600 research outputs found
Shaking during Ion-Atom Collisions
Shaking (shakeup + shakeoff) probabilities accompanying ion-atom collisions
are studied using hydrogenic wavefunctions for K-, L-, M- shell electrons in
the sudden approximation limit. The role of recoil velocity in the shaking
processes is discussed. Further, it is found that the suddenness of collision
between projectile and target nuclei plays a major factor in shaking of
respective atomic system than the recoil of nuclei.Comment: 10 page
Study of dynamical charge fluctuations in the hadronic medium
The dynamical charge fluctuations have been studied in ultra-relativistic
heavy-ion collisions by using hadronic model simulations, such as UrQMD and
HIJING. The evolution of fluctuations has been calculated at different time
steps during the collision as well as different observation window in
pseudorapidity (\DelEta). The final state effects on the fluctuations have been
investigated by varying ~ and the time steps with the aim
of obtaining an optimum observation window for capturing maximum fluctuations.
It is found that ~ between 2.0 and 3.5 gives the best
coverage for the fluctuations studies. The results of these model calculations
for Au+Au collisions at ~=~7.7 to 200~GeV and for Pb+Pb
collisions at 2.76 TeV are presented and compared with available experimental
data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron
Collider (LHC).Comment: 6 pages, 4 Figure
Effect of Hagedorn States on Isothermal Compressibility of Hadronic Matter formed in Heavy-Ion Collisions: From NICA to LHC Energies
In this work, we have studied the isothermal compressibility () as
a function of temperature, baryon chemical potential and centre-of-mass energy
() using hadron resonance gas (HRG) and excluded-volume hadron
resonance gas (EV-HRG) models. A mass cut-off dependence of isothermal
compressibility has been studied for a physical resonance gas. Further, we
study the effect of heavier resonances ( 2 GeV) on the isothermal
compressibility by considering the Hagedorn mass spectrum,
. Here, the parameters, and
are extracted after comparing the results of recent lattice QCD
simulations at finite baryonic chemical potential. We find a significant
difference between the results obtained in EV-HRG and HRG models at a higher
temperatures and higher baryochemical potentials. The inclusion of the Hagedorn
mass spectrum in the partition function for hadron gas has a large effect at a
higher temperature. A higher mass cut-off in the Hagedorn mass spectrum takes
the isothermal compressibility to a minimum value, which occurs near the
Hagedorn temperature (). We show explicitly that at the future low energy
accelerator facilities like FAIR (CBM), Darmstadt and NICA, Dubna the created
matter would be incompressible compared to the high energy facilities like RHIC
and LHC.Comment: Same as published pape
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