Thu·Feb 9, 2017Thursday·February 9, 2017

1. 01*

   Nuclear thermodynamics with isospin degree of freedom: from first results to future possibilities with A and Z identification arrays

   B. Borderie🇫🇷

   Nuclear thermodynamics studies evidenced the existence of a first order phase transition, namely of the liquid-gas type, without paying attention to the isospin degree of freedom. On the other hand, only few results with the introduction of the isospin variable have been so far obtained. Moreover above all a key question remains. It concerns the origin of the dynamics of the phase transition: spinodal instabilities or not with possible consequences and new signatures related to the introduction of the isospin variable.

   nucl-exnucl-thNuovo Cim.C(2017)·0 citations
2. 02*

   Nuclear matrix element of neutrinoless double-$\beta$ decay: Relativity and short-range correlations

   L. S. Song🇨🇳 · J. M. Yao🇺🇸 · P. Ring🇨🇳 · J. Meng🇨🇳

   Background: The discovery of neutrinoless double-beta ($0\nu \beta \beta$) decay would demonstrate the nature of neutrinos, have profound implications for our understanding of matter-antimatter mystery, and solve the mass hierarchy problem of neutrinos. The calculations for the nuclear matrix elements $M^{0\nu }$ of $0\nu \beta \beta$ decay are crucial for the interpretation of this process. Purpose: We study the effects of relativity and nucleon-nucleon short-range correlations on the nuclear matrix elements $M^{0\nu }$ by assuming the mechanism of exchanging light or heavy neutrinos for the $0\nu \beta \beta$ decay. Methods: The nuclear matrix elements $M^{0\nu }$ are calculated within the framework of covariant density functional theory, where the beyond-mean-field correlations are included in the nuclear wave functions by configuration mixing of both angular-momentum and particle-number projected quadrupole deformed mean-field states. Results: The nuclear matrix elements $M^{0\nu }$ are obtained for ten $0\nu \beta \beta$-decay candidate nuclei. The impact of relativity is illustrated by adopting relativistic or nonrelativistic decay operators. The effects of short-range correlations are evaluated. Conclusions: The effects of relativity and short-range correlations play an important role in the mechanism of exchanging heavy neutrinos though the influences are marginal for light neutrinos. Combining the nuclear matrix elements $M^{0\nu }$ with the observed lower limits on the $0\nu \beta \beta$-decay half-lives, the predicted strongest limits on the effective masses are $|⟨m_{\nu }⟩|<0.06\mathrm{eV}$ for light neutrinos and $|⟨m_{{\nu }_h}^{-1}⟩{|}^{-1}>3.065\times 10^8\mathrm{GeV}$ for heavy neutrinos.

   ↳ nucl-thhep-phnucl-exPRC(2017)·118 citations
3. 03*

   Nuclear cluster structure effect on elliptic and triangular flows in heavy-ion collisions

   S. Zhang🇨🇳 · Y. G. Ma🇨🇳 · J. H. Chen🇨🇳 · W. B. He🇨🇳 · C. Zhong🇨🇳

   The initial geometry effect on collective flows, which are inherited from initial projectile structure, is studied in relativistic heavy-ion collisions of ${}^{12}$C + Au by using a multi-phase transport model (AMPT). Elliptic flow ($v_2$) and triangular flow ($v_3$) which are significantly resulted from the chain and triangle structure of ${}^{12}\mathrm{C}$ with three-$\alpha$ clusters, respectively, in central ${}^{12}\mathrm{C}$+${}^{197}\mathrm{Au}$ collisions are compared with the flow from the Woods-Saxon distribution of nucleons in ${}^{12}\mathrm{C}$. $v_3/v_2$ is proposed as a probe to distinguish the pattern of $\alpha$-clustered ${}^{12}\mathrm{C}$. This study demonstrates that the initial geometry of the collision zone inherited from nuclear structure can be explored by collective flow at the final stage in heavy-ion collisions.

   ↳ nucl-thnucl-exPRC(2017)·69 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.