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1. B- and D-meson leptonic decay constants and quark masses from four-flavor lattice QCD

   TUMQCD and Fermilab Lattice and MILC Collaborations: Bazavov, A.; Bernard, C; Brambilla, N.; Brown, N.; DeTar, C.; El Khadra, A.X.; Gámiz, E.; Gottlieb, S.; Heller, U.M.; Komijani, J.; et al (January 2019, 13th Conference on the Intersections of Particle and Nuclear Physics)

   We describe a recent lattice-QCD calculation of the leptonic decay con- stants of heavy-light pseudoscalar mesons containing charm and bottom quarks and of the masses of the up, down, strange, charm, and bottom quarks. Results for these quantities are of the highest precision to date. Calculations use 24 isospin-symmetric ensembles of gauge-field configura- tions with six different lattice spacings as small as approximately 0.03 fm and several values of the light quark masses down to physical values of the average up- and down-sea-quark masses. We use the highly-improved staggered quark (HISQ) formulation for valence and sea quarks, includ- ing the bottom quark. The analysis employs heavy-quark effective theory (HQET). A novel HQET method is used in the determination of the quark masses. 

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2. B- and D-meson semileptonic decays with highly improved staggered quarks

   https://doi.org/10.22323/1.396.0109  

   Jay, William; Lytle, Andrew; DeTar, Carleton; El-Khadra, Aida X; Gamiz, Elvira; Gelzer, Zechariah; Gottlieb, Steven; Kronfeld, Andreas; Simone, Jim; Vaquero, Alejandro (May 2022, The 38th International Symposium on Lattice Field Theory (LATTICE2021))

   We present results for B(s)- and D(s)-meson semileptonic decays from ongoing calculations by the Fermilab Lattice and MILC Collaborations. Our calculation employs the highly improved stag- gered quark (HISQ) action for both sea and valence quarks and includes several ensembles with physical-mass up, down, strange, and charm quarks and lattice spacings ranging from a ≈ 0.15 fm down to 0.06 fm. At most lattice spacings, an ensemble with physical-mass light quarks is included. The use of the highly improved action, combined with the MILC Collaboration’s gauge ensembles with lattice spacings down to a ≈ 0.042 fm, allows heavy valence quarks to be treated with the same discretization as the light and strange quarks. This unified treatment of the valence quarks allows (in some cases) for absolutely normalized currents, bypassing the need for perturbative matching, which has been a leading source of uncertainty in previous calculations of B-meson decay form factors by our collaboration. All preliminary form-factor results are blinded. 

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3. Excited state analysis in the quasi-PDF matrix elements

   https://doi.org/10.22323/1.334.0097  

   Li, Ruizi; Yang, Yi-Bo; Lin, Huey-Wen (May 2019, The 36th Annual International Symposium on Lattice Field Theory (LATTICE2018))

   We study and demonstrate the ground-state extrapolation of the unpolarized and polarized nucleon quark quasi-PDF matrix elements in a highly boosted hadron frame on the lattice. The calculation is done using the Wilson clover quark on a MILC’s dynamical Nf = 2+1+1 highly improved staggered quarks (HISQ) ensemble with one step hypercubic smearing, and with the lattice spacing a∼0.09 fm and pion mass 310 MeV. Applying the Gaussian momentum-smeared quark sources and comparing various fits in 1-, 2-, and 3-state fitting models, we show that excited state contributions can be under control in the lattice calculation of the nucleon quark quasi-PDF matrix elements. 

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4. Gluon Parton Distribution of the Pion from Lattice QCD

   Zhouyou Fan, Huey-Wen Lin (January 2021, Physics letters)

   null (Ed.)

   We present the first determination of the x-dependent pion gluon distribution from lattice QCD using the pseudo-PDF approach. We use lattice ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration, at two lattice spacings a≈0.12 and 0.15~fm and three pion masses Mπ≈220, 310 and 690 MeV. We use clover fermions for the valence action and momentum smearing to achieve pion boost momentum up to 2.29 GeV. We find that the dependence of the pion gluon parton distribution on lattice spacing and pion mass is mild. We compare our results from the lightest pion mass ensemble with the determination by JAM and xFitter global fits. 

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5. Hadronic vacuum polarization of the muon on 2+1+1-flavor HISQ ensembles: an update.

   https://doi.org/10.22323/1.396.0526  

   Lahert, Shaun; DeTar, Carleton; El-Khadra, Aida X; Gámiz, Elvira; Gottlieb, Steven; Kronfeld, Andreas; Neil, Ethan; Peterson, Curtis T.; Van de Water, Ruth (May 2022, The 38th International Symposium on Lattice Field Theory (LATTICE2021))

   We give an update on the status of the Fermilab Lattice-HPQCD-MILC calculation of the con- tribution 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^ll_{\mu W}. The calculation is performed on Nf = 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 contribution, 𝑎𝑙𝑙 . The calculation is performed on the 0.15 fm ensemble where we see a factor of four improvement over traditional noise reduction techniques. 

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