{"id":{"repo_id":"heid-diss","oai_identifier":"oai:archiv.ub.uni-heidelberg.de:1878"},"canonical_url":"https://search.dev.ndltd.org/etd/heid-diss/oai:archiv.ub.uni-heidelberg.de:1878","repository":{"repo_id":"heid-diss","name":"Universität Heidelberg","base_url":"http://archiv.ub.uni-heidelberg.de/volltextserver/cgi/oai2"},"display":{"title":"Exclusive Pomeron- and Odderon induced photoproduction of omega- and f2 mesons at HERA","abstract":"The topics of this thesis are the analyses of exclusive photoproduction of $omega$- and $f_{2}$-mesons at mean $gp$ centre of mass energies of $langle Wangleapprox 200$ GeV at HERA. The former process is thought to be induced by photon-Pomeron interactions, and its cross section is measured to be $sigma(gpoomega p)=(1.3 pm 0.2(ext{stat}) pm 0.2(ext{syst})),muext{b}$, where the decay $omegaopigao3gamma$ is used to analyse the events. The diffractive slope $b$ describing the exponential fall of $ds/d|t|proptoexp(-b|t|)$ is measured by analysing the acceptance corrected differential distribution $d N/d|t|$. The value found for this parameter amounts to $b=(10.7pm 1.1(ext{stat})pm 2.0(ext{syst})),ext{GeV}^{-2}$. The corrected differential cross section $ds/d|t|$ is also found to be in accordance with the prediction of the Stochastic Vacuum Model for $ ho^{0}$-photoproduction scaled by a factor of $2/9$. The decay angular distributions $d N/dcosvartheta^{*}$ and $d N/dvarphi^{*}$ are found to be compatible with $s$-channel helicity conservation. The predictions of the Stochastic Vacuum Model for Odderon induced $f_{2}$-photoproduction of $21$ nb cannot be confirmed, but a $95$ confidence level upper limit on the cross section of $sigma(gpo f_{2}X)<12.4,ext{nb}$ is given. The contributions of the $f_{2}$ are looked for in the $pipi$ mass spectrum, where the $f_{2}$ is thought to contribute via its decay $f_{2}opipio4gamma$.","abstract_html":"The topics of this thesis are the analyses of exclusive photoproduction of $omega$- and <span class=\"etd-inline-math\">f<sub>2</sub></span>-mesons at mean $gp$ centre of mass energies of $langle Wangleapprox 200$ GeV at HERA. The former process is thought to be induced by photon-Pomeron interactions, and its cross section is measured to be $sigma(gpoomega p)=(1.3 pm 0.2(ext{stat}) pm 0.2(ext{syst})),muext{b}$, where the decay $omegaopigao3gamma$ is used to analyse the events. The diffractive slope $b$ describing the exponential fall of $ds/d|t|proptoexp(-b|t|)$ is measured by analysing the acceptance corrected differential distribution $d N/d|t|$. The value found for this parameter amounts to <span class=\"etd-inline-math\">b=(10.7pm 1.1(ext{stat})pm 2.0(ext{syst})),ext{GeV}<sup>-2</sup></span>. The corrected differential cross section $ds/d|t|$ is also found to be in accordance with the prediction of the Stochastic Vacuum Model for <span class=\"etd-inline-math\"> ho<sup>0</sup></span>-photoproduction scaled by a factor of $2/9$. The decay angular distributions <span class=\"etd-inline-math\">d N/dcosvartheta<sup>*</sup></span> and <span class=\"etd-inline-math\">d N/dvarphi<sup>*</sup></span> are found to be compatible with $s$-channel helicity conservation. The predictions of the Stochastic Vacuum Model for Odderon induced <span class=\"etd-inline-math\">f<sub>2</sub></span>-photoproduction of $21$ nb cannot be confirmed, but a $95$ confidence level upper limit on the cross section of <span class=\"etd-inline-math\">sigma(gpo f<sub>2</sub>X)&lt;12.4,ext{nb}</span> is given. The contributions of the <span class=\"etd-inline-math\">f<sub>2</sub></span> are looked for in the $pipi$ mass spectrum, where the <span class=\"etd-inline-math\">f<sub>2</sub></span> is thought to contribute via its decay <span class=\"etd-inline-math\">f<sub>2</sub>opipio4gamma</span>.","abstract_has_math":true,"creators":["Berndt, Thomas"],"institution":"Universität Heidelberg","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Meier, Karl-Heiz"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001-12-05","date_published":"2001-12-05","updated_at":"2026-07-24T02:29:09Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://www.ub.uni-heidelberg.de/archiv/1878","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Meier, Karl-Heiz"]},{"key":"dc:creator","label":"Author","values":["Berndt, Thomas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universitätsbibliothek Heidelberg"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Heidelberg"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The topics of this thesis are the analyses of exclusive photoproduction of $omega$- and $f_{2}$-mesons at mean $gp$ centre of mass energies of $langle Wangleapprox 200$ GeV at HERA. The former process is thought to be induced by photon-Pomeron interactions, and its cross section is measured to be $sigma(gpoomega p)=(1.3 pm 0.2(ext{stat}) pm 0.2(ext{syst})),muext{b}$, where the decay $omegaopigao3gamma$ is used to analyse the events. The diffractive slope $b$ describing the exponential fall of $ds/d|t|proptoexp(-b|t|)$ is measured by analysing the acceptance corrected differential distribution $d N/d|t|$. The value found for this parameter amounts to $b=(10.7pm 1.1(ext{stat})pm 2.0(ext{syst})),ext{GeV}^{-2}$. The corrected differential cross section $ds/d|t|$ is also found to be in accordance with the prediction of the Stochastic Vacuum Model for $ ho^{0}$-photoproduction scaled by a factor of $2/9$. The decay angular distributions $d N/dcosvartheta^{*}$ and $d N/dvarphi^{*}$ are found to be compatible with $s$-channel helicity conservation. The predictions of the Stochastic Vacuum Model for Odderon induced $f_{2}$-photoproduction of $21$ nb cannot be confirmed, but a $95$ confidence level upper limit on the cross section of $sigma(gpo f_{2}X)<12.4,ext{nb}$ is given. The contributions of the $f_{2}$ are looked for in the $pipi$ mass spectrum, where the $f_{2}$ is thought to contribute via its decay $f_{2}opipio4gamma$."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Exclusive Pomeron- and Odderon induced photoproduction of omega- and f2 mesons at HERA","Exklusive Pomeron- und Odderon induzierte omega- und f2 Photoproduktion bei HERA"]}]}],"canonical_facts":{"dc:contributor":["Meier, Karl-Heiz"],"dc:creator":["Berndt, Thomas"],"dc:description.abstract":["The topics of this thesis are the analyses of exclusive photoproduction of $omega$- and $f_{2}$-mesons at mean $gp$ centre of mass energies of $langle Wangleapprox 200$ GeV at HERA. The former process is thought to be induced by photon-Pomeron interactions, and its cross section is measured to be $sigma(gpoomega p)=(1.3 pm 0.2(ext{stat}) pm 0.2(ext{syst})),muext{b}$, where the decay $omegaopigao3gamma$ is used to analyse the events. The diffractive slope $b$ describing the exponential fall of $ds/d|t|proptoexp(-b|t|)$ is measured by analysing the acceptance corrected differential distribution $d N/d|t|$. The value found for this parameter amounts to $b=(10.7pm 1.1(ext{stat})pm 2.0(ext{syst})),ext{GeV}^{-2}$. The corrected differential cross section $ds/d|t|$ is also found to be in accordance with the prediction of the Stochastic Vacuum Model for $ ho^{0}$-photoproduction scaled by a factor of $2/9$. The decay angular distributions $d N/dcosvartheta^{*}$ and $d N/dvarphi^{*}$ are found to be compatible with $s$-channel helicity conservation. The predictions of the Stochastic Vacuum Model for Odderon induced $f_{2}$-photoproduction of $21$ nb cannot be confirmed, but a $95$ confidence level upper limit on the cross section of $sigma(gpo f_{2}X)<12.4,ext{nb}$ is given. The contributions of the $f_{2}$ are looked for in the $pipi$ mass spectrum, where the $f_{2}$ is thought to contribute via its decay $f_{2}opipio4gamma$."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universitätsbibliothek Heidelberg"],"dc:title":["Exclusive Pomeron- and Odderon induced photoproduction of omega- and f2 mesons at HERA","Exklusive Pomeron- und Odderon induzierte omega- und f2 Photoproduktion bei HERA"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Heidelberg"]},"updated_at":"2026-07-24T02:29:09Z"}