Search for long lived heaviest nuclei beyond the valley of stability

Journal Article · Tue Apr 15 04:00:00 EDT 2008 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.77.044603· OSTI ID:21189915

Chowdhury, P Roy ^[1]; Samanta, C ^[1]; Basu, D N ^[2]

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1. Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700 064 (India)
2. Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700 064 (India)

The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and {alpha}-decay processes. According to microscopic nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide the extra stability to such SHN to have long enough lifetime to be observed. To investigate whether the so-called 'stability island' could really exist around the above Z, N values, the {alpha}-decay half-lives along with the spontaneous fission and {beta}-decay half-lives of such nuclei are studied. The {alpha}-decay half-lives of SHN with Z=102-120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using Q{sub {alpha}} values from three different mass formulas prescribed by Koura-Uno-Tachibana-Yamada (KUTY), Myers-Swiatecki (MS), and Muntian-Hofmann-Patyk-Sobiczewski (MMM). Calculation of spontaneous fission (SF) half-lives for the same SHN are carried out using a phenomenological formula and compared with SF half-lives predicted by Smolanczuk et al. A possible source of discrepancy between the calculated {alpha}-decay half-lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN, is discussed. In the region of Z=106-108 with N{approx}160-164, the {beta}-stable SHN {sub 106}{sup 268}Sg{sub 162} is predicted to have highest {alpha}-decay half-life (T{sub {alpha}}{approx}3.2 h) using Q{sub {alpha}} value from MMM. Interestingly, it is much greater than the recently measured T{sub {alpha}} ({approx}22 s) of deformed doubly magic {sub 108}{sup 270}Hs{sub 162} nucleus. A few fission-survived long-lived SHN which are either {beta}-stable or having large {beta}-decay half-lives are predicted to exist near {sup 294}110{sub 184}, {sup 293}110{sub 183}, {sup 296}112{sub 184}, and {sup 298}114{sub 184}. These nuclei might decay predominantly through {alpha}-particle emission.

• OSTI ID: 21189915
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 4 Vol. 77; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
ALPHA PARTICLES
BETA DECAY
EMISSION
HALF-LIFE
HEAVY NUCLEI
INTERACTIONS
LIFETIME
MASS FORMULAE
NUCLEAR DECAY
NUCLEAR THEORY
SIMULATION
SPHERICAL CONFIGURATION
SPONTANEOUS FISSION
STABILITY
TRANSACTINIDE ELEMENTS
TUNNEL EFFECT