| dc.identifier.uri | http://hdl.handle.net/11401/76680 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | Direct photons are produced during all stages of a heavy-ion collision. Due to their very small interaction cross section with the dense hadronic medium, they can escape the collision almost undisturbed and transport information about their production environment to a detector making them an excellent probe in heavy-ion physics. The observation of both a large yield and strong elliptical flow $v_2$ of soft direct photons in heavy ion collisions at RHIC has sparked a lot of interest. While a large yield seems to point towards abundant production from the early, hot stages of the interaction, large elliptical flow can be better understood in a picture of predominately late production when the overall flow of the medium has built up. Telling different production scenarios for soft direct photons apart has be difficult. We map out the centrality-dependence of direct photon observables and present results for dependence of the soft direct photon yield and flow as functions of centrality in the momentum range $0.4\,\mathrm{GeV}/c < p_T < 5.0\,\mathrm{GeV}/c$ from a sample of externally converted photons. Here we exploit the good momentum resolution of our detector for charged particles at low momenta and reconstruct photons in electron-positron pairs from conversions in specific locations in the detector material. We find that the yield of soft direct photons has approximately a power-law dependence on the number of participants in the collision, and that their flow is en par with the flow of photons from hadron decays, indicative of relatively late production. | |
| dcterms.available | 2017-09-20T16:50:57Z | |
| dcterms.contributor | Shuryak, Edward | en_US |
| dcterms.contributor | Drees, Axel | en_US |
| dcterms.contributor | Calder, Alan | en_US |
| dcterms.contributor | Sakaguchi, Takao. | en_US |
| dcterms.creator | Bannier, Benjamin | |
| dcterms.dateAccepted | 2017-09-20T16:50:57Z | |
| dcterms.dateSubmitted | 2017-09-20T16:50:57Z | |
| dcterms.description | Department of Physics. | en_US |
| dcterms.extent | 128 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/76680 | |
| dcterms.issued | 2014-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:50:57Z (GMT). No. of bitstreams: 1
Bannier_grad.sunysb_0771E_11879.pdf: 21686956 bytes, checksum: f82c37c1a1492fe598ab3249aaee363c (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | direct photons, flow, heavy ions | |
| dcterms.subject | Nuclear physics | |
| dcterms.title | Systematic studies of soft direct photon production in Au+Au collisions at sqrt(s_NN) = 200 GeV | |
| dcterms.type | Dissertation | |
