Fri·Feb 2, 2018Friday·February 2, 2018

1. 01*

   High-spin spectroscopy and shell-model interpretation of the N < 126 radium isotopes ${}^{212}$Ra and ${}^{213}$Ra

   T. Palazzo · G.J. Lane🇦🇺 · A.E. Stuchbery🇦🇺 · A.J. Mitchell🇬🇧 · A. Akber🇦🇺 · M.S.M. Gerathy🇦🇺 · S.S. Hota🇦🇺 · T. Kibédi🇦🇺 · B.Q. Lee · N. Palalani · M.W. Reed🇦🇺

   The level structures of ${}^{212}$Ra and ${}^{213}$Ra have been established via time-correlated $\gamma$-ray spectroscopy following the ${}^{204}$Pb(${}^{12}$C,4$n$)${}^{212}$Ra and ${}^{204}$Pb(${}^{13}$C,4$n$)${}^{213}$Ra reactions. In ${}^{212}$Ra, levels up to $\sim 6.2$ MeV were identified and firm spin-parity assignments were achieved to a $J^{\pi }=19^{+}$ isomer with a mean life of 31(3) ns. For ${}^{213}$Ra the corresponding values were $\sim 4.5$ MeV in excitation energy and $J^{\pi }=33/2^{+}$. Two isomeric states with $J^{\pi }=23/2^{+}$, $\tau =27(3)$ ns and $J^{\pi }=33/2^{+}$, $\tau =50(3)$ ns were discovered in ${}^{213}$Ra. The experimental data were compared with semiempirical shell-model calculations, which allowed dominant configurations to be assigned to most of the observed levels.

   nucl-exPRC(2018)·7 citations
2. 02*

   Precise half-life measurement of the superallowed emitter 30S

   V.E. Iacob🇺🇸 · J.C. Hardy🇺🇸 · L. Chen🇨🇳 · V. Horvat🇺🇸 · M. Bencomo🇺🇸 · N. Nica🇺🇸 · H.I. Park🇺🇸 · B.T. Roeder🇺🇸 · A. Saastamoinen🇺🇸

   We have measured the half-life of 30S, the parent of a superallowed 0+-to-0+ beta transition, to high precision using very pure sources and a 4pi proportional gas counter to detect the decay positrons. Our result for the half-life is 1.17992(34) s. As a byproduct of this measurement, we determined the half-life of its daughter, 30P, to be 2.501(2) min.

   nucl-exPRC(2018)·4 citations
3. 03*

   Anisotropic flow: A case for Bottomonia

   Debasish Das (1) · Nirupam Dutta (2) ((1) SINP · (2) NISER)

   Studies of $J/$$\psi$ $v_2$ at RHIC and LHC energies have provided important elements towards the understanding on the production mechanisms and on the thermalization of charm quarks. Bottomonia has an advantage since it is a cleaner probe. A brief discussion has been provided for ${\rm Y}(1S)$ $v_2$, which can become the new probe for QGP, including the necessity of studies for small systems.

   nucl-exhep-exhep-phnucl-thInt.J.Mod.Phys.A(2018)·11 citations
4. 04*

   Direct photon production in relativistic heavy-ion collisions -- a theory update

   Charles Gale🇨🇦

   For tomographic studies of relativistic nuclear collisions and of the quark-gluon plasma, photons (real and virtual) are unique. They are the only probes than can be both soft and penetrating. First we report on advances in modelling the hadron dynamics of heavy-ion collisions using a hybrid approach which consists of IP-Glasma, relativistic fluid dynamics, and hadronic cascade components. We briefly discuss the "photon flow puzzle", and then focus on a recent development in the theory of photon emission from a non-equilibrium, strongly interacting medium.

   ↳ hep-phnucl-exnucl-thPoS(2019)·10 citations
5. 05*

   Combination of complex momentum representation and Green's function methods in relativistic mean-field theory

   Min Shi🇨🇳 · Zhong-Ming Niu🇨🇳 · Haozhao Liang🇯🇵

   We have combined the complex momentum representation method with the Green's function method in the relativistic mean-field framework to establish the RMF-CMR-GF approach. This new approach is applied to study the halo structure of ${}^{74}$Ca. All the continuum level density of concerned resonant states are calculated accurately without introducing any unphysical parameters, and they are independent of the choice of integral contour. The important single-particle wave functions and densities for the halo phenomenon in ${}^{74}$Ca are discussed in detail.

   ↳ nucl-thnucl-exPRC(2018)·16 citations
6. 06*

   Phenomenology of anomalous chiral transports in heavy-ion collisions

   Xu-Guang Huang🇨🇳

   High-energy Heavy-ion collisions can generate extremely hot quark-gluon matter and also extremely strong magnetic fields and fluid vorticity. Once coupled to chiral anomaly, the magnetic fields and fluid vorticity can induce a variety of novel transport phenomena, including the chiral magnetic effect, chiral vortical effect, etc. Some of them require the environmental violation of parity and thus provide a means to test the possible parity violation in hot strongly interacting matter. We will discuss the underlying mechanism and implications of these anomalous chiral transports in heavy-ion collisions.

   ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2018)·1 citation
7. 07*

   Angular correlation results from ALICE

   Monika Varga-Kofarago (for the ALICE collaboration)🇭🇺

   In heavy-ion collisions, the quark-gluon plasma is expected to be produced, which is an almost perfect liquid that made up the Universe a few microseconds after the Big Bang. In these collisions, jets are also formed from hadronizing partons with high transverse momentum, and they traverse the hot and dense medium and interact with it. Their properties can be modified by these interactions, therefore these modifications, if present, can give insight into the properties of the plasma itself. Angular correlation measurements can be used to study jets in Pb-Pb collisions in a transverse momentum ($p_{\mathrm{T}}$) regime where jets are not easily reconstructable above the fluctuating background. Small collision systems (e.g., pp or p-Pb) can be used as reference for these measurements; however, these collisions themselves are of interest. For example, particle production mechanisms and conservation laws can be tested in these systems. Results from Pb-Pb and pp collisions recorded by the ALICE detector are presented in this paper.

   ↳ hep-exnucl-exPoS(2019)·0 citations
8. 08*

   Multiparticle azimuthal cumulants in p+Pb collisions from a multiphase transport model

   Mao-Wu Nie🇨🇳 · Peng Huo🇺🇸 · Jiangyong Jia🇺🇸 · Guo-Liang Ma🇨🇳

   A new subevent cumulant method was recently developed, which can significantly reduce the non-flow contributions in long-range correlations for small systems compared to the standard cumulant method. In this work, we study multi-particle cumulants in $p$+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with a multiphase transport model (AMPT), including two- and four-particle cumulants ($c_2\{2\}$ and $c_2\{4\}$) and symmetric cumulants [SC(2, 3) and SC(2, 4)]. Our numerical results show that $v_2\{2\}$ is consistent with the experimental data, while the magnitude of $c_2\{4\}$ is smaller than the experimental data, which may indicate either the collectivity is underestimated or some dynamical fluctuations are absent in the AMPT model. For the symmetric cumulants, we find that the results from the standard cumulant method are consistent with the experimental data, but those from the subevent cumulant method show different behaviors. The results indicate that the measurements from the standard cumulant method are contaminated by non-flow effects, especially when the number of produced particles is small. The subevent cumulant method is a better tool to explore the $real$ collectivity in small systems.

   ↳ hep-phnucl-exnucl-thPRC(2018)·30 citations
9. 09*

   Studying Antimatter Gravity with Muonium

   MAGE Collaboration: Aldo Antognini🇨🇭 · Daniel M. Kaplan🇺🇸 · Klaus Kirch🇨🇭 · Andreas Knecht🇨🇭 · Derrick C. Mancini🇺🇸 · James D. Phillips🇺🇸 · Thomas J. Phillips🇺🇸 · Robert D. Reasenberg🇺🇸 · Thomas J. Roberts🇺🇸 · Anna Soter🇨🇭

   The gravitational acceleration of antimatter, gbar, has yet to be directly measured; an unexpected outcome of its measurement could change our understanding of gravity, the universe, and the possibility of a fifth force. Three avenues are apparent for such a measurement: antihydrogen, positronium, and muonium, the last requiring a precision atom interferometer and novel muonium beam under development. The interferometer and its few-picometer alignment and calibration systems appear feasible. With 100 nm grating pitch, measurements of gbar to 10%, 1%, or better can be envisioned. These could constitute the first gravitational measurements of leptonic matter, of 2nd-generation matter, and possibly, of antimatter.

   ↳ physics.ins-detgr-qchep-exnucl-ex+1Atoms(2018)·37 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.