Fri·Jun 30, 2017Friday·June 30, 2017

1. 01*

   Experimental Determination of One- and Two-Neutron Separation Energies for Neutron-Rich Copper Isotopes

   Mian YU🇨🇳 · Hui-Ling Wei🇨🇳 · Yi-Dan Song🇨🇳 · Chun-Wang Ma🇨🇳

   A method is proposed to determine the one-neutron $S_n$ or two-neutron $S_{2n}$ separation energy of neutron-rich isotopes. Relationships between $S_n$ ($S_{2n}$) and isotopic cross sections have been deduced from an empirical formula, i.e., the cross section of an isotope exponentially depends on the average binding energy per nucleon $B/A$. The proposed relationships have been verified using the neutron-rich copper isotopes measured in the 64$A$ MeV ${}^{86}$Kr + ${}^9$Be reaction. $S_n$, $S_{2n}$, and $B/A$ for the very neutron-rich ${}^{77,78,79}$Cu isotopes are determined from the proposed correlations. It is also proposed that the correlations between $S_n$, $S_{2n}$ and isotopic cross sections can be used to find the location of neutron drip line isotopes.

   nucl-exnucl-thCPC(2017)·8 citations
2. 02*

   Identification of a long lived $\beta$ decaying isomer in ${}^{150}$Pm

   A. Saha🇮🇳 · T. Bhattacharjee🇮🇳 · D. Banerjee🇨🇭 · S. S. Alam🇮🇳 · Deepak Pandit🇮🇳 · M. Saha Sarkar🇮🇳 · S. Sarkar🇮🇳 · P. Das🇮🇳 · Soumik Bhattacharya🇮🇳 · R. Guin🇮🇳 · S. K. Das🇮🇳 · S. R. Banerjee🇮🇳

   The decay of odd-odd ${}^{150}$Pm has been studied by populating the nucleus with the ${}^{150}$Nd(p,n)${}^{150}$Pm reaction at E${}_{beam}$ = 8.0 MeV using 97$\%$ enriched ${}^{150}$Nd target. The presence of an isomeric state with $\beta$ decay half life of 2.2(1) h could be identified in ${}^{150}$Pm by following the half lives of the observed $\gamma$ transitions. The decay of the isomer to the excited levels of ${}^{150}$Sm has been confirmed by observing the $\gamma -\gamma$ coincidence with the VENUS array of six Compton suppressed Clover HPGe detectors. The $\beta$ decay end-point energies corresponding to the decay from the ${}^{150g}$Pm and ${}^{150m}$Pm have been measured using a $\beta -\gamma$ coincidence setup of two thin window Planar HPGe detectors and four Clover HPGe detectors of the VENUS array. The systematics of the similar isomeric states in neighboring nuclei has been studied to understand the underlying structure of these states. Shell model calculation has been performed by using OXBASH code which indicates the presence of a 5${}^{-}$ isomeric state at very low excitation in the nucleus. The calculation also suggests hindered electromagnetic decay of this isomer and supports the possibility of its $\beta$ decay to the excited levels of ${}^{150}$Sm.

   nucl-ex0 citations
3. 03*

   Meson-nucleus potentials and the search for meson-nucleus bound states

   V. Metag🇩🇪 · M. Nanova🇩🇪 · E. Ya. Paryev🇷🇺

   Recent experiments studying the meson-nucleus interaction to extract meson-nucleus potentials are reviewed. The real part of the potentials quantifies whether the interaction is attractive or repulsive while the imaginary part describes the meson absorption in nuclei. The review is focused on mesons which are sufficiently long-lived to potentially form meson-nucleus quasi-bound states. The presentation is confined to meson production off nuclei in photon-, pion-, proton-, and light-ion induced reactions and heavy-ion collisions at energies near the production threshold. Tools to extract the potential parameters are presented. In most cases, the real part of the potential is determined by comparing measured meson momentum distributions or excitation functions with collision model or transport model calculations. The imaginary part is extracted from transparency ratio measurements. Results on $K^{+},K^0,K^{-},\eta ,{\eta }^{\prime },\omega$, and $\varphi$ mesons are presented and compared with theoretical predictions. The interaction of $K^{+}$ and $K^0$ mesons with nuclei is found to be weakly repulsive, while the $K^{-},\eta ,{\eta }^{\prime },\omega$ and $\varphi$ meson-nucleus potentials are attractive, however, with widely different strengths. Because of meson absorption in the nuclear medium the imaginary parts of the meson-nucleus potentials are all negative, again with a large spread. An outlook on planned experiments in the charm sector is given. In view of the determined potential parameters, the criteria and chances for experimentally observing meson-nucleus quasi-bound states are discussed. The most promising candidates appear to be the $\eta$ and ${\eta }^{\prime }$ mesons.

   nucl-exnucl-thPPNP(2017)·126 citations
4. 04*

   Top-quark pair production cross sections at NNLO+NNLL in pPb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV

   David d'Enterria🇨🇭

   Total and fiducial top pair ($t\bar{t}$) production cross sections in proton-lead (pPb) collisions at $\sqrt{s_{NN}}$ = 8.16 TeV are computed at next-to-next-to-leading-order (NNLO) accuracy including next-to-next-to-leading-log (NNLL) gluon resummation, using the CT14 and CT10 proton parton distribution functions (PDF), and the EPPS16 and EPS09 nuclear PDF parametrizations for the lead ion. The total cross sections amount to $\sigma (pPb\to t\bar{t}+X)=59.0\pm 5.3$(CT14+EPPS16)${}_{-2.1}^{+1.6}$(scale) nb, and $57.5\pm {}_{-3.3}^{+4.3}$(CT10+EPS09)${}_{-2.0}^{+1.5}$(scale) nb, with small modifications with respect to the result computed using the free proton PDF alone. The normalized ratio of pPb to pp cross sections (nuclear modification factor) is $R_{pPb}=1.04{}_{\pm 0.03(EPS09)}^{\pm 0.07(EPPS16)}$. In the lepton+jets decay mode, $t\bar{t}\to b\bar{b}W(\ell \nu )W(q{\bar{q}}^{\prime })$, one expects $\sim$600 $t\bar{t}$ events in the 180 nb${}^{-1}$ integrated luminosity collected in pPb collisions at the LHC so far, after typical acceptance and efficiency losses. Differential cross sections at NLO accuracy are presented as a function of transverse momentum and rapidity of the top quarks, and of their decay b-jets and isolated leptons.

   ↳ hep-phhep-exnucl-exnucl-thNPA(2019)·4 citations
5. 05*

   Using hadron-in-jet data in a global analysis of $D^{\ast }$ fragmentation functions

   Daniele P. Anderle🇬🇧 · Tom Kaufmann🇩🇪 · Felix Ringer🇺🇸 · Marco Stratmann🇩🇪 · Ivan Vitev🇺🇸

   We present a novel global QCD analysis of charged $D^{\ast }$-meson fragmentation functions at next-to-leading order accuracy. This is achieved by making use of the available data for single-inclusive $D^{\ast }$-meson production in electron-positron annihilation, hadron-hadron collisions, and, for the first time, in-jet fragmentation in proton-proton scattering. It is shown how to include all relevant processes efficiently and without approximations within the Mellin moment technique, specifically for the in-jet fragmentation cross section. The presented technical framework is generic and can be straightforwardly applied to future analyses of fragmentation functions for other hadron species, as soon as more in-jet fragmentation data become available. We choose to work within the Zero Mass Variable Flavor Number Scheme which is applicable for sufficiently high energies and transverse momenta. The obtained optimum set of parton-to-$D^{\ast }$ fragmentation functions is accompanied by Hessian uncertainty sets which allow one to propagate hadronization uncertainties to other processes of interest.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2017)·73 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.