Tue·Jul 15, 2014Tuesday·July 15, 2014

1. 01*

   Accurate correction of magnetic field instabilities for high-resolution isochronous mass measurements in storage rings

   P. Shuai🇨🇳 · H. S. Xu🇨🇳 · Y. H. Zhang🇨🇳 · Yu. A. Litvinov🇨🇳 · M. Wang🇨🇳 · X. L. Tu🇨🇳 · K. Blaum🇩🇪 · X. H. Zhou🇨🇳 · Y. J. Yuan🇨🇳 · G. Audi🇫🇷 · X. L. Yan🇨🇳 · X. C. Chen🇨🇳 and 11 other authors

   Isochronous mass spectrometry (IMS) in storage rings is a successful technique for accurate mass measurements of short-lived nuclides with relative precision of about $10^{-5}-10^{-7}$. Instabilities of the magnetic fields in storage rings are one of the major contributions limiting the achievable mass resolving power, which is directly related to the precision of the obtained mass values. A new data analysis method is proposed allowing one to minimise the effect of such instabilities. The masses of the previously measured at the CSRe ${}^{41}$Ti, ${}^{43}$V, ${}^{47}$Mn, ${}^{49}$Fe, ${}^{53}$Ni and ${}^{55}$Cu nuclides were re-determined with this method. An improvement of the mass precision by a factor of $\sim 1.7$ has been achieved for ${}^{41}$Ti and ${}^{43}$V. The method can be applied to any isochronous mass experiment irrespective of the accelerator facility. Furthermore, the method can be used as an on-line tool for checking the isochronous conditions of the storage ring.

   nucl-ex14 citations
2. 02*

   Photoproduction of the $\omega$ meson off the proton near threshold

   I. I. Strakovsky🇺🇸 · S. Prakhov🇩🇪 · Y. I. Azimov🇷🇺 · P. Aguar-Bartolome🇩🇪 · J. R. M. Annand🇬🇧 · H. J. Arends🇩🇪 · K. Bantawa🇺🇸 · R. Beck🇩🇪 · V. Bekrenev🇷🇺 · H. Berghaeuser🇩🇪 · A. Braghieri🇮🇹 · W. J. Briscoe🇺🇸 and 62 other authors

   An experimental study of $\omega$ photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The $\gamma p\to \omega p$ differential cross sections are measured from threshold to the incident-photon energy $E_{\gamma }=1.40$ GeV ($W=1.87$ GeV for the center-of-mass energy) with 15-MeV binning in $E_{\gamma }$ and full production-angle coverage. The quality of the present data near threshold gives access to a variety of interesting physics aspects. As an example, an estimation of the $\omega N$ scattering length ${\alpha }_{\omega p}$ is provided.

   nucl-exhep-exhep-phPRC(2015)·54 citations
3. 03*

   Multiple Parton Interactions with ALICE: from pp to p-Pb

   Andreas Morsch (ALICE Collaboration)🇨🇭

   The study of multiplicity dependent di-hadron angular correlations allows us to assess the contribution of multiple-parton interactions to particle production. We will review these measurements in pp and p-Pb collisions with the ALICE detector at the LHC and discuss the results in the context of centrality determination and other multiplicity dependent observables in p-Pb.

   nucl-exhep-exJ.Phys.Conf.Ser.(2014)·5 citations
4. 04*

   Measurement of the Transverse Single-Spin Asymmetries for ${\pi }^0$ and Jet-like Events at Forward Rapidities at STAR in $p+p$ Collisions at $\sqrt{s}$ = 500 GeV

   Mriganka Mouli Mondal (for the STAR Collaboration)🇺🇸

   Large transverse single-spin asymmetries ($A_N$) have been observed for forward inclusive hadron production in $p+p$ collisions at various experiments. In the collinear perturbative scattering picture, twist-3 multi-parton correlations can give rise to such an asymmetry. A transversely polarized quark can also give rise to a spin-dependent distribution of its hadron fragments via the higher twist effects or the Collins fragmentation function. The observed $A_N$ may involve contributions from both processes. These can be disentangled by studying asymmetries for jets, direct photons and jet-fragments. The STAR Forward Meson Spectrometer (FMS), a Pb-glass electromagnetic calorimeter covering the pseudo-rapidity ($\eta$) range 2.6-4.2 and full azimuth, can detect photons, neutral pions and eta mesons. We are measuring $A_N$ for ${\pi }^0$ and jet-like events reconstructed from photons in the FMS in $p+p$ collisions at $\sqrt{s}$ = 500 GeV that were recorded during the 2011 RHIC run. We study $A_N$ as a function of the number of observed photons in the FMS, thereby exploring asymmetries for a range of event classes. We further study $A_N$ for forward jets and its dependency on forward-midrapidity jet correlation. The current status of the analysis will be discussed.

   nucl-exPoS(2014)·16 citations
5. 05*

   Using L/E Oscillation Probability Distributions

   A. A. Aguilar-Arevalo🇲🇽 · B. C. Brown🇺🇸 · L. Bugel🇺🇸 · G. Cheng🇺🇸 · E. D. Church🇺🇸 · J. M. Conrad🇺🇸 · R. Dharmapalan🇺🇸 · Z. Djurcic🇺🇸 · D. A. Finley🇺🇸 · R. Ford🇺🇸 · F. G. Garcia🇺🇸 · G. T. Garvey🇺🇸 and 32 other authors

   This paper explores the use of $L/E$ oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, $L$ is the distance of neutrino travel and $E$ is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparisons, the $L/E$ distributions are shown to give qualitative information on the agreement of an experiment's data with a simple two-neutrino oscillation model. In more detail, this paper also outlines how the $L/E$ distributions can be best calculated and used for model comparisons. Specifically, the paper presents the $L/E$ data points for the final MiniBooNE data samples and, in the Appendix, explains and corrects the mistaken analysis published by the ICARUS collaboration.

   ↳ hep-exhep-phnucl-ex4 citations
6. 06*

   Spectroscopic factors of magic and semimagic nuclei within the self-consistent theory of finite Fermi systems

   N. V. Gnezdilov🇷🇺 · E. E. Saperstein🇷🇺 · S. V. Tolokonnikov🇷🇺

   A scheme is presented to find single-particle spectroscopic factors (SF) of magic and semimagic nuclei within the self-consistent theory of finite Fermi systems (TFFS). In addition to the energy dependence of the mass operator $\Sigma$ induced by the surface-phonon coupling effects which are commonly considered in this problem, the in-volume energy dependence of the operator $\Sigma$ inherent in the self-consistent TFFS is also taken into account. This dependence arises due to the effect of high-lying particle-hole excitations and persists in nuclear matter. The self-consistent basis of the energy density functional method by Fayans {\it et al.} is used. Both the surface and in-volume contributions to the SFs turned out to be of comparable magnitude. The results for magic ${}^{40,48}$Ca and ${}^{208}$Pb nuclei and semimagic lead isotopes are presented.

   ↳ nucl-thnucl-exEPL(2014)·7 citations
7. 07*

   Electromagnetic reactions on light nuclei

   Sonia Bacca🇨🇦 · Saori Pastore🇺🇸

   Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the calculated structure properties of nuclear targets. We present an overview on recent theoretical ab-initio calculations of electron-scattering and photonuclear reactions involving light nuclei. We encompass both the conventional approach and the novel theoretical framework provided by chiral effective field theories. Because both strong and electromagnetic interactions are involved in the processes under study, comparison with available experimental data provides stringent constraints on both many-body nuclear Hamiltonians and electromagnetic currents. We discuss what we have learned from studies on electromagnetic observables of light nuclei, starting from the deuteron and reaching up to nuclear systems with mass number A=16.

   ↳ nucl-thnucl-exJ.Phys.G(2014)·142 citations
8. 08*

   Three-body model calculation of the 2${}^{+}$ state in ${}^{26}$O

   K. Hagino🇯🇵 · H. Sagawa🇯🇵

   We discuss the energy of the excited 2${}^{+}$ state in the unbound nucleus ${}^{26}$O using the three-body model of ${}^{24}$O+$n$+$n$. This model fully takes into account the continuum effects as well as the dineutron correlation of the valence neutrons. The present calculation yields the energy of 1.354 MeV, which is slightly smaller than the unperturbed energy, 1.54 MeV. The energy shifts for the ground and the 2${}^{+}$ states with respect to the unperturbed energy suggest that 0${}^{+}$ and the 2${}^{+}$ states in ${}^{26}$O show a typical spectrum well described by a short-range pairing interaction acting on two valence nucleons in the same orbit.

   ↳ nucl-thnucl-exPRC(2014)·19 citations
9. 09*

   Exciting flavored bound states

   E. Rojas🇧🇷 · B. El-Bennich🇧🇷 · J. P. B. C. de Melo🇧🇷

   We study ground and radial excitations of flavor singlet and flavored pseudoscalar mesons within the framework of the rainbow-ladder truncation using an infrared massive and finite interaction in agreement with recent results for the gluon-dressing function from lattice QCD and Dyson-Schwinger equations. Whereas the ground-state masses and decay constants of the light mesons as well as charmonia are well described, we confirm previous observations that this truncation is inadequate to provide realistic predictions for the spectrum of excited and exotic states. Moreover, we find a complex conjugate pair of eigenvalues for the excited $D_{(s)}$ mesons, which indicates a non-Hermiticity of the interaction kernel in the case of heavy-light systems and the present truncation. Nevertheless, limiting ourselves to the leading contributions of the Bethe-Salpeter amplitudes, we find a reasonable description of the charmed ground states and their respective decay constants.

   ↳ nucl-thhep-exhep-lathep-ph+1PRD(2014)·71 citations
10. 10*

    Heavy flavor puzzle at RHIC: analysis of the underlying effects

    Magdalena Djordjevic🇷🇸 · Marko Djordjevic🇷🇸

    Suppressions of light and heavy flavor observables are considered to be excellent probes of QCD matter created in ultra-relativistic heavy ion collisions. Suppression predictions of quark and gluon jets appear to suggest a clear hierarchy according to which neutral pions should be more suppressed than D mesons, which in turn should be more suppressed than single electrons. However, joint comparison of neutral pion (light probe) and non-photonic single electron (heavy probe) suppression data at RHIC unexpectedly showed similar jet suppression for these two probes, which presents the well-known heavy flavor puzzle at RHIC. We here analyze which effects are responsible for this unexpected result, by using the dynamical energy loss formalism. We find that the main effect is a surprising reversal in the suppression hierarchy between neutral pions and D mesons, which is due to the deformation of the suppression patterns of light partons by fragmentation functions. Furthermore, we find that, due to the decay functions, the single electron suppression approaches the D meson suppression. Consequently, we propose that these two effects, taken together, provide a clear intuitive explanation of this longstanding puzzle.

    ↳ nucl-thhep-phnucl-exPRC(2014)·29 citations
11. 11*

    Hot strong matter

    Katarzyna Grebieszkow🇵🇱

    The recent results on relativistic heavy-ion collisions are discussed. The most convincing quark-gluon plasma signatures at the LHC and the top RHIC energies are presented. Moreover, the possible methods of evaluating the energy threshold for deconfinement (onset of deconfinement) are described, and the corresponding results from the RHIC Beam Energy Scan and the SPS programs are shown. Additionally, the first signatures of creating dense and collectively behaving systems in collisions of small nuclei (or even in elementary interactions) are discussed. Finally, the current status of experimental search for the critical point of strongly interacting matter is summarized.

    ↳ hep-exnucl-exPoS(2014)·3 citations
12. 12*

    Development of a highly pixelated direct charge sensor, Topmetal-I, for ionizing radiation imaging

    Yan Fan🇨🇳 · Chaosong Gao🇨🇳 · Guangming Huang🇨🇳 · Xiaoting Li🇨🇳 · Yuan Mei🇺🇸 · Hua Pei🇨🇳 · Quan Sun🇨🇳 · Xiangming Sun🇺🇸 · Dong Wang🇨🇳 · Zhen Wang🇨🇳 · Le Xiao🇨🇳 · Ping Yang🇨🇳

    Using industrial standard 0.35{\mu}m CMOS Integrated Circuit process, we realized a highly pixelated sensor that directly collects charge via metal nodes placed on the top of each pixel and forms two dimensional images of charge cloud distribution. The first version, Topmetal-I, features a 64x64 pixel array of 80{\mu}m pitch size. Direct charge calibration reveals an average capacitance of 210fF per pixel. The charge collection noise is near the thermal noise limit. With the readout, individual pixel channels exhibit a most probable equivalent noise charge of 330e-.

    ↳ physics.ins-dethep-exnucl-exphysics.med-ph8 citations
13. 13*

    Hadronic contributions to the muon anomalous magnetic moment Workshop. $(g-2{)}_{\mu }$: Quo vadis? Workshop. Mini proceedings

    Maurice Benayoun · Johan Bijnens · Tom Blum · Irinel Caprini · Gilberto Colangelo · Henryk Czyż · Achim Denig · Cesareo A. Dominguez · Simon Eidelman · Christian S. Fischer · Paolo Gauzzi · Yuping Guo and 28 other authors

    We present the mini-proceedings of the workshops Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of the accuracy of the theoretical prediction and $(g-2{)}_{\mu }$: Quo vadis?, both held in Mainz from April 1${}^{\mathrm{rst}}$ to 5${}^{\mathrm{th}}$ and from April 7${}^{\mathrm{th}}$ to 10${}^{\mathrm{th}}$, 2014, respectively.

    ↳ hep-phhep-exhep-latnucl-ex+184 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.