BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Hyperons Gluon Helicity from Lattice QCD
DTSTART;VALUE=DATE-TIME:20261010T095000Z
DTEND;VALUE=DATE-TIME:20261010T100500Z
DTSTAMP;VALUE=DATE-TIME:20261005T083245Z
UID:indico-contribution-2859@indico.itp.ac.cn
DESCRIPTION:Speakers: 昕然 刘 (Nanjing Normal University)\nWe present t
 he first lattice QCD calculation of the total gluon helicity contribution 
 $\\Delta G_H$ to the spin of $\\Lambda$\, $\\Sigma$\, and $\\Xi$ hyperons.
 \nThe calculation employs the Coulomb-gauge fixed topological current $K^\
 \mu$\, whose forward matrix element in the infinite momentum frame yields 
 $\\Delta G_H$ without non-trivial perturbative matching.\nUsing a single $
 N_f=2+1$ flavor dynamical ensemble with lattice spacing $a\\approx 0.105\\
  \\mathrm{fm}$ and pion mass $m_\\pi\\approx 292\\ \\mathrm{MeV}$\, we ext
 ract the bare matrix elements via the Feynman-Hellmann method\, with disti
 llation and momentum smearing to control excited-state contamination.\nThe
  bare matrix elements are non-perturbatively renormalized in the RI/MOM sc
 heme and subsequently converted to the $\\overline{\\mathrm{MS}}$ scheme\;
  the renormalization factor $\\bar{Z}_{11}^{\\mathrm{lat}}$ is employed\, 
 whose state-independence is guaranteed by the intrinsic nature of operator
  ultraviolet divergences.\nAfter infinite-momentum extrapolation and renor
 malization\, we obtain\n$\\Delta G_{\\Lambda} = 0.165(19)_{\\rm stat}(19)_
 {\\rm ren}$\,\n$\\Delta G_{\\Xi} = 0.160(14)_{\\rm stat}(19)_{\\rm ren}$\,
  and\n$\\Delta G_{\\Sigma} = 0.232(24)_{\\rm stat}(28)_{\\rm ren}$\nat the
  $\\overline{\\mathrm{MS}}$ scale $\\mu^2 = 10\\ \\mathrm{GeV}^2$\, corres
 ponding to approximately\n$37(5)_{\\rm stat}(4)_{\\rm ren}\\%$\,\n$33(3)_{
 \\rm stat}(4)_{\\rm ren}\\%$\, and\n$48(5)_{\\rm stat}(6)_{\\rm ren}\\%$ o
 f the hyperon total spin\, respectively.\nThe temporal and spatial compone
 nts of $K^\\mu$ yield consistent results\, confirming Lorentz covariance o
 f the approach beyond the nucleon sector.\nThese first-principles results 
 reveal the impact of flavor-symmetry breaking on gluon polarization across
  the baryon octet.\n\nhttps://indico.itp.ac.cn/event/437/contributions/285
 9/
LOCATION:会议楼2 CXII103
URL:https://indico.itp.ac.cn/event/437/contributions/2859/
END:VEVENT
END:VCALENDAR