Tue·Aug 4, 2020Tuesday·August 4, 2020

1. 01*

   $\beta$ Decay of ${}^{132}$In and Spectroscopy of ${}^{132}$Sn and ${}^{131}$Sb with the GRIFFIN Spectrometer

   K. Whitmore🇨🇦 · C. Andreoiu🇨🇦 · F. H. Garcia🇨🇦 · K. Ortner🇨🇦 · J. D. Holt🇨🇦 · T. Miyagi🇨🇦 · G. C. Ball🇨🇦 · N. Bernier🇨🇦 · H. Bidaman🇨🇦 · V. Bildstein🇨🇦 · M. Bowry🇨🇦 · D. S. Cross🇨🇦 and 16 other authors

   Spectroscopy of doubly magic ${}_{50}^{132}$Sn${}_{82}$ has been performed with the GRIFFIN spectrometer at TRIUMF-ISAC following the $\beta$ decay of ${}_{49}^{132}$In${}_{83}$. The analysis has allowed for the placement of a total of 70 transitions and 29 excited states in ${}^{132}$Sn. Detailed spectroscopy has also been performed on ${}^{131}$Sb, resulting from the $\beta$ decay of ${}^{131}$Sn, produced from the $\beta$-delayed neutron decay of ${}^{132}$In. Measurement of $\gamma$-rays in both ${}^{131}$Sn and ${}^{131}$Sb has led to the determination of the $\beta$-delayed neutron emission probability, $P_n$, from ${}^{132}$In. This is the first time the $P_n$ has been measured for this nucleus using $\gamma$ spectroscopy, and the new value of 12.3(4)% is consistent with the most recent $\beta -n$ counting experiment. Additionally, $\gamma$-$\gamma$ angular correlations have been performed in ${}^{132}$Sn, supporting the spin assignments of several excited states. Novel ab initio calculations are presented which describe several of the excited states, and these are compared to the experimental spectrum.

   nucl-exPRC(2020)·7 citations
2. 02*

   Considerations on the suppression of charged particles and ${\pi }^0$ in high energy heavy ion collisions

   M.Petrovici🇷🇴 · A. Lindner🇷🇴 · A. Pop🇷🇴

   Experimental results related to charged particle and ${\pi }^0$ suppression obtained at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven for Au-Au (Cu-Cu) collisions and at the Large Hadron Collider (LHC) at CERN for Pb-Pb (Xe-Xe) collisions are compiled in terms of the usual nuclear modification factors, $R_{AA}$ and $R_{CP}$, and of the newly introduced $R_{AA}^N$ and $R_{CP}^N$ as a function of $⟨N_{part}⟩$ and $⟨d{N}_{ch}/d\eta ⟩$. The studies are focused on a $p_T$ range in the region of maximum suppression evidenced in the experiments. The core contribution to $R_{AA}$ is presented. Considerations on the missing suppression in high charged particle multiplicity events for pp collisions at 7 TeV are presented. The trends of $R_{CP}$ and $R_{CP}^N$ for charged particles and $R_{AA}^{{\pi }^0}$ and $(R_{AA}^N{)}^{{\pi }^0}$ as a function of $\sqrt{s_{NN}}$, measured at RHIC in Au-Au collisions and at LHC in Pb-Pb collisions, show a suppression that becomes larger from $\sqrt{s_{NN}}$ = 39 GeV up to $\sqrt{s_{NN}}$=200 GeV, followed by a saturation up to the highest energy of $\sqrt{s_{NN}}$ =5.02 TeV in Pb-Pb collisions. A clear change in the dependence of $(1-R_{AA}^{{\pi }^0})/⟨dN/dy⟩$ for the most central collisions as a function of collision energy is evidenced in the region of $\sqrt{s_{NN}}$ =62.4 - 130 GeV.

   nucl-exhep-phPRC(2021)·4 citations
3. 03*

   Selected Science Opportunities for the EicC

   Xurong Chen🇨🇳 · Feng-Kun Guo🇨🇳 · Craig D. Roberts🇨🇳 · Rong Wang🇨🇳

   An electron ion collider has been proposed in China (EicC). It is anticipated that the facility would provide polarised electrons, protons and ion beams, in collisions with large centre-of-mass energy. This discussion highlights its potential to address issues that are central to understanding the emergence of mass within the Standard Model, using examples that range from the exploration of light-meson structure, through measurements of near-threshold heavy-quarkonia production, and on to studies of the spectrum of exotic hadrons.

   ↳ hep-phhep-exhep-latnucl-ex+1Few Body Syst.(2020)·89 citations
4. 04*

   Evaluation of Experimental Constraints on the ${}^{44}$Ti($\alpha$,p)${}^{47}$V Reaction Cross Section Relevant for Supernovae

   Kelly A. Chipps🇺🇸 · Philip Adsley🇫🇷 · Manoel Couder🇺🇸 · W. Raphael Hix🇺🇸 · Zachary Meisel🇺🇸 · Konrad Schmidt🇩🇪

   Due to its importance as an astronomical observable in core-collapse supernovae (CCSNe), the reactions producing and destroying ${}^{44}$Ti must be well constrained. Generally, statistical model calculations such as Hauser-Feshbach are employed when experimental cross sections are not available, but the variation in such adopted rates can be large. Here, data from the literature is compared with statistical model calculations of the ${}^{44}$Ti($\alpha$,p)${}^{47}$V reaction cross section and used to constrain the possible reaction rate variation over the temperatures relevant to CCSNe. Suggestions for targeted future measurements are given.

   ↳ astro-ph.SRastro-ph.HEnucl-exnucl-thPRC(2020)·5 citations
5. 05*

   Jet Charge: A Flavor Prism for Spin Asymmetries at the EIC

   Zhong-Bo Kang🇺🇸 · Xiaohui Liu🇨🇳 · Sonny Mantry🇺🇸 · Ding Yu Shao🇺🇸

   We propose the jet charge observable as a novel probe of flavor structure in the nucleon spin program at the Electron Ion Collider (EIC). We show that jet charge measurements can substantially enhance the sensitivity of spin asymmetries to different partonic flavors in the nucleon. This sensitivity can be further improved by constructing the jet charge using only a subset of hadron species (pions or kaons) in the jet. As an example, we use the Sivers asymmetry in back-to-back electron-jet production at the EIC to show that the jet charge can be a unique tool in constraining the Sivers function for different partonic flavors.

   ↳ hep-phhep-exnucl-exnucl-thPRL(2020)·67 citations
6. 06*

   Double-heavy tetraquark states with heavy diquark-antiquark symmetry

   Jian-Bo Cheng🇨🇳 · Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Zong-Guo Si🇨🇳 · Tao Yao🇨🇳

   We calculate the masses of the $QQ\bar{q}\bar{q}$ ($Q=c,b$; $q=u,d,s$) tetraquark states with the aid of heavy diquark-antiquark symmetry (HDAS) and the chromomagnetic interaction (CMI) model. The masses of the highest-spin ($J=2$) tetraquarks that have only the $(QQ{)}_{{\bar{3}}_c}(\bar{q}\bar{q}{)}_{3_c}$ color structure are related with those of conventional hadrons using HDAS. Thereafter, the masses of their partner states are determined with the mass splittings in the CMI model. Our numerical results reveal that: (i) the lightest $cc\bar{n}\bar{n}$ ($n=u,d$) is an $I(J^P)=0(1^{+})$ state around 3929 MeV (53 MeV above the $D{D}^{\ast }$ threshold) and none of the double-charm tetraquarks are stable; (ii) the stable double-bottom tetraquarks are the lowest $0(1^{+})$ $bb\bar{n}\bar{n}$ around 10488 MeV ($\approx 116$ MeV below the $B{B}^{\ast }$ threshold) and the lowest $1/2(1^{+})$ $bb\bar{n}\bar{s}$ around 10671 MeV ($\approx 20$ MeV below the $B{B}_s^{\ast }/B_s{B}^{\ast }$ threshold); and (iii) the two lowest $bc\bar{n}\bar{n}$ tetraquarks, namely the lowest $0(0^{+})$ around 7167 MeV and the lowest $0(1^{+})$ around 7223 MeV, are near-threshold states. Moreover, we discuss the constraints on the masses of double-heavy hadrons. Specifically, for the lowest nonstrange tetraquarks, we obtain $T_{cc}<3965$ MeV, $T_{bb}<10627$ MeV, and $T_{bc}<7199$ MeV.

   ↳ hep-phhep-exhep-latnucl-ex+1CPC(2021)·96 citations
7. 07*

   Prospect of undoped inorganic scintillators at 77 Kelvin for the detection of non-standard neutrino interactions at the Spallation Neutron Source

   Keyu Ding · Daniel Pershey · Dmitry Chernyak · Jing Liu

   Investigated in this work are sensitivities to non-standard neutrino interactions (NSI) of a prototype detector placed about 20 meters away from the Spallation Neutron Source at the Oak Ridge National Laboratory in two years of data taking. The presumed prototype consists of 10 kg undoped CsI scintillation crystals directly coupled with SiPM arrays operated at 77 K. Compared to the COHERENT CsI(Na) detector, a much higher light yield is assumed for the prototype. An experiment with a cylindrical undoped CsI crystal coupled directly to a photomultiplier tube at about 77 K was conducted to verify the light yield assumption. A yield of $33.5\pm 0.7$ photoelectrons per keV electron-equivalent (PE/keVee) was achieved in [13, 60] keVee, which is much closer to the relevant energy region for the NSI search than some of the early studies.

   ↳ physics.ins-dethep-exnucl-exEPJC(2020)·16 citations
8. 08*

   The Core of ${}^{25}$F in the Rotational Model

   A.O.Macchiavelli🇺🇸 · R.M.Clark🇺🇸 · H.L.Crawford🇺🇸 · P.Fallon🇺🇸 · I.Y.Lee🇺🇸 · C.Morse · C.M.Campbell🇺🇸 · M.Cromaz🇺🇸 · C.Santamaria🇫🇷

   In a recent experiment, carried out at RIBF/RIKEN, the ${}^{25}$F$(p,2p)$${}^{24}$O reaction was studied at 270 MeV/A in inverse kinematics. Derived spectroscopic factors suggest that the effective core of ${}^{25}$F significantly differs from a free ${}^{24}$O nucleus. We interpret these results within the Particle-Rotor Model and show that the experimental level scheme of ${}^{25}$F can be understood in the rotation-aligned coupling scheme, with its $5/2_1^{+}$ ground state as the band-head of a decoupled band. The excitation energies of the observed $1/2_1^{+}$ and $9/2_1^{+}$ states correlate strongly with the rotational energy of the effective core, seen by the odd proton, and allow us to estimate its $2^{+}$ energy at $\approx$ 3.2 MeV and a moderate quadrupole deformation, ${ϵ}_2\approx 0.15$. The measured fragmentation of the $\pi d_{5/2}$ single-particle strength is discussed and some further experiments suggested.

   ↳ nucl-thnucl-exPRC(2020)·4 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.