Tue·Jul 29, 2014Tuesday·July 29, 2014

1. 01*

   First Measurement of the $\Sigma$ Beam Asymmetry in ${\eta }^{\prime }$ Photoproduction off the Proton near Threshold

   P. Levi Sandri🇮🇹 · G. Mandaglio🇮🇹 · V. De Leo🇮🇹 · O. Bartalini🇮🇹 · V. Bellini🇮🇹 · J.P. Bocquet🇫🇷 · M. Capogni🇮🇹 · F. Curciarello🇮🇹 · A. D'Angelo🇮🇹 · J.P. Didelez🇫🇷 · R. Di Salvo🇮🇹 · A. Fantini🇮🇹 and 24 other authors

   The $\Sigma$ beam asymmetry in ${\eta }^{\prime }$ photoproduction off the proton was measured at the GrAAL polarised photon beam with incoming photon energies of 1.461 and 1.480 GeV. For both energies the asymmetry as a function of the meson production angle shows a clear structure, more pronounced at the lowest one, with a change of sign around 90${}^o$. The observed behaviour is compatible with P-wave D-wave (or S-wave F-wave) interference, the closer to threshold the stronger. The results are compared to the existing state-of-the-art calculations that fail to account for the data.

   nucl-exEPJA(2015)·39 citations
2. 02*

   Inclusive Psi(2S) production in p-Pb collisions with ALICE

   Roberta Arnaldi (for the ALICE Collaboration)🇮🇹

   The ALICE Collaboration has studied the inclusive $\psi (2S)$ production in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV at the CERN LHC. Measurements are performed, in the ${\mu }^{+}{\mu }^{-}$ decay channel, in a forward (2.03$<y_{\mathrm{cms}}<$3.53) and in a backward (-4.46$<y_{\mathrm{cms}}<$-2.96) centre of mass rapidity ranges, as a function of transverse momentum or event activity. The $\psi (2S)$ production is compared to the $J/\psi$ one through the double ratio $[{\sigma }_{\psi (2S)}/{\sigma }_{J/\psi }{]}_{\mathrm{pPb}}/[{\sigma }_{\psi (2S)}/{\sigma }_{J/\psi }{]}_{\mathrm{pp}}$ between the cross sections evaluated in p-Pb and pp collisions and by calculating the $J/\psi$ and $\psi (2S)$ nuclear modification factors. Results indicate that the $\psi (2S)$ production is suppressed with respect to pp and, in particular in the backward rapidity region, the suppression is stronger than the $J/\psi$ one. This unexpected difference between the $J/\psi$ and $\psi (2S)$ behaviour, not accounted for by theoretical models based on nuclear parton shadowing and coherent energy loss mechanisms, indicates the presence of sizeable final state effects on the $\psi (2S)$ production.

   nucl-exNPA(2014)·16 citations
3. 03*

   Measurement of the ionization yield of nuclear recoils in liquid argon at 80 and 233 keV

   A. Bondar🇷🇺 · A. Buzulutskov🇷🇺 · A. Dolgov🇷🇺 · E. Grishnyaev🇷🇺 · S. Polosatkin🇷🇺 · L. Shekhtman🇷🇺 · E. Shemyakina🇷🇺 · A. Sokolov🇷🇺

   The energy calibration of nuclear recoil detectors is of primary importance to rare-event experiments such as those of direct dark matter search and coherent neutrino-nucleus scattering. In particular, such a calibration is performed by measuring the ionization yield of nuclear recoils in liquid Ar and Xe detection media, using neutron elastic scattering off nuclei. In the present work, the ionization yield for nuclear recoils in liquid Ar has for the first time been measured in the higher energy range, at 80 and 233 keV, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The ionization yield in liquid Ar at an electric field of 2.3 kV/cm amounted to 7.8+/-1.1 and 9.7+/-1.3 e-/keV at 80 and 233 keV respectively. The Jaffe model for nuclear recoil-induced ionization, in contrast to that Thomas-Imel, can probably consistently describe the energy dependence of the ionization yield.

   ↳ physics.ins-dethep-exnucl-exEPL(2014)·15 citations
4. 04*

   Associated-quarkonium production

   J.P. Lansberg🇫🇷

   We discuss the growing interest to measure associated-quarkonium production in a number of channels at the LHC. Whereas back-to-back production of quarkonium + isolated photon provides a unique way to extract gluon TMDs, observables such as quarkonium + W/Z can be of great help to better understand the quarkonium production mechanism as well as to shed light on double-parton scatterings. Along these lines, we also argue that quarkonium-pair production is a potentially rich source of information which only has started to be harvested. Finally, we discuss the relevance of studying the production of quarkonium + heavy-quark, as e.g. J/psi + charm and Upsilon + non-prompt J/psi.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2014)·1 citation
5. 05*

   Test of a single module of the J-PET scanner based on plastic scintillators

   P. Moskal🇵🇱 · Sz. Niedźwiecki🇵🇱 · T. Bednarski🇵🇱 · E. Czerwiński🇵🇱 · Ł. Kapłon🇵🇱 · E. Kubicz🇵🇱 · I. Moskal🇵🇱 · M. Pawlik-Niedźwiecka🇵🇱 · N.G. Sharma🇵🇱 · M. Silarski🇵🇱 · M. Zieliński🇵🇱 · N. Zoń🇵🇱 and 18 other authors

   Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this article we report on tests of a single detection module built out from BC-420 plastic scintillator strip (with dimensions of 5x19x300mm^3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50ps intervals. The time resolution of the prototype module was established to be better than 80ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93cm (sigma) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to sigma(E)/E = 0.044/sqrt(E[MeV]) and corresponds to the sigma(E)/E of 7.5% at the Compton edge.

   ↳ physics.ins-dethep-exnucl-exphysics.med-phNucl.Instrum.Meth.A(2014)·135 citations
6. 06*

   The $\bar{p}p\to \varphi \varphi$ reaction in an effective Lagrangian approach

   Ju-Jun Xie🇨🇳 · Li-Sheng Geng🇨🇳 · Xu-Rong Chen🇨🇳

   We investigate the $\bar{p}p\to \varphi \varphi$ reaction within an effective Lagrangian approach.We show that the inclusion of either a scalar meson $f_0$ or a tensor meson $f_2$ in the $s$-channel can lead to a fairly good description of the bump structure of the total cross section around the invariant $\bar{p}p$ mass $W\simeq 2.2$ GeV, which cannot be reproduced with only the "background" contributions from $t$- and $u$-channel $N^{\ast }(1535)$ resonance as studied in a previous work. From the fits, we infer the properties of the involved scalar or tensor resonances.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2014)·7 citations
7. 07*

   Strong decays of higher excited heavy-light mesons in a chiral quark model

   Li-Ye Xiao🇨🇳 · Xian-Hui Zhong🇨🇳

   The strong decay properties of the higher excited heavy-light mesons from the first radially excited states up to the first $F$-wave states are studied in a constituent quark model. It is found many missing excitations have good potentials to be found in future experiments for their narrow widths, some of them dominantly decay into the first orbital excitations rather than into ground states. In future observations, one should focus on the decay processes not only into the ground states, but also into the low-lying $P$-wave excitations with $J^P=0^{+},1^{+}$. Furthermore, the nature of the newly observed states $D_J(3000)$, $D_J^{\ast }(3000)$ and B(5970) is discussed. It is predicted that $D_J(3000)$ seems to be a partner of $D_{sJ}(3040)$, which could be identified as the high-mass mixed state $|2P_1{>}_L$ ($J^P=1^{+}$) via the $2^1{P}_1$-$2^3{P}_1$ mixing. The $D_J^{\ast }(3000)$ resonance seems to favor the $1^3{F}_4$ state, however, the quantum numbers $J^P=0^{+}$ and $2^{+}$ can not be excluded complectly, more experimental observations are needed to determine its $J^P$ values. The B(5970) resonance is most likely to be the $1^3{D}_3$ with $J^P=3^{-}$.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2014)·57 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.