Thu·Oct 8, 2015Thursday·October 8, 2015

1. 01*

   A Study of a Mini-drift GEM Tracking Detector

   B. Azmoun🇺🇸 · B. DiRuzza🇺🇸 · A. Franz🇺🇸 · A. Kiselev🇺🇸 · R. Pak🇺🇸 · M. Phipps🇺🇸 · M.L. Purschke🇺🇸 · C. Woody🇺🇸

   A GEM tracking detector with an extended drift region has been studied as part of an effort to develop new tracking detectors for future experiments at RHIC and for the Electron Ion Collider that is being planned for BNL or JLAB. The detector consists of a triple GEM stack with a small drift region that was operated in a mini TPC type configuration. Both the position and arrival time of the charge deposited in the drift region were measured on the readout plane which allowed the reconstruction of a short vector for the track traversing the chamber. The resulting position and angle information from the vector could then be used to improve the position resolution of the detector for larger angle tracks, which deteriorates rapidly with increasing angle for conventional GEM tracking detectors using only charge centroid information. Two types of readout planes were studied. One was a COMPASS style readout plane with 400 micron pitch XY strips and the other consisted of 2x10mm2 chevron pads. The detector was studied in test beams at Fermilab and CERN, along with additional measurements in the lab, in order to determine its position and angular resolution for incident track angles up to 45 degrees. Several algorithms were studied for reconstructing the vector using the position and timing information in order to optimize the position and angular resolution of the detector for the different readout planes. Applications for large angle tracking detectors at RHIC and EIC are also discussed.

   ↳ physics.ins-detnucl-exIEEE Trans.Nucl.Sci.(2016)·7 citations
2. 02*

   Looking for a hidden-charm pentaquark state with strangeness $S=-1$ from ${\Xi }_b^{-}$ decay into $J/\psi K^{-}\Lambda$

   Hua-Xing Chen🇨🇳 · Li-Sheng Geng🇨🇳 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸 · En Wang🇨🇳 · Ju-Jun Xie🇨🇳

   Assuming that the recently observed hidden-charm pentaquark state, $P_c(4450)$, is of molecular nature as predicted in the unitary approach, we propose to study the decay of ${\Xi }_b^{-}\to J/\psi K^{-}\Lambda$ to search for the strangeness counterpart of the $P_c(4450)$. There are three ingredients in the decay mechanism: the weak decay mechanism, the hadronization mechanism, and the finite state interactions in the meson-baryon system of strangeness $S=-2$ and isospin $I=1/2$ and of the $J/\psi \Lambda$. All these have been tested extensively. As a result, we provide a genuine prediction of the differential cross section where a strangeness hidden-charm pentaquark state, the counterpart of the $P_c(4450)$, can be clearly seen. The decay rate is estimated to be of similar magnitude as the ${\Lambda }_b^0\to J/\psi K^{-}p$ observed by the LHCb collaboration.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2016)·123 citations
3. 03*

   Theory status of quarkonium production in proton-nucleus collisions

   J.P. Lansberg🇫🇷

   I give a brief overview of the recent theoretical progress in the study of quarkonium production in proton-nucleus collisions in view of the recent LHC and RHIC results. A special emphasis is put on the excited states such as the psi', Upsilon(2S) and Upsilon(3S).

   ↳ nucl-thhep-exhep-phnucl-exJ.Phys.Conf.Ser.(2016)·4 citations
4. 04*

   Accessing transversity GPDs in neutrino-production of a charmed meson

   B. Pire🇫🇷 · L. Szymanowski🇵🇱

   We demonstrate that the transversity chiral odd generalized parton distributions can be accessed through the azimuthal dependence of the nu N -> l D N' or nubar N -> l D N' differential cross sections, in the framework of the colinear QCD approach, where GPDs factorize from perturbatively calculable coefficient functions calculated up to order mc/Q.

   ↳ hep-phhep-exnucl-exnucl-thActa Phys.Polon.Supp.(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.