Wed·Mar 30, 2022Wednesday·March 30, 2022

1. 01*

   Study of the production and decay properties of neutron-deficient nobelium isotopes

   M.S. Tezekbayeva🇷🇺 · A.V. Yeremin🇷🇺 · A.I. Svirikhin🇷🇺 · A. Lopez-Martens🇫🇷 · M.L. Chelnokov🇷🇺 · V.I. Chepigin🇷🇺 · A.V. Isaev🇷🇺 · I.N. Izosimov🇷🇺 · A.V. Karpov🇷🇺 · A.A. Kuznetsova🇷🇺 · O.N. Malyshev🇷🇺 · R.S. Mukhin🇷🇺 and 16 other authors

   The new neutron-deficient isotope ${}^{249}$No was synthesized for the first time in the fusion-evaporation reaction ${}^{204}$Pb(${}^{48}$Ca,3n)${}^{249}$No. After separation, using the kinematic separator SHELS, the new isotope was identified with the GABRIELA detection system through genetic correlations with the known daughter and granddaughter nuclei ${}^{245}$Fm and ${}^{241}$Cf. The alpha-decay activity of ${}^{249}$No has an energy of 9129(22) keV and half-life 38.3(2.8) ms. An upper limit of 0.2\% was measured for the fission branch of ${}^{249}$No. Based on the present data and recent information on the decay properties of ${}^{253}$Rf and aided by Geant4 simulations, the ground state of ${}^{249}$No is assigned the 5/2${}^{+}$[622] neutron configuration and a partial decay scheme from ${}^{253}$Rf to ${}^{245}$Fm could be established. The production cross-section was found to be $\sigma$(3n)=0.47(4) nb at a mid-target beam energy of 225.4 MeV, which corresponds to the maximum of the calculated excitation function. Correlations of the ${}^{249}$No alpha activity with subsequent alpha decays of energy 7728(20) keV and half-life $1.2_{-0.4}^{+1.0}$ min provided a firm measurement of the electron-capture or ${\beta }^{+}$ branch of ${}^{245}$Fm to ${}^{245}$Es. The excitation function for the 1n, 2n and 3n evaporation channels was measured. In the case of the 2n-evaporation channel ${}^{250}$No, a strong variation of the ground state and isomeric state populations as a function of bombarding energy could be evidenced.

   nucl-exEPJA(2022)·15 citations
2. 02*

   Search for the chiral magnetic effect in collisions between two isobars with deformed and neutron-rich nuclear structures

   Xin-Li Zhao🇨🇳 · Guo-Liang Ma🇨🇳

   Isobar collisions which were thought to have the same background and different magnetic fields provide an opportunity to verify the chiral magnetic effect (CME) in relativistic heavy-ion collisions. However, the first result from the RHIC-STAR isobar experiment did not observe the CME signal, but discovered that the backgrounds are different between ${}_{44}^{96}\text{Ru}{+}_{44}^{96}\text{Ru}$ and ${}_{40}^{96}\text{Zr}{+}_{40}^{96}\text{Zr}$ collisions. We test eighteen cases of Woods-Saxon parameter settings resulting from different nuclear deformation or nuclear structure effects using a mutiphase transport model. We find out that seven cases can reasonably reproduce three reference ratios measured by the STAR experiment. Considering both the halo-type neutron skin structure and CME-like charge separation, we demonstrate that it is difficult for the CME observables ($\Delta \delta$, $\Delta \delta$ ratio, $\Delta \gamma$ and $\Delta \gamma$ ratio) to distinguish the presence or absence of the CME, if the CME strength is weak in isobar collisions. It is because the final state interactions significantly weaken the initial CME signal, resulting in non-linear sensitivities of the CME observables to the CME strength. Therefore, more sensitive observables are required to search for the possible small CME signal in isobar collisions.

   ↳ nucl-thhep-phnucl-exPRC(2022)·29 citations
3. 03*

   An accurate relativistic chiral nucleon-nucleon interaction up to the next-to-next-to-leading order

   Jun-Xu Lu🇨🇳 · Yang Xiao🇨🇳 · Chun-Xuan Wang🇨🇳 · Li-Sheng Geng🇨🇳

   We report on the construction of an accurate relativistic chiral nucleon-nucleon interaction up to the next-to-next-to-leading (NNLO) order. We compare the so-obtained neutron-proton phaseshifts with the next-to-next-to-next-to-leading order (N${}^3$LO) nonrelativistic ones and we show that up to $T_{lab.}=200$ MeV, the relativistic chiral nuclear force can describe the PWA93 phaseshifts and inelasticities as well as its N${}^3$LO nonrelativistic counterparts. As a result, the relativistic chiral nuclear force can be readily used for relativistic ab initio nuclear structure, reaction, as well astrophysical studies.

   ↳ nucl-thhep-lathep-phnucl-exPoS(2024)·2 citations
4. 04*

   Harmonic flow correlations in Au+Au reactions at 1.23 AGeV: A new testing ground for the Equation-of-State and expansion geometry

   Tom Reichert🇩🇪 · Jan Steinheimer🇩🇪 · Christoph Herold🇹🇭 · Ayut Limphirat🇹🇭 · Marcus Bleicher🇩🇪

   Correlations between the harmonic flow coefficients $v_1$, $v_2$, $v_3$ and $v_4$ of nucleons in semi-peripheral Au+Au collisions at a beam energy of 1.23~AGeV are investigated within the hadronic transport approach Ultra-relativistic Quantum Molecular Dynamics (UrQMD). In contrast to ultra-relativistic collision energies (where the flow coefficients are evaluated with respect to the respective event plane), we predict strong correlations between the flow harmonics with respect to the reaction plane. Based on an event-by-event selection of the midrapidity final state elliptic flow of protons we show that as a function of rapidity, I) the sign of the triangular flow changes, II) that the shape of $v_4$ changes from convex to concave, and III) that $v_3\propto v_1{v}_2$ and $v_4\propto v_2^2$ for all different event classes, indicating strong correlations between all investigated harmonic flow coefficients.

   ↳ nucl-thnucl-exEPJC(2022)·11 citations
5. 05*

   Nuclear coherent population transfer to the ${}^{229m}$Th isomer using x-ray pulses

   Tobias Kirschbaum · Nikolay Minkov🇧🇬 · Adriana Pálffy🇩🇪

   Population of the 8 eV ${}^{229m}$Th isomer via the second nuclear excited state at 29.19 keV by means of coherent x-ray pulses is investigated theoretically. We focus on two nuclear coherent population transfer schemes using partially overlapping x-ray pulses known from quantum optics: stimulated Raman adiabatic passage (STIRAP), and successive $\pi$ pulses. Numerical results are presented for three possible experimental setups. Our results identify the Gamma Factory as the most promising scenario, where two ultraviolet pulses combined with relativistically accelerated ions deliver the required intensities for efficient isomer population. Our simulations require knowledge of the in-band and cross-band nuclear transition probabilities. We give theoretically predicted values for the latter and discuss them in the context of recent experiments.

   ↳ nucl-thnucl-exphysics.acc-phPRC(2022)·16 citations
6. 06*

   $\Lambda$ spin polarization in event-by-event relativistic heavy-ion collisions

   Sahr Alzhrani🇺🇸 · Sangwook Ryu🇺🇸 · Chun Shen🇺🇸

   We present a systematic study of $\Lambda$ hyperon's polarization observables using event-by-event (3+1)D relativistic hydrodynamics. The effects of initial hot spot size and QGP's specific shear viscosity on the polarization observables are quantified. We examine the effects of the two formulations of the thermal shear tensor on the polarization observables using the same hydrodynamic background. With event-by-event simulations, we make predictions for the Fourier coefficients of $\Lambda$'s longitudinal polarization $P^z$ with respect to the event planes of different orders of anisotropic flow. We propose new correlations among the Fourier coefficients of $P^z$ and charged hadron anisotropic flow coefficients to further test the mapping from fluid velocity gradients to hyperon's polarization. Finally, we present a system size scan with Au+Au, Ru+Ru, and O+O collisions at $\sqrt{s_{\mathrm{NN}}}=200$ GeV to study the system size dependence of polarization observables at the Relativistic Heavy-ion Collider.

   ↳ nucl-thhep-phnucl-exPRC(2022)·77 citations
7. 07*

   Prospects for precise predictions of $a_{\mu }$ in the Standard Model

   G. Colangelo🇨🇭 · M. Davier🇫🇷 · A. X. El-Khadra🇺🇸 · M. Hoferichter🇨🇭 · C. Lehner🇩🇪 · L. Lellouch🇫🇷 · T. Mibe🇯🇵 · B. L. Roberts🇺🇸 · T. Teubner🇬🇧 · H. Wittig🇩🇪 · B. Ananthanarayan🇮🇳 · A. Bashir🇲🇽 and 70 other authors

   We discuss the prospects for improving the precision on the hadronic corrections to the anomalous magnetic moment of the muon, and the plans of the Muon $g-2$ Theory Initiative to update the Standard Model prediction.

   ↳ hep-phhep-exhep-latnucl-ex+1136 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.