α -decay properties of 118296 from double-folding potentials

Abstract

α-decay properties of the yet unknown nucleus 296 118 are predicted using the systematic behavior of parameters of α-nucleus double-folding potentials. The results are Qα = 11.655 ± 0.095 MeV and T 1/2 = 0.825 ms with an uncertainty of about a factor of 4.PACS numbers: 23.60.+e,27.90.+b,21.60.Gx Very recently, Sobiczewski [1] has analyzed the decay properties of the yet unknown nucleus 296 118 using a combination of Q α values from mass models and a phenomenological formula for the α-decay half-lives. This study was motivated by ongoing experiments which attempt to synthesize this heaviest nucleus to date. The present work uses a completely different approach which is based on the smooth and systematic bahavior of α-decay parameters using double-folding potentials [2].Sobiczewski Cn ("chain-2") where only the two latter α-decays are known from experiment. The selection of the mass formulae leads to a restricted range of Q α for 296 118 from 11.62 MeV (WS3+), 11.73 MeV (WS4+), and 12.06 MeV (HN), and the corresponding α-decay half-lives are 4.8 ms (WS3+), 2.7 ms (WS4+), and 0.50 ms (HN). This range of predictions of almost one order of magnitude for the α-decay half-life of 296 118 does not yet include an additional uncertainty of the phenomenological formula of [3] which is on average a factor of 1.34 for even-even nuclei and does not exceed a factor of 1.78 in most cases [3].In a further study Budaca et al. [9] have applied empirical fitting formulae for the prediction of the decay properties of 296 118. They obtain a slightly lower Q α = 11.45 MeV and half-lives of about 3 ms. A very low value of Q α = 10.185 MeV is derived from mass formulae in [10,11], leading to predicted half-lives up to minutes for 296 118. Half-lives of the order of 1 ms have been obtained in [12] using the WS4+ Q α and various empirical formulae for the half-life, and similar half-lives slightly below 1 ms were found very recently in [13, 14] * Email: WidmaierMohr@t-online.de; mohr@atomki.mta.hu which are also based on Q α from WS4+.For completeness it has to be mentioned that α-decay is the dominant decay mode of 296 118. Partial half-lives of 296 118 for spontaneous fission have been estimated in [1,15]; they exceed the α-decay half-life by several orders of magnitude.Contrary to the study of Sobiczewski and the other recent calculations for 296 118 [9][10][11][12], the present approach does not use mass models for the prediction of the unknown Q α of 296 118 which is the most important quantity for the prediction of its half-life. Instead, the smooth behavior of parameters is used which is obtained in calculations with systematic double-folding potentials [2]. This method is particularly well suited for the present case where the available experimental results for chain-1 and chain-2 have to be extrapolated only to a very close neighbor. For completeness it should be noted that there is another method for an independent determination of Q α from the systematics of Q α differences of neighboring nuclei; unfortunately, the publishe...

Nuclear energy density functional and the nuclear α decay

“…[48] that gives 0.5 ms ∼ 4.8 ms based on realistic mass formulas and with the prediction of Ref. [47] which obtained 0.825 ms using the double-folding potential model. (See also Refs.…”

“…The sightly lower barrier in Ref. [47] is compensated by a preformation factor of 0.09, finally leading to half-lives close to each other.…”

Search for the heaviest atomic nuclei among the products from reactions of mixed-Cf with a Ca48 beam

“…We especially thank the personnel operating the U400 cyclotron, the associates of the ion-source group for obtaining intense 48 Og are shown as solid and dashed lines, respectively. The x-axis refers to references Muntian01 : [57], Warda12 : [58], Jachimowicz14 : [59], Wang16 : [60], Adamian16 : [25], Sobicziewski16 : [55], Mohr17 : [61], Hosseini17 : [62], Bao17 : [63], Zhang17 : [64], Lim17 : [65], and Cui18 : [66].…”

基于神经网络预测重核α衰变半衰期

“…, [214][215][216]221 U [3,[6][7][8], 219,220,222−224 Np [1,2,[9][10][11], 220,221 Pa [12,13], 236 Bk [14], 240 Es [14], 和 224 Md [15]. 在这些研究中，α衰变是一 种重要手段，通过对α衰变的研究，可以得到原子 核的基态半衰期，结合能, 壳结构信息，是重核合 成的重要鉴别手段。 对 α 衰 变 的 理 论 研 究 始 于19世 纪， Gamow [16]， Gurney [17] [24][25][26][27][28][29][30][31][32]，多道团簇模型(MCCM) [33,34]， 通用衰变律(GLDM) [35,36]，四次波函数方法 [37,38]，以及四因子模型 [39]。一些经验公式 [40][41][42] [40,41]。从已有的经验公式中，α衰变的Q值,原 子核的质子数和质量数Z，A被用来计算半衰期， 半衰期与Q值成负相关，与Z和A成正相关。我们对 源数据作如下处理:…”