<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC"^^ . "The Quark-Gluon Plasma (QGP), a strongly interacting state of matter in which quarks and gluons are\r\ndeconfined, is hypothesized to have existed merely a few micro-seconds after the Big Bang. This state can\r\nbe studied experimentally in heavy ion collisions at the current high-energy particle accelerators, like the\r\nLarge Hadron Collider (LHC). However, recently the size of the collision system, which is required to create\r\na QGP has been been put into question and many measurements suggests that this might even be possible in\r\nhigh multiplicity pp or p–Pb collisions. The research\r\nstudy of direct carried out in this thesis focuses on the\r\nphotons and neutral mesons in pp collisions at √s = 2.76 TeV and p–Pb collisions at √sNN = 5.02 TeV\r\nwith the ALICE detector at the LHC. The neutral pion and η meson have been reconstructed in their two\r\nphoton decay channels. For that up to four different reconstruction methods have been pursued within this\r\nthesis, out of which two are entirely new within ALICE, exploiting the full photon detection capabilities\r\nof ALICE. Like this the neutral pion spectra could be measured up to transverse momenta of 40 GeV/c\r\nin pp collision and a new level of precision could be reached for identified particle measurements in p–Pb\r\ncollisions at √sNN = 5.02 TeV. For pp collisions new high precision inputs for the determination of the\r\nfragmentation functions for neutral pions and η mesons are provided and the current models are compared\r\nto the obtained results. For p–Pb collisions a small suppression can be observed beyond 4 GeV/c with respect\r\nto an interpolated pp reference at the same center-of-mass energy. It is investigated further through the\r\ncomparison with various models and results from other identified particles, in order to test whether another\r\nansatz, taking into account only cold nuclear matter effects, would yield a similar suppression. For the direct\r\nphotons three partially independent reconstruction techniques are presented, two of which are entirely new\r\nin ALICE, as well as, their combined results for in minimum bias pp and p–Pb collisions. The combination of\r\nthe results yields a significant direct photon excess in p–Pb collisions beyond 6 GeV/c, which is in agreement\r\nwith the predicted excess from prompt photons in this collision system. Below these momenta and for pp\r\ncollision at √s = 2.76 TeV upper limits on the possible direct photon production can be provided. In this\r\nregion a possible thermal photon signal of 2 − 3% cannot be excluded within the current uncertainties."^^ . "2017" . . . . . . . "Friederike"^^ . "Bock"^^ . "Friederike Bock"^^ . . . . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (PDF)"^^ . . . "PHDThesis_SubmissionVersion_20171016.pdf"^^ . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (Other)"^^ . . . . . . "small.jpg"^^ . . . "Measurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #23888 \n\nMeasurement of Direct Photons and Neutral Mesons in Small Collisions Systems with the ALICE Experiment at the LHC\n\n" . "text/html" . . . "530 Physik"@de . "530 Physics"@en . .