Tue·Sep 16, 2003Tuesday·September 16, 2003

1. 01*

   Insight into nucleon structure from generalized parton distributions

   LHPC Collaboration · SESAM Collaboration: J.W. Negele · R.C. Brower · P. Dreher · R. Edwards · G. Fleming · Ph. Hagler · Th. Lippert · A.V.Pochinsky · D.B. Renner · D. Richards · K. Schilling · W. Schroers

   The lowest three moments of generalized parton distributions are calculated in full QCD and provide new insight into the behavior of nucleon electromagnetic form factors, the origin of the nucleon spin, and the transverse structure of the nucleon.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·10 citations
2. 02*

   Confinement-deconfinement and universal string effects from random percolation

   Ferdinando Gliozzi🇮🇹 · Marco Panero🇮🇹 · Antonio Rago🇮🇹

   The 't Hooft criterion leading to confinement out of a percolating cluster of central vortices suggests defining a novel three-dimensional gauge theory directly on a random percolation process. Wilson loop is viewed as a counter of topological linking with the random clusters. Beyond the percolation threshold large Wilson loops decay with an area law and show the universal shape effects due to flux tube fluctuations. Wilson loop correlators define a non-trivial glueball spectrum. The crumbling of the percolating cluster when one periodic direction narrows accounts for the finite temperature deconfinement, which belongs to 2D percolation universality class.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·4 citations
3. 03*

   The deconfinement phase transition in Yang-Mills theory with general Lie group G

   K. Holland (San Diego U.)🇺🇸 · M. Pepe (Bern U.)🇨🇭 · U.-J. Wiese (Bern U. and MIT)🇨🇭

   We present numerical results for the deconfinement phase transition in Sp(2) and Sp(3) Yang-Mills theories in (2+1)-D and (3+1)-D. We then make a conjecture on the order of this phase transition in Yang-Mills theories with general Lie groups G = SU(N), SO(N), Sp(N) and with exceptional groups G = G(2), F(4), E(6), E(7), E(8).

   hep-latNucl.Phys.B Proc.Suppl.(2004)·23 citations
4. 04*

   A Transverse Lattice QCD Model for Mesons

   Apoorva Patel🇮🇳 · Raghunath Ratabole🇮🇳

   QCD is analysed with two light-front continuum dimensions and two transverse lattice dimensions. In the limit of large number of colours and strong transverse gauge coupling, the contributions of light-front and transverse directions factorise in the dynamics, and the theory can be analytically solved in a closed form. An integral equation is obtained, describing the properties of mesons, which generalises the 't Hooft equation by including spin degrees of freedom. The meson spectrum, light-front wavefunctions and form factors can be obtained by solving this equation numerically. These results would be a good starting point to model QCD observables which only weakly depend on transverse directions, e.g. deep inelastic scattering structure functions.

   hep-lathep-phhep-thNucl.Phys.B Proc.Suppl.(2004)·3 citations
5. 05*

   The Matter Density Distribution for Mesons and Baryons

   C. Alexandrou (Univ. of Cyprus)🇨🇾 · Ph. de Forcrand (CERN & ETH Zurich)🇨🇭 · A. Tsapalis (Univ. of Cyprus)🇨🇾

   The matter density distribution inside a hadron is evaluated using gauge-invariant correlation functions within the quenched and the unquenched theory. Comparison with the charge density distribution suggests that hadron deformation is a consequence of the relativistic motion of the quarks.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·6 citations
6. 06*

   Moments of nucleon spin-dependent generalized parton distributions

   W. Schroers (1)🇺🇸 · R.C. Brower (2)🇺🇸 · P. Dreher (1)🇺🇸 · R. Edwards (3)🇺🇸 · G. Fleming (3)🇺🇸 · Ph. Hagler (1)🇳🇱 · U.M. Heller (4)🇺🇸 · Th. Lippert (5)🇩🇪 · J.W. Negele (1)🇺🇸 · A.V. Pochinsky (1)🇺🇸 · D.B. Renner (1)🇺🇸 · D. Richards (3)🇺🇸 · K. Schilling (5) ((1) MIT, (2) Boston U., (3) JLab, (4) APS, (5) Wuppertal U.)🇩🇪

   We present a lattice measurement of the first two moments of the spin-dependent GPD H-tilde(x,xi,t). From these we obtain the axial coupling constant and the second moment of the spin-dependent forward parton distribution. The measurements are done in full QCD using Wilson fermions. In addition, we also present results from a first exploratory study of full QCD using Asqtad sea and domain-wall valence fermions.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·25 citations
7. 07*

   The continuum limit of perturbative coefficients calculated with a large field cutoff

   L. Li🇺🇸 · Y. Meurice🇺🇸

   We report MC calculations of perturbative coefficients for lattice scalar field theory in dimensions 1, 2 and 3, where the large field contributions are cutoff. This produces converging (instead of asymptotic) perturbative series. We discuss the statistical errors and the lattice effects and show that accurate calculations are possible even in a crossover region where no approximation works. We show that the field cutoff is also a UV regulator. We point out the relevance for QCD questions discussed by Tomboulis and Trottier at this conference.

   hep-latcond-mathep-thNucl.Phys.B Proc.Suppl.(2004)·3 citations
8. 08*

   Axial anomaly in the reduced model: Higher representations

   Teruaki Inagaki (Ibaraki Univ.)🇯🇵 · Yoshio Kikukawa (Nagoya Univ.)🇯🇵 · Hiroshi Suzuki (Ibaraki Univ.)🇯🇵

   The topological charge in the $\text{U}(N)$ vector-like reduced model can be defined by using the overlap Dirac operator. We obtain its large $N$ limit for a fermion in a general gauge-group representation under a certain restriction of gauge field configurations which is termed $\text{U}(1)$ embedding.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·2 citations
9. 09*

   Deflation of Eigenvalues for Iterative Methods in Lattice QCD

   Dean Darnell🇺🇸 · Ronald B. Morgan🇺🇸 · Walter Wilcox🇺🇸

   Work on generalizing the deflated, restarted GMRES algorithm, useful in lattice studies using stochastic noise methods, is reported. We first show how the multi-mass extension of deflated GMRES can be implemented. We then give a deflated GMRES method that can be used on multiple right-hand sides of $Ax=b$ in an efficient manner. We also discuss and give numerical results on the possibilty of combining deflated GMRES for the first right hand side with a deflated BiCGStab algorithm for the subsequent right hand sides.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·12 citations
10. 10*

    A precise determination of the decay constant of the D(s)-meson in quenched QCD

    Andreas Juttner🇩🇪 · Juri Rolf🇩🇪

    We present a precise determination of the leptonic decay constant F_D(s) of the D(s)-meson in quenched lattice QCD. This work is particularly focused on the analysis and discussion of all sources of systematic errors. We simulate directly at the physical quark masses for five different lattice spacings between 0.1fm and 0.03fm using O(a)-improvement. The finest lattice is still work in progress. After taking the continuum limit and setting the scale with the Kaon decay constant F_K=160MeV we arrive at a value of F_D(s)=252(9)MeV. Setting the scale with the nucleon mass instead leads to a decrease of about 20MeV of F_D(s).

    hep-latNucl.Phys.B Proc.Suppl.(2004)·4 citations
11. 11*

    Penguin diagrams for the HYP staggered fermions

    Keunsu Choi🇰🇷 · Weonjong Lee🇰🇷

    We present results of the one-loop corrections originating from the penguin diagrams for the improved staggered fermion operators constructed using various fat links such as Fat7, Fat7+Lepage, $\overline{Fat7}$, HYP (I) and HYP (II). The main results include the diagonal/off-diagonal mixing coefficients and the matching formula between the continuum and lattice operators.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·5 citations
12. 12*

    Non-perturbative renormalization of the axial current with improved Wilson quarks

    R. Hoffmann🇩🇪 · F. Knechtli🇩🇪 · J. Rolf🇩🇪 · R. Sommer🇩🇪 · U. Wolff🇩🇪

    We present a new normalization condition for the axial current, which is derived from the PCAC relation with non-vanishing mass. Using this condition reduces the O(r_0 m) corrections to the axial current normalization constant Z_A for an easier chiral extrapolation in the cases, where simulations at zero quark-mass are not possible. The method described here also serves as a preparation for a determination of Z_A in the full two-flavor theory.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·6 citations
13. 13*

    Towards a precision computation of f_Bs in quenched QCD

    J. Rolf🇩🇪 · M. Della Morte🇩🇪 · S. Durr🇩🇪 · J. Heitger🇩🇪 · A. Juttner🇩🇪 · H. Molke🇩🇪 · A. Shindler🇩🇪 · R. Sommer🇩🇪

    We present a computation of the decay constant f_Bs in quenched QCD. Our strategy is to combine new precise data from the static approximation with an interpolation of the decay constant around the charm quark mass region. This computation is the first step in demonstrating the feasability of a strategy for f_B in full QCD. The continuum limits in the static theory and at finite mass are taken separately and will be further improved.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·26 citations
14. 14*

    Hadronic decays from the lattice

    UKQCD Collaboration: C. Michael🇬🇧 · C. McNeile🇬🇧

    We discuss strategies to determine hadronic decay couplings from lattice studies. As an application, we explore the decay of a vector meson to two pseudoscalar mesons with $N_f=2$ flavours of sea quark. Although we are working with quark masses that do not allow a physical decay, we show how the transition rate can be evaluated from the amplitude for $\rho \to \pi \pi$ and from the annihilation component of $\pi \pi \to \pi \pi$. We explore the decay amplitude for two different pion momenta and find consistent results. The coupling strength we find is in agreement with experiment. We also find evidence for a shift in the $\rho$ mass caused by mixing with two pion states.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·0 citations
15. 15*

    Simulating the Schroedinger functional with two pseudo-fermions: algorithmic study and the running mass

    F. Knechtli🇩🇪 · M. Della Morte🇩🇪 · J. Rolf🇩🇪 · R. Sommer🇩🇪 · I. Wetzorke🇩🇪 · U. Wolff (ALPHA collaboration)🇩🇪

    We present an algorithmic study for the simulation of two massless flavors of O(a) improved Wilson quarks with Schroedinger functional boundary conditions. The algorithm used is Hybrid Monte Carlo with two pseudo-fermion fields as proposed by M. Hasenbusch. A gain in CPU cost of a factor two is reached when compared to one pseudo-fermion field due to the larger possible step-size. This study is integrated in the ALPHA project for the computation of the running of the renormalized quark mass. We include an update on these physics results.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·5 citations
16. 16*

    I=2 pion scattering length with the parametrized fixed point action

    K. J. Juge (for the BGR Collaboration)🇨🇭

    We report on the pion-pion scattering length in the I=2 channel using the parametrized fixed point action. Pion masses of 320 MeV were reached in this quenched calculation of the scattering length.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·22 citations
17. 17*

    The Factorization Method for Monte Carlo Simulations of Systems With a Complex Action

    J. Ambjorn (Niels Bohr)🇩🇰 · K. N. Anagnostopoulos (U. Crete)🇬🇷 · J. Nishimura (KEK)🇯🇵 · J.J.M. Verbaarschot (SUNY, Stony Brook)🇺🇸

    We propose a method for Monte Carlo simulations of systems with a complex action. The method has the advantages of being in principle applicable to any such system and provides a solution to the overlap problem. In some cases, like in the IKKT matrix model, a finite size scaling extrapolation can provide results for systems whose size would make it prohibitive to simulate directly.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·0 citations
18. 18*

    The equation of state for two flavor QCD at finite density

    S. Ejiri🇩🇪 · C.R. Allton🇬🇧 · S.J. Hands🇬🇧 · O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · E. Laermann🇩🇪 · C. Schmidt🇩🇪

    We discuss the equation of state for QCD at non-zero temperature and density. We present results of a simulation for QCD with 2 flavors of p4-improved staggered fermions. Derivatives of $\ln \mathcal{Z}$ with respect to quark chemical potential ${\mu }_q$ up to fourth order are calculated, enabling estimates of the pressure, quark number density and associated susceptibilities as functions of ${\mu }_q$ via a Taylor series expansion. We also discuss the radius of convergence of the expansion as a function of temperature. It is found that the fluctuations in the quark number density increase in the vicinity of the phase transition temperature and the susceptibilities start to develop a pronounced peak as ${\mu }_q$ is increased. This suggests the presence of a critical endpoint in the $(T,{\mu }_q)$ plane.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·0 citations
19. 19*

    Accelerating Hasenbusch's acceleration of Hybrid Monte Carlo

    A. Ali Khan🇩🇪 · T. Bakeyev🇷🇺 · M. Göckeler🇩🇪 · R. Horsley🇬🇧 · D. Pleiter🇩🇪 · P.E.L. Rakow🇬🇧 · A. Schäfer🇩🇪 · G. Schierholz🇩🇪 · H. Stüben🇩🇪

    Hasenbusch has proposed splitting the pseudo-fermionic action into two parts, in order to speed-up Hybrid Monte Carlo simulations of QCD. We have tested a different splitting, also using clover-improved Wilson fermions. An additional speed-up between 5 and 20% over the original proposal was achieved in production runs.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·6 citations
20. 20*

    Baryonic Operators for Lattice Simulations

    LHP Collaboration: R. Edwards🇺🇸 · R. Fiebig🇺🇸 · G. Fleming🇺🇸 · U.M. Heller🇺🇸 · C. Morningstar🇺🇸 · D. Richards🇺🇸 · I. Sato🇺🇸 · S. Wallace🇺🇸

    The construction of baryonic operators for determining the N* excitation spectrum is discussed. The operators are designed with one eye towards maximizing overlaps with the low-lying states of interest, and the other eye towards minimizing the number of sources needed in computing the required quark propagators. Issues related to spin identification are outlined. Although we focus on tri-quark baryon operators, the construction method is applicable to both mesons and penta-quark operators.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·11 citations
21. 21*

    Static quarks with improved statistical precision

    M. Della Morte🇩🇪 · S. Durr🇩🇪 · J.Heitger🇩🇪 · H. Molke🇩🇪 · J. Rolf🇩🇪 · A. Shindler🇩🇪 · R. Sommer🇩🇪

    We present a numerical study for different discretisations of the static action, concerning cut-off effects and the growth of statistical errors with Euclidean time. An error reduction by an order of magnitude can be obtained with respect to the Eichten-Hill action, for time separations beyond 1.3 fm, keeping discretization errors small. The best actions lead to a big improvement on the precision of the quark mass Mb and F_Bs in the static approximation.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·12 citations
22. 22*

    The mass of the charm quark from unquenched lattice QCD at fixed lattice spacing

    UKQCD Collaboration · A. Dougall · C. M. Maynard · C. McNeile

    We determine the mass of the charm quark ($m_c$) from lattice QCD with two flavors of dynamical quarks with a mass around the strange quark. We compare this to a determination in quenched QCD which has the same lattice spacing (0.1 fm). We investigate different formulations of the quark mass, based on the Vector Ward Identity, PCAC relation and the FNAL heavy quark formalism. Based on these preliminary results we find no effects due to sea quarks with a mass around strange.

    hep-lathep-phNucl.Phys.B Proc.Suppl.(2004)·4 citations
23. 23*

    Classical issues in electroweak baryogenesis

    Jan Smit🇳🇱 · Anders Tranberg🇳🇱

    In one scenario of baryogenesis, the matter-antimatter asymmetry was generated in the early universe during a cold electroweak transition. We model this transition by changing the sign of the effective mass-squared parameter of the Higgs field from positive to negative. The resulting `tachyonic' instability leads to a rapid growth of occupation numbers, such that a classical approximation can be made in computing subsequent developments in real time. We solve the classical equations of motion in the SU(2)-Higgs model under the influence of effective CP-violation. The resulting baryon asymmetry follows from the generated Chern-Simons number using the anomaly equation. The `classical' difficulties with lattice implementations of these observables are avoided here because the fields are smooth on the lattice scale.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·2 citations
24. 24*

    Meson Correlation Functions in the epsilon-Regime

    T. Chiarappa🇩🇪 · W. Bietenholz🇩🇪 · K. Jansen🇩🇪 · K.-I. Nagai🇩🇪 · S. Shcheredin🇩🇪

    We present a numerical pilot study of the meson correlation functions in the epsilon-regime of chiral perturbation theory. Based on simulations with overlap fermions we measured the axial and pseudo-scalar correlation functions, and we discuss the implications for the leading low energy constants in the chiral Lagrangian.

    hep-lathep-phNucl.Phys.B Proc.Suppl.(2004)·6 citations
25. 25*

    The RHMC Algorithm for 2 Flavours of Dynamical Staggered Fermions

    M. A. Clark🇬🇧 · A. D. Kennedy🇬🇧

    We describe an implementation of the Rational Hybrid Monte Carlo (RHMC) algorithm for dynamical computations with two flavours of staggered quarks. We discuss several variants of the method, the performance and possible sources of error for each of them, and we compare the performance and results to the inexact R algorithm.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·162 citations
26. 26*

    Volume dependence of light hadron masses in full lattice QCD

    B. Orth🇩🇪 · T. Lippert🇩🇪 · K. Schilling🇩🇪

    The aim of the GRAL project is to simulate full QCD with standard Wilson fermions at light quark masses on small to medium-sized lattices and to obtain infinite-volume results by extrapolation. In order to establish the functional form of the volume dependence we study systematically the finite-size effects in the light hadron spectrum. We give an update on the status of the GRAL project and show that our simulation data for the light hadron masses depend exponentially on the lattice size.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·12 citations
27. 27*

    Progress in automated perturbation theory for heavy quark physics

    Matthew Nobes🇨🇦 · Howard Trottier🇨🇦

    We review our perturbative techniques for improved heavy quark actions. A new procedure for computing improvement coefficients is suggested, where the continuum limit of a lattice-regularized theory provides the matching conditions.We also use a gauge-invariant infrared regulator that is well suited to higher-order calculations in lattice gauge theory. We report on preliminary tests of our method, as well as a possible way to reduce systematic errors in these calculations.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·20 citations
28. 28*

    Improved bilinears in unquenched lattice QCD

    Tanmoy Bhattacharya🇺🇸 · Rajan Gupta🇺🇸 · Weonjong Lee🇰🇷 · Stephen R. Sharpe🇺🇸 · Jackson M. S. Wu🇺🇸

    We summarize the extent to which one can use Ward identities to non-perturbatively improve flavor singlet and non-singlet bilinears with three flavors of non-degenerate dynamical Wilson-like fermions.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·5 citations
29. 29*

    Pion and kaon physics with improved staggered quarks

    MILC Collaboration: C. Aubin🇺🇸 · C. Bernard🇺🇸 · C. DeTar🇺🇸 · Steven Gottlieb🇺🇸 · E.B. Gregory🇺🇸 · Urs M. Heller🇺🇸 · J.E. Hetrick🇺🇸 · J. Osborn🇺🇸 · R. Sugar🇺🇸 · D. Toussaint🇺🇸

    We compute pseudoscalar meson masses and decay constants using staggered quarks on lattices with three flavors of sea quarks and lattice spacings $\approx 0.12$ fm and $\approx 0.09$ fm. We fit partially quenched results to ``staggered chiral perturbation theory'' formulae, thereby taking into account the effects of taste-symmetry violations. Chiral logarithms are observed. From the fits we calculate $f_{\pi }$ and $f_K$, extract Gasser-Leutwyler parameters of the chiral Lagrangian, and (modulo rather large perturbative errors) find the light and strange quark masses.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·27 citations
30. 30*

    New advances in numerical simulations of theta-vacuum systems

    V. Azcoiti🇪🇸 · G. Di Carlo🇮🇹 · A. Galante🇮🇹 · V. Laliena🇪🇸

    We proposed two different methods for simulating theta-vacuum systems. Both can be affected by systematic effects but these errors can be controlled by comparing the results of the two unrelated methods. This has been done for some analytically soluble models and here the same procedure is successfully applied to the interesting case of CP^9 in the scaling region.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·1 citation
31. 31*

    Pentaquark hadrons from lattice QCD

    F.Csikor🇭🇺 · Z. Fodor🇭🇺 · S.D. Katz🇩🇪 · T.G. Kovacs🇩🇪

    We study spin 1/2 isoscalar and isovector candidates in both parity channels for the recently discovered \Theta^+(1540) pentaquark particle in quenched lattice QCD. Our analysis takes into account all possible uncertainties, such as statistical, finite size and quenching errors when performing the chiral and continuum extrapolations and we have indications that our signal is separated from scattering states. The lowest mass that we find in the I^P=0^- channel is in complete agreement with the experimental value of the \Theta^+ mass. On the other hand, the lowest mass state in the opposite parity I^P=0^+ channel is much higher. Our findings suggests that the parity of the \Theta^+ is negative.

    hep-lathep-exhep-phnucl-thJHEP(2003)·232 citations
32. 32*

    Mass spectrum of N* and source optimization

    LHP Collaboration: S. Basak🇺🇸 · R. Edwards🇺🇸 · R. Fiebig🇺🇸 · G. Fleming🇺🇸 · U. M. Heller🇺🇸 · C. Morningstar🇺🇸 · D. Richards🇺🇸 · I. Sato🇺🇸 · S. Wallace🇺🇸

    We have computed correlation functions for nucleons and extracted the masses for positive- and negative-parities. Use of group theory plays an important role in obtaining sources that have good overlap to higher spin states and minimum contamination from unwanted states. In the simulation three distinct sources and corresponding sinks that transform according to the $G_1$ irreducible representations are tested and used to form matrices of correlation functions. Diagonalizations give us clear mass splittings between low-lying states and excited states for both parities.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·5 citations
33. 33*

    Progress Calculating Decay Constants with NRQCD and AsqTad Actions

    Matthew Wingate🇺🇸 · Christine Davies🇬🇧 · Alan Gray🇬🇧 · Emel Gulez · G. Peter Lepage🇺🇸 · Junko Shigemitsu🇺🇸

    We combine a light AsqTad antiquark with a nonrelativistic heavy quark to compute the decay constants of heavy-light pseudoscalar mesons using the ensemble of 3-flavor gauge field configurations generated by the MILC collaboration. Preliminary results for $f_{B_s}$ and $f_{D_s}$ are given and status of the chiral extrapolation to $f_B$ is reported. We also touch upon results of the perturbative calculation which matches matrix elements in the effective theory to the full theory at 1-loop order.

    hep-latNucl.Phys.B Proc.Suppl.(2004)·16 citations
34. 34*

    Instantons and Scalar Multiquark States: From Small to Large N_c

    Thomas Schaefer (North Carolina State and Riken-BNL)🇺🇸

    We study scalar quark-anti-quark and two-quark-two-anti-quark correlation functions in the instanton liquid model. We show that the instanton liquid supports a light scalar-isoscalar (sigma) meson, and that this state is strongly coupled to both $(\bar{q}q)$ and $(\bar{q}q{)}^2$. The scalar-isovector $a_0$ meson, on the other hand, is heavy. We also show that these properties are specific to QCD with three colors. In the large $N_c$ limit the scalar-isoscalar meson is not light, and it is mainly coupled to $(\bar{q}q)$.

    ↳ hep-phhep-latPRD(2003)·22 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.