We derive chiral Ward identities for lattice QCD with Wilson quarks and
N
f
≥
3
flavours, on small lattices with Schrödinger functional boundary conditions and vanishingly small quark masses. These ...identities relate the axial variation of the non-singlet pseudoscalar density to the scalar one, thus enabling the non-perturbative determination of the scale-independent ratio
Z
S
/
Z
P
of the renormalisation parameters of these operators. We obtain results for
N
f
=
3
QCD with tree-level Symanzik-improved gluons and Wilson-Clover quarks, for bare gauge couplings which cover the typical range of large-volume
N
f
=
2
+
1
simulations with Wilson fermions at lattice spacings below
0.1
fm. The precision of our results varies from 0.3 to 1%, except for the coarsest lattice, where it is 2%. We discuss how the
Z
S
/
Z
P
ratio can be used in the non-perturbative calculations of
O
(
a
)
improved renormalised quark masses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report on non-perturbative computations of the improvement coefficient cV and the renormalization factor ZV of the vector current in three-flavour O(a) improved lattice QCD with Wilson quarks and ...tree-level Symanzik improved gauge action. To reduce finite quark mass effects, our improvement and normalization conditions exploit massive chiral Ward identities formulated in the Schrödinger functional setup, which also allow deriving a new method to extract the ratio ZS/ZP of scalar to pseudoscalar renormalization constants. We present preliminary results of a numerical evaluation of ZV and cV along a line of constant physics with gauge couplings corresponding to lattice spacings of about 0:09 fm and below, relevant for phenomenological applications.
We present our preliminary results of the non-perturbative determination of the valence mass dependent coefficients bA - bP and bm as well as the ratio ZPZm=ZA entering the flavour non-singlet PCAC ...relation in lattice QCD with Nf = 3 dynamical flavours. We apply the method proposed in the past for quenched approximation and Nf = 2 cases, employing a set of finite-volume ALPHA configurations with Schrödinger functional boundary conditions, generated with O(a) improved Wilson fermions and the tree-level Symanzik-improved gauge action for a range of couplings relevant for simulations at lattice spacings of about 0.09 fm and below.
The determination of quark masses from lattice QCD simulations requires a non-perturbative renormalization procedure and subsequent scale evolution to high energies, where a conversion to the ...commonly used scheme can be safely established. We present our results for the non-perturbative running of renormalized quark masses in Nf = 3 QCD between the electroweak and a hadronic energy scale, where lattice simulations are at our disposal. Recent theoretical advances in combination with well-established techniques allows to follow the scale evolution to very high statistical accuracy, and full control of systematic effects.
Abstract We derive chiral Ward identities for lattice QCD with Wilson quarks and $$N_{\mathrm{f}}\ge 3$$ Nf≥3 flavours, on small lattices with Schrödinger functional boundary conditions and ...vanishingly small quark masses. These identities relate the axial variation of the non-singlet pseudoscalar density to the scalar one, thus enabling the non-perturbative determination of the scale-independent ratio $$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$ ZS/ZP of the renormalisation parameters of these operators. We obtain results for $$N_{\mathrm{f}}=3$$ Nf=3 QCD with tree-level Symanzik-improved gluons and Wilson-Clover quarks, for bare gauge couplings which cover the typical range of large-volume $$N_{\mathrm{f}}= 2+1$$ Nf=2+1 simulations with Wilson fermions at lattice spacings below $$0.1\,$$ 0.1 fm. The precision of our results varies from 0.3 to 1%, except for the coarsest lattice, where it is 2%. We discuss how the $$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$ ZS/ZP ratio can be used in the non-perturbative calculations of $${\mathrm {O}}(a)$$ O(a) improved renormalised quark masses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
We derive chiral Ward identities for lattice QCD with Wilson quarks and
$$N_{\mathrm{f}}\ge 3$$
N
f
≥
3
flavours, on small lattices with Schrödinger functional boundary conditions and ...vanishingly small quark masses. These identities relate the axial variation of the non-singlet pseudoscalar density to the scalar one, thus enabling the non-perturbative determination of the scale-independent ratio
$$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$
Z
S
/
Z
P
of the renormalisation parameters of these operators. We obtain results for
$$N_{\mathrm{f}}=3$$
N
f
=
3
QCD with tree-level Symanzik-improved gluons and Wilson-Clover quarks, for bare gauge couplings which cover the typical range of large-volume
$$N_{\mathrm{f}}= 2+1$$
N
f
=
2
+
1
simulations with Wilson fermions at lattice spacings below
$$0.1\,$$
0.1
fm. The precision of our results varies from 0.3 to 1%, except for the coarsest lattice, where it is 2%. We discuss how the
$$Z_{\mathrm {S}}/Z_{\mathrm {P}}$$
Z
S
/
Z
P
ratio can be used in the non-perturbative calculations of
$${\mathrm {O}}(a)$$
O
(
a
)
improved renormalised quark masses.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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