Speaker
Description
$\mathrm{Vlasnikov A.K.}, \fbox{Zippa A.I.}, \mathrm{Mikhajlov V.M.}$,
St. Petersburg State University, St. Petersburg, Russia
E-mail: a.vlasnikov@spbu.ru
If an ideal energy surface around a deformed nucleus with even $N$ and $Z$
existed and were linear and quadratic in deviations $s$ and $t$ from $N$ and $Z$
respectively $(|s| / N \ll 1,|t| / Z \ll 1)$
$\begin{aligned} E(N+s, Z+t)=M &(N+s, Z+t)-m_{n}(N+s)-m_{p}(Z+t)=\mathscr{E}(N, Z)+d_{1 n} s+d_{1 p} t+\\ &+d_{2 n} s^{2} / 2+d_{2 p} t^{2} / 2+d_{1 n 1 p} s t \end{aligned}$
$\left(E, M \text { are nuclear energy and mass, } m_{n}, m_{p}\right.$ are nucleon masses), then parameters $\mathscr{E}(N, Z)$ and $d_{\text {inkp }}$ should not depend on those adjacent nuclei which are used for calculations of these parameters. In particular, a measured $E(N, Z)$ has to coincide with a calculated parameter $\mathscr{E}(N, Z) .$
For determination of $E(N, Z)-\mathscr{E}(N, Z)$ and other parameters three groups of even-even nuclei are applied: $s$ -Appr. (Approximation, $s=\pm 2,\pm 4, t=0,$ i. e. isotopes); $t$ -Appr. $(s=0,$ $t=\pm 2,\pm 4, \text { i.e. isotones })$ and $(s t)-$ Appr. in which $s=\pm 2, t=\mp 2 ; s=\pm 4, t=\mp 4$
Calculated quantities $E(N, Z)-\mathscr{E}(N, Z)$ are given in Table $[1],$ which shows
that these quantities are sign variable in different approximations and a maximum divergence attains $\simeq 120 \mathrm{keV} .$ Approximately the same difference is found in other parameters. Thus, description of the energy surface around a deformed even-even nucleus by Eq. (1) is rather approximate. This information is useful for prediction of unknown masses and calculations of the pairing energies.
The reported study was funded by RFBR, project number 20-02-20032.
- M.Wang, G.Audi, F.G.Kondev et al. // Chinese Phys. C. 2017. V. 41. 030003.
