Master Thesis Open Access
Heidelbach, Alexander
{
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"@type": "ScholarlyArticle",
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"creator": [
{
"@type": "Person",
"affiliation": "KIT/ETP",
"name": "Heidelbach, Alexander"
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"datePublished": "2022-04-28",
"description": "<p>In a set of simple extensions of the Standard Model, Axion Like Particles (ALPs) arise as pseudo Nambu-Goldstone bosons of theories with a spontaneously broken Peccei-Quinn symmetry that is anomalous under the Standard Model gauge symmetry. Due to constraints in flavour-changing current (FCNC) processes, involving the coupling of ALPs directly to Standard Model fermions and gluons, direct couplings of ALPs to the electroweak gauge bosons are particularly interesting. As a result of a coupling to $W$ bosons, ALPs can emerge in FCNC $b\\to s$ transitions. Depending on the ALP mass and the coupling strength to photons a possible experimental signature is $B^{\\pm}\\to K^{\\pm}a, a\\to\\gamma\\gamma$ with long lived ALP decays. This thesis performs a sensitivity study in the search for the $B^{\\pm}\\to K^{\\pm}a, a\\to\\gamma\\gamma$ signature based on Belle II simulation samples corresponding to an integrated luminosity of 100\\,fb$^{-1}$. The sensitivity study includes an optimised candidate selection and signal yield scans of the invariant di-photon mass distribution in the range of $0.175\\,\\text{GeV/c}^2$ to $4.600\\,\\text{GeV/c}^2$ for eight different ALP lifetimes between $0\\,\\text{cm}$ and $50\\,\\text{cm}$. Resulting expected limits are comparable to a similar search for $B^{\\pm}\\to K^{\\pm}a, a\\to\\gamma\\gamma$ on data collected by the BABAR experiment. </p>",
"headline": "Sensitivity Study in the Search for $B^{\\pm}\\to K^{\\pm}a$ (displaced $a\\to\\gamma\\gamma$) Decays at Belle II",
"image": "https://publish.etp.kit.edu/static/img/logos/zenodo-gradient-round.svg",
"inLanguage": {
"@type": "Language",
"alternateName": "eng",
"name": "English"
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"keywords": [
"Belle II",
"Analysis",
"Search for New Physics",
"ALPs"
],
"name": "Sensitivity Study in the Search for $B^{\\pm}\\to K^{\\pm}a$ (displaced $a\\to\\gamma\\gamma$) Decays at Belle II",
"url": "https://publish.etp.kit.edu/record/22123"
}