FLOW OF STRANGE PARTICLES FROM FOPI AT SIS

2007 ◽  
Vol 22 (02n03) ◽  
pp. 608-611
Author(s):  
◽  
YOUNG JIN KIM
Keyword(s):  
Nuclear Matter ◽  
Theoretical Calculations ◽  
Medium Effect ◽  
Baryonic Matter ◽  
Medium Effects ◽  
Transport Models ◽  
Strange Particles ◽  
Threshold Energies

Study of strange particles produced at (sub)threshold energies in nucleus-nucleus collisions can deliver insights into fundamental questions about the in-medium properties of hadrons in dense baryonic matter. Many theoretical calculations for the production and propagation of strangeness at SIS energies lead to various predictions concerning the existence and the magnitude of in-medium effects for strange particles in nuclear matter. FOPI measured the flow of strange particles in Ni + Ni collisions at 1.93A GeV and the results are compared with transport models which are favorable to in-medium effect.

scholarly journals Quarkonium measurements in heavy-ion collisions with the STAR experiment

2018 ◽  
Vol 171 ◽  
pp. 18015
Author(s):  
Xinjie Huang
Keyword(s):  
Transverse Momentum ◽  
Nuclear Matter ◽  
Heavy Ion Collisions ◽  
Theoretical Calculations ◽  
Heavy Ion ◽  
Matter Effects ◽  
Nuclear Modification ◽  
Ion Collisions ◽  
Star Experiment ◽  
Nuclear Modification Factors

In these proceedings, we present the latest measurements of J/ψ and ϒ by the STAR experiment. The J/ψ and ϒ production measured in p+p collisions provide new baselines for similar measurements in Au+Au collisions, while the measurements in p+Au collisions can help quantify the cold nuclear matter effects. The J/ψ υ2 is measured in both U+U and Au+Au collisions to place constraints on the amount of J/ψ arising from recombination of deconfined charm and anti-charm pairs. Furthermore, the nuclear modification factors for ground and excited ϒ states as a function of transverse momentum and centrality are presented, and compared to those measured at the LHC as well as to theoretical calculations.

Wallach rearrangement of azoxypyridines and azoxypyridine N-oxides — Charge distributions and dramatic reactivity differences

2008 ◽  
Vol 86 (4) ◽  
pp. 298-304 ◽  
Author(s):  
Erwin Buncel ◽  
Sam-Rok Keum ◽  
Srinivasan Rajagopal ◽  
Eric Kiepek ◽  
Robin A Cox
Keyword(s):  
Sulfuric Acid ◽  
Positive Charge ◽  
Theoretical Calculations ◽  
Medium Effect ◽  
Mulliken Charge ◽  
Reaction Intermediates ◽  
Charge Distributions ◽  
First Time ◽  
Acid Region

Extension of our studies of the generic Wallach rearrangement (of azoxybenzene to 4-hydroxyazobenzene) to the heteroaromatic series (azoxypyridines and axoxypyridine N-oxides) has revealed some dramatic reactivity differences, particularly for the α and β compounds. We have studied the 3-isomers and the 4-isomers in each series, each with α and β forms, eight compounds in all, in the 100 wt% sulfuric acid region of acidity. In those cases in which a product could be observed, the α and β isomers both give the same one, the corresponding 4′-hydroxyazo compounds. All the compounds react much more slowly than does azoxybenzene itself, presumably because of the extra positive charge present in the substrates, but the β isomers have half-lives of seconds and the α isomers half-lives of hundreds of hours in the 100 wt% H2SO4 acidity region. The α compounds have measurable pKBH+ values, but the β compounds do not, exhibiting only a medium effect in the acidity region in which the α compounds protonate. This means that for the β compounds, the protonated intermediates must be much less stable and the postulated reaction intermediates must be much more stable than for the α compounds. To clarify this, we have obtained Mulliken charge distributions for the various species concerned, calculating the charge carried by each half of the molecule, larger charge separations being taken to indicate lesser stability. As far as we can establish, this is the first time that this technique has been used to indicate the stabilities of carbocationic species.Key words: azoxypyridines, azoxypyridine N-oxides, Wallach rearrangement, excess acidity, basicities, theoretical calculations, charge distributions, reactivities.

scholarly journals THE IMPACT OF KAON POLARIZATION IN NUCLEAR MATTER ON THE K− PRODUCTION IN HEAVY-ION COLLISIONS

1996 ◽  
Vol 05 (02) ◽  
pp. 313-328 ◽  
Author(s):  
E.E. KOLOMEITSEV ◽  
D.N. VOSKRESENSKY ◽  
B. KÄMPFER
Keyword(s):  
Nuclear Matter ◽  
Cross Sections ◽  
Heavy Ion Collisions ◽  
Particle Production ◽  
Heavy Ion ◽  
Strange Particle ◽  
Intermediate Energy ◽  
Medium Effects ◽  
Ion Collisions ◽  
The Impact

The impact of the kaon polarization in nuclear matter on the K− yield in intermediate-energy heavy-ion collisions is investigated. Our scenario of the strange particle production and dynamics is based on an expanding fireball model. This allows for a proper account of in-medium effects. A relation between observed K+ and K− yields is derived. Differential K− cross-sections are calculated and compared with available experimental data taken at various collision energies. It turns out that in-medium effects can modify the K− yields by factors 2 to 5 at beam energies between 2 and 1 AGeV.

Theoretical calculations of the aqueous medium effects on the basicities of primary amines

1980 ◽  
Vol 102 (1) ◽  
pp. 424-426 ◽  
Author(s):  
M. Taagepera ◽  
D. DeFrees ◽  
W. J. Hehre ◽  
R. W. Taft
Keyword(s):  
Aqueous Medium ◽  
Theoretical Calculations ◽  
Primary Amines ◽  
Medium Effects

scholarly journals Nuclear in-medium effects of strange particles in proton-nucleus collisions

2014 ◽  
Vol 90 (6) ◽  
Author(s):  
Zhao-Qing Feng ◽  
Wen-Jie Xie ◽  
Gen-Ming Jin
Keyword(s):  
Medium Effects ◽  
Strange Particles

scholarly journals In-medium effects for nuclear matter in the Fermi-energy domain

2014 ◽  
Vol 90 (6) ◽  
Author(s):  
O. Lopez ◽  
D. Durand ◽  
G. Lehaut ◽  
B. Borderie ◽  
J. D. Frankland ◽  
...  
Keyword(s):  
Nuclear Matter ◽  
Fermi Energy ◽  
Medium Effects ◽  
Energy Domain

scholarly journals A Geant4-based Monte Carlo Tool for Nuclear Astrophysics

2018 ◽  
Vol 184 ◽  
pp. 02008
Author(s):  
D. Lattuada ◽  
M. La Cognata ◽  
A. Anzalone ◽  
D.L. Balabanski ◽  
S. Chesnevskaya ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Theoretical Calculations ◽  
Nuclear Astrophysics ◽  
Target Thickness ◽  
Event Generator ◽  
Great Opportunity ◽  
Threshold Energies

Present and future gamma-beam facilities represent a great opportunity to validate and evaluate the cross-sections of many photonuclear reactions at near-threshold energies, whose data mostly come from theoretical calculations. We developed a Monte Carlo (MC) software that makes use of the validatedtracking Geant4 libraries and the n-body event generator of ROOT libraries in order to provide a fast, realiable and complete MC tool to be used for nuclear physics experiments, with a particular focus on photo-nuclear processes. We discuss the results of the MC simulations performed in order to evaluate the effects of the electromagnetic background, the straggling of the emitted particles due to the target thickness and the resolution of the silicon detectors. Finally we present the preliminary results on some nuclear reactions involved in the p-process, which will be studied with ELISSA and the GBS at ELI-NP.

NEUTRINO PROPAGATION IN HOT NUCLEAR MATTER AND ITS APPLICATIONS TO THE SUPERNOVAE EXPLOSION

2006 ◽  
Vol 15 (02) ◽  
pp. 511-514
Author(s):  
G. WLAZŁOWSKI
Keyword(s):  
Nuclear Matter ◽  
Linear Response ◽  
Medium Effects ◽  
Skyrme Interaction ◽  
Asymmetric Nuclear Matter ◽  
Hartree Fock ◽  
Wide Range ◽  
Response Method ◽  
Neutrino Propagation

The neutrino propagation in asymmetric nuclear matter is studied in the framework of the linear response method. The medium effects are treated in the Hartree-Fock approach with an effective Skyrme interaction. The neutrino opacity for the nuclear matter has been calculated in a wide range of densities and temperatures.

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