204
K. P. Santhosh
The observation of first hypernuclear fragment was made by Danysz and Pniewski
[1] in 1952, which was a boron nucleus in which a neutron was replaced by a
hyperon. Various properties of hypernuclei have been studied since its first evidence
[2–8]. The stability of hypernuclei can be understood by studying its binding and
separation energies. Different theoretical methods are proposed for studying the binding and separation energies of hypernuclei [9–17]. The decay studies of hypernuclei
suggest that within the nuclear environment because of Pauli’s blocking effect, nonmesonic decay modes are dominant over the mesonic decay modes. The possibilities
of decays of excited hypernuclei triggered by strong interactions [18–21] have also
been a subject of study.
An extended BWMF for finding the binding energies of hypernuclei and a
new formula for obtaining the separation energies are presented. The alpha and
cluster decays from hyper Po, hyper Ra, and hyper Ac nuclei are performed using
the Coulomb and proximity potential model (CPPM) [22] with the inclusion of a
-nucleus potential.
Since the superheavy elements up to Z = 118 have been confirmed in the laboratory, the study of SHE with Z > 118 now becomes an important topic in the
nuclear physics research. SHEs were synthesized via two methods; hot fusion reaction at JINR-FLNR, Dubna for Z = 114−118 [23–28] and cold-fusion reaction
at GSI, Darmstadt and at RIKEN, Japan for Z = 102−112 [29, 30]. The element
Z = 113 was synthesized successfully by hot fusion reaction using
48 Ca +
237 Np by
Oganessian et al. [31] and by cold-fusion reaction using
70 Zn+
209 Bi by Morita et al.
[32]. However, it is difficult to produce SHE with Z = 113 in cold-fusion reactions
because of the smaller production cross sections. The discovery of superheavy nuclei
in the fusion reactions of
48 Ca +
238 U →
249 Cf were reviewed by Oganessian and
Utyonkov in 2015 [33]. Recently Khuyagbaatar et al. [34] predicted the ER cross
section for the isotope of Ts (Z = 117) for which the experiment was performed
at the gas-filled recoil separator TASCA and confirmed the previous findings at the
Dubna Gas-Filled Recoil Separator [25, 26, 35].
The ER residue cross section depends on the projectile-target pair, center-of-mass
energy which in turn depends on probability of CN formation, excitation energy, fission barrier of CN, and survival probability. Hence, the predictions of the favorable
reactions and beam energy are very important for the synthesis of superheavy elements. In the present paper, we have studied the decay modes and production cross
section for the SHE with Z = 121. The evidence for the synthesis of Z = 121 is not
reported yet and this study may helpful for future experimental investigations.
K. P. Santhosh
The observation of first hypernuclear fragment was made by Danysz and Pniewski
[1] in 1952, which was a boron nucleus in which a neutron was replaced by a
hyperon. Various properties of hypernuclei have been studied since its first evidence
[2–8]. The stability of hypernuclei can be understood by studying its binding and
separation energies. Different theoretical methods are proposed for studying the binding and separation energies of hypernuclei [9–17]. The decay studies of hypernuclei
suggest that within the nuclear environment because of Pauli’s blocking effect, nonmesonic decay modes are dominant over the mesonic decay modes. The possibilities
of decays of excited hypernuclei triggered by strong interactions [18–21] have also
been a subject of study.
An extended BWMF for finding the binding energies of hypernuclei and a
new formula for obtaining the separation energies are presented. The alpha and
cluster decays from hyper Po, hyper Ra, and hyper Ac nuclei are performed using
the Coulomb and proximity potential model (CPPM) [22] with the inclusion of a
-nucleus potential.
Since the superheavy elements up to Z = 118 have been confirmed in the laboratory, the study of SHE with Z > 118 now becomes an important topic in the
nuclear physics research. SHEs were synthesized via two methods; hot fusion reaction at JINR-FLNR, Dubna for Z = 114−118 [23–28] and cold-fusion reaction
at GSI, Darmstadt and at RIKEN, Japan for Z = 102−112 [29, 30]. The element
Z = 113 was synthesized successfully by hot fusion reaction using
48 Ca +
237 Np by
Oganessian et al. [31] and by cold-fusion reaction using
70 Zn+
209 Bi by Morita et al.
[32]. However, it is difficult to produce SHE with Z = 113 in cold-fusion reactions
because of the smaller production cross sections. The discovery of superheavy nuclei
in the fusion reactions of
48 Ca +
238 U →
249 Cf were reviewed by Oganessian and
Utyonkov in 2015 [33]. Recently Khuyagbaatar et al. [34] predicted the ER cross
section for the isotope of Ts (Z = 117) for which the experiment was performed
at the gas-filled recoil separator TASCA and confirmed the previous findings at the
Dubna Gas-Filled Recoil Separator [25, 26, 35].
The ER residue cross section depends on the projectile-target pair, center-of-mass
energy which in turn depends on probability of CN formation, excitation energy, fission barrier of CN, and survival probability. Hence, the predictions of the favorable
reactions and beam energy are very important for the synthesis of superheavy elements. In the present paper, we have studied the decay modes and production cross
section for the SHE with Z = 121. The evidence for the synthesis of Z = 121 is not
reported yet and this study may helpful for future experimental investigations.