive to the density gradient between participant and quasispectator nuclear matter, in the so called neck fragmentation mechanism. By comparing the data to a stochastic mean field (SMF) simulation we show that this method gives valuable constraints on the symmetry energy term of nuclear equation of state at subsaturation densities. An indication emerges for a linear density dependence of the symmetry energy.

Published
2012

43. Nucleus-nucleus cold fusion reactions analyzed with thel-dependent 'fusion by diffusion' model

Author

J. Wilczyński, T. Cap, and K. Siwek-Wilczyńska

Subjects
Excitation function, Physics, Nuclear reaction, Nuclear and High Energy Physics, Inverse, Production (computer science), Neutron, Atomic physics, Nuclear Experiment, Nucleon, Energy (signal processing), Cold fusion
Abstract

We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section ${\ensuremath{\sigma}}_{\text{cap}}(l)$, the fusion probability ${P}_{\text{fus}}(l)$, and the survival probability ${P}_{\text{surv}}(l)$. The fusion hindrance factor, the inverse of ${P}_{\text{fus}}(l)$, is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The $l$ dependence of ${P}_{\text{fus}}(l)$ results from the $l$-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1$n$ reaction is determined by the $Q$ value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

Published
2011

44. O16breakup in quasielastic reactions near the Fermi energy

Author

Yuen-Dat Chan, E. Chavez-Lomeli, S. B. Gazes, J. Wilczynski, R. G. Stokstad, E. Plagnol, A. Dacal, M.E. Ortiz, and K. Siwek-Wilczyńska

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, Nuclear Theory, Alpha particle, Inelastic scattering, Breakup, 01 natural sciences, Charged particle, Excited state, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

The quasielastic breakup of an [sup 16]O nucleus at 32.5 MeV/nucleon on a [sup 197]Au target has been investigated by measuring the projectilelike fragments in coincidence with the emitted light charged particles. It is found that the breakup proceeds via sequential, two-step processes in which inelastic scattering and one-neutron pickup are the most significant components in the formation of the primary fragment. This is followed by statistical decay of the highly excited primary fragment. A Monte Carlo simulation was used to identify these processes and to deduce differential and total cross sections for the breakup of [sup 16]O into the [alpha]+[sup 12,13]C channels.

Published
1993

45. Symmetric and asymmetric ternary fission of hot nuclei

Author

J. Wilczyński, H.K.W. Leegte, A Panasiewicz, K. Siwek-Wilczyńska, A. Wieloch, Rudolf Siemssen, K. Grotowski, H. W. Wilschut, and Zbigniew Sosin

Subjects
DYNAMICS, Nuclear reaction, Physics, Nuclear and High Energy Physics, TIME SCALES, Cluster decay, Fission, SCISSION, Nuclear Theory, Alpha particle, SYSTEMATICS, Spectral line, Charged particle, FUSION-FISSION, Atomic physics, EMISSION, Nuclear Experiment, Ternary fission, Ternary operation, HE-4, FRAGMENTS
Abstract

Emission of [alpha] particles accompanying fusion-fission processes in the [sup 40]Ar +[sup 232]Th reaction at [ital E]([sup 40]Ar) = 365 MeV was studied in a wide range of in-fission-plane and out-of-plane angles. The exact determination of the emission angles of both fission fragments combined with the time-of-flight measurements allowed us to reconstruct the complete kinematics of each ternary event. The coincident energy spectra of [alpha] particles were analyzed by using predictions of the energy spectra of the statistical code CASCADE . The analysis clearly demonstrates emission from the composite system prior to fission, emission from fully accelerated fragments after fission, and also emission during scission. The analysis is presented for both symmetric and asymmetric fission. The results have been analyzed using a time-dependent statistical decay code and confronted with dynamical calculations based on a classical one-body dissipation model. The observed near-scission emission is consistent with evaporation from a dinuclear system just before scission and evaporation from separated fragments just after scission. The analysis suggests that the time scale of fission of the hot composite systems is long (about 7[times]10[sup [minus]20] s) and the motion during the descent to scission almost completely damped.

Published
1993

46. Aligned breakup of heavy nuclear systems as a new type of deep inelastic collisions at small impact parameters

Author

W. Zipper, F. Amorini, G. Cardella, L. Zetta, Z. Majka, M. Trimarchi, S. Pirrone, F. Rizzo, I. Skwira-Chalot, E. La Guidara, Maria Colonna, S. Cavallaro, E. De Filippo, C. Maiolino, P. Guazzoni, A. Anzalone, M. B. Chatterjee, M. Papa, K. Siwek-Wilczyńska, P. Russotto, E. Geraci, J. Brzychczyk, J. Wilczynski, F. Porto, E. Piasecki, K. Schmidt, R. Płaneta, Angelo Pagano, S. Kowalski, W. Gawlikowicz, J. Łukasik, M. Di Toro, V. Baran, Antonio Trifiro, G. Lanzalone, Ł. Świderski, N. G. Nicolis, A. Grzeszczuk, A. Sochocka, Lucrezia Auditore, G. Politi, J.P. Wieleczko, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Inelastic collision, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Inelastic scattering, Breakup, Deep inelastic scattering, 01 natural sciences, Nuclear physics, 0103 physical sciences, 25.70.Lm, 25.70.Mn, Impact parameter, Nuclear Experiment, 010306 general physics, Nucleon, Ternary operation
Abstract

An interesting process of violent reseparation of a heavy nuclear system into three or four fragments of comparable size was recently observed in {sup 197}Au+{sup 197}Au collisions at 15 MeV/nucleon. Combined analysis of the binary deep inelastic events and the ternary and quaternary breakup events demonstrates that the newly observed ternary and quaternary reactions belong to the same wide class of deep inelastic collisions as the conventional (binary) damped reactions. It is shown that the ternary and quaternary breakup reactions occur at extremely inelastic collisions corresponding to small impact parameters, while more peripheral collisions lead to well-known binary deep inelastic reactions.

Published
2010

47. Two-proton knockout fromMg32: Intruder amplitudes inNe30and implications for the binding ofF29,31

Author

I. Y. Lee, Elena Rodriguez-Vieitez, B. A. Brown, P. Fallon, D.-C. Dinca, W. F. Mueller, P. Adrich, D. Bazin, Alexandra Gade, M. D. Bowen, Yutaka Utsuno, Stanley G. Prussin, C. M. Campbell, K. Yoneda, J. R. Terry, T. Glasmacher, D. Weisshaar, M. Cromaz, J. M. Cook, M. Wiedeking, A. O. Macchiavelli, K. Siwek, S. McDaniel, R. M. Clark, J. A. Tostevin, Taka Otsuka, and A. Ratkiewicz

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Proton, Isotopes of neon, Neutron emission, Excited state, Atomic physics, Nuclear Experiment, Nucleon, Ground state, Isotopes of magnesium
Abstract

gamma-ray decays from excited states in {sup 30}Ne and inclusive and exclusive cross sections were measured in the {sup 9}Be({sup 32}Mg,{sup 30}Ne+gamma)X two-proton knockout reaction at incident beam energies of 99.7 and 86.7 MeV/nucleon. The measured cross section is suppressed compared to calculations and is indicative of a reduced overlap of initial and final state wave functions in {sup 32}Mg and {sup 30}Ne. We interpret this reduction as due to large 4p4h amplitudes present in the {sup 30}Ne ground state wave function, but not {sup 32}Mg. Such large intruder components are predicted to help stabilize the heavier fluorine isotopes against neutron emission.

Published
2010

48. Observation of fast collinear partitioning of theAu197 +Au197system into three and four fragments of comparable size

Author

M. Di Toro, V. Baran, E. La Guidara, F. Amorini, L. Zetta, Z. Majka, M. Trimarchi, G. Lanzalone, W. Zipper, Maria Colonna, Antonio Trifiro, J.P. Wieleczko, J. Łukasik, G. Cardella, F. Porto, K. Siwek-Wilczyńska, J. Brzychczyk, S. Pirrone, A. Sochocka, E. De Filippo, A. Anzalone, A. Grzeszczuk, Ł. Świderski, K. Schmidt, R. Płaneta, N. G. Nicolis, M. B. Chatterjee, E. Geraci, E. Piasecki, Lucrezia Auditore, S. Cavallaro, A. Pagano, P. Guazzoni, G. Politi, I. Skwira-Chalot, S. Kowalski, Michele Papa, W. Gawlikowicz, C. Maiolino, F. Rizzo, J. Wilczyński, and P. Russotto

Subjects
Physics, Nuclear and High Energy Physics, Angular momentum, 010308 nuclear & particles physics, Hadron, Inelastic collision, Elementary particle, Inelastic scattering, 7. Clean energy, 01 natural sciences, Baryon, 0103 physical sciences, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ternary operation
Abstract

Collisions of a very heavy nonfusing nuclear system $^{197}\mathrm{Au}$$+$$^{197}\mathrm{Au}$ were studied at an energy of $15$ MeV/nucleon. An interesting process of violent reseparation of this heavy system into three or four fragments of comparable size was observed. In the case of ternary partitioning, either the projectile-like fragment (PLF) or target-like fragment (TLF) breaks up almost collinearly with the PLF-TLF separation axis. In the case of quaternary reactions, both PLF and TLF were observed breaking up along this direction. By comparison with a dynamical model of deep inelastic collisions it was concluded that the ternary and quaternary reactions occur in semiperipheral collisions, in a range of angular momenta corresponding to about $0.5--0.7$ of the maximum $L$ value for grazing collisions. The time elapsing from the scission of the binary PLF $+$ TLF system to the secondary scission of PLF or TLF was estimated to be of about $70--80$ fm/$c$ for the ternary reactions and $80--100$ fm/$c$ for the quaternary reactions.

Published
2010

49. Fusionlike processes in theN14+232Th reaction at 30 MeV/nucleon

Author

A.L. Boonstra, J. Wilczyński, K. Siwek-Wilczyńska, Z. Sosin, E.E. Koldenhof, Rudolf Siemssen, J.D. Hinnefeld, H. W. Wilschut, and H.K.W. Leegte

Subjects
Physics, Nuclear reaction, Coalescence (physics), Nuclear and High Energy Physics, Photon, Neutron emission, Fission, Momentum transfer, Atomic physics, Nuclear Experiment, Nucleon, Charged particle
Abstract

Fusionlike processes were studied in the {sup 14}N+{sup 232}Th reaction at 30 MeV per nucleon. Partition of the fusionlike cross section was determined by detecting nonequilibrium charged particles with an array of phoswich detectors (plastic wall) in coincidence with fission fragments for which the folding angle and thus the momentum transfer was measured. By measuring both single and multiple hits in the plastic wall and by correcting for its incomplete angular coverage a very extensive database of the fusionlike channels was obtained. The results were compared with model predictions comprising the BUU, Fermi jetting, the Boltzmann master equation model, and the nucleon-exchange transport model. It was found that these models which globally describe the dependence of the inclusive momentum transfer in fusionlike reactions cannot account for the associated particle production, in particular if the nucleons bound in the observed complex particles ({ital d},{ital t},{alpha}) are included in the comparison. Calculations of the energy spectra of the complex particles with the coalescence formalism indicate that a large fraction of the observed complex particles in the fusionlike reactions cannot be accounted for by pre-equilibrium emission from the fused composite system. They most probably originate from massive-transfer-type reactions that contribute to the beam-velocitymore » component in the energy spectra.« less

Published
1992

50. Selectivity of the one-neutron knockout reaction onCl45and the collapse of theN=28shell closure

Author

B. A. Brown, P. D. Cottle, B. A. Hartl, J. M. Cook, D. A. Garland, T. Baugher, C. Aa. Diget, K. Siwek, Alexandra Gade, D. C. Stoken, K. E. Hosier, J. A. Tostevin, P. Adrich, D. Bazin, A. Ratkiewicz, K. W. Kemper, L. A. Riley, T. Glasmacher, and D. Weisshaar

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, Landé g-factor, Nuclear Theory, Population, Shell (structure), Momentum, Closure (mathematics), Valley of stability, Neutron, Atomic physics, Nuclear Experiment, education, Ground state
Abstract

Neutron hole states in the exotic $N=27$ isotope $^{44}\mathrm{Cl}$ have been populated using the intermediate-energy single-neutron knockout reaction $^{9}\mathrm{Be}(^{45}\mathrm{Cl},^{44}\mathrm{Cl})\mathrm{X}$. The momentum distribution of the residual $^{44}\mathrm{Cl}$ nuclei after direct population of the ground state is consistent with removal of an $l=1$ neutron. This observation and comparison with a shell-model calculation imply that ${p}_{3/2}$ neutrons from above the $N=28$ major shell closure play important roles in the ground states of both $^{44}\mathrm{Cl}$ and $^{45}\mathrm{Cl}$. The present result is significant because $^{44}\mathrm{Cl}$ is even closer to the valley of stability than $^{43}\mathrm{S}$, where a similar result was recently obtained using a $g$-factor measurement.

Published
2009

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