Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering
Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering
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DissertationPrüfungsdatum
08.08.2014Datum der Veröffentlichung
25.08.2014Erstgutachter
Meißner, Ulf-G.Zweitgutachter
Haidenbauer, JohannMetadaten
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Inhalt
Chiral effective field theory (EFT) is a powerful tool to study the low energy hadron physics. Combining the heavy quark symmetry and chiral symmetry, the heavy hadron (moson and baryon) chiral perturbation theory is constructed. Among them, the heavy meson chiral perturbation theory describes the interaction between pseudoscalar and (heavy) B (or D) mesons, and the heavy baryon chiral perturbation theory deals with the pseudoscalar-baryon interaction, where the baryon (including the nucleon) is treated nonrelativistically. In this thesis, we apply these chiral Lagrangians to the semileptonic decay of B meson as well as the antinucleon-nucleon interaction. The final state interactions between the hadrons are taken into account model-independently. We summarize the pertinent points contained in this thesis as below:
The Cabibbo--Kobayashi--Maskawa (CKM) matrix element |Vub| has been determined by both inclusive decay modes B→Xuℓνℓ and exclusive ones B→π(ρ)ℓνℓ, but they do not match within uncertainties, which is the well-known “|Vub| puzzle”. Our emphasis is put on the reexamination of the theoretical uncertainties in the exclusive mode B→ρℓνℓ. In fact we note that this transition suffers from sizable uncertainties due to the large width of ρ meson, and instead, one should rely on the analysis of a full four-body semileptonic channel B→ππℓνℓ, which also serves as a cross check for the extraction of |Vub|. The form factors of hadronic matrix elements of B to ππ transitions are analyzed by dispersion theory, which is a model-independent approach to take into account the ππ final state interactions. The heavy meson chiral perturbation theory is used as an input to fix the subtraction constants appearing in the dispersion relations. Our formalism allows, for the first time, to use the full information for ππ invariant mass below 1 GeV to extract |Vub| without the need to refer to a particular resonance such as ρ or f0(980). The partial decay rate dΓ/(|Vub| ds dsℓ) below s=1 GeV2 at fixed sℓ=(mB-1 GeV)2 is presented for illustration, where s and sℓ denote the invariant mass squared for pion pairs and lepton pairs, respectively. Our such proposal can be examined in Belle and LHCb and thus the experimental data is highly desirable.
We observe that there is still no satisfactory description of antinucleon-nucleon scattering in view of chiral EFT. The tools available are the various phenomenological models, which played a very important role in the history of studying the nuclear force. However, they do not have the obvious connections with the underlying theory: quantum chromodynamics (QCD). Chiral EFT is related to QCD through the chiral symmetry, and a systematic improvement can be done due to the power counting rule. The recent partial-wave analysis of the antiproton-proton(pp) scattering data provides an opportunity to examine how the chiral EFT works for the antinucleon-nucleon interactions. We then calculate the antinucleon-nucleon potential up to next-to-next-to-leading order using the chiral EFT based on a modified Weinberg power counting, in close analogy to pertinent studies of the nucleon-nucleon interaction. Solving the Lippmann-Schwinger equation one obtains the scattering amplitude and futher observables. Our results show that the overall quality of the achieved description of the NN amplitudes is comparable to the one found in case of the nucleon-nucleon interaction at the same order. A good agreement is achieved for the phase shifts and inelasticities in most of the S-wave channels and several P-wave channels. We also calculate the scattering length, and the level shifts and widths of antiprotonic hydrogen atom, by our potential utilizing effective theory. They are all in line with the experimental information, as well as the Jülich model D (as an example of a phenomenological model). We also find there are bound states by the strong interaction in isospin-0 3P0 and isospin-0 3S1 - 3D1 partial waves, and their positions and widths are provided.
A significant enhancement in the cross section near the pp threshold is observed in various reactions, e.g., J/ψ→γpp, J/ψ→ωpp, ψ'→γpp as well as the one e+e-→pp we are considering. This enhancement phenomenon in the decay J/ψ→γpp is the most prominent one. Several theoretical explanations have been proposed, e.g., it is induced by the pp bound states, or the unobserved resonance so far, or even an exotic state like a glueball. However, in all these processes that contain a pp pair, the pp interaction is an important ingredient and can have large influence on the energy dependence of an observable. In the reactions e+e-↔pp, only 3S1 and 3D1 partial waves are allowed assuming the one-photon exchange approximation. Then we rigorously take into account the pp interactions in the initial or final states. It is shown that the existing experimental data including integrated and differential cross sections are well described in our approach. We also present spin-dependent observables as predictions for the future measurements.
Klassifikation (DDC)
530 PhysikKang, Xian-Wei: Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering. - Bonn, 2014. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-37147
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-37147
@phdthesis{handle:20.500.11811/6151,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-37147,
author = {{Xian-Wei Kang}},
title = {Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2014,
month = aug,
note = { for the decay B→ππℓνℓ
The Cabibbo--Kobayashi--Maskawa (CKM) matrix element |Vub| has been determined by both inclusive decay modes B→Xuℓνℓ and exclusive ones B→π(ρ)ℓνℓ, but they do not match within uncertainties, which is the well-known “|Vub| puzzle”. Our emphasis is put on the reexamination of the theoretical uncertainties in the exclusive mode B→ρℓνℓ. In fact we note that this transition suffers from sizable uncertainties due to the large width of ρ meson, and instead, one should rely on the analysis of a full four-body semileptonic channel B→ππℓνℓ, which also serves as a cross check for the extraction of |Vub|. The form factors of hadronic matrix elements of B to ππ transitions are analyzed by dispersion theory, which is a model-independent approach to take into account the ππ final state interactions. The heavy meson chiral perturbation theory is used as an input to fix the subtraction constants appearing in the dispersion relations. Our formalism allows, for the first time, to use the full information for ππ invariant mass below 1 GeV to extract |Vub| without the need to refer to a particular resonance such as ρ or f0(980). The partial decay rate dΓ/(|Vub| ds dsℓ) below s=1 GeV2 at fixed sℓ=(mB-1 GeV)2 is presented for illustration, where s and sℓ denote the invariant mass squared for pion pairs and lepton pairs, respectively. Our such proposal can be examined in Belle and LHCb and thus the experimental data is highly desirable. for the antinucleon-nucleon interaction
We observe that there is still no satisfactory description of antinucleon-nucleon scattering in view of chiral EFT. The tools available are the various phenomenological models, which played a very important role in the history of studying the nuclear force. However, they do not have the obvious connections with the underlying theory: quantum chromodynamics (QCD). Chiral EFT is related to QCD through the chiral symmetry, and a systematic improvement can be done due to the power counting rule. The recent partial-wave analysis of the antiproton-proton(pp) scattering data provides an opportunity to examine how the chiral EFT works for the antinucleon-nucleon interactions. We then calculate the antinucleon-nucleon potential up to next-to-next-to-leading order using the chiral EFT based on a modified Weinberg power counting, in close analogy to pertinent studies of the nucleon-nucleon interaction. Solving the Lippmann-Schwinger equation one obtains the scattering amplitude and futher observables. Our results show that the overall quality of the achieved description of the NN amplitudes is comparable to the one found in case of the nucleon-nucleon interaction at the same order. A good agreement is achieved for the phase shifts and inelasticities in most of the S-wave channels and several P-wave channels. We also calculate the scattering length, and the level shifts and widths of antiprotonic hydrogen atom, by our potential utilizing effective theory. They are all in line with the experimental information, as well as the Jülich model D (as an example of a phenomenological model). We also find there are bound states by the strong interaction in isospin-0 3P0 and isospin-0 3S1 - 3D1 partial waves, and their positions and widths are provided. for the reactions e+e-↔pp
A significant enhancement in the cross section near the pp threshold is observed in various reactions, e.g., J/ψ→γpp, J/ψ→ωpp, ψ'→γpp as well as the one e+e-→pp we are considering. This enhancement phenomenon in the decay J/ψ→γpp is the most prominent one. Several theoretical explanations have been proposed, e.g., it is induced by the pp bound states, or the unobserved resonance so far, or even an exotic state like a glueball. However, in all these processes that contain a pp pair, the pp interaction is an important ingredient and can have large influence on the energy dependence of an observable. In the reactions e+e-↔pp, only 3S1 and 3D1 partial waves are allowed assuming the one-photon exchange approximation. Then we rigorously take into account the pp interactions in the initial or final states. It is shown that the existing experimental data including integrated and differential cross sections are well described in our approach. We also present spin-dependent observables as predictions for the future measurements. },
url = {https://hdl.handle.net/20.500.11811/6151}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-37147,
author = {{Xian-Wei Kang}},
title = {Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2014,
month = aug,
note = {
Chiral effective field theory (EFT) is a powerful tool to study the low energy hadron physics. Combining the heavy quark symmetry and chiral symmetry, the heavy hadron (moson and baryon) chiral perturbation theory is constructed. Among them, the heavy meson chiral perturbation theory describes the interaction between pseudoscalar and (heavy) B (or D) mesons, and the heavy baryon chiral perturbation theory deals with the pseudoscalar-baryon interaction, where the baryon (including the nucleon) is treated nonrelativistically. In this thesis, we apply these chiral Lagrangians to the semileptonic decay of B meson as well as the antinucleon-nucleon interaction. The final state interactions between the hadrons are taken into account model-independently. We summarize the pertinent points contained in this thesis as below:
The Cabibbo--Kobayashi--Maskawa (CKM) matrix element |Vub| has been determined by both inclusive decay modes B→Xuℓνℓ and exclusive ones B→π(ρ)ℓνℓ, but they do not match within uncertainties, which is the well-known “|Vub| puzzle”. Our emphasis is put on the reexamination of the theoretical uncertainties in the exclusive mode B→ρℓνℓ. In fact we note that this transition suffers from sizable uncertainties due to the large width of ρ meson, and instead, one should rely on the analysis of a full four-body semileptonic channel B→ππℓνℓ, which also serves as a cross check for the extraction of |Vub|. The form factors of hadronic matrix elements of B to ππ transitions are analyzed by dispersion theory, which is a model-independent approach to take into account the ππ final state interactions. The heavy meson chiral perturbation theory is used as an input to fix the subtraction constants appearing in the dispersion relations. Our formalism allows, for the first time, to use the full information for ππ invariant mass below 1 GeV to extract |Vub| without the need to refer to a particular resonance such as ρ or f0(980). The partial decay rate dΓ/(|Vub| ds dsℓ) below s=1 GeV2 at fixed sℓ=(mB-1 GeV)2 is presented for illustration, where s and sℓ denote the invariant mass squared for pion pairs and lepton pairs, respectively. Our such proposal can be examined in Belle and LHCb and thus the experimental data is highly desirable.
We observe that there is still no satisfactory description of antinucleon-nucleon scattering in view of chiral EFT. The tools available are the various phenomenological models, which played a very important role in the history of studying the nuclear force. However, they do not have the obvious connections with the underlying theory: quantum chromodynamics (QCD). Chiral EFT is related to QCD through the chiral symmetry, and a systematic improvement can be done due to the power counting rule. The recent partial-wave analysis of the antiproton-proton(pp) scattering data provides an opportunity to examine how the chiral EFT works for the antinucleon-nucleon interactions. We then calculate the antinucleon-nucleon potential up to next-to-next-to-leading order using the chiral EFT based on a modified Weinberg power counting, in close analogy to pertinent studies of the nucleon-nucleon interaction. Solving the Lippmann-Schwinger equation one obtains the scattering amplitude and futher observables. Our results show that the overall quality of the achieved description of the NN amplitudes is comparable to the one found in case of the nucleon-nucleon interaction at the same order. A good agreement is achieved for the phase shifts and inelasticities in most of the S-wave channels and several P-wave channels. We also calculate the scattering length, and the level shifts and widths of antiprotonic hydrogen atom, by our potential utilizing effective theory. They are all in line with the experimental information, as well as the Jülich model D (as an example of a phenomenological model). We also find there are bound states by the strong interaction in isospin-0 3P0 and isospin-0 3S1 - 3D1 partial waves, and their positions and widths are provided.
A significant enhancement in the cross section near the pp threshold is observed in various reactions, e.g., J/ψ→γpp, J/ψ→ωpp, ψ'→γpp as well as the one e+e-→pp we are considering. This enhancement phenomenon in the decay J/ψ→γpp is the most prominent one. Several theoretical explanations have been proposed, e.g., it is induced by the pp bound states, or the unobserved resonance so far, or even an exotic state like a glueball. However, in all these processes that contain a pp pair, the pp interaction is an important ingredient and can have large influence on the energy dependence of an observable. In the reactions e+e-↔pp, only 3S1 and 3D1 partial waves are allowed assuming the one-photon exchange approximation. Then we rigorously take into account the pp interactions in the initial or final states. It is shown that the existing experimental data including integrated and differential cross sections are well described in our approach. We also present spin-dependent observables as predictions for the future measurements.
url = {https://hdl.handle.net/20.500.11811/6151}
}
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