Wed·Dec 8, 2021Wednesday·December 8, 2021

1. 01*

   Nuclear Charge Radii of the Nickel Isotopes ${}^{58-68,70}$Ni

   S. Malbrunot-Ettenauer🇨🇭 · S. Kaufmann🇩🇪 · S. Bacca🇩🇪 · C. Barbieri🇮🇹 · J. Billowes🇬🇧 · M. L. Bissell🇬🇧 · K. Blaum🇩🇪 · B. Cheal🇬🇧 · T. Duguet🇫🇷 · R. F. Garcia Ruiz🇨🇭 · W. Gins🇧🇪 · C. Gorges🇩🇪 and 29 other authors

   Collinear laser spectroscopy is performed on the nickel isotopes ${}^{58-68,70}$Ni, using a time-resolved photon counting system. From the measured isotope shifts, nuclear charge radii $R_c$ are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, the chiral interaction NNLO${}_{\mathrm{sat}}$, which allows an assessment of their accuracy. We find agreement with experiment in differential radii $\delta ⟨r_{\mathrm{c}}^2⟩$ for all employed ab initio methods and interactions, while the absolute radii are consistent with data only for NNLO${}_{\mathrm{sat}}$. Within nuclear density functional theory, the Skyrme functional SV-min matches experiment more closely than the Fayans functional Fy($\Delta r$,HFB).

   nucl-exnucl-thPRL(2022)·78 citations
2. 02*

   Pole position of the $a_1(1260)$ resonance in a three-body unitary framework

   Daniel Sadasivan🇺🇸 · Andrei Alexandru🇺🇸 · Hakan Akdag🇩🇪 · Felipe Amorim🇺🇸 · Ruairí Brett🇺🇸 · Chris Culver🇬🇧 · Michael Döring🇺🇸 · Frank X. Lee🇺🇸 · Maxim Mai🇺🇸

   Masses, widths, and branching ratios of hadronic resonances are quantified by their pole positions and residues with respect to transition amplitudes on the Riemann sheets of the complex energy-plane. In this study we discuss the analytic structure in the physical energy region of three-body scattering amplitudes on such manifolds. As an application, we determine the pole position of the $a_1(1260)$ meson from the ALEPH experiment by allowing for $\pi \rho$ coupled channels in S- and D-wave. We find it to be $\sqrt{s_0}=(1232_{-0-11}^{+15+9}-i266_{-22-27}^{+0+15})\text{MeV}$.

   ↳ hep-phnucl-exnucl-thPRD(2022)·50 citations
3. 03*

   Higher-order transverse momentum fluctuations in heavy-ion collisions

   Somadutta Bhatta🇺🇸 · Chunjian Zhang🇺🇸 · Jiangyong Jia🇺🇸

   In relativistic heavy-ion collisions, the event-by-event mean transverse momentum fluctuations are sensitive to overlap area and energy density fluctuations in initial state. We present a framework to calculate $p_{\mathrm{T}}$ fluctuations up to $4^{\mathrm{th}}$-order using standard and subevent methods, which is validated using the HIJING model. We observe a power-law dependence for cumulants of all orders as a function of charged particle multiplicity $N_{\mathrm{ch}}$, consistent with a simple independent source picture. The fluctuation in $pp$ collisions is observed to be larger than for $p+$Pb, Pb+Pb and Xe+Xe collisions at the same $N_{\mathrm{ch}}$ due to bias in number of contributing sources. The short-range correlations are greatly suppressed in subevent method in comparison to calculations based on the standard method. This study provides a baseline for transverse momentum fluctuations without the presence of final state effects.

   ↳ nucl-thhep-phnucl-exPRC(2022)·24 citations
4. 04*

   Low Energy Neutrino Detection with a Portable Water-based Liquid Scintillator Detector

   Ayse Bat🇹🇷 · Emrah Tiras🇹🇷 · Vincent Fischer🇺🇸 · Mirac Kamislioglu🇹🇷

   In this study, the conceptual design and physics simulations of a near-field Water-based Liquid Scintillator (WbLS) detector placed 100 meters from the Akkuyu Nuclear Power Plant (ANPP), currently under construction and aiming at being Turkey's first nuclear power plant, is presented. The ANPP is an excellent opportunity for neutrino studies and the development of an R&D program for neutrino detectors in Turkey. The Reactor Neutrino Experiments of Turkey (RNET) program includes a compact and portable detector with a 2.5-ton volume of WbLS and a ~30% photo-coverage, and the program is planned to be expanded with a medium-size 30-ton detector that will be an international testbed for low energy neutrino studies for WbLS and new detector technologies. In the following, the focus will be on the smaller ~2.5-ton detector, instrumented with 8-inch high quantum efficiency PMTs and two layers of cosmic veto paddles, covering all sides of the detector, to track and veto cosmic particles. Inverse Beta Decay (IBD) events from electronic antineutrinos generated in the reactor core are simulated using the RAT-PAC simulation package and several liquids with different percentages of Liquid Scintillator (LS) and Gadolinium (Gd) are investigated.

   ↳ physics.ins-dethep-exnucl-exEPJC(2022)·11 citations
5. 05*

   Density dependence of the nuclear symmetry energy and neutron skin thickness in the KIDS framework

   Panagiota Papakonstantinou🇰🇷

   The KIDS framework for the nuclear equation of state (EoS) and energy density functional (EDF) offers the possibility to explore systematically the effect of EoS parameters on predictions for a variety of observables. The EoS parameters can be varied independently of each other and independently of assumptions regarding the in-medium nucleon effective mass. Here I present a pilot study of the neutron skin thickness (NST) in nuclei of current interest. The results indicate that variations of the symmetry energy slope parameter L by roughly 10 MeV and variations of the droplet-model counterpart of the curvature parameter $K_{\tau }$ by roughly 20 MeV affect predictions by comparable amounts. However, structural details may also have sizable effects on predictions, notably in the cases of ${}^{68}$Ni and ${}^{208}$Pb. This work is part of a systematic investigation of the NST within the KIDS framework and of a broader effort to constrain the density dependence of the nuclear symmetry energy.

   ↳ nucl-thnucl-exAdv.Nucl.Phys.(2022)·2 citations
6. 06*

   Collision centrality and system size dependences of light nuclei production via dynamical coalescence mechanism

   Yi-Lin Cheng🇩🇪 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳

   Light (anti-)nuclei in relativistic heavy-ion collisions are considered to be formed by the coalescence mechanism of (anti-)nucleons in the present work. Using a dynamical phase-space coalescence model coupled with a multi-phase transport (AMPT) model, we explore the formation of light clusters such as deuteron, triton and their anti-particles in different centralities for ${}^{197}$Au + ${}^{197}$Au collisions at $\sqrt{s_{NN}}=39$ GeV. The calculated transverse momentum spectra of protons, deuterons, and tritons are comparable to those of experimental data from the RHIC-STAR collaboration. Both coalescence parameters $B_2$ for (anti-)deuteron and $B_3$ for triton increase with the transverse momentum as well as the collision centrality, and they are comparable with the measured values in experiments. The effect of system size on the production of light nuclei is also investigated by ${}^{10}$B + ${}^{10}$B, ${}^{16}$O + ${}^{16}$O, ${}^{40}$Ca + ${}^{40}$Ca, and ${}^{197}$Au + ${}^{197}$Au systems in central collisions. The results show that yields of light nuclei increase with system size, while the values of coalescence parameters present an opposite trend. It is interesting to see that the system size, as well as the centrality dependence of $B_A$ ($A$ = 2, 3), falls into the same group, which further demonstrates production probability of light nuclei is proportional to the size of the fireball. Furthermore, we compare our coalescence results with other models, such as the thermal model and analytic coalescence model, it seems that the description of light nuclei production is consistent with each other.

   ↳ nucl-thnucl-exEPJA(2021)·11 citations
7. 07*

   Event topology and global observables in heavy-ion collisions at the Large Hadron Collider

   Suraj Prasad🇮🇳 · Neelkamal Mallick🇮🇳 · Debadatta Behera🇮🇳 · Raghunath Sahoo🇮🇳 · Sushanta Tripathy🇮🇹

   Particle production and event topology are very strongly correlated in high-energy hadronic and nuclear collisions. Event topology is decided by the underlying particle production dynamics and medium effects. Transverse spherocity is an event shape observable, which has been used in pp and heavy-ion collisions to separate the events based on their geometrical shapes. It has the unique capability to distinguish between jetty and isotropic events. In this work, we have implemented transverse spherocity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV using A Multi-Phase Transport Model (AMPT). While awaiting for experimental explorations, we perform a feasibility study of dependence of transverse spherocity on some of the global observables in heavy-ion collisions at the Large Hadron Collider energies. These global observables include the Bjorken energy density (${ϵ}_{{\mathrm{B}}_{\mathrm{j}}}$), speed of sound ($c_{\mathrm{s}}^2$) in the medium and the kinetic freeze-out properties for different collision centralities. The present study reveals about the usefulness of event topology dependent measurements in heavy-ion collisions in contrast to proton-proton collisions.

   ↳ hep-phhep-exnucl-exnucl-thSci.Rep.(2022)·34 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.