HEP Lattice·hep-lat

Thu·Dec 23, 2021Thursday·December 23, 2021

11 papers—7 primary·4 cross-listed·reconstructed*

01*
Hadronic vacuum polarization of the muon on 2+1+1-flavor HISQ ensembles: an update
Shaun Lahert🇺🇸 · Carleton DeTar🇺🇸 · Aida El-Khadra🇺🇸 · Elvira Gámiz🇪🇸 · Steven Gottlieb🇺🇸 · Andreas Kronfeld🇺🇸 · Ethan Neil🇺🇸 · Curtis T. Peterson🇺🇸 · Ruth Van de Water🇺🇸
We give an update on the status of the Fermilab Lattice-HPQCD-MILC calculation of the contribution to the muon's anomolous magnetic moment from the light-quark, connected hadronic vacuum polarization. We present preliminary, blinded results in the intermediate window for this contribution, $a_{μ, W}^{l l}$ . The calculation is performed on $N_{f} = 2 + 1 + 1$ highly-improved staggered quark (HISQ) ensembles from the MILC collaboration with physical pion mass at four lattice spacings between 0.15 fm and 0.06 fm. We also present preliminary results for a study of the two-pion contributions to the vector-current correlation function performed on the 0.15 fm ensemble where we see a factor of four improvement over traditional noise reduction techniques.
hep-latPoS(2022)·12 citations
02*
2+1 flavor fine lattice simulation at finite temperature with domain-wall fermions
Sinya Aoki (1)🇯🇵 · Yasumichi Aoki (2)🇯🇵 · Hidenori Fukaya (3)🇯🇵 · Shoji Hashimoto (4 and 5)🇯🇵 · Issaku Kanamori (2)🇯🇵 · Takashi Kaneko (4 and 5)🇯🇵 · Yoshifumi Nakamura (2) ((1) YITP, (2) R-CCS, (3) Osaka-U, (4) KEK, (5) Sokendai)🇯🇵
Simulations for the thermodynamics of the 2+1 flavor QCD are performed employing chiral fermions. The use of Möbius domain-wall fermions with stout-link smearing is more effective on the finer lattices where all the relevant chiral symmetries are realized more accurately. We report on the initial simulations near the (pseudo) critical point using the line of constant physics with an average $u d$ quark mass slightly heavier than physical at $a ≲ 0.1$ fm.
hep-latPoS(2022)·9 citations
03*
Near-Physical Point Lattice Calculation of Isospin-Breaking Corrections to $K_{ℓ 2} / π_{ℓ 2}$
Andrew Zhen Ning Yong🇬🇧 · Peter Boyle🇺🇸 · Matteo Di Carlo🇬🇧 · Felix Erben🇬🇧 · Vera Gülpers🇬🇧 · Maxwell T. Hansen🇬🇧 · Tim Harris🇬🇧 · Nils Hermansson-Truedsson🇨🇭 · Raoul Hodgson🇬🇧 · Andreas Jüttner🇬🇧 · Antonin Portelli🇬🇧 · James Richings🇬🇧
In recent years, lattice determinations of non-perturbative quantities such as $f_{K}$ and $f_{π}$ , which are relevant for $V_{u s}$ and $V_{u d}$ , have reached an impressive precision of $O (1%)$ or better. To make further progress, electromagnetic and strong isospin breaking effects must be included in lattice QCD simulations. We present the status of the RBC/UKQCD lattice calculation of isospin-breaking corrections to light meson leptonic decays. This computation is performed in a (2+1)-flavor QCD simulation using Domain Wall Fermions with near-physical quark masses. The isospin-breaking effects are implemented via a perturbative expansion of the action in $α$ and $(m_{u} - m_{d})$ . In this calculation, we work in the electro-quenched approximation and the photons are implemented in the Feynman gauge and $QED_{L}$ formulation.
hep-latPoS(2022)·1 citation
04*
Density of states for gravitational waves
Felix Springer🇬🇧 · David Schaich🇬🇧
We present ongoing investigations of the first-order confinement transition of a composite dark matter model, to predict the resulting spectrum of gravitational waves. To avoid long autocorrelations at the first-order transition, we employ the Logarithmic Linear Relaxation (LLR) density of states algorithm. After testing our calculations by reproducing existing results for compact U(1) lattice gauge theory, we focus on the pure-gauge SU(4) theory related to the Stealth Dark Matter model.
hep-latPoS(2022)·17 citations
05*
Hamiltonian Lattice QCD from Strong Coupling Expansion
Pratitee Pattanaik🇩🇪 · Wolfgang Unger🇩🇪
We present generalizations of Hamiltonian Lattice QCD as derived from the continuous time limit of strong coupling lattice QCD: we discuss the flavor dependence and the effect of gauge corrections. This formalism can be applied at finite temperature and baryon density as well as isospin density and allows both for analytic and numeric investigations that are sign problem-free.
hep-latPoS(2022)·3 citations
06*
Analytic expansions of two- and three-particle excited-state energies
Dorota M. Grabowska🇨🇭 · Maxwell T. Hansen🇬🇧
The last years have seen significant developments in methods relating two- and three-particle finite-volume energies to scattering observables. These relations hold for both weakly and strongly interacting systems, and studying their predictions in limiting cases can provide important cross checks as well as giving useful insights into the general formulae. In these proceedings, we present analytic results for finite-volume excited states, recovered by expanding the general relations in powers of the interaction strength. We highlight elegant patterns that emerge, especially for excited three-particle energies, and discuss various applications of the results. The two-particle results summarized here are described in more detail in the full manuscript, and the three-particle results are detailed in a manuscript to appear.
hep-latPoS(2022)·1 citation
07*
A note on improved stochastic trace estimation for fermionic string fluctuations
Valentina Forini🇬🇧 · Bjoern Leder🇩🇪 · Nils Wauschkuhn🇩🇪
We report on the use of a stochastic trace estimator algorithm, based on mutually unbiased bases, for evaluating the trace of a matrix differential operator appearing in the context of lattice simulations for the discretized superstring worldsheet. A study of the variance, in a setup which is slightly modified with respect to the original one, confirms advantages with respect to more traditional methods like the Gaussian estimator.
hep-lathep-th4 citations
08*
Symplectic quantization of multi-field Generalized Proca electrodynamics
Verónica Errasti Díez🇩🇪 · Marina Krstic Marinkovic🇨🇭
We explicitly carry out the symplectic quantization of a family of multi-field Generalized Proca (GP) electrodynamics theories. In the process, we provide an independent derivation of the so-called secondary constraint enforcing relations -- consistency conditions that significantly restrict the allowed interactions in multi-field settings already at the classical level. Additionally, we unveil the existence of quantum consistency conditions, which apply in both single- and multi-field GP scenarios. Our newly found conditions imply that not all classically well-defined (multi-)GP theories are amenable to quantization. The extension of our results to the most general multi-GP class is conceptually straightforward, albeit algebraically cumbersome.
↳ hep-thhep-latquant-phPRD(2022)·6 citations
09*
Two-dimensional $Z_{2}$ lattice gauge theory on a near-term quantum simulator: variational quantum optimization, confinement, and topological order
Luca Lumia🇮🇹 · Pietro Torta🇮🇹 · Glen B. Mbeng🇦🇹 · Giuseppe E. Santoro🇮🇹 · Elisa Ercolessi🇮🇹 · Michele Burrello🇩🇰 · Matteo M. Wauters🇩🇰
We propose an implementation of a two-dimensional $Z_{2}$ lattice gauge theory model on a shallow quantum circuit, involving a number of single and two-qubits gates comparable to what can be achieved with present-day and near-future technologies. The ground state preparation is numerically analyzed on a small lattice with a variational quantum algorithm, which requires a small number of parameters to reach high fidelities and can be efficiently scaled up on larger systems. Despite the reduced size of the lattice we consider, a transition between confined and deconfined regimes can be detected by measuring expectation values of Wilson loop operators or the topological entropy. Moreover, if periodic boundary conditions are implemented, the same optimal solution is transferable among all four different topological sectors, without any need for further optimization on the variational parameters. Our work shows that variational quantum algorithms provide a useful technique to be added in the growing toolbox for digital simulations of lattice gauge theories.
↳ quant-phhep-latPRX Quantum(2022)·41 citations
10*
Quantum walks, limits and transport equations
Giuseppe Di Molfetta🇫🇷
This manuscript gathers and subsumes a long series of works on using QW to simulate transport phenomena. Quantum Walks (QWs) consist of single and isolated quantum systems, evolving in discrete or continuous time steps according to a causal, shift-invariant unitary evolution in discrete space. We start reminding some necessary fundamentals of linear algebra, including the definitions of Hilbert space, tensor state, the definition of linear operator and then we briefly present the principles of quantum mechanics on which this thesis is grounded. After having reviewed the literature of QWs and the main historical approaches to their study, we then move on to consider a new property of QWs, the plasticity. Plastic QWs are those ones admitting both continuous time-discrete space and continuous spacetime time limit. We show that such QWs can be used to quantum simulate a large class of physical phenomena described by transport equations. We investigate this new family of QWs in one and two spatial dimensions, showing that in two dimensions, the PDEs we can simulate are more general and include dispersive terms. We show that the above results do not need to rely on the grid and we prove that such QW-based quantum simulators can be defined on 2-complex simplicia, i.e. triangular lattices. Finally, we extend the above result to any arbitrary triangulation, proving that such QWs coincide in the continuous limit to a transport equation on a general curved surface, including the curved Dirac equation in 2+1 spacetime dimensions.
↳ quant-phcs.DMcs.NAhep-lat+32 citations
11*
3+1d Boundaries with Gravitational Anomaly of 4+1d Invertible Topological Order for Branch-Independent Bosonic Systems
Zheyan Wan🇨🇳 · Juven Wang🇺🇸 · Xiao-Gang Wen🇺🇸
We study bosonic systems on a spacetime lattice defined by path integrals of commuting fields. We introduce branch-independent bosonic (BIB) systems, whose path integral is independent of the branch structure of the spacetime simplicial complex, even for a spacetime with boundaries. In contrast, a generic lattice bosonic (GLB) system's path integral may depend on the branch structure. We find the invertible topological order characterized by the Stiefel-Whitney cocycle (e.g., 4+1d w $_{2}$ w $_{3}$ ) to be nontrivial for BIB systems, but this topological order and a trivial gapped tensor product state belong to the same phase for GLB systems. The invertible topological orders in GLB systems are not classified by the oriented cobordism. The branch dependence on a lattice may be related to the orthonormal frame of smooth manifolds and the framing anomaly of continuum field theories. The branch structure on a discretized lattice may be related to a frame structure on a smooth manifold that trivializes any Stiefel-Whitney classes. We construct BIB systems to realize the w $_{2}$ w $_{3}$ topological order, and its 3+1d gapped or gapless boundaries. A 3+1d $Z_{2}$ gauge theory with (1) fermionic $Z_{2}$ gauge charge particle trivializes w $_{2}$ and (2) fermionic $Z_{2}$ gauge flux line trivializes w $_{3}$ . In particular, if the flux loop's worldsheet is unorientable, then an orientation-reversal 1d worldline corresponds to a fermion worldline carrying no $Z_{2}$ gauge charge. Spin and Spin $^{c}$ structures trivialize the w $_{2}$ w $_{3}$ global pure gravitational anomaly to zero (which helps to construct 3+1d $Z_{2}$ and all-fermion U(1) gauge theories), but the Spin $^{h}$ and Spin $\times_{Z_{2}}$ Spin $(n \geq 3)$ structures modify the w $_{2}$ w $_{3}$ into a global mixed gauge-gravitational anomaly, which helps to constrain Grand Unifications (e.g., $n = 10, 18$ ) or construct new models.
↳ cond-mat.str-elhep-lathep-phhep-th+1PRB(2022)·13 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.