Fri·Apr 7, 2023Friday·April 7, 2023

1. 01*

   Electric-charge-dependent directed flow splitting of produced quarks in Au+Au collisions

   STAR Collaboration

   We report directed flow ($v_1$) of multistrange baryons ($\Xi$ and $\Omega$) and improved $v_1$ data for $K^{-}$, $\bar{p}$, $\bar{\Lambda }$ and $\varphi$ in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=$27 and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). We focus on particles whose constituent quarks are not transported from the incoming nuclei but instead are produced in the collisions. At intermediate impact parameters, we examine quark coalescence behavior for particle combinations with identical quark content, and search for any departure from this behavior (``splitting'') for combinations having non-identical quark content. Under the assumption of quark coalescence for produced quarks, the splitting strength appears to increase with the electric charge difference of the constituent quarks in the combinations, consistent with electromagnetic effect expectations.

   nucl-exhep-phnucl-thPLB(2025)·12 citations
2. 02*

   Asymptotic normalization coefficients of alpha-particle removal from ${}^{16}$O($3^{-},2^{+},1^{-}$)

   L. D. Blokhintsev · A. S. Kadyrov · A. M. Mukhamedzhanov · D. A. Savin

   Asymptotic normalization coefficients (ANC) determine the overall normalization of cross sections of peripheral radiative capture reactions. In a recent paper [Blokhintsev et al., Eur. Phys. J. A 58, 257 (2022)], we considered the ANC $C_0$ for the virtual decay ${}^{16}$O$(0^{+};6.05$ MeV)$\to \alpha {+}^{12}$C(g.s.). In the present paper, which can be regarded as a continuation of the previous, we treat the ANCs $C_l$ for the vertices ${}^{16}$O$(J^{\pi })\to \alpha {+}^{12}$C(g.s.) corresponding to the other three bound excited states of ${}^{16}$O ($J^{\pi }=3^{-}$, $2^{+}$, $1^{-}$, $l=J$). ANCs $C_l$ ($l=3,2,1$) are found by analytic continuation in energy of the ${\alpha }^{12}$C $l$-wave partial scattering amplitudes, known from the phase-shift analysis of experimental data, to the pole corresponding to the ${}^{16}$O bound state and lying in the unphysical region of negative energies. To determine $C_l$, the scattering data are approximated by the sum of polynomials in energy in the physical region and then extrapolated to the pole. For a more reliable determination of the ANCs, various forms of functions expressed in terms of phase shifts were used in analytical approximation and subsequent extrapolation.

   ↳ nucl-thastro-ph.SRnucl-ex0 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.