Thu·Feb 25, 2021Thursday·February 25, 2021

1. 01*

   Spontaneous double alpha decay: First experimental limit and prospects of investigation

   V.I. Tretyak🇺🇦

   Nuclear decays with simultaneous emission of two alpha particles are energetically possible for a number of nuclides. Prospects of searching for such kind of decay for nuclides present in the natural isotopic composition of elements are discussed here. The first experimental limit on half-life for 2alpha decay is set for 209Bi as T1/2 > 2.9e20 y at 90% C.L., using the data of work [P. de Marcillac et al., Nature 422 (2003) 876]. Theoretical T1/2 estimations for the process are also given. Using these values, which are on the level of 1e33 y or more, one can conclude that the prospects of experimental observation of 2alpha decay are very pessimistic.

   nucl-exnucl-thNucl.Phys.Atom.Energy(2021)·19 citations
2. 02*

   Measurements of mixed harmonic cumulants in Pb-Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV

   ALICE Collaboration

   Correlations between moments of different flow coefficients are measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV recorded with the ALICE detector. These new measurements are based on multiparticle mixed harmonic cumulants calculated using charged particles in the pseudorapidity region $|\eta |<0.8$ with the transverse momentum range $0.2<p_{\mathrm{T}}<5.0$ GeV/$c$. The centrality dependence of correlations between two flow coefficients as well as the correlations between three flow coefficients, both in terms of their second moments, are shown. In addition, a collection of mixed harmonic cumulants involving higher moments of $v_2$ and $v_3$ is measured for the first time, where the characteristic signature of negative, positive and negative signs of four-, six- and eight-particle cumulants are observed, respectively. The measurements are compared to the hydrodynamic calculations using iEBE-VISHNU with AMPT and TRENTo initial conditions. It is shown that the measurements carried out using the LHC Run 2 data in 2015 have the precision to explore the details of initial-state fluctuations and probe the nonlinear hydrodynamic response of $v_2$ and $v_3$ to their corresponding initial anisotropy coefficients ${\epsilon }_2$ and ${\epsilon }_3$. These new studies on correlations between three flow coefficients as well as correlations between higher moments of two different flow coefficients will pave the way to tighten constraints on initial-state models and help to extract precise information on the dynamic evolution of the hot and dense matter created in heavy-ion collisions at the LHC.

   nucl-exhep-exPLB(2021)·44 citations
3. 03*

   Production of high purity ${}^{52g}$Mn from ${}^{nat}$V targets with $\alpha$-beams at cyclotrons

   A. Colombi🇮🇹 · M.P. Carante🇮🇹 · F. Barbaro🇮🇹 · L. Canton🇮🇹 · A. Fontana🇮🇹

   Radioisotope ${}^{52g}$Mn is of special interest for multimodal imaging. Using state-of-art nuclear reaction codes, we study the alternative nuclear reaction route ${}^{nat}$V($\alpha$,x)${}^{52g}$Mn in comparison with the standard production routes based upon the use of chromium targets. The integral yields of ${}^{52g}$Mn and contaminants have been evaluated. The main outcome of this investigation is that the production of the main contaminant isotope ${}^{54}$Mn is expected to be lower than with ${}^{nat}$Cr. The study also reveals a large spread in the cross-section data set and points out the need of more precise measurements of the reaction ${}^{nat}$V($\alpha$,x)${}^{52g}$Mn as well as the need of a more accurate theoretical description.

   nucl-exnucl-thphysics.med-ph2 citations
4. 04*

   Resolving the LMA-dark NSI degeneracy with coherent neutrino-nucleus scattering

   Mariano Esteves Chaves🇧🇷 · Thomas Schwetz🇩🇪

   In the presence of non-standard neutrino interactions (NSI), a degeneracy exists in neutrino oscillation data, which involves the flipping of the octant of the mixing angle ${\theta }_{12}$ and the type of the neutrino mass ordering. In this article, we revisit the status of this degeneracy in the light of recent data on coherent elastic neutrino-nucleus scattering (CE$\nu$NS) from the COHERENT experiment. For general relative couplings to up and down quarks, the degeneracy is disfavoured at the $2\sigma$ level by the latest data but remains at a higher confidence level. We investigate the requirements of future CE$\nu$NS measurements to resolve the degeneracy with high significance. We find that a measurement involving both, electron and muon neutrino flavours and a target with a neutron-to-proton ratio close to 1 is required. For example, an experiment with a silicon target at the European Spallation Source can resolve the degeneracy at more than $4\sigma$ for arbitrary relative couplings to up and down quarks.

   ↳ hep-phhep-exnucl-exJHEP(2021)·22 citations
5. 05*

   Hot and dense quark-gluon plasma thermodynamics from holographic black holes

   Joaquin Grefa🇺🇸 · Jorge Noronha🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇧🇷

   We present new results on the equation of state and transition line of hot and dense strongly interacting QCD matter, obtained from a bottom-up Einstein-Maxwell-Dilaton holographic model. We considerably expand the previous coverage in baryon densities in this model by implementing new numerical methods to map the holographic black hole solutions onto the QCD phase diagram. We are also able to obtain, for the first time, the first-order phase transition line in a wide region of the phase diagram. Comparisons with the most recent lattice results for the QCD thermodynamics are also presented.

   ↳ nucl-thhep-phnucl-exPRD(2021)·107 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.