Dr
Takashi Kaneko
(KEK)
7/24/18, 6:45 PM
Poster
We report our preliminary results for the $B \to D^{(*)}\ell\nu$
semileptonic form factors at zero and nonzero recoils in 2+1 flavor
QCD. The Moebius domain-wall action is employed for light, charm
and bottom quarks at lattice cutoffs $a^{-1}$ = 2.5 and 3.6 GeV.
We take bottom quark masses up to 2.4 times the physical charm mass
to control discretization effects. We test the heavy quark...
Dr
Saul Cohen
(NVIDIA)
7/24/18, 6:45 PM
Algorithms and Machines
Poster
This year, 2018, the QUDA library for Lattice QCD on NVIDIA GPUs celebrates its tenth birthday. QUDA has evolved from an acceleration library for solvers into an open-source framework for developing QCD simulations. It supports many different fermion discretizations, and features algorithms like adaptive multigrid, deflation and block Krylov-space methods. QUDA uses various techniques such as...
Mr
Shuhei Yamamoto
(The University of Utah)
7/24/18, 6:45 PM
Poster
We describe a computation of the contribution to the anomalous magnetic moment of the muon from the disconnected part of the hadronic vacuum polarization. We use the highly-improved staggered quark (HISQ) formulation for the current density with gauge configurations generated with four flavors of HISQ sea quarks. The computation is performed by stochastic estimation of the current density...
Prof.
Anna Hasenfratz
(university of colorado boulder)
7/24/18, 6:45 PM
Standard Model Parameters and Renormalization
Poster
We calculate the step scaling function for twelve fundamental flavors
nonperturbatively by determining the gradient flow coupling on gauge field configurations generated with dynamical stout smeared Möbius domain wall fermions and Symanzik gauge action. Using Zeuthen, Symanzik, and Wilson flow we measure the energy density with three different operators. Our updated analysis is now based on...
Mr
Dillon Frame
(Michigan State University)
7/24/18, 6:45 PM
Hadron Spectroscopy and Interactions
Poster
Eigenvector Continuation is a new method designed to aid in the calculation of lattice observables in situations where conventional methods, like perturbation theory, fails. We present the details of this method, and results for simulations of the Coulomb interaction in $^{4}$He and $^{8}$Be, using both Auxiliary Field Monte Carlo and Eigenvector Continuation.
Zhouyou Fan
(Michigan State University)
7/24/18, 6:45 PM
Hadron Structure
Poster
Parton distribution functions (PDFs) are central to the study of the hadron scattering cross sections with(within) collinear factorization. Recently, the Large-momentum effective theory (LaMET) introduced the quasi-PDF, providing the possibility to explore the entire PDF instead of just the first few moments. Since then, a lot of studies have been done on the quark quasi-PDFs. Compared to the...
Dr
Paulo Silva
(University of Coimbra)
7/24/18, 6:45 PM
Vacuum Structure and Confinement
Poster
We report on results for the Landau gauge gluon propagator computed from large statistical ensembles and look at the compatibility of the results with the Gribov-Zwanziger tree level prediction for its refined and very refined versions. Our results show that the data is well described by the tree level estimate only up to momenta p ≲1 GeV, while clearly favoring the so-called Refined...
Mr
Aditya Savanur
(Michigan State University)
7/24/18, 6:45 PM
Hadron Structure
Poster
The hyperon axial couplings are important parameters
entering the low-energy effective field theory description
of the octet baryons. In addition, the coupling constants appear
in the non-leptonic decays of hyperons, and hyperon-hyperon and
hyperon-nucleon scattering processes, which can be used in the
description of neutron stars. In this poster, we present preliminary
results on...
Dr
Piotr Korcyl
(Jagiellonian University and University of Regensburg)
7/24/18, 6:45 PM
Poster
We port the most critical part of the Lattice Quantum Chromodynamics code, the iterative solver, to modern
FPGA devices. More precisely, we discuss a single-node, double precision implementation
of the Conjugate Gradient algorithm and use it to invert numerically the Dirac-Wilson operator on a
4-dimensional grid on a Xilinx Zynq evaluation board. We propose a separation of...
Dr
Shoji Hashimoto
(KEK)
7/24/18, 6:45 PM
Weak Decays and Matrix Elements
Poster
A lattice calculation of inclusive decay structure functions for
$B¥to X_c¥ell¥nu$ is compared with the corresponding estimates
based on the heavy quark expansion. Both methods are applicable
in the region away from the resonances/cuts due to final charmed
states, and one can test the theoretical methods employed on both
sides.
Colin Lauer
(Temple University)
7/24/18, 6:45 PM
Hadron Structure
Poster
We present a study of volume effects for Nf=2 twisted mass fermions using simulations at the physical point. The main focus will be given to nucleon quantities such as the axial charge and quark momentum fraction. The two volumes that we compare are 4.5fm and 6 fm
Jian Liang
(University of Kentucky)
7/24/18, 6:45 PM
Hadron Structure
Poster
We report our calculation of the neutron electric dipole moment of the contribution from the $\theta$ term with overlap fermions on the 2+1-flavor RBC/UKQCD domain wall lattices 24I and 32ID. For the 24I lattice the size is 2.65 fm and the pion mass is 337 MeV and for the 32ID lattice the size is 4.58 fm and the pion mass is 171 MeV. In order to solve the large-volume problem, the...
Anthony Grebe
(Massachusetts Institute of Technology)
7/24/18, 6:45 PM
Hadron Structure
Poster
The charge radius of the proton has been measured in scattering and spectroscopy experiments using both electronic and muonic probes. The electronic and muonic measurements have a currently unresolved five sigma discrepancy, giving rise to what is known as the proton radius puzzle.
Since the neutron charge radius is known, measurement of the proton charge radius on the lattice typically...
Ming Gong
7/24/18, 6:45 PM
Algorithms and Machines
Poster
We are developing a code package for the supercomputer Shenwei Taihu-Light in China. There is an optimized D-slash function and some inverter functions in the code pacakge. We will show the working progress of this project.
Dr
Nils Meyer
(University of Regensburg)
7/24/18, 6:45 PM
Poster
We present our experiences porting Lattice QCD code to upcoming ARM processor architectures,
which will be used for future supercomputers such as QPACE 4 (University of Regensburg, Germany) and Post-K (RIKEN, Japan). These processors will support the ARM Scalable Vector Extension (SVE). SVE allows to design processor cores providing significantly higher performance compared to the
cores...
Prof.
Xu Feng
(Peking University)
7/24/18, 6:45 PM
Weak Decays and Matrix Elements
Poster
Recently four experiments have demonstrated new levels of sensitivity to neutrinoless double beta ($0\nu\beta\beta$) decay. Such decay, if exists, would prove that neutrinos are Majorana fermions. The light-neutrino exchange is the most popular mechanism to explain the $0\nu\beta\beta$ decay. In this mechanism, the decay amplitude is proportional to the effective neutrino mass $m_{\beta\beta}$...
Mr
Erik Gustafson
(University of Iowa)
7/24/18, 6:45 PM
Physics Beyond the Standard Model
Poster
We examine mass splittings in a linear sigma model which is an effective theory for a SU(3) gauge theory with $N_1$ flavors of mass $m_1$ and $N_2$ flavors of mass $m_2$.
We discuss the consequences for current simulations done by various collaborations. We explain the relevance for BSM model building.
Mr
Jose Angel Romero Jurado
(Instituto de Fisica Teorica)
7/24/18, 6:45 PM
Weak Decays and Matrix Elements
Poster
We will present a detailed description of the matching of a valence Nf=2+1+1
fully-twisted tmQCD action with an Nf=2+1, non-perturbatively O(a)-improved
Wilson sea. Extensive preliminary results for meson and quark masses, as well as
for pseudoscalar decay constants, are available for several CLS ensembles. A
comparison of the scaling behaviour of the two actions in the light and...
Prof.
Christine Davies
(University of Glasgow)
7/24/18, 6:45 PM
Hadron Structure
Poster
Lattice QCD can provide direct determination of the electromagnetic form factors of mesons as a prediction to be compared to upcoming experiments at Jefferson Lab. At the same time we can compare to expectations from perturbative QCD, which take a very simple form at high Q^2.
We will show recent results from HPQCD, building on the work in 1701.04250.
We give predictions for pi and K...
Dr
Andrea Bussone
(IFT, UAM-CSIC)
7/24/18, 6:45 PM
Standard Model Parameters and Renormalization
Poster
We propose a particular 'line of constant physics' (i.e., a scheme) for computing isospin breaking corrections to hadronic quantities. We show this scheme is in a class of schemes that allow for the separation of the electromagnetic and strong isospin breaking corrections at leading order, such that scheme-ambiguities are higher order in isospin breaking effects.
Mr
Tanjib Khan
(The College of William and Mary)
7/24/18, 6:45 PM
Poster
We present a calculation of the low-lying spectra for the positive-parity Delta and Nucleon using the distillation approach applied on an isotropic $32^3 \times 64$ lattice at a pion mass of around 360 MeV, using a non-relativistic basis of operators together with so-called hybrid-type operators. The spectra are extracted from two-point functions using variational analysis. The results are...
Mr
Benjamin Jaedon Choi
(Seoul National University)
7/24/18, 6:45 PM
Standard Model Parameters and Renormalization
We present matching factors for $Z_q$ calculated perturbatively at the one-loop level with improved staggered quarks. We calculate $Z_q$ with HYP-smeared staggered quarks and Symanzik-improved gluons in RI- and RI$'$-MOM scheme. Using the conversion factor, we also present $Z_q$ in MSbar scheme. As a byproduct, we present the quark mass renormalization ...
Dr
Issaku Kanamori
(Hiroshima University)
7/24/18, 6:45 PM
Algorithms and Machines
Poster
We port Domain-Decomposed-alpha-AMG solver to K computer.
The system has 8 cores and 16 GB memory par node, of which theoretical
peak is 128 GFlops (82,944 nodes in total). Its feature, as many as 256
registers par core and as large as 0.5 byte/Flop ratio, requires
a different tuning from other machines.
In order to use more registers, we change some of the data structure
and rewrite...
Mr
Manuel Scherzer
(Institut for theoretical Physics Heidelberg University)
7/24/18, 6:45 PM
Nonzero Temperature and Density
Poster
We perform CLE simulations both in the confining and in the deconfining phases of QCD at large temperature and in a wide chemical potential domain (up to \mu/T ~10). We show preliminary results for the deconfining transition at \beta = 5.9 for 2 flavors of Wilson fermions. Most of the data are taken at rather large quark masses (m_\pi ~ 1GeV) and small spatial volumes (8^3 and 12^3 ). This and...
Ms
Kimmy Cushman
(Yale University)
7/24/18, 6:45 PM
Hadron Spectroscopy and Interactions
Poster
A Prony method is an algebraic approach to extracting spectral energies from hadronic correlation functions. The simplest example is the effective mass commonly used in lattice gauge theory. We show our exploration of this method to extract multiple excited states for a pion point-point correlation function for an SU(3) gauge theory with 8 flavors. We discuss our approach for dealing with...
Daniel Hackett
(University of Colorado, Boulder)
7/24/18, 6:45 PM
Algorithms and Machines
Poster
Numerical studies in lattice gauge theory require the organization and analysis of large volumes of data. These data and analyses thereof can be viewed as a sequence of maps and reductions, a structure that can be represented naturally using relational databases. Organized in this way, the analysis of even large, heterogenous datasets is straightforward to automate. We present in abstract our...
Mr
Felix Ziegler
(Institute for Theoretical Physics, Heidelberg University)
7/24/18, 6:45 PM
Nonzero Temperature and Density
Poster
One of the main challenges in simulations on Lefschetz thimbles is the computation of the relative weights of contributing thimbles. In this paper we propose a solution to that problem by means of computing those weights using a reweighting procedure. Besides we present recipes for finding parametrizations of thimbles and anti-thimbles for a given theory. Moreover, we study some approaches to...
Dr
Chulwoo Jung
(Brookhaven National Laboratory)
7/24/18, 6:45 PM
Algorithms and Machines
Poster
The increasing unbalance between computing capabilities of individual
nodes and internode communication makes it highly desirable for any
Lattice QCD algorithm to minimize the amount of off-node communication.
One of the relatively new methods for this is the 'split-grid' or
'split-domain', where data is rearranged within the running of a single binary,
so that the routines which...
Nouman Butt
(Syracuse University)
7/24/18, 6:45 PM
Physics Beyond the Standard Model
Poster
We study a model of four reduced staggered fermions transforming in the bifundamental representation of an SU(2)xSU(2) symmetry group.
Single site mass terms are prohibited by this symmetry but a particular four fermi term is allowed. We gauge one of the SU(2) subgroups and examine
the phase structure of the model. We find evidence that the theory forms a symmetric four fermion condensate at...
Mr
Raghav Govind Jha
(Syracuse University)
7/24/18, 6:45 PM
Physics Beyond the Standard Model
Poster
We consider 1+1-dimensional maximally supersymmetric Yang–Mills theory (SYM) at large N and strong ’t Hooft coupling which is dual to D1 branes. One can have different tori based on the expansion of the gauge links in the moduli space, which is required to target the correct continuum theory. In our previous work, we explored a special skewed torus corresponding to A2* geometry. Here, we will...
Mr
Giovanni Pederiva
(Michigan State University)
7/24/18, 6:45 PM
Algorithms and Machines
Poster
We present a recently started project of a new implementation of a C++ code-base to perform lattice QCD calculations.
As a first step, we have implemented a Multi-Hit Metropolis algorithm for generating configurations in Yang-Mills theory and a third order Runge-Kutta scheme for
applying the Gradient Flow to the gauge fields.
We performed tests of the autocorrelation time of...
Prof.
Ross Young
(University of Adelaide)
7/24/18, 6:45 PM
Poster
The low-lying hadron spectrum has been of tremendous phenomenological significance in resolving the nature of quark masses in strong interaction dynamics. In particular, the pseudoscalar mesons provide the foundation of the framework of chiral perturbation theory, the low-energy effective theory of QCD. Modern lattice calculations of pure QCD now provide excellent precision in the resolution...