Tue·Nov 14, 2017Tuesday·November 14, 2017

1. 01*

   Systematic study of high $p_{\mathrm{T}}$ hadron production in small collision systems by the PHENIX experiment at RHIC

   Takao Sakaguchi (for the PHENIX collaboration)🇺🇸

   High $p_{\mathrm{T}}$ hadrons in the small systems of $d{/}^3$He+Au and $p$+Al/Au collisions have been measured at the midrapidity ($|\eta |<0.35$) as well as at the forward and backward rapidities ($1.2<|\eta |<2.4$) at $\sqrt{s_{NN}}$=200GeV. A clear system and centrality ordering in the $R_{p/d/\mathrm{HeA}}$ was observed for midrapidity ${\pi }^0$ production. Hadron $R_{\mathrm{cp}}$ as a function of rapidity in forward and backward regions show an opposite trend to what HIJING++ predicted. Together with the difference of $R_{\mathrm{cp}}$ in $p$+Al/Au collisions, the observation can be understood consistently with the measured long-range two-particle correlations, hinting the possible medium creation similar to A+A collisions.

   nucl-exhep-exEPJ Web Conf.(2018)·1 citation
2. 02*

   The KDK (potassium decay) experiment

   P.C.F. Di Stefano🇨🇦 · N. Brewer🇺🇸 · A. Fijałkowska🇺🇸 · Z. Gai🇺🇸 · K.C. Goetz🇺🇸 · R. Grzywacz🇺🇸 · D. Hamm🇺🇸 · P. Lechner🇩🇪 · Y. Liu🇨🇳 · E. Lukosi🇺🇸 · M. Mancuso🇩🇪 · C. Melcher🇺🇸 and 11 other authors

   Potassium-40 (${}^{40}$K) is a background in many rare-event searches and may well play a role in interpreting results from the DAMA dark-matter search. The electron-capture decay of ${}^{40}$K to the ground state of ${}^{40}$Ar has never been measured and contributes an unknown amount of background. The KDK (potassium decay) collaboration will measure this branching ratio using a ${}^{40}$K source, an X-ray detector, and the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory.

   nucl-exphysics.ins-detJ.Phys.Conf.Ser.(2020)·3 citations
3. 03*

   Coulomb interaction on pion production in Au+Au collisions at relativistic energies

   Catalin Ristea🇷🇴 · Oana Ristea🇷🇴 · Alexandru Jipa🇷🇴

   Coulomb effects on charged pion transverse momentum spectra produced in Au+Au collisions at RHIC-BES energies are investigated. From these spectra the {\pi}-/{\pi}+ ratios as a function of transverse momentum are obtained and used to extract the Coulomb kick (a momentum change due to Coulomb interaction) and initial pion ratio for three different collision energies and various centrality classes. The Coulomb kick shows a decrease with the increase of beam energy and a clear centrality dependence, with larger values for the most central collisions. The results are connected with the kinetic freeze-out dynamics and discussed.

   nucl-ex0 citations
4. 04*

   Nuclear medium modifications of properties of kaons measured around threshold with FOPI

   K. Piasecki (FOPI Collaboration)🇵🇱

   We report on the investigation of modifications of basic properties of K${}^{+}$ and K${}^{-}$ mesons emitted from collisions of Ni+Ni at beam energy of 1.91A GeV. Experimental K${}^{-}$/K${}^{+}$ ratio are presented in a wide range of phase space parameterized by kinetic energy and emission angle in the nucleon-nucleon centre of mass. The $v_1$ component of the azimuthal distribution was extracted as a function of rapidity and transverse momentum for central, and semi-peripheral collisions. A comparison of these patterns with the HSD transport model favours the existence of the kaon-nucleon in-medium potential. For the IQMD model, this interaction scenario is confirmed in case of K${}^{-}$, whereas for K${}^{+}$ the picture is less clear.

   nucl-exPoS(2017)·0 citations
5. 05*

   Inclusive heavy quark photoproduction in $pp$, $pPb$ and $PbPb$ collisions at Run 2 LHC energies

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

   In this paper we present a comprehensive analysis of the inclusive heavy quark photoproduction in $pp$, $pPb$ and $PbPb$ collisions at Run 2 LHC energies using the Color Dipole formalism. The rapidity distributions and total cross sections for the charm and bottom production are estimated considering the more recent phenomenological models for the dipole - proton scattering amplitude, which are based on the Color Glass Condensate formalism and are able to describe the inclusive and exclusive $ep$ HERA data. Moreover, we present, by the first time, the predictions for the transverse momentum distributions of the $D$ and $B$ mesons produced in the photon -- induced interactions.

   ↳ hep-phhep-exnucl-exnucl-thNPA(2018)·20 citations
6. 06*

   Insight into particle production mechanisms via angular correlations of identified particles measured with ALICE in pp collisions at $\sqrt{\text{s}}=7$ TeV

   Małgorzata Anna Janik (for the ALICE Collaboration)🇵🇱

   Two-particle correlations as a function of $\Delta \eta$ and $\Delta \phi$ are used in all collision systems to study a wide range of physical phenomena. Examples include the collective behavior of the quark-gluon plasma medium, jets, quantum statistics or Coulomb effects, conservation laws, and resonance decays. In this work, measurements of the correlations of identified particles and their antiparticles (for $\pi$, K, p, $\Lambda$) are reported in pp collisions at $\sqrt{s}=7$ TeV at low transverse momenta. The analysis reveals differences in particle production between baryons and mesons. The correlation functions for mesons exhibit the expected peak dominated by effects of mini-jet fragmentation and are reproduced well by general purpose Monte Carlo generators. For baryon pairs where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak; our experimental observation present a challenge to the contemporary models (PYTHIA, PHOJET). This effect is further interpreted in the context of baryon production mechanisms in the fragmentation processes.

   ↳ hep-exnucl-exEPJ Web Conf.(2018)·1 citation
7. 07*

   Nonmesonic weak decay of charmed hypernuclei

   C. E. Fontoura🇧🇷 · F. Krmpotić🇦🇷 · A. P. Galeão🇧🇷 · C De Conti🇧🇷 · G. Krein🇧🇷

   We present a study of the nonmesonic weak decay (NMWD) of charmed hypernuclei using a relativistic formalism. We work within the framework of the independent particle shell model and employ a ($\pi$,$K$) one-meson-exchange model for the decay dynamics. We implement a fully relativistic treatment of nuclear recoil. Numerical results are obtained for the one-neutron-induced transition NMWD rates of the ${}_{{\Lambda }_c^{+}}^{12}$N. The effect of nuclear recoil is sizable and goes in the direction to decrease the nuclear decay rate. We found that the NMWD decay rate of ${}_{{\Lambda }_c^{+}}^{12}$N is of the same order of magnitude as the partial decay rate for the corresponding mesonic decay ${\Lambda }_c^{+}\to \Lambda +{\pi }^{+}$, suggesting the feasibility of experimental detection of such heavy-flavor nuclear processes.

   ↳ nucl-thhep-latnucl-exJ.Phys.G(2018)·4 citations
8. 08*

   Exclusive neutrino-production of a charmed vector meson and transversity gluon GPDs

   B. Pire🇫🇷 · L. Szymanowski🇵🇱

   We calculate at the leading order in ${\alpha }_s$ the QCD amplitude for exclusive neutrino production of a $D^{\ast }$ or $D_s^{\ast }$ charmed vector meson on a nucleon. We work in the framework of the collinear QCD approach where generalized parton distributions (GPDs) factorize from perturbatively calculable coefficient functions. We include $O(m_c)$ terms in the coefficient functions and $O(m_D)$ term in the definition of heavy meson distribution amplitudes. The show that the analysis of the angular distribution of the decay $D_{(s)}^{\ast }\to D_{(s)}\pi$ allows to access the transversity gluon GPDs.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2017)·21 citations
9. 09*

   Demonstration of Single Barium Ion Sensitivity for Neutrinoless Double Beta Decay using Single Molecule Fluorescence Imaging

   A.D.McDonald · B.J.P. Jones🇺🇸 · D.R.Nygren · C. Adams🇺🇸 · V.Alvarez · C.D.R. Azevedo🇵🇹 · J.M. Benlloch-Rodrıguez · F.I.G.M. Borges🇵🇹 · A. Botas🇪🇸 · S. Carcel🇪🇸 · J.V. Carrion🇪🇸 · S. Cebrian🇪🇸 and 62 other authors

   A new method to tag the barium daughter in the double beta decay of ${}^{136}$Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba${}^{++}$) resolution at a transparent scanning surface has been demonstrated. A single-step photo-bleach confirms the single ion interpretation. Individual ions are localized with super-resolution ($\sim$2~nm), and detected with a statistical significance of 12.9~$\sigma$ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

   ↳ physics.ins-dethep-exnucl-exPRL(2018)·73 citations
10. 10*

    Monte Carlo Simulation Of Active Neutron Interrogation System Developed For Detection Of Illicit Materials

    A.Sh. Georgadze

    Nowadays, the current threat of international terrorism is set to a severe level, demanding worldwide enhanced security. Radioactive materials that could be fashioned into a radiation dispersal device typically emit gamma rays, while fissile materials such as uranium and plutonium emit both neutrons and gamma rays via spontaneous or induced fission. Therefore, the detection and identification of hazardous materials has become increasingly important. We present the results of GEANT4 Monte Carlo simulation of an active neutron interrogation system based on highly segmented neutron/gamma-ray detector and pulsed neutron generator. This system is capable of detecting and imaging radioactive and special nuclear materials, explosives and drugs. The segmented scintillation detector works as a scatter camera, allowing selection of a gamma ray events that undergo multiple interaction in detector blocks for radioactive source localization. The detector consist of blocks made of plastic scintillator which provide scattering and blocks of CsI, used as an absorber, used as an absorber, which has to be efficient to detect the characteristic gamma radiation for the identification. Because of this imaging capability background events can be significantly rejected, decreasing the number of events required for high confidence detection and thereby greatly improving its sensitivity. A scatter imager for the detection of shielded radioactive materials has been conceptualized, simulated, and refined to maximize sensitivity while minimizing cost.

    ↳ physics.ins-detnucl-exActa Phys.Polon.B(2017)·0 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.