Fri·Nov 8, 2019Friday·November 8, 2019

1. 01*

   First search for $\alpha$ decays of naturally occurring Hf nuclides with emission of $\gamma$ quanta

   F.A. Danevich🇺🇦 · M. Hult🇧🇪 · D.V. Kasperovych🇺🇦 · G.P. Kovtun🇺🇦 · K.V. Kovtun🇺🇦 · G. Lutter🇧🇪 · G. Marissens🇧🇪 · O.G. Polischuk🇺🇦 · S.P. Stetsenko🇺🇦 · V.I. Tretyak🇺🇦

   The first ever search for $\alpha$ decays to the first excited state in Yb was performed for six isotopes of hafnium (174, 176, 177, 178, 179, 180) using a high purity Hf-sample of natural isotopic abundance with a mass of 179.8 g. For ${}^{179}$Hf, also $\alpha$ decay to the ground state of ${}^{175}$Yb was searched for thanks to the $\beta$-instability of the daughter nuclide ${}^{175}$Yb. The measurements were conducted using an ultra low-background HPGe-detector system located 225 m underground. After 75 d of data taking no decays were detected but lower bounds for the half-lives of the decays were derived on the level of $\lim T_{1/2}\sim 10^{15}-10^{18}$~a. The decay with the shortest half-life based on theoretical calculation is the decay of ${}^{174}$Hf to the first $2^{+}$ 84.3~keV excited level of ${}^{170}$Yb. The experimental lower bound was found to be $T_{1/2}\ge 3.3\times 10^{15}$ a.

   nucl-exEPJA(2020)·11 citations
2. 02*

   From Parton Saturation to Proton Spin: the Impact of BFKL Equation and Reggeon Evolution

   Yuri V. Kovchegov🇺🇸

   Lev Lipatov was a giant in the field of strong interactions and a dominant force in high-energy QCD for many decades. His work deeply influenced both how we think about QCD and how we perform calculations in the theory. Below we describe the work in two related research directions: the physics of parton saturation and proton spin at small $x$. Both developments would have been impossible without Lipatov's groundbreaking work. Saturation physics would not have happened without the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation. The recent progress in our theoretical understanding of the proton spin contribution coming from small-$x$ partons started with the seminal paper by Kirschner and Lipatov resumming double logarithms of energy in the Reggeon evolution.

   ↳ hep-phnucl-exnucl-th0 citations
3. 03*

   Study of open heavy-flavour hadron production in pp and p$-$Pb collisions with ALICE

   Preeti Dhankher (on behalf of ALICE collaboration)🇮🇳

   Measurement of heavy-flavour production in small systems can be used to test the Quantum ChromoDynamic (QCD) models. In this manuscript, the production cross section of D mesons at midrapidity and open heavy-flavour decay muons (HFM) measured at forward rapidity in pp collisions at $\sqrt{s}$ = 5.02 TeV, and open heavy-flavour decay electrons (HFE) measured at midrapidity in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE detector will be presented. The self-normalized yield of open heavy-flavour decay electrons and muons as a function of multiplicity in pp and p$-$Pb collisions will be presented. Finally, the latest result on nuclear modification factor ($Q_{\mathrm{pPb}}$) of D mesons and the ${\nu }_2$ of open heavy-flavour decay electrons and muons in p$-$Pb collisions will be discussed.

   ↳ hep-exnucl-exSpringer Proc.Phys.(2020)·0 citations
4. 04*

   Analytic Response Relativistic Coupled-Cluster Theory: The first application to indium isotope shifts

   B.K. Sahoo🇮🇳 · A.R. Vernon🇬🇧 · R.F. Garcia Ruiz🇨🇭 · C.L. Binnersley🇬🇧 · J. Billowes🇬🇧 · M.L. Bissell🇬🇧 · T.E. Cocolios🇧🇪 · G.J. Farooq-Smith🇬🇧 · K.T. Flanagan🇬🇧 · W. Gins🇧🇪 · R.P. de Groote🇧🇪 · A. Koszorus🇧🇪 and 7 other authors

   With increasing demand for accurate calculation of isotope shifts of atomic systems for fundamental and nuclear structure research, an analytic energy derivative approach is presented in the relativistic coupled-cluster theory framework to determine the atomic field shift and mass shift factors. This approach allows the determination of expectation values of atomic operators, overcoming fundamental problems that are present in existing atomic physics methods, i.e. it satisfies the Hellmann-Feynman theorem, does not involve any non-terminating series, and is free from choice of any perturbative parameter. As a proof of concept, the developed analytic response relativistic coupled-cluster theory has been applied to determine mass shift and field shift factors for different atomic states of indium. High-precision isotope-shift measurements of ${}^{104-127}$In were performed in the 246.8-nm (5p ${}^2$P${}_{3/2}$ $\to$ 9s ${}^2$S${}_{1/2}$) and 246.0-nm (5p ${}^2$P${}_{1/2}$ $\to$ 8s ${}^2$S${}_{1/2}$) transitions to test our theoretical results. An excellent agreement between the theoretical and measured values is found, which is known to be challenging in multi-electron atoms. The calculated atomic factors allowed an accurate determination of the nuclear charge radii of the ground and isomeric states of the ${}^{104-127}$In isotopes, providing an isotone-independent comparison of the absolute charge radii.

   ↳ physics.atom-phnucl-exNew J.Phys.(2020)·27 citations
5. 05*

   Exclusive heavy quark photoproduction in $pp$, $pPb$ and $PbPb$ collisions at the LHC and FCC energies

   V. P. Goncalves🇧🇷 · G. Sampaio dos Santos🇧🇷 · C. R. Sena🇧🇷

   In this paper we present a comprehensive analysis of the exclusive heavy quark photoproduction in $pp$, $pPb$ and $PbPb$ collisions at LHC and FCC energies using the color dipole formalism and taking into account of nonlinear corrections to the QCD dynamics. We estimate the rapidity distributions and cross sections for the charm and bottom production considering three phenomenological models for the dipole-proton scattering amplitude that are able to describe the $ep$ HERA data. Our results indicate that a future experimental analysis of this process is feasible, which will allow us to improve our understanding of the QCD dynamics.

   ↳ hep-phhep-exnucl-exNPA(2020)·6 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.