Tue·Dec 11, 2018Tuesday·December 11, 2018

1. 01*

   The structure of 70Fe: Single-particle and collective degrees of freedom

   A. Gade🇺🇸 · R. V. F. Janssens🇺🇸 · J. A. Tostevin🇬🇧 · D. Bazin🇺🇸 · J. Belarge · P. C. Bender🇨🇦 · S. Bottoni🇮🇹 · M. P. Carpenter🇺🇸 · B. Elman · S. J. Freeman🇬🇧 · T. Lauritsen🇺🇸 · S. M. Lenzi🇮🇹 and 7 other authors

   Excited states in the neutron-rich \nuc{70}{Fe} nucleus were populated in a one-proton removal reaction from \nuc{71}{Co} projectiles at 87~MeV/nucleon. A new transition was observed with the $\gamma$-ray tracking array GRETINA and shown to feed the previously assigned $4_1^{+}$ state. In comparison to reaction theory calculations with shell-model spectroscopic factors, it is argued that the new $\gamma$ ray possibly originates from the $6_1^{+}$ state. It is further shown that the Doppler-reconstructed $\gamma$-ray spectra are sensitive to the very different lifetimes of the $2^{+}$ and $4^{+}$ states, enabling their approximate measurement. The emerging structure of \nuc{70}{Fe} is discussed in comparison to LNPS-new large-scale shell-model calculations.

   nucl-exPRC(2019)·13 citations
2. 02*

   Strong absorption of hadrons with hidden and open strangeness in nuclear matter

   J. Adamczewski-Musch · O. Arnold · E. T. Atomssa · C. Behnke · A. Belounnas · A. Belyaev · J. C. Berger-Chen · J. Biernat · A. Blanco · C. Blume · M. Böhmer · S. Chernenko and 106 other authors

   We present the first observation of K- and \phi absorption within nuclear matter by means of \pi- -induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K-/K+)W / (K-/K+)C is found to be 0.319 \pm 0.009(stat)+0.014-0.012 (syst) indicating a larger absorption of K- in heavier targets as compared to lighter ones. The measured \phi/K- ratios in \pi-+C and \pi^- +W reactions within the HADES acceptance are found to be equal to $0.55\pm 0.03(stat)+0.06-0.07$ (syst) and to $0.63\pm 0.05(stat)-0.11+0.11$ (syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the \phi meson in nuclear medium is strongly coupled to the K- dynamics. The large difference in the \phi production off C and W nuclei is discussed in terms of a strong \phiN in-medium coupling.

   nucl-exPRL(2019)·35 citations
3. 03*

   Dispersive Evaluation of the Inner Radiative Correction in Neutron and Nuclear $\beta$-decay

   Chien Yeah Seng🇨🇳 · Mikhail Gorchtein🇩🇪 · Michael J. Ramsey-Musolf🇺🇸

   We propose a novel dispersive treatment of the so-called inner radiative correction to the neutron and nuclear $\beta$-decay. We show that it requires knowledge of the parity-violating structure function $F_3^{(0)}$ that arises from the interference of the axial vector charged current and the isoscalar part of the electromagnetic current. By isospin symmetry, we relate this structure function to the charged current inelastic scattering of neutrinos and antineutrinos. Applying this new data-driven analysis we obtain a new, more precise evaluation for the universal radiative correction ${\Delta }_R^{V,new}=0.02467(22)$ that supersedes the previous estimate by Marciano and Sirlin, ${\Delta }_R^V=0.02361(38)$. The substantial shift in the central value of ${\Delta }_R^V$ reflects in a respective shift of $V_{ud}$ and a considerable tension in the unitarity constraint on the first row of the CKM matrix which is used as one of the most stringent constraints on New Physics contributions in the charged current sector. We also point out that dispersion relations offer a unifying tool for treating hadronic and nuclear corrections within the same framework. We explore the potential of the dispersion relations for addressing the nuclear structure corrections absorbed in the $\mathcal{F}t$ values, a crucial ingredient alongside ${\Delta }_R^V$ in extracting $V_{ud}$ from superallowed nuclear decays.

   ↳ nucl-thhep-phnucl-exPRD(2019)·204 citations
4. 04*

   Non-flow effects in three-particle mixed-harmonic azimuthal correlations in small collision systems

   Chunjian Zhang🇨🇳 · Jiangyong Jia🇺🇸 · Jun Xu🇨🇳

   The Multi-particle technique has been used to unravel the nature of the long-range collectivity in small collision systems. A large three-particle mixed-harmonic correlation signal was recently observed by the ATLAS Collaboration, but the role of non-flow correlations is not yet studied. We estimate the influence of non-flow correlations to the three-particle correlators in $pp$ and $p$+Pb collisions using PYTHIA and HIJING models, and compare with the ATLAS results. The large non-flow effects from the jet and dijet production is found to be largely suppressed in $p$+Pb collisions using the subevent cumulant method by calculating the azimuthal correlation between two or more longitudinal pseudorapidity ranges. Depending on the experimental subevent method, however, the non-flow effects may still be significant in $pp$ collisions.

   ↳ nucl-thnucl-exPLB(2019)·14 citations
5. 05*

   Two-photon exchange on neutron and the hyperfine splitting

   Oleksandr Tomalak🇩🇪

   We calculate the contribution from the two-photon exchange on the neutron to the hyperfine splitting of S energy levels. We update the value of the neutron Zemach radius, estimate total recoil and polarizability corrections. The resulting two-photon exchange in electronic atoms exceeds by an order of magnitude the leading Zemach term and has different sign both in electronic and muonic hydrogen.

   ↳ nucl-thhep-phnucl-exphysics.atom-phPRD(2019)·12 citations
6. 06*

   Quasi equilibrium state of expanding quantum fields and two-pion Bose-Einstein correlations in $pp$ collisions at the LHC

   S.V. Akkelin🇺🇦

   We argue that the two-particle momentum correlation functions of high-multiplicity $p+p$ collisions at the LHC provide a signal for a ground state structure of a quasi equilibrium state of the longitudinally boost-invariant expanding quantum field which lies in the future light cone of a collision. The physical picture is that pions are produced by the expanding quantum emitter with two different scales approximately attributed to the expanding ideal gas in local equilibrium state and ground-state condensate. Specifically, we show that the effect of suppressing the two-particle Bose-Einstein momentum correlation functions increases with increasing transverse momentum of a like-sign pion pair due to different momentum-dependence of the corresponding particle emission regions.

   ↳ hep-phhep-exnucl-exnucl-thEPJA(2019)·7 citations
7. 07*

   Isotope Harvesting at FRIB: Additional opportunities for scientific discovery

   E. Paige Abel · Mikael Avilov · Virginia Ayres · Eva Birnbaum🇺🇸 · Georg Bollen🇺🇸 · Greg Bonito · Todd Bredeweg · Hannah Clause · Aaron Couture🇺🇸 · Joe DeVore · Matt Dietrich · Paul Ellison and 28 other authors

   The Facility for Rare Isotope Beams (FRIB) at Michigan State University provides a unique opportunity to access some of the nation's most specialized scientific resources: radioisotopes. An excess of useful radioisotopes will be formed as FRIB fulfills its basic science mission of providing rare isotope beams. In order for the FRIB beams to reach high-purity, many of the isotopes are discarded and go unused. If harvested, the unused isotopes could enable cutting-edge research for diverse applications ranging from medical therapy and diagnosis to nuclear security. Given that FRIB will have the capability to create about 80 percent of all possible atomic nuclei, harvesting at FRIB will provide a fast path for access to a vast array of isotopes of interest in basic and applied science investigations. To fully realize this opportunity, infrastructure investment is required to enable harvesting and purification of otherwise unused isotopes. An investment in isotope harvesting at FRIB will provide the nation with a powerful resource for development of crucial isotope applications.

   ↳ physics.ins-detnucl-exJ.Phys.G(2019)·26 citations
8. 08*

   Rejecting cosmic background for exclusive neutrino interaction studies with Liquid Argon TPCs; a case study with the MicroBooNE detector

   MicroBooNE collaboration: C. Adams · M. Alrashed · R. An · J. Anthony · J. Asaadi · A. Ashkenazi · M. Auger · S. Balasubramanian · B. Baller · C. Barnes · G. Barr · M. Bass and 162 other authors

   Cosmic ray (CR) interactions can be a challenging source of background for neutrino oscillation and cross-section measurements in surface detectors. We present methods for CR rejection in measurements of charged-current quasielastic-like (CCQE-like) neutrino interactions, with a muon and a proton in the final state, measured using liquid argon time projection chambers (LArTPCs). Using a sample of cosmic data collected with the MicroBooNE detector, mixed with simulated neutrino scattering events, a set of event selection criteria is developed that produces an event sample with minimal contribution from CR background. Depending on the selection criteria used a purity between 50% and 80% can be achieved with a signal selection efficiency between 50% and 25%, with higher purity coming at the expense of lower efficiency. While using a specific dataset from the MicroBooNE detector and selection criteria values optimized for CCQE-like events, the concepts presented here are generic and can be adapted for various studies of exclusive {\nu}{\mu} interactions in LArTPCs.

   ↳ physics.ins-dethep-exnucl-exphysics.data-anEPJC(2019)·22 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.