Tue·Aug 14, 2018Tuesday·August 14, 2018

1. 01*

   Investigation of the Cross Section for dd Elastic Scattering and dd$\to$ n${}^3$He Reactions at 160 MeV

   I. Ciepał🇵🇱 · J. Kuboś🇵🇱 · K. Bodek🇵🇱 · N. Kalantar-Nayestanaki🇳🇱 · G. Khatri🇺🇸 · St. Kistryn🇵🇱 · B. Kłos🇵🇱 · A. Kozela🇵🇱 · P. Kulessa🇵🇱 · A. Magiera🇵🇱 · J. Messchendorp🇳🇱 · I. Mazumdar🇮🇳 and 9 other authors

   Differential cross sections of ${}^2$H(d, d)d elastic scattering and proton transfer ${}^2$H(d, ${}^3$He)n reactions at 160 MeV beam energy have been obtained. They have been normalized relative to the existing cross-section data for the ${}^2$H(d, d)d elastic scattering at 180 and 130 MeV, benefiting from the negligible energy dependence of this observable at certain range of the four momentum transfer. The experiment was performed at KVI in Groningen, the Netherlands using the BINA detector. The elastic scattering data are compared to theoretical predictions based on the lowest-order term in the Neumann series expansion for four-nucleon transition operators. The calculations underpredict the data. The data presented in this paper can be used to validate the future theoretical findings.

   nucl-exPRC(2019)·8 citations
2. 02*

   Measurement of the azimuthal anisotropy of charged particles produced in $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV Pb+Pb collisions with the ATLAS detector

   ATLAS Collaboration

   Measurements of the azimuthal anisotropy in lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are presented using a data sample corresponding to 0.49 ${\mathrm{nb}}^{-1}$ integrated luminosity collected by the ATLAS experiment at the LHC in 2015. The recorded minimum-bias sample is enhanced by triggers for "ultra-central" collisions, providing an opportunity to perform detailed study of flow harmonics in the regime where the initial state is dominated by fluctuations. The anisotropy of the charged-particle azimuthal angle distributions is characterized by the Fourier coefficients, $v_2-v_7$, which are measured using the two-particle correlation, scalar-product and event-plane methods. The goal of the paper is to provide measurements of the differential as well as integrated flow harmonics $v_n$ over wide ranges of the transverse momentum, 0.5 $<p_{\mathrm{T}}<$ 60 GeV, the pseudorapidity, $|\eta |<$ 2.5, and the collision centrality $0-80$%. Results from different methods are compared and discussed in the context of previous and recent measurements in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV and 5.02 TeV. In particular, the shape of the $p_{\mathrm{T}}$ dependence of elliptic or triangular flow harmonics is observed to be very similar at different centralities after scaling the $v_n$ and $p_{\mathrm{T}}$ values by constant factors over the centrality interval $0-60$% and the $p_{\mathrm{T}}$ range $0.5<p_{\mathrm{T}}<5$ GeV.

   nucl-exhep-exEPJC(2018)·142 citations
3. 03*

   Searching for the QCD Critical Point through Fluctuations at RHIC

   Roli Esha🇺🇸

   Fluctuations and correlations of conserved quantities (baryon number, strangeness, and charge) can be used to probe phases of strongly interacting QCD matter and the possible existence of a critical point in the phase diagram. The cumulants of the multiplicity distributions related to these conserved quantities are expected to be sensitive to possible increased fluctuations near a critical point and ratios of the cumulants can be directly compared to the ratios of the susceptibilities from Lattice QCD calculations. In these proceedings, the measurements of the cumulants of net-proton multiplicity distributions from Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4 (up to fourth order) and 200 GeV (up to sixth order) as measured by the STAR experiment at RHIC will be presented. Multi-particle correlation functions will also be presented. The measurement of higher-order cumulants are sensitive to experimental artifacts. Current efficiency correction methods are based on the assumption that the tracking efficiency is strictly binomial. An unfolding technique is used to account for multiplicity dependent detector responses and efficiency variations. A large sample of AMPT events will be used to check the validity of the unfolding technique. The comparison of the various correction approaches should provide important guidance towards a reliable experimental determination of the multiplicity cumulants.

   nucl-ex0 citations
4. 04*

   Precision Mass Measurement of ${}^{58-63}$Cr: Nuclear Collectivity towards the \emph{N}=40 Island of Inversion

   Maxime Mougeot🇫🇷 · Dinko Atanasov🇩🇪 · Klaus Blaum🇩🇪 · Katherina Chrysalidis🇨🇭 · Tom Day Goodacre🇨🇭 · Dmitrii Fedorov🇷🇺 · Valentin Fedosseev🇨🇭 · Sebastian George🇩🇪 · Frank Herfurth🇩🇪 · Jason D. Holt🇨🇦 · David Lunney🇫🇷 · Vladimir Manea🇨🇭 and 13 other authors

   The neutron-rich isotopes ${}^{58-63}$Cr were produced for the first time at the ISOLDE facility and their masses were measured with the ISOLTRAP spectrometer. The new values are up to 300 times more precise than those in the literature and indicate significantly different nuclear structure from the new mass-surface trend. A gradual onset of deformation is found in this proton and neutron mid-shell region, which is a gateway to the second island of inversion around \emph{N}=40. In addition to comparisons with density-functional theory and large-scale shell-model calculations, we present predictions from the valence-space formulation of the \emph{ab initio} in-medium similarity renormalization group, the first such results for open-shell chromium isotopes.

   nucl-exnucl-thPRL(2018)·53 citations
5. 05*

   Explore nuclear multiple chirality in $A\sim 60$ mass region within covariant density functional theory

   J. Peng · Q. B. Chen🇩🇪

   The nuclear multiple chirality in $A\sim 60$ mass region is explored by the adiabatic and configuration-fixed constrained covariant density functional theory for cobalt isotopes. The potential-energy curves and triaxiality parameters $\gamma$ as functions of the deformation parameter $\beta$ in ${}^{54,56,57,58,59,60}$Co are obtained. It is found that there are high-$j$ particle(s) and hole(s) configurations with prominent triaxially deformed shapes in these isotopes. This points towards that the existence of chirality or multiple chirality in $A\sim 60$ mass region are highly anticipated.

   ↳ nucl-thnucl-exPRC(2018)·21 citations
6. 06*

   Insight into nuclear midshell structures by study of $K$-isomers in rare-earth neutron-rich nuclei

   Xiao-Tao He🇨🇳 · Yu-Chun Li🇨🇳

   Inspired by the newly discovered isomeric states in the rare-earth neutron-rich nuclei, high-$K$ isomeric states in neutron-rich samarium and gadolinium isotopes are investigated within the framework of the cranked shell model (CSM) with pairing correlation treated by a particle-number-conserving (PNC) method. The experimental multi-particle state energies and moments of inertia are reproduced quite well by the PNC-CSM calculations. A remarkable effect from the high-order deformation ${\epsilon }_6$ is demonstrated. Based on the occupation probabilities, the configurations are assigned to the observed high-$K$ isomeric states. The lower $5^{-}$ isomeric state in ${}^{158}$Sm is preferred as the two-proton state with configuration $\pi {\frac{5}{2}}^{+}[413]\otimes \pi {\frac{5}{2}}^{-}[532]$. More low-lying two-particle states are predicted. The systematics of the electronic quadrupole transition probabilities, $B(E2)$ values along the neodymium, samarium, gadolinium and dysprosium isotopes and $N=96,98,100,102$ isotones chains is investigated to reveal the midshell collectivities.

   ↳ nucl-thnucl-exPRC(2018)·17 citations
7. 07*

   Extracting strange quark freeze-out information in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV from $\varphi$ and $\Omega$ production

   Jie Pu🇨🇳 · Kai-Jia Sun🇨🇳 · Lie-Wen Chen🇨🇳

   Using a covariant quark coalescence model combined with a blast-wave-like analytical parametrization for (anti-)strange quark phase-space freeze-out configuration, we extract information on strange quark freeze-out dynamics in Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV by fitting the measured transverse momentum spectra and elliptic flows ($v_2$) of $\varphi$ mesons and $\Omega$ baryons. We find that although both the measured and calculated $v_2$ of $\varphi$ and $\Omega$ satisfy the number-of-constituent-quark (NCQ) scaling, the NCQ-scaled $v_2$ is significantly smaller than the $v_2$ of strange quarks, implying that the NCQ-scaled $v_2$ of $\varphi$ and $\Omega$ cannot be simply identified as the $v_2$ of strange quarks at hadronization. Meanwhile, our results indicate that the covariant quark coalescence model can nicely describe the spectra and elliptic flows of $\varphi$ and $\Omega$ simultaneously, suggesting the coalescence mechanism is still valid for $\varphi$ and $\Omega$ production in Pb+Pb collisions at LHC energies.

   ↳ nucl-thhep-phnucl-exPRC(2018)·5 citations
8. 08*

   Angle and magnitude decorrelation in the factorization breaking of collective flow

   Piotr Bozek🇵🇱

   The collective harmonic flow in heavy-ion collisions correlates particles at all transverse momenta to be emitted preferably some directions. The factorization breaking coefficient measures the small decorrelation of the flow harmonics at two different transverse momenta. Using the hydrodynamic model I study in details the decorrelation of the harmonic flow due to the flow angle and the flow magnitude decorrelation at two transverse momenta. The effect can be seen in experiment measuring factorization breaking coefficients for the square of the harmonic flow vector at two transverse momenta. The hydrodynamic model predicts that the decorrelation of the flow magnitudes is about one half of the decorrelation of the overall flow (combining flow angle and flow magnitude decorrelations). These results are consistent with the principal component analysis of correlators of flow vectors squared.

   ↳ nucl-thhep-exnucl-exPRC(2018)·18 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.