62
P. Bansal et al.
5.4 Summary
In summary, we have studied the effect of isospin degree of freedom on the peak
energy production and multiplicity of heavy mass fragments (HMFs), medium mass
fragments (MMFs), and intermediate mass fragments (IMFs). We observed that the
peak energy of HMFs, MMFs, and IMFs decreases with an increase in the neutron
content for isobaric pairs, while the different behavior is observed for the isotopic
partners. The multiplicity of HMFs remains insensitive to neutron content of colliding
pair, while production of MMFs and IMFs increases with neutron content for isotopic
pairs. Further, we found that symmetry potential is responsible for the decrease in the
peak energy of HMFs, MMFs, and IMFs for isobaric neutron-rich colliding nuclei.
Also, we have studied the yield of gas and liquid content as a function of incident
energy in the fragmentation of asymmetric reactions by varying the mass asymmetry
from 0 to 0.8. Here, the total system mass was fixed (100 units). Our results indicate
that the mass asymmetry influences the cross-over energy significantly. The crossover energy is enhanced with mass asymmetry. This is because of the decrease in
the participant zone for asymmetric reactions. We again noticed that the symmetry
potential has more influence on the cross-over energy in comparison to NN scattering
cross section. Thus, our study concludes that the cross-over energy is a sensitive probe
to study the density dependence of nuclear symmetry energy.
Acknowledgements The author (PB) is thankful to Prof. Rajeev K. Puri for giving access to various
computer codes developed by him for the present work.
References
1. J. Pochodzalla et al., Probing the nuclear liquid-gas phase transition. Phys. Rev. Lett. 75,
1040–1044 (1995)
2. M.B. Tsang et al., Onset of nuclear vaporization in 197 Au+ 197 Au collisions. Phys. Rev. Lett.
71, 1502–1505 (1993)
3. K.S. Vinayak, S. Kumar, Multifragmentation around the transition energy in intermediateenergy heavy-ion collisions. Phys. Rev. C 83, 034614 (2011)
4. Y.K. Vermani, R.K. Puri, Mass dependence of the onset of multifragmentation in low energy
heavy-ion collisions. J. Phys. G: Nucl. Part. Phys. 36, 105103 (2009)
5. D. Sisan et al., Intermediate mass fragment emission in heavy-ion collisions: energy and system
mass dependence. Phys. Rev. C 63, 027602 (2001)
6. S. Kaur, A.D. Sood, Model ingredients and peak mass production in heavy-ion collisions. Phys.
Rev. C 82, 054611 (2010)
7. J.K. Dhawan, R.K. Puri, Multifragmentation at the energy of vanishing flow in central heavy-ion
collisions. Phys. Rev. C 74, 054610 (2006)
8. S. Goyal, Multifragmentation at the balance energy of mass-asymmetric colliding nuclei. Phys.
Rev. C 84, 044614 (2011)
9. V. Kaur, S. Kumar, Systematic study of multifragmentation in asymmetric colliding nuclei.
Phys. Rev. C 81, 064610 (2010)
10. S. Kaur, R.K. Puri, Isospin effects on the energy of peak mass production. Phys. Rev. C 87,
014620 (2013)
P. Bansal et al.
5.4 Summary
In summary, we have studied the effect of isospin degree of freedom on the peak
energy production and multiplicity of heavy mass fragments (HMFs), medium mass
fragments (MMFs), and intermediate mass fragments (IMFs). We observed that the
peak energy of HMFs, MMFs, and IMFs decreases with an increase in the neutron
content for isobaric pairs, while the different behavior is observed for the isotopic
partners. The multiplicity of HMFs remains insensitive to neutron content of colliding
pair, while production of MMFs and IMFs increases with neutron content for isotopic
pairs. Further, we found that symmetry potential is responsible for the decrease in the
peak energy of HMFs, MMFs, and IMFs for isobaric neutron-rich colliding nuclei.
Also, we have studied the yield of gas and liquid content as a function of incident
energy in the fragmentation of asymmetric reactions by varying the mass asymmetry
from 0 to 0.8. Here, the total system mass was fixed (100 units). Our results indicate
that the mass asymmetry influences the cross-over energy significantly. The crossover energy is enhanced with mass asymmetry. This is because of the decrease in
the participant zone for asymmetric reactions. We again noticed that the symmetry
potential has more influence on the cross-over energy in comparison to NN scattering
cross section. Thus, our study concludes that the cross-over energy is a sensitive probe
to study the density dependence of nuclear symmetry energy.
Acknowledgements The author (PB) is thankful to Prof. Rajeev K. Puri for giving access to various
computer codes developed by him for the present work.
References
1. J. Pochodzalla et al., Probing the nuclear liquid-gas phase transition. Phys. Rev. Lett. 75,
1040–1044 (1995)
2. M.B. Tsang et al., Onset of nuclear vaporization in 197 Au+ 197 Au collisions. Phys. Rev. Lett.
71, 1502–1505 (1993)
3. K.S. Vinayak, S. Kumar, Multifragmentation around the transition energy in intermediateenergy heavy-ion collisions. Phys. Rev. C 83, 034614 (2011)
4. Y.K. Vermani, R.K. Puri, Mass dependence of the onset of multifragmentation in low energy
heavy-ion collisions. J. Phys. G: Nucl. Part. Phys. 36, 105103 (2009)
5. D. Sisan et al., Intermediate mass fragment emission in heavy-ion collisions: energy and system
mass dependence. Phys. Rev. C 63, 027602 (2001)
6. S. Kaur, A.D. Sood, Model ingredients and peak mass production in heavy-ion collisions. Phys.
Rev. C 82, 054611 (2010)
7. J.K. Dhawan, R.K. Puri, Multifragmentation at the energy of vanishing flow in central heavy-ion
collisions. Phys. Rev. C 74, 054610 (2006)
8. S. Goyal, Multifragmentation at the balance energy of mass-asymmetric colliding nuclei. Phys.
Rev. C 84, 044614 (2011)
9. V. Kaur, S. Kumar, Systematic study of multifragmentation in asymmetric colliding nuclei.
Phys. Rev. C 81, 064610 (2010)
10. S. Kaur, R.K. Puri, Isospin effects on the energy of peak mass production. Phys. Rev. C 87,
014620 (2013)