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G. von Hippel

Bio: G. von Hippel is an academic researcher from University of Mainz. The author has contributed to research in topics: Quantum chromodynamics & Nucleon. The author has an hindex of 8, co-authored 11 publications receiving 683 citations.

Papers
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TL;DR: In this paper, the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment, are highlighted, highlighting how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as searches for physics beyond the Standard Model.
Abstract: We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

433 citations

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TL;DR: In this article, the nucleon axial charge in QCD with two flavors of dynamical quarks was calculated and a detailed investigation of systematic errors was performed, with a particular focus on contributions from excited states to three-point correlation functions.
Abstract: We report on our calculation of the nucleon axial charge ${g}_{\mathrm{A}}$ in QCD with two flavors of dynamical quarks. A detailed investigation of systematic errors is performed, with a particular focus on contributions from excited states to three-point correlation functions. The use of summed operator insertions allows for a much better control over such contamination. After performing a chiral extrapolation to the physical pion mass, we find ${g}_{\mathrm{A}}=1.223\ifmmode\pm\else\textpm\fi{}0.063(\mathrm{stat}{)}_{\ensuremath{-}0.060}^{+0.035}(\mathrm{syst})$, in good agreement with the experimental value.

124 citations

Journal ArticleDOI
TL;DR: In this paper, a lattice calculation of the nucleon isovector axial and induced pseudoscalar form factors on the CLS ensembles using Nf = 2 dynamical flavors of nonperturbatively 𝒪(a)-improved Wilson f
Abstract: We present a lattice calculation of the nucleon isovector axial and induced pseudoscalar form factors on the CLS ensembles using Nf = 2 dynamical flavors of nonperturbatively 𝒪(a)-improved Wilson f

61 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment) using the improved Wilson fermions in the Coordinated Lattice Simulations ensembles.
Abstract: We present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment). The analysis is performed using $\mathcal{O}(a)$ improved Wilson fermions in ${N}_{f}=2$ QCD measured on the Coordinated Lattice Simulations ensembles. Particular focus is placed on a systematic evaluation of the influence of excited states in three-point correlation functions, which lead to a biased evaluation, if not accounted for correctly. We argue that the use of summed operator insertions and fit Ans\"atze including excited states allow us to suppress and control this effect. We employ a novel method to perform joint chiral and continuum extrapolations, by fitting the form factors directly to the expressions of covariant baryonic chiral effective field theory. The final results for the charge radii and magnetic moment from our lattice calculations include, for the first time, a full error budget. We find that our estimates are compatible with experimental results within their overall uncertainties.

60 citations

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TL;DR: The first application of the background field method to nonrelativistic QCD (NRQCD) on the lattice is presented in order to determine the one-loop radiative corrections to the coefficients of the NRQCD action in a manifestly gauge-covariant manner.
Abstract: We present the first application of the background field method to nonrelativistic QCD (NRQCD) on the lattice in order to determine the one-loop radiative corrections to the coefficients of the NRQCD action in a manifestly gauge-covariant manner. The coefficients of the $\mathbit{\ensuremath{\sigma}}\ifmmode\cdot\else\textperiodcentered\fi{}\mathbit{B}$ term in the NRQCD action and the four-fermion spin-spin interaction are computed at the one-loop level; the resulting shift of the hyperfine splitting of bottomonium is found to bring the lattice predictions in line with experiment.

33 citations


Cited by
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Journal ArticleDOI
TL;DR: Recently, the LHCb Collaboration discovered two hidden-charm pentaquark states, which are also beyond the quark model as discussed by the authors, and investigated various theoretical interpretations of these candidates of the multiquark states.

1,083 citations

Journal ArticleDOI
TL;DR: In this article, the authors review experimental evidences of various candidates of hadronic molecules, and methods of identifying such structures Nonrelativistic effective field theories are the suitable framework for studying hadronic molecule, and are discussed in both the continuum and finite volumes.
Abstract: A large number of experimental discoveries especially in the heavy quarkonium sector that did not at all fit to the expectations of the until then very successful quark model led to a renaissance of hadron spectroscopy Among various explanations of the internal structure of these excitations, hadronic molecules, being analogues of light nuclei, play a unique role since for those predictions can be made with controlled uncertainty We review experimental evidences of various candidates of hadronic molecules, and methods of identifying such structures Nonrelativistic effective field theories are the suitable framework for studying hadronic molecules, and are discussed in both the continuum and finite volumes Also pertinent lattice QCD results are presented Further, we discuss the production mechanisms and decays of hadronic molecules, and comment on the reliability of certain assertions often made in the literature

1,016 citations

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TL;DR: The determination of the light-quark masses, the form factor, and the decay-constant ratio arising in semileptonic $$K \rightarrow \pi $$K→π transition at zero momentum transfer are reported on.
Abstract: We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f+(0), arising in semileptonic K -> pi transition at zero momentum transfer, as well as the decay constant ratio fK/fpi of decay constants and its consequences for the CKM matrix elements Vus and Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)LxSU(2)R and SU(3)LxSU(3)R Chiral Perturbation Theory and review the determination of the BK parameter of neutral kaon mixing. The inclusion of heavy-quark quantities significantly expands the FLAG scope with respect to the previous review. Therefore, for this review, we focus on D- and B-meson decay constants, form factors, and mixing parameters, since these are most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. In addition we review the status of lattice determinations of the strong coupling constant alpha_s.

901 citations

Journal ArticleDOI
T. Aoyama1, Nils Asmussen2, M. Benayoun3, Johan Bijnens4  +146 moreInstitutions (64)
TL;DR: The current status of the Standard Model calculation of the anomalous magnetic moment of the muon is reviewed in this paper, where the authors present a detailed account of recent efforts to improve the calculation of these two contributions with either a data-driven, dispersive approach, or a first-principle, lattice approach.

801 citations

Journal ArticleDOI
TL;DR: It is concluded that the maximal radius of a 1.4-solar-mass neutron star is 13.6 km, and that the smallest allowed tidal deformability of a similar-mass star is Λ(1.4 M_{⊙})=120.4%.
Abstract: The detection of gravitational waves originating from a neutron-star merger, GW170817, by the LIGO and Virgo Collaborations has recently provided new stringent limits on the tidal deformabilities of the stars involved in the collision. Combining this measurement with the existence of two-solar-mass stars, we generate a generic family of neutron-star-matter equations of state (EOSs) that interpolate between state-of-the-art theoretical results at low and high baryon density. Comparing the results to ones obtained without the tidal-deformability constraint, we witness a dramatic reduction in the family of allowed EOSs. Based on our analysis, we conclude that the maximal radius of a 1.4-solar-mass neutron star is 13.6 km, and that the smallest allowed tidal deformability of a similar-mass star is Λ(1.4 M_{⊙})=120.

775 citations