Thu·Nov 28, 2024Thursday·November 28, 2024

1. 01*

   On formation of the ${}^{12}$C(0${}_2^{+}$) and ${}^{12}$C(3${}^{-}$) states in relativistic dissociation of light nuclei

   A.A. Zaitsev · P.I. Zarubin🇷🇺

   The formation of the excited states ${}^{12}$C(0${}_2^{+}$) and ${}^{12}$C(3${}^{-}$) is investigated in the dissociation of ${}^{12}$C $\to$ 3$\alpha$ and ${}^{16}$O $\to$ 4$\alpha$ at the energy of 3.65 GeV per nucleon in the nuclear emulsion. The identification becomes possible by reconstructing the invariant mass from measurements of emission angles in the approximation of conservation of momentum per nucleon of the parent nucleus. The contribution of the decays ${}^{12}$C(0${}_2^{+}$) and ${}^{12}$C(3${}^{-}$) to the dissociation ${}^{12}$C $\to$ 3$\alpha$ is 11 and 19%, and in ${}^{16}$O $\to$ 4$\alpha$ it is - 20 and 30%, correspondingly.

   nucl-exnucl-thPhys.Atom.Nucl.(2025)·0 citations
2. 02*

   "Nuclear thermometers" reveal the origin of the universal r-process nucleosynthesis

   José Nicolás Orce🇿🇦

   The resembling behaviour of giant dipole resonances built on ground and excited states supports the validity of the Brink-Axel hypothesis and assigns giant dipole resonances as spectroscopic probes -- or ``nuclear thermometers'' -- to explore the cooling of the kilonova ejecta in neutron-star mergers down to the production of heavy elements beyond iron through the rapid-neutron capture or r-process. In previous work, we found a slight energy increase in the giant dipole resonance built on excited states at the typical temperatures of $1.0⪆T⪆0.7$ MeV where seed nuclei are produced, before ongoing neutron capture. Crucial data are presented here supporting an enhanced symmetry energy at $T=0.51$ MeV (or $5.9\times 10^9$ K) -- where the r-process occurs -- that lowers the binding energy in the Bethe-Weizsäcker semi-empirical mass formula and results in the close in of the neutron drip line. Ergo, providing an origin to the universality of elemental abundances by limiting the reaction network for r-process nucleosynthesis. An enhanced symmetry energy away from the ground state is further supported by shell-model calculations of the nuclear electric dipole ({\sc E1}) polarizability -- inversely proportional to the symmetry energy -- as a result of the destructive contribution of the products of off-diagonal {\sc E1} matrix elements.

   ↳ astro-ph.SRnucl-exnucl-th0 citations
3. 03*

   Demonstration of the light collection stability of a PEN-based wavelength shifting reflector in a tonne scale liquid argon detector

   V. Gupta🇳🇱 · G. R. Araujo🇨🇭 · M. Babicz🇨🇭 · L. Baudis🇨🇭 · P.-J. Chiu🇨🇭 · S. Choudhary🇵🇱 · M. Goldbrunner🇩🇪 · A. Hamer🇬🇧 · M. Kuźniak🇵🇱 · M. Kuźwa🇵🇱 · A. Leonhardt🇩🇪 · E. Montagna🇮🇹 and 9 other authors

   Liquid argon detectors rely on wavelength shifters for efficient detection of scintillation light. The current standard is tetraphenyl butadiene (TPB), but it is challenging to instrument on a large scale. Poly(ethylene 2,6-naphthalate) (PEN), a polyester easily manufactured as thin sheets, could simplify the coverage of large surfaces with wavelength shifters. Previous measurements have shown that commercial grades of PEN have approximately 50% light conversion efficiency relative to TPB. Encouraged by these results, we conducted a large-scale measurement using $4m^2$ combined PEN and specular reflector foils in a two-tonne liquid argon dewar to assess its stability over approximately two weeks. This test is crucial for validating PEN as a viable substitute for TPB. The setup used for the measurement of the stability of PEN as a wavelength shifter is described, together with the first results, showing no evidence of performance deterioration over a period of 12 days.

   ↳ physics.ins-detastro-ph.IMhep-exnucl-exJINST(2025)·2 citations
4. 04*

   Production of exotic hadrons in $pp$ and nuclear collisions

   Jinhui Chen · Feng-Kun Guo · Yu-Gang Ma · Cheng-Ping Shen · Qiye Shou · Qian Wang · Jia-Jun Wu · Bing-Song Zou

   Exotic hadrons beyond the conventional quark model have been discovered in the past two decades. Investigations of these states can lead to deep understanding of nonperturbative dynamics of the strong interaction. In this concise review, we focus on the productions of exotic hadrons in $pp$, $p\bar{p}$, and nuclear collisions. Experimental observations of light nuclei and hypernuclei, as prototypes of hadronic molecules, in heavy ion collisions will also be briefly discussed.

   ↳ hep-phhep-exnucl-exnucl-thNucl.Sci.Tech.(2025)·47 citations
5. 05*

   High density symmetry energy: A key to the solution of the hyperon puzzle

   Jun-Ting Ye🇨🇳 · Rui Wang🇮🇹 · Si-Pei Wang🇨🇳 · Lie-Wen Chen🇨🇳

   The recently developed nuclear effective interaction based on the so-called N3LO Skyrme pseudopotential is extended to include the hyperon-nucleon and hyperon-hyperon interactions by assuming the similar density, momentum, and isospin dependence as for the nucleon-nucleon interaction. The parameters in these interactions are determined from either experimental information if any or chiral effective field theory or lattice QCD calculations of the hyperon potentials in nuclear matter around nuclear saturation density ${\rho }_0$. We find that varying the high density behavior of the symmetry energy $E_{\mathrm{sym}}(\rho )$ can significantly change the critical density for hyperon appearance in the neutron stars and thus the maximum mass $M_{\mathrm{TOV}}$ of static hyperon stars. In particular, a symmetry energy which is soft around $2-3{\rho }_0$ but stiff above about $4{\rho }_0$, can lead to $M_{\mathrm{TOV}}\gtrsim 2M_{\odot }$ for hyperon stars and simultaneously be compatible with (1) the constraints on the equation of state of symmetric nuclear matter at suprasaturation densities obtained from flow data in heavy-ion collisions; (2) the microscopic calculations of the equation of state for pure neutron matter; (3) the star tidal deformability extracted from gravitational wave signal GW170817; (4) the mass-radius relations of PSR J0030+0451, PSR J0740+6620 and PSR J0437-4715 measured from NICER; (5) the observation of the unusually low mass and small radius in the central compact object of HESS J1731-347. Furthermore, the sound speed squared of the hyperon star matter naturally displays a strong peak structure around baryon density of $3-4{\rho }_0$, consistent with the model-independent analysis on the multimessenger data. Our results suggest that the high density symmetry energy could be a key to the solution of the hyperon puzzle in neutron star physics.

   ↳ nucl-thastro-ph.HEhep-phnucl-exApJ(2025)·24 citations
6. 06*

   In Search of Truth: In memory of Balraj Singh

   José Nicolás Orce🇿🇦 · Boris Pritychenko🇺🇸 · Tibor Kibédi🇦🇺 · Jun Chen🇨🇳

   Born in Punjab (India) in December 1941, Balraj Singh is not only the single most prolific nuclear data evaluator and disseminator of nuclear structure and decay data with 148 evaluations in Nuclear Data Sheets -- 85 as the first and often only author -- plus other journals, but his upmost curiosity and dedication brought him to be one of the finest nuclear physicists, with an everlasting influence on many of us. Balraj passed away about a year ago on 9 October 2023 in Ottawa, Ontario (Canada) at the age of 81, and at Atomic Data and Nuclear Data Tables we would like to commemorate some of his scientific achievements.

   ↳ nucl-thnucl-exphysics.hist-phAtom.Data Nucl.Data Tabl.(2025)·0 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.