In the Jefferson Lab E12-16-007 (J/psi-007) experiment we measured the differential J/psi photo-production cross section as a function of photon energy, E_gamma and Mandelstam variable t - the momentum transfer from the initial photon to the produced J/psi - in the energy region where all the charm pentaquark states were discovered by the LHCb (Large Hadron Collider beauty) collaboration. The J/psi-007 experiment was conducted in the experimental Hall C of the Thomas Jefferson National Accelerator Facility using a high-intensity real photon beam generated by a 10.6 GeV incident electron beam traversing a copper radiator upstream of a liquid hydrogen target. Two arm spectrometers of Hall C, HMS (High Momentum Spectrometer), and SHMS (Super High Momentum Spectrometer) were used to detect the e+ e- di-lepton J/psi decay pairs in coincidence. The spectrometers' four momentum and angle settings scanned a photon beam energy range between 9.1 and 10.6 GeV and |t| up to 5 GeV^2. An enhanced sensitivity to the s-channel resonant J/psi photo-production was achieved by optimizing the spectrometer settings at a higher t region where the non-resonant standard t-channel J/psi production cross section is strongly suppressed. No evidence for pentaquarks was observed and, the cross section upper limits for each LHCb pentaquark candidate were determined and are presented in this document. / Physics
| Identifer | oai:union.ndltd.org:TEMPLE/oai:scholarshare.temple.edu:20.500.12613/6869 |
| Date | January 2021 |
| Creators | Duran, Burcu |
| Contributors | Sparveris, Nikolaos, Meziani, Zein-Eddine, Constantinou, Martha, Jones, Mark, Chen, J. P. (Jian-ping) |
| Publisher | Temple University. Libraries |
| Source Sets | Temple University |
| Language | English |
| Detected Language | English |
| Type | Thesis/Dissertation, Text |
| Format | 203 pages |
| Rights | IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available., http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | http://dx.doi.org/10.34944/dspace/6851, Theses and Dissertations |
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