A5006347284- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Nuclear physics research studies
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
- Scientific Computing and Data Management
- Quantum chaos and dynamical systems
- Advanced NMR Techniques and Applications
- Cold Fusion and Nuclear Reactions
- Atomic and Subatomic Physics Research
- Medical Imaging Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Neutrino Physics Research
- Advanced Numerical Analysis Techniques
- Galaxies: Formation, Evolution, Phenomena
- Inorganic Fluorides and Related Compounds
- Stellar, planetary, and galactic studies
- Seismic Imaging and Inversion Techniques
- Research Data Management Practices
- Particle Accelerators and Free-Electron Lasers
- Digital Radiography and Breast Imaging
University of Bern
2016-2025
University of Zurich
1999-2024
Paul Scherrer Institute
2022-2024
University of Bonn
2016-2022
Universidad Complutense de Madrid
2022
University of Washington
2016-2020
University of California, San Diego
2019-2020
University of Vienna
2016-2019
Indiana University Bloomington
2016
Thomas Jefferson National Accelerator Facility
2016
We review the present status of Standard Model calculation anomalous magnetic moment muon. This is performed in a perturbative expansion fine-structure constant $\alpha$ and broken down into pure QED, electroweak, hadronic contributions. The QED contribution by far largest has been evaluated up to including $\mathcal{O}(\alpha^5)$ with negligible numerical uncertainty. electroweak suppressed $(m_\mu/M_W)^2$ only shows at level seventh significant digit. It two loops known better than one...
We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible nuclear particle communities. More specifically, we report on determination light-quark masses, form factor $f_+(0)$ arising in semileptonic $K \to \pi$ transition at zero momentum transfer, as well decay constant ratio $f_K/f_\pi$ its consequences for CKM matrix elements $V_{us}$ $V_{ud}$. Furthermore, describe obtained some low-energy constants...
Abstract We review lattice results related to pion, kaon, D -meson, B and nucleon physics with the aim of making them easily accessible nuclear particle communities. More specifically, we report on determination light-quark masses, form factor $$f_+(0)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>f</mml:mi> <mml:mo>+</mml:mo> </mml:msub> <mml:mo>(</mml:mo> <mml:mn>0</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> arising in semileptonic $$K...
We present a detailed analysis of $e^+e^-\toπ^+π^-$ data up to $\sqrt{s}=1\,\text{GeV}$ in the framework dispersion relations. Starting from family $ππ$ $P$-wave phase shifts, as derived previous Roy-equation scattering, we write down an extended Omnès representation pion vector form factor terms few free parameters and study which extent modern high-statistics sets can be described by resulting fit function that follows general principles QCD. find statistically acceptable fits do become...
We demonstrate that near the threshold, pi scattering amplitude contains a pole with quantum numbers of vacuum--commonly referred to as sigma--and determine its mass and width within small uncertainties. Our derivation does not involve models or parametrizations but relies on straightforward calculation based Roy equation for isoscalar S wave.
Recently, it was shown that insertions of hadronic vacuum polarization at O(alpha^4) generate non-negligible effects in the calculation anomalous magnetic moment muon. This result raises question if other diagrams this order might become relevant for next round g-2 measurements as well. In note we show a potentially enhanced such contribution, light-by-light scattering combination with electron polarization, is already sufficiently suppressed.
A bstract While the low-energy part of hadronic light-by-light (HLbL) tensor can be constrained from data using dispersion relations, for a full evaluation its contribution to anomalous magnetic moment muon ( g − 2) μ also mixed- and high-energy regions need estimated. Both addressed within operator product expansion (OPE), either configurations where all photon virtualities become large or one them remains finite. Imposing such short-distance constraints (SDCs) on HLbL is thus major aspect...
We present the physics program of Belle II experiment, located on intensity frontier SuperKEKB $e^+e^-$ collider. collected its first collisions in 2018, and is expected to operate for next decade. It anticipated collect 50/ab collision data over lifetime. This book outcome a joint effort collaborators theorists through theory interface platform (B2TiP), an that commenced 2014. The aim B2TiP was elucidate potential impacts program, which includes wide scope topics: B physics, charm, tau,...
In the original version of this manuscript, an error was introduced on pp352. '2.7nb:1.6nb' has been corrected to '2.4nb:1.3nb' in current online and printed version. doi:10.1093/ptep/ptz106.
The hadronic light-by-light contribution to the anomalous magnetic moment of muon was recently analyzed in framework dispersion theory, providing a systematic formalism where all input quantities are expressed terms on-shell form factors and scattering amplitudes that principle accessible experiment. We briefly review main ideas behind this discuss various experimental ingredients needed for evaluation one- two-pion intermediate states. In particular, we identify processes absence data...
In this third paper of a series dedicated to dispersive treatment the hadronic light-by-light (HLbL) tensor, we derive partial-wave formulation for two-pion intermediate states in HLbL contribution anomalous magnetic moment muon (g − 2) μ , including detailed discussion unitarity relation arbitrary partial waves. We show that obtaining final expression free from unphysical helicity waves is subtle issue, which thoroughly clarify. As by-product, obtain set sum rules could be used constrain...
At low energies hadronic vacuum polarization (HVP) is strongly dominated by two-pion intermediate states, which are responsible for about 70% of the HVP contribution to anomalous magnetic moment muon, aμHVP. Lattice-QCD evaluations latter indicate that it might be larger than calculated dispersively on basis e+e−→ hadrons data, at a level would contest long-standing discrepancy with aμ measurement. In this Letter we study extent 2π can modified without, same time, producing conflict...
We present a first model-independent calculation of ππ intermediate states in the hadronic-light-by-light (HLBL) contribution to anomalous magnetic moment muon (g-2)_{μ} that goes beyond scalar QED pion loop. To this end, we combine recently developed dispersive description HLBL tensor with partial-wave expansion and demonstrate known scalar-QED result is recovered after resummation. Using fits high-statistics data for vector form factor, provide an evaluation full box a_{μ}^{π...
In this paper we make a further step towards dispersive description of the hadronic light-by-light (HLbL) tensor, which should ultimately lead to data-driven evaluation its contribution (g − 2) μ . We first provide Lorentz decomposition HLbL tensor performed according general recipe by Bardeen, Tung, and Tarrach, generalizing extending our previous approach, was constructed in terms basis helicity amplitudes. Such has several advantages: role gauge invariance crossing symmetry becomes fully...
A key ingredient in the evaluation of hadronic light-by-light (HLbL) scattering anomalous magnetic moment muon $(g-2)_\mu$ concerns short-distance constraints (SDCs) that follow from QCD by means operator product expansion. Here we concentrate on most important such constraint, longitudinal amplitudes, and show it can be implemented efficiently terms a Regge sum over excited pseudoscalar states, constrained phenomenological input masses, two-photon couplings, as well SDCs HLbL transition...
We reassess the impact of short-distance constraints for longitudinal component hadronic light-by-light amplitude on anomalous magnetic moment muon, $a_\mu=(g-2)_\mu/2$, by comparing different solutions that have recently appeared in literature. In particular, we analyze relevance exact axial anomaly and its $a_\mu$ conclude it remains rather limited. show all proposed agree well within uncertainties numerical estimate $a_\mu$, despite differences concrete implementation. also take into...