Tue·Sep 30, 2014Tuesday·September 30, 2014

1. 01*

   A White Paper on SoLID (Solenoidal Large Intensity Device)

   J.P. Chen · H. Gao · T.K. Hemmick · Z.-E. Meziani · P.A. Souder · the SoLID Collaboration

   In order to fully exploit the physics potential of Jefferson Lab after 12 GeV energy upgrade, a new Solenoidal Large Acceptance Device (SoLID) is proposed. The SoLID spectrometer, with its unique capability of large acceptance and high luminosity, is ideal for precision measurements in semi-inclusive DIS to study transverse spin and transverse-momentum-dependent parton distributions of the nucleon, and for parity-violating Deep Inelastic Scattering (DIS) to perform precision tests of the Standard Model at low energy as well as addressing specific issues in nucleon structure including charge symmetry violation, d/u ratio and higher-twist effects due to di-quark. SoLID is also essential for precision measurements of J/\psi electroproduction in the threshold region to study non-perturbative gluon dynamics and interaction. Five highly rated SoLID experiments and two "run group" experiments have been approved by the JLab Physics Advisory Committee. The physics program is presented along with an overview of the SoLID instrumentation and its current status.

   nucl-ex87 citations
2. 02*

   Cross-section measurement of the ${}^{130}$Ba(p,$\gamma$)${}^{131}$La reaction for $\gamma$-process nucleosynthesis

   L. Netterdon🇩🇪 · A. Endres🇩🇪 · G. G. Kiss🇭🇺 · J. Mayer🇩🇪 · T. Rauscher🇬🇧 · P. Scholz🇩🇪 · K. Sonnabend🇩🇪 · Zs. Török🇭🇺 · A. Zilges🇩🇪

   A measurement of total cross-section values of the ${}^{130}$Ba(p,$\gamma$)${}^{131}$La reaction at low proton energies allows a stringent test of statistical model predictions with different proton+nucleus optical model potentials. Since no experimental data are available for proton-capture reactions in this mass region around A~$\approx$~130, this measurement can be an important input to test the global applicability of proton+nucleus optical model potentials. The total reaction cross-section values were measured by means of the activation method. After the irradiation with protons, the reaction yield was determined by use of $\gamma$-ray spectroscopy using two clover-type high-purity germanium detectors. In total, cross-section values for eight different proton energies could be determined in the energy range between 3.6 MeV $\le E_p\le$ 5.0 MeV, thus, inside the astrophysically relevant energy region. The measured cross-section values were compared to Hauser-Feshbach calculations using the statistical model codes TALYS and SMARAGD with different proton+nucleus optical model potentials. With the semi-microscopic JLM proton+nucleus optical model potential used in the SMARAGD code, the absolute cross-section values are reproduced well, but the energy dependence is too steep at the lowest energies. The best description is given by a TALYS calculation using the semi-microscopic Bauge proton+nucleus optical model potential using a constant renormalization factor.

   nucl-exPRC(2014)·18 citations
3. 03*

   Inclusive J/$\psi$ and $\psi$(2S) production in pp and p-Pb collisions at forward rapidity with ALICE at the LHC

   Biswarup Paul (for the ALICE Collaboration)🇮🇳

   The ALICE collaboration has studied inclusive J/$\psi$ and $\psi$(2S) production at forward rapidities in pp collisions at $\sqrt{s}=7$ TeV with the ALICE Muon Spectrometer. The analysis has been carried out on a data sample corresponding to an integrated luminosity ${\mathcal{L}}_{\mathrm{int}}$ = 1.35 pb${}^{-1}$. The production cross-sections of J/$\psi$ and $\psi$(2S), integrated over the transverse momentum (0 $<$ $p_{\mathrm{T}}$ $<$ 20 GeV/$c$) and rapidity (2.5 $<$ $y$ $<$ 4), have been measured. The J/$\psi$ and $\psi$(2S) differential cross-sections, in transverse momentum and rapidity, have also been measured, significantly extending the $p_{\mathrm{T}}$ reach of previous measurements performed in the same $y$-range. The results have been compared with the previously published ALICE results (${\mathcal{L}}_{\mathrm{int}}$ = 15.6 nb${}^{-1}$) and also with the measurement performed by the LHCb collaboration. The $\psi$(2S)/J/$\psi$ ratio, integrated over $p_{\mathrm{T}}$ and $y$, has been measured. This ratio has also been evaluated as a function of transverse momentum and rapidity and compared with the LHCb measurement. Finally, recent results on cross-sections, $\psi$(2S)/J/$\psi$ production ratio, nuclear modification factor ($R_{\mathrm{pPb}}$) and forward-to-backward yield ratio ($R_{\mathrm{FB}}$) in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV will be discussed.

   nucl-exProc.Indian Natl.Sci.Acad.(2015)·2 citations
4. 04*

   Gradient Correction to Photon Emission Rate at Strong Coupling

   Kiminad A. Mamo🇺🇸 · Ho-Ung Yee🇺🇸

   We compute the correction to the photon emission rate in first order of shear components of fluid velocity gradients, ${\sigma }_{ij}$, in near-equilibrium hydrodynamic plasma at strong coupling regime, using the real-time Schwinger-Keldysh formalism in AdS/CFT correspondence. Our result is an integral of an analytic expression. We observe that the gradient correction to the photon emission rate at strong coupling is about 0.3 - 0.4 times of the equilibrium rate in units of ${\sigma }_{ij}/T$.

   ↳ nucl-thhep-phhep-thnucl-exPRD(2015)·5 citations
5. 05*

   Hadron production measurements to constrain accelerator neutrino beams

   Alexander Korzenev🇨🇭

   A precise prediction of expected neutrino fluxes is required for a long-baseline accelerator neutrino experiment. The flux is used to measure neutrino cross sections at the near detector, while at the far detector it provides an estimate of the expected signal for the study of neutrino oscillations. In the talk several approaches to constrain the neutrino flux are presented. The first is the traditional one when an interaction chain for the neutrino parent hadrons is stored to be weighted later with real measurements. In this approach differential hadron cross sections are used which, in turn, are measured in ancillary hadron production experiments. The approach is certainly model dependent because it requires an extrapolation to different incident nucleon momenta assuming x_F scaling as well as extrapolation between materials having different atomic numbers. In the second approach one uses a hadron production yields off a real target exploited in the neutrino beamline. Yields of neutrino parent hadrons are parametrized at the surface of the target, thus one avoids to trace the particle interaction history inside the target. As in the case of the first approach, a dedicated ancillary experiment is mandatory. Recent results from the hadron production experiments - NA61/SHINE at CERN (measurements for T2K) and MIPP at Fermilab (measurements for NuMI) - are reviewed.

   ↳ hep-exnucl-exphysics.ins-detAIP Conf.Proc.(2015)·4 citations
6. 06*

   Momentum scale dependence of the net quark number fluctuations near chiral crossover

   Kenji Morita🇯🇵 · Krzysztof Redlich🇵🇱

   We investigate properties of the net baryon number fluctuations near chiral crossover in a hot and dense medium of strongly interacting quarks. The chirally invariant quark-antiquark interactions are modeled by an effective quark-meson Lagrangian. To preserve remnants of criticality in the O(4) universality class, we apply the functional renormalization group method to describe thermodynamics near chiral crossover. Our studies are focused on the influence of the momentum cuts on the critical behavior of different cumulants of the net quark number fluctuations. We use the momentum scale dependence of the flow equation to examine how the suppression of the momentum modes in the infrared and ultraviolet regime modifies generic properties of fluctuations expected in the O(4) universality class. We show, that the pion mass $m_{\pi }$ is a natural soft momentum scale at which cumulants are saturated at their critical values, whereas for scales larger than $2m_{\pi }$ the characteristic O(4) structure of the higher order cumulants get lost. These results indicate, that when measuring fluctuations of the net baryon number in heavy ion collisions to search for a partial restoration of chiral symmetry or critical point, a special care have to be made when introducing kinematical cuts on the fluctuation measurements.

   ↳ hep-phnucl-exnucl-thPTEP(2015)·13 citations
7. 07*

   Examination of the stability of a rod-shaped structure in ${}^{24}$Mg

   Yoritaka Iwata🇩🇪 · Takatoshi Ichikawa🇯🇵 · Naoyuki Itagaki🇯🇵 · Joachim A. Maruhn🇩🇪 · Takaharu Otsuka🇯🇵

   The stable existence of a six-$\alpha$ linear structure in highly excited states of ${}^{24}$Mg is studied based on a systematic Cranked Hartree-Fock calculation with various Skyrme-type interactions. Its stability is examined by allowing the transition of the cluster structure to the shell-model like structure. Especially, the six-$\alpha$ linear state is exposed to two major instabilities: the bending motion, which is the main path for the transition to low-lying states, and the spin-orbit interaction, which is the driving force to break the $\alpha$ clusters and enhance the independent motion of the nucleons. The linear structure with large angular momentum is obtained as a meta-stable stationary state.

   ↳ nucl-thnucl-exPRC(2015)·19 citations
8. 08*

   Extracting femtoscopic radii in the presence of significant additional correlation sources

   Łukasz Kamil Graczykowski🇵🇱 · Adam Kisiel🇵🇱 · Małgorzata Anna Janik🇵🇱 · Przemysław Karczmarczyk🇵🇱

   The Large Hadron Collider has provided large amounts of data on collisions of small systems, such as proton-proton and proton-lead at unprecedented collision energies. Their space-time size and structure can be inferred from the measurement of the femtoscopic correlations for pairs of identical particles. The analysis is complicated by the presence of significant additional sources of two-particle correlations, which influence the correlation function in the region of the femtoscopic effect. In this work we use p-Pb events generated in a model that includes such additional correlation sources to characterize them and propose a robust method of taking them into account in the extraction of the femtoscopic information.

   ↳ nucl-thnucl-exActa Phys.Polon.B(2014)·4 citations
9. 09*

   The iEBE-VISHNU code package for relativistic heavy-ion collisions

   Chun Shen (Ohio State and McGill Univ.)🇺🇸 · Zhi Qiu (Ohio State)🇺🇸 · Huichao Song (Ohio State and Peking Univ.)🇨🇳 · Jonah Bernhard (Duke Univ.)🇺🇸 · Steffen Bass (Duke Univ.)🇺🇸 · Ulrich Heinz (Ohio State)🇺🇸

   The iEBE-VISHNU code package performs event-by-event simulations for relativistic heavy-ion collisions using a hybrid approach based on (2+1)-dimensional viscous hydrodynamics coupled to a hadronic cascade model. We present the detailed model implementation, accompanied by some numerical code tests for the package. iEBE-VISHNU forms the core of a general theoretical framework for model-data comparisons through large scale Monte-Carlo simulations. A numerical interface between the hydrodynamically evolving medium and thermal photon radiation is also discussed. This interface is more generally designed for calculations of all kinds of rare probes that are coupled to the temperature and flow velocity evolution of the bulk medium, such as jet energy loss and heavy quark diffusion.

   ↳ nucl-thhep-phnucl-exComput.Phys.Commun.(2016)·603 citations
10. 10*

    Yield estimation of neutron-rich rare isotopes induced by 200 MeV/u ${}^{132}$Sn beams by using GEANT4

    Jae Won Shin🇰🇷 · Kyung Joo Min · Cheolmin Ham🇰🇷 · Tae-Sun Park🇰🇷 · Seung-Woo Hong🇰🇷

    A so-called "two-step reaction scheme", in which neutron-rich rare isotopes obtained from ISOL are post-accelerated and bombarded on a second target, is employed to estimate the production yields of exotic rare isotopes. The production yields of neutron-rich rare isotope fragments induced by 200 MeV/u ${}^{132}$Sn beams bombarded on a ${}^9$Be target are estimated with Monte Carlo code, GEANT4. To substantiate the use of GEANT4 for this study, benchmark calculations are done for 80 MeV/u ${}^{59}$Co, 95 MeV/u ${}^{72}$Zn, 500 MeV/u ${}^{92}$Mo, and 950 MeV/u ${}^{132}$Sn beams on the ${}^9$Be target. It is found that ${}^{132}$Sn beams can produce neutron-rich rare isotopes with 45 $\le$ Z $\le$ 50 more effectively than ${}^{238}$U beams at the same energy per nucleon.

    ↳ physics.comp-phnucl-exphysics.acc-phNucl.Instrum.Meth.B(2015)·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.