Long-distance effects in rare B decays
Long-distance effects in rare B decays
Dokument öffnen (1.5MB)Art der Hochschulschrift
DissertationPrüfungsdatum
11.05.2025Datum der Veröffentlichung
02.06.2026Erstgutachter
Kubis, BastianZweitgutachter
van Dyk, DannyMetadaten
Zur Langanzeige
Zitierbare Links 
Inhalt
The physics underlying the change of quark flavor provides important constraints on physics beyond our current best understanding. These indirect searches for signs of New Physics require the comparison of high-precision predictions with high-precision measurements. In this work, I refine two types of hadronic matrix elements, which are essential ingredients for these indirect searches. My work is grounded in methods that respect the analyticity and unitarity properties of these matrix elements.
After an overview about the used foundations, the first project applies dispersion relations to a set of B → y* form factors used in B− → ℓ− νℓℓ'− ℓ'+ decays. By that, the form factors are related to well-known B → V form factors exploiting a vector meson dominance model in the isospin contributions for I = 0 and I = 1. The form factors are defined such that they avoid kinematic singularities by the use of the Bardeen–Tung–Tarrach procedure, which is modified to be applicable to massive gauge bosons instead of photons. Following that, a discussion with recent literature is given. At last, the formalism is subtracted once to match the subtraction constant to measurements and, thus, improve on the predictive abilities of the method.
The second project analyzes e+e− → open charm data in the vicinity of the ψ(3770) resonance, using a fully analytic K-matrix formalism. For that, the phase space parametrization is analytically continued enabling an evaluation of the S-matrix poles on the second Riemann sheet. The pole parameters are used to extract the mass and width of the ψ(3770) resonance and to compute cross section in the analyzed energy region. The results are discussed in comparison to recent literature, where discrepancies to prevailing opinions in the field are found.
After an overview about the used foundations, the first project applies dispersion relations to a set of B → y* form factors used in B− → ℓ− νℓℓ'− ℓ'+ decays. By that, the form factors are related to well-known B → V form factors exploiting a vector meson dominance model in the isospin contributions for I = 0 and I = 1. The form factors are defined such that they avoid kinematic singularities by the use of the Bardeen–Tung–Tarrach procedure, which is modified to be applicable to massive gauge bosons instead of photons. Following that, a discussion with recent literature is given. At last, the formalism is subtracted once to match the subtraction constant to measurements and, thus, improve on the predictive abilities of the method.
The second project analyzes e+e− → open charm data in the vicinity of the ψ(3770) resonance, using a fully analytic K-matrix formalism. For that, the phase space parametrization is analytically continued enabling an evaluation of the S-matrix poles on the second Riemann sheet. The pole parameters are used to extract the mass and width of the ψ(3770) resonance and to compute cross section in the analyzed energy region. The results are discussed in comparison to recent literature, where discrepancies to prevailing opinions in the field are found.
Schlagwörter
rare decays, B-meson decays, high energy physics, transition form factors, Bardeen–Tung–Tarrach procedure, vector-meson dominance, CKM matrix, flavor physics, bottom, K matrix, unitarity, dispersion relations
Klassifikation (DDC)
530 PhysikZugehörige Publikation(en)
https://doi.org/10.1103/PhysRevD.107.053006https://doi.org/10.1140/epjc/s10052-024-12785-8
Kürten, Stephan: Long-distance effects in rare B decays. - Bonn, 2026. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5-90343
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5-90343
@phdthesis{handle:20.500.11811/14184,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5-90343,
author = {{Stephan Kürten}},
title = {Long-distance effects in rare B decays},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2026,
month = jun,
note = {The physics underlying the change of quark flavor provides important constraints on physics beyond our current best understanding. These indirect searches for signs of New Physics require the comparison of high-precision predictions with high-precision measurements. In this work, I refine two types of hadronic matrix elements, which are essential ingredients for these indirect searches. My work is grounded in methods that respect the analyticity and unitarity properties of these matrix elements.
After an overview about the used foundations, the first project applies dispersion relations to a set of B → y* form factors used in B− → ℓ− νℓℓ'− ℓ'+ decays. By that, the form factors are related to well-known B → V form factors exploiting a vector meson dominance model in the isospin contributions for I = 0 and I = 1. The form factors are defined such that they avoid kinematic singularities by the use of the Bardeen–Tung–Tarrach procedure, which is modified to be applicable to massive gauge bosons instead of photons. Following that, a discussion with recent literature is given. At last, the formalism is subtracted once to match the subtraction constant to measurements and, thus, improve on the predictive abilities of the method.
The second project analyzes e+e− → open charm data in the vicinity of the ψ(3770) resonance, using a fully analytic K-matrix formalism. For that, the phase space parametrization is analytically continued enabling an evaluation of the S-matrix poles on the second Riemann sheet. The pole parameters are used to extract the mass and width of the ψ(3770) resonance and to compute cross section in the analyzed energy region. The results are discussed in comparison to recent literature, where discrepancies to prevailing opinions in the field are found.},
url = {https://hdl.handle.net/20.500.11811/14184}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5-90343,
author = {{Stephan Kürten}},
title = {Long-distance effects in rare B decays},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2026,
month = jun,
note = {The physics underlying the change of quark flavor provides important constraints on physics beyond our current best understanding. These indirect searches for signs of New Physics require the comparison of high-precision predictions with high-precision measurements. In this work, I refine two types of hadronic matrix elements, which are essential ingredients for these indirect searches. My work is grounded in methods that respect the analyticity and unitarity properties of these matrix elements.
After an overview about the used foundations, the first project applies dispersion relations to a set of B → y* form factors used in B− → ℓ− νℓℓ'− ℓ'+ decays. By that, the form factors are related to well-known B → V form factors exploiting a vector meson dominance model in the isospin contributions for I = 0 and I = 1. The form factors are defined such that they avoid kinematic singularities by the use of the Bardeen–Tung–Tarrach procedure, which is modified to be applicable to massive gauge bosons instead of photons. Following that, a discussion with recent literature is given. At last, the formalism is subtracted once to match the subtraction constant to measurements and, thus, improve on the predictive abilities of the method.
The second project analyzes e+e− → open charm data in the vicinity of the ψ(3770) resonance, using a fully analytic K-matrix formalism. For that, the phase space parametrization is analytically continued enabling an evaluation of the S-matrix poles on the second Riemann sheet. The pole parameters are used to extract the mass and width of the ψ(3770) resonance and to compute cross section in the analyzed energy region. The results are discussed in comparison to recent literature, where discrepancies to prevailing opinions in the field are found.},
url = {https://hdl.handle.net/20.500.11811/14184}
}
Die folgenden Nutzungsbestimmungen sind mit dieser Ressource verbunden:
