Thu·Jan 6, 2022Thursday·January 6, 2022

1. 01*

   Measurement of alpha induced reaction cross-sections on ${}^{nat}$Mo with detailed covariance analysis

   Mahesh Choudhary · A. Gandhi · Aman Sharma · Namrata Singh · S. Dasgupta · J. Datta · A. Kumar

   In the present study we have measured the excitation functions for the nuclear reactions ${}^{100}$Mo($\alpha$,n)${}^{103}$Ru, ${}^{nat}$Mo($\alpha$,x)${}^{97}$Ru, ${}^{nat}$Mo($\alpha$,x)${}^{95}$Ru, ${}^{nat}$Mo($\alpha$,x)${}^{96g}$Tc, ${}^{nat}$Mo($\alpha$,x)${}^{95g}$Tc and ${}^{nat}$Mo($\alpha$,x)${}^{94g}$Tc in the energy range 11-32 MeV. We have used the stacked foil activation technique followed by off-line gamma ray spectroscopy technique to measure the excitation functions. In this study we have also documented detailed uncertainty analysis for these nuclear reactions and their corresponding covariance matrix are also presented. The excitation functions are compared with the available experimental data from EXFOR data library and the theoretical prediction from TALYS nuclear reaction code. The present measurements are found to be consistent with the available experimental data.

   nucl-exEPJA(2022)·18 citations
2. 02*

   The structure of ${}^{36}$Ca under the Coulomb magnifying glass

   L. Lalanne🇫🇷 · O. Sorlin🇫🇷 · A. Poves🇪🇸 · M. Assié🇫🇷 · F. Hammache🇫🇷 · S. Koyama🇯🇵 · F. Flavigny🇫🇷 · V. Girard-Alcindor🇫🇷 · A. Lemasson🇫🇷 · A. Matta🇫🇷 · T. Roger🇫🇷 · D. Beaumel🇫🇷 and 19 other authors

   Detailed spectroscopy of the neutron-deficient nucleus ${}^{36}$Ca was obtained up to 9 MeV using the ${}^{37}$Ca($p$,$d$)${}^{36}$Ca and the ${}^{38}$Ca($p$,$t$)${}^{36}$Ca transfer reactions. The radioactive nuclei, produced by the LISE spectrometer at GANIL, interacted with the protons of the liquid Hydrogen target CRYPTA, to produce light ejectiles (the deuteron $d$ or triton $t$) that were detected in the MUST2 detector array, in coincidence with the heavy residues %identified by a zero degree detection system. %States have been measured up to 9 MeV. Our main findings are: i) a similar shift in energy for the 1${}_1^{+}$ and 2${}_1^{+}$ states by about -250 keV, as compared to the mirror nucleus ${}^{36}$S, ii) the discovery of an intruder 0${}_2^{+}$ state at 2.83(13) MeV, which appears below the first 2${}^{+}$ state, in contradiction with the situation in ${}^{36}$S, and iii) a tentative 0${}_3^{+}$ state at 4.83(17) MeV, proposed to exhibit a bubble structure with two neutron vacancies in the 2s${}_{1/2}$ orbit. The inversion between the 0${}_2^{+}$ and 2${}_1^{+}$ states is due to the large mirror energy difference (MED) of -516(130) keV for the former. This feature is reproduced by Shell Model (SM) calculations, using the $sd$-$pf$ valence space, predicting an almost pure intruder nature for the 0${}_2^{+}$ state, with two protons (neutrons) being excited across the $Z$=20 magic closure in ${}^{36}$Ca (${}^{36}$S). This mirror system has the largest MEDs ever observed, if one excludes the few cases induced by the effect of the continuum.

   nucl-exnucl-thPRL(2022)·24 citations
3. 03*

   Nucleon momentum gap in asymmetric nuclear matter

   Gao-Chan Yong🇨🇳

   For more than half a century, nucleons are considered to move continuously in the nuclei. Recent electron-scattering experiments indicate about 20$\sim$25\% nucleons in heavier nuclei are involved in the neutron-proton short-range correlations. Nucleons in the nuclei thus have abnormal behavior unlike those in the non-interaction fermi gas. In the neutron-rich nuclei, around the Fermi momentum, the neutron-proton short-range correlations lead to a momentum gap in the proton momentum distribution, which is circumstantially supported by the pionic experimental data. Likewise, there should also be a neutron momentum gap in the proton-rich nuclei. Nucleon momentum gap is thought to have profound and extensive implications in the studies ranging from particle physics to neutron stars as well as ultra-cold atomic gases.

   ↳ nucl-thnucl-exPRC(2022)·5 citations
4. 04*

   MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario

   A. A. Aguilar-Arevalo🇲🇽 · B. C. Brown🇺🇸 · J. M. Conrad🇺🇸 · R. Dharmapalan🇺🇸 · A. Diaz🇺🇸 · Z. Djurcic🇺🇸 · D. A. Finley🇺🇸 · R. Ford🇺🇸 · G. T. Garvey🇺🇸 · S. Gollapinni🇺🇸 · A. Hourlier🇺🇸 · E.-C. Huang🇺🇸 and 27 other authors

   This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone, and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive CCQE analysis (inclusive analysis) are $\Delta m^2=0.29e{V}^2(0.33e{V}^2)$, $|U_{e4}{|}^2=0.016(0.500)$, $|U_{\mu 4}{|}^2=0.500(0.500)$, and ${\sin }^2(2{\theta }_{\mu e})=0.0316(1.0)$. Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a $\Delta {\chi }^2/\text{dof}=24.7/3(17.3/3)$, a $4.3\sigma (3.4\sigma )$ preference assuming the asymptotic approximation given by Wilks' theorem.

   ↳ hep-exhep-phnucl-exPRL(2022)·52 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.