Conveners
Hadron structure
- Thomas Blum
Hadron structure
- Luchang Jin
Hadron structure
- CARLETON DETAR (University of Utah)
Hadron structure
- Vera Guelpers (University of Edinburgh)
Hadron structure
- yibo yang (I)
Hadron structure
- Jianhui Zhang (University of Regensburg)
Hadron structure
- Tanmoy Bhattacharya (T-2)
Hadron structure
- Ross Young (University of Adelaide)
Hadron structure
- Shigemi Ohta (KEK High Energy Accelerator Organization)
Hadron structure
- Hiroshi Ohki
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Christoph Lehner (Uni Regensburg, BNL)17/06/2019, 14:20Hadron structureParallel
I present the current status of the lattice QCD+QED calculation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment by RBC/UKQCD
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Carleton DeTar (University of Utah)17/06/2019, 14:40Hadron structureParallel
We present an update on the Fermilab Lattice, HPQCD, and MILC Collaborations' ongoing calculations of the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon. Our project employs ensembles with four flavors of highly improved staggered fermions, physical light-quark masses, and a range of lattice spacings of $a\approx 0.06-0.15$~fm.
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Dr Marco Cè (Johannes Gutenberg-Universität Mainz)17/06/2019, 15:00Hadron structureParallel
The electroweak mixing angle, or Weinberg angle, $\theta_{\mathrm{W}}$ is a parameter of the Standard Model that parametrizes the mixing between the electromagnetic and weak couplings.
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We present a lattice study of the leading hadronic contribution to the running of $\sin^2\theta_{\mathrm{W}}$, given by the hadronic vacuum polarization (HVP) of the electromagnetic current with the vector part... -
Miguel Teseo San José Pérez (Johannes Gutenberg Universität)17/06/2019, 15:20Hadron structureParallel
The electromagnetic coupling that intervenes in the interactions between charged particles varies with the energy due to off-shell processes. In this work we compute the leading hadronic contribution to this running at low energies, where QCD is fully non-perturbative.
We employ a subset of CLS (Coordinated Lattice Simulations) ensembles with Nf = 2+1 and O(a) improved Wilson fermions in open...
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Prof. Laurent Lellouch (CNRS & Aix-Marseille U.)17/06/2019, 15:40Hadron structureParallel
To deliver a precise determination of the hadronic vacuum polarization contribution of light quarks to the muon $(g-2)$, lattice calculations must overcome a number of challenges. These include a signal-to-noise problem, finite-volume effects and, when staggered fermions are used, significant taste-breaking effects. I will present some of the solutions which the BMW collaboration has been...
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Prof. Christopher Aubin (Fordham University)17/06/2019, 16:30Hadron structureParallel
We present results for the leading hadronic contribution to the muon g-2 from configurations with 2+1+1 flavors of HISQ quarks. The ensembles have been generated by the MILC collaboration at three lattice spacings. Using the time-momentum representation of the electromagnetic current correlator, we calculate the finite volume effects up to next-to-next-to-leading-order in Chiral Perturbation Theory.
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Nils Hermansson Truedsson (Lund University)17/06/2019, 16:50Hadron structureParallel
The present $3.5 \, \sigma$ discrepancy between the theoretical prediction and experimental value of the muon anomalous magnetic moment requires improved accuracy for both measurements and calculations. On the theory side, the hadronic vacuum polarisation (HVP) is one of the main sources of uncertainty at the moment. This can be calculated in finite volume (FV) on the lattice, and in order to...
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Davide Giusti (Università degli Studi Roma Tre and INFN Sezione di Roma Tre)17/06/2019, 17:10Hadron structureParallel
We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contributions to the anomalous magnetic moments of charged leptons $a_\ell$ and an estimate of the contribution to $a_\mu^{\rm HVP}$ not covered by the MUonE experiment, including leading-order strong and electromagnetic isospin-breaking corrections from first principles. Our lattice results are obtained in the...
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Aaron Meyer (Brookhaven National Laboratory)17/06/2019, 17:30Hadron structureParallel
The Hadronic Vacuum Polarization (HVP) is a dominant contribution to the theoretical uncertainty of the muon anomalous magnetic moment. The uncertainty in lattice QCD calculations of the HVP are dominated by the long-distance contribution to the vector correlation function. With explicit studies of the exclusive channels of the HVP diagram, it is possible to reconstruct the long-distance...
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Andreas Risch (Universität Mainz), Hartmut Wittig18/06/2019, 14:20Hadron structureParallel
We discuss leading isospin breaking effects in the hadronic vacuum polarisation required for the investigation of the hadronic contribution to $(g-2)_{\mu}$. The calculation proceeds by expanding the relevant correlation functions around the isosymmetric limit. Isosymmetric observables are evaluated on CLS gauge ensembles with $N_{f}=2+1$, $O(a)$ improved Wilson fermions and open boundary...
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Dr Antoine Gérardin (John von Neumann Institute for Computing, DESY)18/06/2019, 14:40Hadron structureParallel
We present a lattice calculation of the leading hadronic vacuum polarization
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contribution to the muon anomalous magnetic moment. We use $N_f=2+1$ Wilson
quarks and apply the O($a$)-improvement programme to reduce discretization
effects. Four lattice spacings with several values of the pion mass down to
its physical value are used to extrapolate to the physical point.
For the connected light... -
Nils Asmussen (Uni Southampton)18/06/2019, 15:00Hadron structureParallel
The anomalous magnetic moment shows a three to four standard deviations
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tension between its experimental value and theory predictions, and
therefore demands further investigation. Experiments at Fermilab and
J-PARC aim to reduce the uncertainty by a factor of four. The
theoretical uncertainty has to be reduced in equal measure. It is
dominated by the hadronic vacuum polarization (HVP) and... -
Thomas Blum18/06/2019, 16:30Hadron Spectroscopy and InteractionsParallel
We update our calculation of the hadronic light-by-light contribution to the muon anomalous magnetic moment. Our results comprise computations done on five gauge field ensembles employing 2+1 flavors of mobius domain wall fermions and Iwasaki and Iwasaki DSDR gluons, all with physical masses. Inverse lattice spacings range from 1 to 2.4 GeV, and lattice sizes from 4.8 to 6.4 fm. We present...
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Taku Izubuchi (Brookhaven National Laboratory)18/06/2019, 16:50Hadron Spectroscopy and InteractionsParallel
We report about calculations of hadronic decay of tau lepton and related topics for muon's anomalous magnetic moment.
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Balint Toth (University of Wuppertal)18/06/2019, 17:10Hadron structureParallel
We use our Nf=2+1+1 staggered lattice QCD configurations to compute the quantum electrodynamics and strong isospin breaking corrections to various hadronic observables. We use quark masses around their physical values, and include QED in our computations using the QED_L formulation.
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Dr Yu-Sheng Liu (Tsung-Dao Lee Institute)19/06/2019, 09:00Hadron structureParallel
Within the framework of large momentum effective theory (LaMET), generalized parton distributions (GPDs) can be extracted from lattice calculations of quasi-GPDs through a perturbative matching relation, up to power corrections that are suppressed by the hadron momentum. In this work, we focus on isovector quark GPDs, including the unpolarized, longitudinally and transversely polarized cases,...
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Dr Jianhui Zhang (Beijing Normal University)19/06/2019, 09:20Hadron structureParallel
Recent years have witnessed rapid progress on computing parton distribution functions (PDFs) from lattice QCD. Such computations have been focused on the isovector quark PDFs which do not involve mixing with gluon PDFs and therefore are the easiest to calculate. In this talk, I present recent developments that allow us to access flavor-singlet quark PDFs as well as gluon PDFs from lattice QCD.
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Krzysztof Cichy19/06/2019, 09:40Hadron structureParallel
We discuss the recent progress in extracting PDFs from the quasi-PDF approach, using twisted mass fermions. This concerns the investigation of several sources of systematic effects. Their careful analysis is a prerequisite to obtain precise determinations of PDFs from the lattice with realistic estimates of all uncertainties. Moreover, we present preliminary results from our new simulations at...
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David Richards (Jefferson Lab)19/06/2019, 10:00Hadron structureParallel
The hadronic matrix elements of bi-local operators at short Euclidean
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separations evaluated as a function of Ioffe time can be related to
the convolution of the universal parton distribution functions (PDFs) and a
short-distance kernel. In this talk, we describe the method,
beginning with the needed renormalizations for the
case of quark and antiquark fields separated by a Wilson line, and... -
Colin Egerer (College of William and Mary)19/06/2019, 10:20Hadron structureParallel
A general framework for the study of hadronic structure from Lattice QCD, dubbed "good lattice cross-sections", leverages QCD collinear factorization and ideas from the global PDF fitting community to reliably extract the full x-dependence of PDFs from the lattice. The calculation of pseudo-PDFs and gauge invariant two-current correlations within a hadron are two established realizations of...
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Charles Shugert (Stony Brook University and Brookhaven National Lab)19/06/2019, 11:10Hadron structureParallel
We present results of the pion valence-quark PDF using quasi-PDF and pseudo-PDF
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methods. Using quasi-PDF's one relies on highly-boosted hadronic states in order
for LaMET to reliably match the quasi-PDF to the light-cone PDF. Alternativly
one can study pseudo PDF's, Fourier-transforms of the pseudo Ioffe-Time distribution
from $\nu$-space to x-space at fixed $z^2$ with $z$ being the... -
Christian Zimmermann19/06/2019, 11:30Hadron structureParallel
We calculate correlation functions of two local operators within the nucleon carrying momentum. We resolve their dependence on the spatial distance of the currents. This is carried out for all Wick contractions, taking into account several operator insertion types. The resulting four-point functions can be related to double parton distributions as well as to parton distribution functions. For...
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Ross Young (University of Adelaide)19/06/2019, 11:50Hadron structureParallel
The partonic structure of hadrons plays an important role in a vast array of high-energy and nuclear physics experiments. It also underpins the theoretical understanding of hadron structure. Recent developments in lattice QCD offer new opportunities for reliably studying partonic structure from first principles. He we report on the use of Feynman-Hellmann to study the forward Compton amplitude...
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Shigemi Ohta (KEK High Energy Accelerator Organization)20/06/2019, 14:00Hadron structureParallel
The current status of nucleon isovector charges calculation from joint LHP+RBC Collaborations using the 2+1-flavor dynamical domain-wall lattice QCD ensemble generated by joint RBC+UKQCD Collaborations at 1.730(4)-GeV lattice cut off will be reported.
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Simon Weishäupl20/06/2019, 14:20Hadron structureParallel
The experimentally well known nucleon axial coupling $g_A$ has been computed extensively on the lattice and serves as a benchmark quantity for lattice calculations. The axial couplings for the other octet baryons (hyperons), like e.g. $\Sigma$ and $\Xi$ baryons are less well known. We will present not only results for the hyperon axial charges but also for other isovector charges, e.g., the...
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Dr André Walker-Loud (Lawrence Berkeley National Laboratory)20/06/2019, 14:40Hadron structureParallel
I will discuss various aspects of the CalLat MDWF on gradient flowed HISQ program including an updated determination of the nucleon axial charge along with a direct comparison with the more standard three-point function calculations.
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Chia Cheng Chang (University of California, Berkeley)20/06/2019, 15:00Hadron structureParallel
Following previous work on the calculation of the nucleon axial coupling using domain-wall valence on HISQ gauge configurations, I will present an overview on our recent progress towards determining more general elastic nucleon form factors. These preliminary results will be based at heavier pion masses, and will focus on overall computational and analysis strategy.
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NATSUKI TSUKAMOTO (Tohoku University)20/06/2019, 15:20Hadron structureParallel
We report the recent progress on our study of the nucleon couplings including the axial, tensor and scalar couplings on a $(10.8\rm fm)^4$ lattice using the PACS10 gauge configuration generated by the PACS Collaboration with the stout-smeared $\mathcal{O}(a)$ improved Wilson fermions and Iwasaki gauge action at $\beta = 1.82$ corresponding to the lattice spacing of 0.084fm. We also estimated...
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Prof. Yi-Bo Yang (ITP/CAS, China)20/06/2019, 16:10Hadron structureParallel
The trace anomaly is one of the most non-trivial property of QCD which violates the scale invariance from the traceless QCD Energy momentum tensor, and then give non-zero mass to nucleon in the chiral limit. It has been predicted by QCD for over forty years, and will be verified by the EIC/EicC experiments in the near future.
I will present several procedures and the related lattice...
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Roger Horsley (University of Edinburgh)20/06/2019, 16:30Hadron structureParallel
Computing the gluon component of momentum in the nucleon is a difficult and computationally expensive problem, as the matrix element involves a quark-line-disconnected gluon operator which suffers from ultra-violet fluctuations. But also necessary for a successful determination is the non-perturbative renormalisation of this operator. We investigate this renormalisation here by using two...
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Liuming Liu (Institute of Modern Physics, Chinese Academy of Sciences)20/06/2019, 16:50Hadron structureParallel
In this talk I present the result on nucleon isovector scalar charge using overlap fermions on 2+1 flavor domain-wall configurations generated by RBC/UKQCD collaboration. The ensembles span four lattice spacings 0.06, 0.08, 0.11 and 0.14 fm and five pion masses in the range from the physical value to 370 MeV. The scalar charge is extracted from the ratio of 3pt and 2pt functions by two-state...
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Mr Lukas Varnhorst (University of Wuppertal)20/06/2019, 17:10Hadron structureParallel
The BMW collaboration's recent calculation of the nucleon sigma terms, based on the Feynman-Hellmann theorem, will be presented. In different stages of the calculation advantages of staggered and Wilson fermions are exploited by fitting data generated with both fermion action. The fitting methods will be explained and the implications of the findings for the quark masses' contributions to the...
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Gen Wang (University of Kentucky)21/06/2019, 14:00Hadron structureParallel
We present a preliminary calculation of the quark energy momentum tensor form factors $T_1(Q^2)$ and $T_1(Q^2)+T_2(Q^2)$ at physical pion mass with valence overlap fermions on 2+1 flavor domain-wall $24^3\times 64$ configurations with $a=0.194\ {\rm{fm}},m_{\pi}=137\ {\rm{MeV}}$ generated by RBC/UKQCD collaboration. With z-expansion fits of the sum of connected and disconneted contributions,...
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Sungwoo Park (Los Alamos National Laboratory)21/06/2019, 14:20Hadron structureParallel
We will present results on the nucleon charges and form factors on five ensembles generated using 2+1 clover fermions by the Jlab/W&M/LANL collaborations. These results will be compared with similar calculations done using 2+1+1 flavor HISQ ensembles.
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Yong-Chull Jang (Brookhaven National Laboratory)21/06/2019, 14:40Hadron structureParallel
Results for the nucleon isovector form factors for the vector and axial-vector currents will be presented. The calculations are done using clover valence quarks on 11 ensembles, including two physical pion mass ensembles, generated with 2+1+1 flavors of HISQ fermions by the MILC collaboration. High statistics are achieved using the truncated solver method with bias correction, and the coherent...
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Jonas Wilhelm (Universität Mainz)21/06/2019, 15:00Hadron structureParallel
We report on our calculation of the strange contribution to the vector and axial vector form factors. The strange charge radii, magnetic moment, and axial charge are extracted by model independent $z$-expansion fits to the $Q^2$-dependence of the respective form factors. Furthermore, the isoscalar contribution to the axial and tensor charge is investigated by combining the calculation of...
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Andrew Jackura (Indiana University)21/06/2019, 15:20Hadron structureParallel
Recently, a framework was developed for studying form factors of two-body states probed with an external current. Finite volume matrix elements that may be computed via lattice QCD are converted to infinite volume generalized form factors. These generalized form factors allow us to study the structure of composite states. In this talk, we consider the application of this formalism to bound...
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Boram Yoon (Los Alamos National Laboratory)21/06/2019, 16:10Hadron structureParallel
Neutrons can have nonvanishing electric dipole moment (EDM) when the theory has broken P and T symmetries. Since the CP violation (CPV) arising from the standard model (SM) is small or strongly suppressed at high temperature, new CPV from beyond the SM (BSM) is needed to explain the baryogenesis, and EDMs of elementary particles, such as the neutron, are good probes of such BSM physics. In...
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Oliver Baer (Humboldt University Berlin, Germany)21/06/2019, 16:30Hadron structureParallel
The $N\pi$ state contribution to nucleon 3-pt functions involving the pseudoscalar density P(x) and the time component $A_{4}(x)$ of the axial vector current are computed to LO in ChPT. In case of the latter the $N\pi$ contribution is O($M_N$) enhanced compared to the single nucleon ground state contribution. In addition, a relative sign in two terms of the $N\pi$-state contribution leads an...
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Finn Stokes (Forschungszentrum Jülich GmbH)21/06/2019, 16:50Hadron structureParallel
The recently-introduced Parity Expanded Variational Analysis (PEVA) technique allows for the isolation of baryon eigenstates on the lattice at finite momentum free from opposite-parity contamination. We find that this technique introduces a statistically significant correction in extractions of the electromagnetic form factors of the ground state nucleon.
It also allows first extractions of...
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Prof. Keh-Fei Liu (University of Kentucky)Hadron structureParallel
We present our results on the neutron and proton electric dipole moments
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from the $\theta$ term with the cluster decomposition error reduction (CDER) technique. The calculation is carried out on two domain-wall fermion lattices with
lattice spacing a = 0.114 fm and 0.145 fm and pion mass at 330 MeV and 170 MeV,
respectively. We use the overlap valence fermion and the topological charge is...