Mon·Nov 23, 2020Monday·November 23, 2020

1. 01*

   Multi-probe study of excited states in ${}^{12}\mathrm{C}$: disentangling the sources of monopole strength between the Hoyle state and $E_x=13$ MeV

   K. C. W. Li · F. D. Smit · P. Adsley · R. Neveling · P. Papka · E. Nikolskii · J. W. Brümmer · L. M. Donaldson · M. Freer · M. N. Harakeh · F. Nemulodi · L. Pellegri and 15 other authors

   Knowledge of the low-lying monopole strength in ${}^{12}\mathrm{C}$, the Hoyle state in particular, is crucial for our understanding of both the astrophysically important $3\alpha$ reaction and of $\alpha$-particle clustering. The ${}^{12}\mathrm{C}(\alpha ,{\alpha }^{\prime }){}^{12}\mathrm{C}$ and ${}^{14}\mathrm{C}(p,t){}^{12}\mathrm{C}$ reactions were employed to populate states in ${}^{12}$C. A self-consistent, simultaneous analysis of the inclusive spectra with lineshapes was performed, which accounted for distortion due to nuclear dynamics and experimental effects. Clear evidence was found for excess monopole strength at $E_x\sim 9$ MeV, particularly in the ${}^{12}\mathrm{C}(\alpha ,{\alpha }^{\prime }){}^{12}\mathrm{C}$ reaction at $0^{\circ }$. This additional strength cannot be reproduced by the previously established monopole states between $E_x=7$ and 13 MeV. An additional $0^{+}$ state at $E_x\sim 9$ MeV yielded a significantly improved fit of the data and is the leading candidate for the predicted breathing-mode excitation of the Hoyle state. Alternatively, the results may suggest that a more sophisticated, physically motivated parameterization of the astrophysically important monopole strengths in ${}^{12}\mathrm{C}$ is required.

   nucl-exPRC(2022)·10 citations
2. 02*

   Latest results on light (anti)nuclei production in Pb-Pb collisions with ALICE at the LHC

   Chiara Pinto (on behalf of the ALICE Collaboration)🇮🇹

   Recent results on the production of light nuclei, including deuterons, tritons, ${}^3$He, ${}^4$He and the corresponding antinuclei in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV are presented and compared with theoretical predictions to provide insight into their production mechanisms in heavy-ion collisions. The large variety of measurements performed with the ALICE apparatus at different energies and collision systems allows us to constrain the models of the production mechanisms of light flavour baryon clusters, in particular those based on the coalescence and statistical hadronisation approaches. Furthermore, new measurements of the elliptic and triangular flow of deuteron and ${}^3$He produced in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV are presented and compared to the expectations from coalescence and hydrodynamic models. The measurement of the elliptic and triangular flow of light nuclei provides a powerful tool to give insight into their production mechanism and freeze-out properties at a late stage of the collision evolution.

   nucl-exhep-exPoS(2021)·0 citations
3. 03*

   The BDX-MINI detector for Light Dark Matter search at JLab

   M.Battaglieri🇺🇸 · P. Bisio🇮🇹 · M. Bondí🇮🇹 · A. Celentano🇮🇹 · P.L. Cole🇺🇸 · M. De Napoli🇮🇹 · R. De Vita🇮🇹 · L. Marsicano🇮🇹 · G. Ottonello🇮🇹 · F. Parodi🇮🇹 · N. Randazzo🇮🇹 · E.S. Smith🇺🇸 and 4 other authors

   This paper describes the design and performance of a compact detector, BDX-MINI, that incorporates all features of a concept that optimized the detection of light dark matter produced by electrons in a beam dump. It represents a reduced version of the future BDX experiment expected to run at JLAB. BDX-MINI was exposed to penetrating particles produced by a 2.176 GeV electron beam incident on the beam dump of Hall A at Jefferson Lab. The detector consists of 30.5 kg of PbWO4 crystals with sufficient material following the beam dump to eliminate all known particles except neutrinos. The crystals are read out using silicon photomultipliers. Completely surrounding the detector are a passive layer of tungsten and two active scintillator veto systems, which are also read out using silicon photomultipliers. The design was validated and the performance of the robust detector was shown to be stable during a six month period during which the detector was operated with minimal access.

   ↳ physics.ins-dethep-exnucl-exEPJC(2021)·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.