Fri·Jan 15, 2016Friday·January 15, 2016

1. 01*

   Competition of $\beta$-delayed protons and $\beta$-delayed $\gamma$ rays in ${}^{56}$Zn and the exotic $\beta$-delayed $\gamma$-proton decay

   S.E.A. Orrigo · B. Rubio · Y. Fujita · B. Blank · W. Gelletly · J. Agramunt · A. Algora · P. Ascher · B. Bilgier · L. Cáceres · R.B. Cakirli · H. Fujita and 16 other authors

   Remarkable results have been published recently on the $\beta$ decay of ${}^{56}$Zn. In particular, the rare and exotic $\beta$-delayed $\gamma$-proton emission has been detected for the first time in the $fp$ shell. Here we focus the discussion on this exotic decay mode and on the observed competition between $\beta$-delayed protons and $\beta$-delayed $\gamma$ rays from the Isobaric Analogue State.

   nucl-exEPJ Web Conf.(2016)·0 citations
2. 02*

   PHENIX results on centrality dependence of yields and correlations in $d$+Au collisions at $\sqrt{s_{{}_{NN}}}$=200\,GeV

   Takao Sakaguchi (for the PHENIX Collaboration)🇺🇸

   PHENIX has measured the transverse momentum ($p_{\mathrm{T}}$) spectra and two particle angular correlations for high $p_{\mathrm{T}}$ particles in $d$+Au collisions at $\sqrt{s_{{}_{NN}}}$=200\,GeV using the RHIC Year-2008 run data. The azimuthal angle correlations for two particles with a large rapidity gap exhibit a ridge like structure. Using the ${\pi }^0$ reconstructed in the EMCal, we have successfully extended the $p_{\mathrm{T}}$ reach of the correlation up to 8\,GeV/$c$. We find that the azimuthal anisotropy of hadrons found at low $p_{\mathrm{T}}$ persists up to 6\,GeV/$c$ with a significant centrality and $p_{\mathrm{T}}$ dependence, similar to what was observed in A+A collisions.

   nucl-exNPA(2016)·1 citation
3. 03*

   An introduction to mesic nuclei

   Colin Wilkin🇬🇧

   There is much speculation and a modest amount of evidence that certain mesons might form quasi-bound states with nuclei to produce really exotic states of matter. For this to be a practical possibility, the interaction between the meson and nucleons at low energies must be strong and attractive and the production rates "healthy". The conditions for this are surveyed for the light mesons. How this might lead to quasi-bound states is then discussed in a few typical cases.

   nucl-exnucl-thActa Phys.Polon.B(2016)·22 citations
4. 04*

   Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p-Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}$ = 5.02 TeV

   ALICE Collaboration

   The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity ($-0.5<y<0$) in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum ($p_{\mathrm{T}}$), the previously published $p_{\mathrm{T}}$ spectra have been extended to include measurements up to 20 GeV/$c$ for seven event multiplicity classes. The $p_{\mathrm{T}}$ spectra for pp collisions at $\sqrt{s}=7$ TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/$c$ to measure the nuclear modification factor ($R_{\mathrm{pPb}}$) in non-single diffractive p-Pb collisions. At intermediate transverse momentum ($2<p_{\mathrm{T}}<10$\,GeV/$c$) the proton-to-pion ratio increases with multiplicity in p-Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The $p_{\mathrm{T}}$ dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high $p_{\mathrm{T}}$ ($>10$ GeV/$c$), the particle ratios are consistent with those reported for pp and Pb-Pb collisions at the LHC energies. At intermediate $p_{\mathrm{T}}$ the (anti)proton $R_{\mathrm{pPb}}$ shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high $p_{\mathrm{T}}$ the charged pion, kaon and (anti)proton $R_{\mathrm{pPb}}$ are consistent with unity within statistical and systematic uncertainties.

   nucl-exhep-exPLB(2016)·234 citations
5. 05*

   Low-energy neutrinos

   Livia Ludhova🇮🇹

   There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the feld of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artifcial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three felds, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.

   nucl-exphysics.ins-detJ.Phys.Conf.Ser.(2016)·0 citations
6. 06*

   On the Analytic Estimation of Radioactive Contamination from Degraded Alphas

   Richard W. Kadel🇺🇸

   The high energy spectrum of alpha particles emitted from a single isotope uniformly contaminating a bulk solid has a flat energy spectrum with a high end cutoff energy equal to the maximal alpha kinetic energy ($T_{\alpha }$) of the decay. In this flat region of the spectrum, we show the surface rate $r_b{\text{(Bq/keV-cm}}^2)$ arising from a bulk alpha contamination ${\rho }_b$ (Bq/cm${}^3$) from a single isotope is given by $r_b={\rho }_b\Delta R/4\Delta E$, where $\Delta E=E_1-E_2>0$ is the energy interval considered (keV) in the flat region of the spectrum and $\Delta R=R_2-R_1$, where $R_2$ ($R_1$) is the amount of the bulk material (cm) necessary to degrade the energy of the alpha from $T_{\alpha }$ to $E_2$ ($E_1$). We compare our calculation to a rate measurement of alphas from ${}^{147}$Sm, ($15.32\%\pm 0.03\%$ of Sm($nat$) and half life of $(1.06\pm 0.01)\times 10^{11}\text{yr}$, and find good agreement, with the ratio between prediction to measurement of $100.2\%\pm 1.6\%\text{(stat)}\pm 2.1\%\text{(sys)}$. We derive the condition for the flat spectrum, and also calculate the relationship between the decay rate measured at the surface for a [near] surface contamination with an exponential dependence on depth and an a second case of an alpha source with a thin overcoat. While there is excellent agreement between our implementation of the sophisticated Monte Carlo program SRIM and our intuitive model in all cases, both fail to describe the measured energy distribution of a ${}^{148}$Gd alpha source with a thin ($\sim 200\mu$g/cm${}^2$) Au overcoat. We discuss possible origins of the disagreement and suggest avenues for future study.

   ↳ physics.ins-detnucl-exJINST(2016)·1 citation
7. 07*

   Measurements of heavy-flavour nuclear modification factor and elliptic flow in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV with ALICE

   Andrea Dubla (for the ALICE collaboration)🇳🇱

   Heavy quarks, i.e. charm and beauty, are sensitive probes of the medium produced in high-energy heavy-ion collisions. They are produced in the early stage of the collisions and are expected to experience the whole collision evolution interacting with the medium constituents via both elastic and inelastic processes. The nuclear modification factor ($R_{\mathrm{AA}}$) and the elliptic flow ($v_2$) are two of the main experimental observables that allow us to investigate the interaction strength of heavy quarks with the medium. The ALICE collaboration measured the production and elliptic flow of open heavy-flavour hadrons via their hadronic and semi-leptonic decays to electrons at mid-rapidity and to muons at forward rapidity in Pb--Pb collisions. Recent results will be discussed, and model calculations including the interaction of heavy quarks with the hot, dense, and deconfined medium will be confronted with the data.

   ↳ hep-exnucl-exNPA(2016)·2 citations
8. 08*

   No-core configuration-interaction model for the isospin- and angular-momentum-projected states

   W. Satula🇵🇱 · P. Baczyk🇵🇱 · J. Dobaczewski🇫🇮 · M. Konieczka🇵🇱

   [Background] Single-reference density functional theory is very successful in reproducing bulk nuclear properties like binding energies, radii, or quadrupole moments throughout the entire periodic table. Its extension to the multi-reference level allows for restoring symmetries and, in turn, for calculating transition rates. [Purpose] We propose a new no-core-configuration-interaction (NCCI) model treating properly isospin and rotational symmetries. The model is applicable to any nucleus irrespective of its mass and neutron- and proton-number parity. It properly includes polarization effects caused by an interplay between the long- and short-range forces acting in the atomic nucleus. [Methods] The method is based on solving the Hill-Wheeler-Griffin equation within a model space built of linearly-dependent states having good angular momentum and properly treated isobaric spin. The states are generated by means of the isospin and angular-momentum projection applied to a set of low-lying (multi)particle-(multi)hole deformed Slater determinants calculated using the self-consistent Skyrme-Hartree-Fock approach. [Results] The theory is applied to calculate energy spectra in N~Z nuclei that are relevant from the point of view of a study of superallowed Fermi beta-decays. In particular, a new set of the isospin-symmetry-breaking corrections to these decays is given. [Conclusions] It is demonstrated that the NCCI model is capable to capture main features of low-lying energy spectra in light and medium-mass nuclei using relatively small model space and without any local readjustment of its low-energy coupling constants. Its flexibility and a range of applicability makes it an interesting alternative to the conventional nuclear shell model.

   ↳ nucl-thnucl-exPRC(2016)·40 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.