Neutron electric dipole moment from lattice QCD

Simple item page
dc.creatorShintani, E.
dc.creatorAoki, S.
dc.creatorIshizuka, N.
dc.creatorKanaya, K.
dc.creatorKikukawa, Y.
dc.creatorKuramashi, Y.
dc.creatorOkawa, M.
dc.creatorTanigchi, Y.
dc.creatorUkawa, A.
dc.creatorYoshié, T.
dc.date2005-05-19
dc.date2005-08-01
dc.date.accessioned2026-07-07T10:28:41Z
dc.date.available2026-07-07T10:28:41Z
dc.descriptionWe carry out a feasibility study for the lattice QCD calculation of the neutron electric dipole moment (NEDM) in the presence of the $θ$ term. We develop the strategy to obtain the nucleon EDM from the CP-odd electromagnetic form factor $F_3$ at small $θ$, in which NEDM is given by $\lim_{q^2\to 0}θF_3(q^2)/(2m_N)$ where $q$ is the momentum transfer and $m_N$ is the nucleon mass. We first derive a formula which relates $F_3$, a matrix element of the electromagnetic current between nucleon states, with vacuum expectation values of nucleons and/or the current. In the expansion of $θ$, the parity-odd part of the nucleon-current-nucleon three-point function contains contributions not only from the parity-odd form factors but also from the parity-even form factors multiplied by the parity-odd part of the nucleon two-point function, and therefore the latter contribution must be subtracted to extract $F_3$. We then perform an explicit lattice calculation employing the domain-wall quark action with the RG improved gauge action in quenched QCD at $a^{-1}\simeq 2$ GeV on a $16^3\times 32\times 16$ lattice. At the quark mass $m_f a =0.03$, corresponding to $m_π/m_ρ\simeq 0.63$, we accumulate 730 configurations, which allow us to extract the parity-odd part in both two- and three-point functions. Employing two different Dirac $γ$ matrix projections, we show that a consistent value for $F_3$ cannot be obtained without the subtraction described above. We obtain $F_3(q^2\simeq 0.58 \textrm{GeV}^2)/(2m_N) =$ $-$0.024(5) $e\cdot$fm for the neutron and $F_3(q^2\simeq 0.58 \textrm{GeV}^2)/(2m_N) =$ 0.021(6) $e\cdot$fm for the proton.
dc.descriptionLaTeX2e, 43 pages, 42 eps figures, uses revtex4 and graphicx, comments added and typos corrected, final version to appear in Phys. Rev. D
dc.identifierhttps://arxiv.org/abs/hep-lat/0505022
dc.identifierhttp://arxiv.org/abs/hep-lat/0505022
dc.identifierPhys.Rev.D72:014504,2005
dc.identifierdoi:10.1103/PhysRevD.72.014504
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/177537
dc.subjectHigh Energy Physics - Lattice
dc.subjectHigh Energy Physics - Phenomenology
dc.subjectNuclear Theory
dc.titleNeutron electric dipole moment from lattice QCD
dc.typetext

Files

Collections

arXiv