Wed·Jun 5, 2019Wednesday·June 5, 2019

1. 01*

   Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich ${}^{122-131}$Sb${}_{51}$ isotopes

   S. Biswas🇫🇷 · A. Lemasson🇫🇷 · M. Rejmund🇫🇷 · A. Navin🇫🇷 · Y.H. Kim🇫🇷 · C. Michelagnoli🇫🇷 · I. Stefan🇫🇷 · R. Banik🇮🇳 · P. Bednarczyk🇵🇱 · S. Bhattacharya🇮🇳 · S. Bhattacharyya🇮🇳 · E. Clément🇫🇷 and 49 other authors

   The neutron-rich ${}^{122-131}$Sb isotopes were produced as fission fragments in the reaction ${}^9$Be(${}^{238}$U,~f) with 6.2 MeV/u beam energy. An unique setup, consisting of AGATA, VAMOS++ and EXOGAM detectors, was used which enabled the prompt-delayed gamma-ray ($\gamma$) spectroscopy of fission fragments in the time range of 100 ns - 200 $\mu$s. New isomers, prompt and delayed transitions were established in the even-A ${}^{122-130}$Sb isotopes. In the odd-A ${}^{123-131}$Sb isotopes, new prompt and delayed $\gamma$-ray transitions were identified, in addition to the confirmation of the previously known isomers. The half-lives of the isomeric states and the $B(E2)$ transition probabilities of the observed transitions depopulating these isomers were extracted. The experimental data was compared with the theoretical results obtained in the framework of Large-Scale Shell-Model (LSSM) calculations in a restricted model space. Modifications of several components of the shell model interaction were introduced to obtain a consistent agreement with the excitation energies and the $B(E2)$ transition probabilities in neutron-rich Sn and Sb isotopes. The isomeric configurations in Sn and Sb were found to be relatively pure. Further, the calculations revealed that the presence of a single valence proton, mainly in the $g_{7/2}$ orbital in Sb isotopes, leads to significant mixing (due to the $\nu \pi$ interaction) of: (i) the neutron seniorities (${\upsilon }_{\nu }$) and (ii) the neutron angular momentum ($I_{\nu }$). The above features have a weak impact on the excitation energies, but have an important impact on the $B(E2)$ transition probabilities. In addition, a constancy of the relative excitation energies irrespective of neutron seniority and neutron number in Sn and Sb was observed.

   nucl-exnucl-thPRC(2019)·16 citations
2. 02*

   Measurement of the inclusive isolated photon production cross section in pp collisions at $\sqrt{s}$ = 7 TeV

   ALICE Collaboration

   The production cross section of inclusive isolated photons has been measured by the ALICE experiment at the CERN LHC in pp collisions at a centre-of-momentum energy of $\sqrt{s}=$ 7 TeV. The measurement is performed with the electromagnetic calorimeter EMCal and the central tracking detectors, covering a range of $|\eta |<0.27$ in pseudorapidity and a transverse momentum range of $10<p_{\mathrm{T}}^{\gamma }<$ 60 GeV/$c$. The result extends the $p_{\mathrm{T}}$ coverage of previously published results of the ATLAS and CMS experiments at the same collision energy to smaller $p_{\mathrm{T}}$. The measurement is compared to next-to-leading order perturbative QCD calculations and to the results from the ATLAS and CMS experiments. All measurements and theory predictions are in agreement with each other.

   nucl-exhep-exEPJC(2019)·54 citations
3. 03*

   $Q_{\text{EC}}$-value determination for ${}^{21}$Na${\to }^{21}$Ne and ${}^{23}$Mg${\to }^{23}$Na mirror-nuclei decays using high-precision mass spectrometry with ISOLTRAP at ISOLDE/CERN

   Jonas Karthein🇨🇭 · Dinko Atanasov🇩🇪 · Klaus Blaum🇩🇪 · Martin Breitenfeldt🇨🇭 · Vira Bondar🇧🇪 · Sebastian George🇩🇪 · Leendert Hayen🇧🇪 · David Lunney🇫🇷 · Vladimir Manea🇨🇭 · Maxime Mougeot🇫🇷 · Dennis Neidherr🇩🇪 · Lutz Schweikhard🇩🇪 and 5 other authors

   We report on high-precision $Q_{\text{EC}}$ values of the ${}^{21}$Na${\to }^{21}$Ne and ${}^{23}$Mg${\to }^{23}$Na mirror $\beta$-transitions from mass measurements with ISOLTRAP at ISOLDE/CERN. A precision of $\delta m/m=9\cdot 10^{-10}$ and $\delta m/m=1.5\cdot 10^{-9}$ was reached for the masses of ${}^{21}$Na and ${}^{23}$Mg, respectively. We reduce the uncertainty of the $Q_{\text{EC}}$ values by a factor five, making them the most precise experimental input data for the calculation of the corrected $\mathcal{F}t$-value of these mixed Fermi/Gamow-Teller transitions. For the ${}^{21}$Na${\to }^{21}$Ne $Q_{\text{EC}}$ value, a $2.3\sigma$ deviation from the literature $Q_{\text{EC}}$-value was found.

   nucl-exPRC(2019)·10 citations
4. 04*

   CP violating effects in coherent elastic neutrino-nucleus scattering processes

   D. Aristizabal Sierra🇨🇱 · V. De Romeri🇪🇸 · N. Rojas🇨🇱

   The presence of new neutrino-quark interactions can enhance, deplete or distort the coherent elastic neutrino-nucleus scattering (CEvNS) event rate. The new interactions may involve CP violating phases that can potentially affect these features. Assuming light vector mediators, we study the effects of CP violation on the CEvNS process in the COHERENT sodium-iodine, liquid argon and germanium detectors. We identify a region in parameter space for which the event rate always involves a dip and another one for which this is never the case. We show that the presence of a dip in the event rate spectrum can be used to constraint CP violating effects, in such a way that the larger the detector volume the tighter the constraints. Furthermore, it allows the reconstruction of the effective coupling responsible for the signal with an uncertainty determined by recoil energy resolution. In the region where no dip is present, we find that CP violating parameters can mimic the Standard Model CEvNS prediction or spectra induced by real parameters. We point out that the interpretation of CEvNS data in terms of a light vector mediator should take into account possible CP violating effects. Finally, we stress that our results are qualitatively applicable for CEvNS induced by solar or reactor neutrinos. Thus, the CP violating effects discussed here and their consequences should be taken into account as well in the analysis of data from multi-ton dark matter detectors or experiments such as CONUS, $\nu$-cleus or CONNIE.

   ↳ hep-phhep-exnucl-exJHEP(2019)·46 citations
5. 05*

   Light (anti)nuclei production in Cu+Cu collisions at $\sqrt{s_{\mathrm{NN}}}=200$GeV

   Liu Feng-Xian🇨🇳 · Chen Gang🇨🇳 · She Zhi-Lei · Zhou Dai-Mei🇨🇳 · Xie Yi-Long🇨🇳

   The production of light (anti)nuclei have been investigated using the dynamically constrained phase-space coalescence model based on the final-state hadrons generated by the PACIAE model in Cu+Cu collisions at $\sqrt{s_{\mathrm{NN}}}=200$GeV with $|\eta |<0.5$ and $0<p_T<8$GeV/c. The results show that there is a strong centrality dependence of yields of $\mathrm{d}$, $\overline{\mathrm{d}}$, ${}^3\mathrm{He}$, ${}^3\overline{\mathrm{He}}$, ${}^4\mathrm{He}$, and ${}^4\overline{\mathrm{He}}$, i.e., their yields decrease rapidly with the increase of centrality, and the greater the mass is, the greater the dependence shows; whereas their ratio of antinucleus to nucleus and coalescence parameter $B_A$ remain constant as the centrality increases. In addition, the yields of (anti)nuclei are strongly dependent on the mass of the (anti)nuclei, indicating that the (anti)nuclei produced have mass scaling properties in high-energy heavy-ion collisions. Our results are consistent with the STAR experimental data.

   ↳ nucl-thnucl-exEPJA(2019)·10 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.