Fri·Apr 3, 2020Friday·April 3, 2020

1. 01*

   A Study of the Properties of the QCD Phase Diagram in High-Energy Nuclear Collisions

   Xiaofeng Luo🇨🇳 · Shusu Shi🇨🇳 · Nu Xu🇨🇳 · Yifei Zhang🇨🇳

   With the aim of understanding the phase structure of nuclear matter created in high-energy nuclear collisions at finite baryon density, a beam energy scan program has been carried out at Relativistic Heavy Ion Collider (RHIC). In this mini-review, most recent experimental results on collectivity, criticality and heavy flavor productions will be discussed. The goal here is to establish the connection between current available data and future heavy-ion collision experiments in a high baryon density region.

   nucl-exnucl-thParticles(2020)·79 citations
2. 02*

   Extending the Southern Shore of the Island of Inversion to ${}^{28}$F

   A. Revel🇫🇷 · O. Sorlin🇫🇷 · F.M. Marques🇫🇷 · Y. Kondo🇯🇵 · J. Kahlbow🇩🇪 · T. Nakamura🇯🇵 · N.A. Orr🇫🇷 · F. Nowacki🇫🇷 · J.A. Tostevin🇬🇧 · C.X. Yuan🇨🇳 · N.L. Achouri🇫🇷 · H. Al Falou🇱🇧 and 80 other authors

   Detailed spectroscopy of the neutron-unbound nucleus ${}^{28}$F has been performed for the first time following proton/neutron removal from ${}^{29}$Ne/${}^{29}$F beams at energies around 230 MeV/nucleon. The invariant-mass spectra were reconstructed for both the ${}^{27}$F${}^{(\ast )}+n$ and ${}^{26}$F${}^{(\ast )}+2n$ coincidences and revealed a series of well-defined resonances. A near-threshold state was observed in both reactions and is identified as the ${}^{28}$F ground state, with $S_n{(}^{28}$F$)=-199(6)$ keV, while analysis of the $2n$ decay channel allowed a considerably improved $S_n{(}^{27}$F$)=1620(60)$ keV to be deduced. Comparison with shell-model predictions and eikonal-model reaction calculations have allowed spin-parity assignments to be proposed for some of the lower-lying levels of ${}^{28}$F. Importantly, in the case of the ground state, the reconstructed ${}^{27}$F$+n$ momentum distribution following neutron removal from ${}^{29}$F indicates that it arises mainly from the $1p_{3/2}$ neutron intruder configuration. This demonstrates that the island of inversion around $N=20$ includes ${}^{28}$F, and most probably ${}^{29}$F, and suggests that ${}^{28}$O is not doubly magic.

   nucl-exPRL(2020)·44 citations
3. 03*

   Spin-parity of the 13.35 MeV state and high-lying states around 20 MeV in excitation energy in ${}^{12}$C nucleus

   A.S. Demyanova (1) · V. I. Starastsin (1) · A. A. Ogloblin (1) · A. N. Danilov (1) · S. V. Dmitriev (1) · W. H. Trzaska (2) · P. Heikkinen (2) · T. L. Belyaeva (3) · S. A. Goncharov (4) · V. A. Maslov (5) · Yu. G. Sobolev (5) · Yu. B. Gurov (6) · N. Burtebaev (7) · D. Janseitov (7,8) ((1) National Research Centre Kurchatov Institute, Moscow, Russia, (2) Department of Physics, University of Jyvaskyla, Finland, (3) Universidad Autonoma del Estado de Mexico, Mexico, (4) M.V. Lomonosov Moscow State University, Moscow, Russia (5) Flerov Laboratory for Nuclear Research, JINR, Russia, (6) National Research Nuclear University MEPhI, Moscow, Russia (7) Institute of Nuclear Physics, Almaty, Republic of Kazakhstan, (8) Kazakh National University, Almaty, Kazakhstan)

   Study of the ${}^{11}$B(${}^3$He,d)${}^{12}$C reaction at incident ${}^3$He energy E${}_{lab}$ = 25 MeV has been performed at the K-130 cyclotron at the University of Jyväskylä, Finland. Differential cross sections have been measured for the 13.35 MeV state and for the states with excitation energy around 20 MeV. The data were analyzed with the DWBA method. A tentative assignment, 4${}^{-}$, is given for the state at 13.35 MeV. For the state at 20.98 MeV, the spin-parity 3${}^{-}$ and the isospin T = 0 are assigned for the first time. Our model description of the broad state at 21.6 MeV is consistent with the previous assignments of isospin T = 0 and spin-parity of 2${}^{+}$ and 3${}^{-}$. The excited state at 22.4 MeV may have possible spin-parities of either 6${}^{+}$ or 5${}^{-}$. The collected statistics was insufficient to solve this question.

   nucl-exnucl-thEPJA(2021)·3 citations
4. 04*

   New estimator for symmetry plane correlations in anisotropic flow analyses

   Ante Bilandzic🇩🇪 · Marcel Lesch🇩🇪 · Seyed Farid Taghavi🇩🇪

   Correlations of symmetry planes are important observables used to quantify anisotropic flow phenomenon and constrain independently the properties of strongly interacting nuclear matter produced in the collisions of heavy ions at the highest energies. In this paper, we point out current problems of measuring correlations between symmetry planes and elaborate on why the available analysis techniques have a large systematic bias. To overcome this problem, we introduce a new approach to approximate multi-harmonic flow fluctuations via a two-dimensional Gaussian distribution. Employing this approximation, we introduce a new estimator, dubbed Gaussian Estimator (GE), to extract pure correlation between symmetry planes. We validate GE by using the realistic event-generator iEBE-VISHNU and demonstrate that it outperforms all existing estimators. Based on event-shape engineering, we propose an experimental procedure to improve GE accuracy even further.

   nucl-exhep-exhep-phnucl-thPRC(2020)·17 citations
5. 05*

   A Comment on "The possible explanation of neutron lifetime beam anomaly" by A. P. Serebrov, et al

   F. E. Wietfeldt🇺🇸 · R. Biswas🇮🇳 · R. W. Haun🇺🇸 · M. S. Dewey🇺🇸 · J. Caylor🇺🇸 · N. Fomin🇺🇸 · G. L. Greene🇺🇸 · C. C. Haddock🇺🇸 · S. F. Hoogerheide · H. P. Mumm🇺🇸 · J. S. Nico🇺🇸 · B. Crawford · W. M. Snow🇺🇸

   We comment on a recent manuscript by A. P. Serebrov, et al. regarding residual gas charge exchange in the beam neutron lifetime experiment

   nucl-exphysics.ins-det4 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.