Isospin Dependence of Intermediate Mass Fragments in 124Sn, 124Xe + 124Sn, 112SnIsospin Dependence of Intermediate Mass Fragments in 124Sn, 124Xe + 124Sn, 112Sn

D. V. Shetty, A. Keksis, E. Martin, A. Ruangma, G.A. Souliotis, M. Veselsky, E.M. Winchester, S.J. Yennello, K.

Hagel, Y.G. Ma, M. Murray, J.B. Natowitz, L. Qin, P. Smith, R. Wada, J. Wang, M. Cinausero, E. Fioretto, G. Prete, D.

Fabris, M. Lunardon, G. Nebbia, V. Rizzi, G. Viesti, J. Cibor, Z. Majka, P. Staszel, R. Alfarro, A. Martinez-Davalos, A.

Menchaca-Rocha, Y. El Masri and T. Keutgen

D. V. Shetty, A. Keksis, E. Martin, A. Ruangma, G.A. Souliotis, M. Veselsky, E.M. Winchester, S.J. Yennello, K.

Hagel, Y.G. Ma, M. Murray, J.B. Natowitz, L. Qin, P. Smith, R. Wada, J. Wang, M. Cinausero, E. Fioretto, G. Prete, D.

Fabris, M. Lunardon, G. Nebbia, V. Rizzi, G. Viesti, J. Cibor, Z. Majka, P. Staszel, R. Alfarro, A. Martinez-Davalos, A.

Menchaca-Rocha, Y. El Masri and T. Keutgen

Cyclotron Institute, Texas A&M University INFN Laboratori Nazionali di Legnaro, Legnaro, Italy

INFN Dipartimento di Fisica, Padova, Italy Jagellonian University, Krakow, Poland UNAM, Mexico City, Mexico UCL, Louvain-la-

Neuve, Belgium

Cyclotron Institute, Texas A&M University INFN Laboratori Nazionali di Legnaro, Legnaro, Italy

INFN Dipartimento di Fisica, Padova, Italy Jagellonian University, Krakow, Poland UNAM, Mexico City, Mexico UCL, Louvain-la-

Neuve, Belgium

Isospin asymmetric matter behaves differently from

symmetric nuclear matter

Theoretical Predictions Isospin Equilibration

Isospin Fractionation Midrapidity

Emission ….

Expt Observables Fragment yield dist, Isotopic & isobaric yields, energy spectras

……

Reactions Studied :Reactions Studied :

124Xe + 112Sn (N/Z) = 1.27 124Sn + 112Sn (N/Z) = 1.36 124Xe + 124Sn (N/Z) = 1.38 124Sn + 124Sn (N/Z) = 1.48

Beam Energy :Beam Energy :

28 MeV/nucleon

Detectors :Detectors :

NIMROD, 4 charged particle array

Isospin Dependence of the Fractional YieldIsospin Dependence of the Fractional Yield

Nearly symmetric isotopic yield distribution

Nearly symmetric isotopic yield distribution

System with lowest N/Z produce the highest fraction of n-deficient isotopes

System with lowest N/Z produce the highest fraction of n-deficient isotopes

System with highest N/Z produce highest fraction of n-rich isotopes

System with highest N/Z produce highest fraction of n-rich isotopes

Isospin Dependence of Isotopic Yield Ratio and Angular Evolution

Isospin Dependence of Isotopic Yield Ratio and Angular Evolution

Angular evolution of isotopic yields depends on

the N/Z of the system

Angular evolution of isotopic yields depends on

the N/Z of the system

Isospin equilibration

at central angle

Isospin equilibration

at central angle

Isospin Distillation and Fragment < N/Z > Dependence

Isospin Distillation and Fragment < N/Z > Dependence

Excess neutrons become available in the form of light and n-rich

clusters

Excess neutrons become available in the form of light and n-rich

clusters

Decrease in <N/Z> with increasing Z supports the idea of two phase split of

nuclear matter (distillation)

Decrease in <N/Z> with increasing Z supports the idea of two phase split of

nuclear matter (distillation)

Isospin Dependence of Isobaric Yield RatiosIsospin Dependence of Isobaric Yield Ratios

Energy Spectra Dependence of the IsotopesEnergy Spectra Dependence of the Isotopes

3 Source fit for Li fragments3 Source fit for Li fragments

Parallel Velocity Distribution as Function of Centrality

Parallel Velocity Distribution as Function of Centrality

Mid-Rapidity Emission of the Light FragmentsMid-Rapidity Emission of the Light Fragments

Centrality Dependence of

the Relative yield

Centrality Dependence of

the Relative yield

1. Fractional yield of the n-rich isotopes increase and those of n-deficient isotopes decrease with increasing N/Z of the system.

2. Isotopic and isobaric yield ratios increase linearly with N/Z of the composite system indicating near equilibration along central angle.

3. Neutron content of the light cluster increase significantly with decreasing temperature.

4. <N/Z> of the fragments indicate excess neutrons becoming available to light and n-rich clusters.

5. Energy spectras for different isotopes of light fragments are appreciably different.

6. Rapidity dist. as a function of centrality show heavier isotopes being emitted closer to midrapidity region.

Conclusions :