FLAG Review 2021 Aoki, Y.; Blum, T.; Colangelo, G. ...
European physical journal. C, Particles and fields,
10/2022, Letnik:
82, Številka:
10
Journal Article
Recenzirano
Odprti dostop
We review lattice results related to pion, kaon,
D
-meson,
B
-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More ...specifically, we report on the determination of the light-quark masses, the form factor
f
+
(
0
)
arising in the semileptonic
K
→
π
transition at zero momentum transfer, as well as the decay constant ratio
f
K
/
f
π
and its consequences for the CKM matrix elements
V
us
and
V
ud
. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of
S
U
(
2
)
L
×
S
U
(
2
)
R
and
S
U
(
3
)
L
×
S
U
(
3
)
R
Chiral Perturbation Theory. We review the determination of the
B
K
parameter of neutral kaon mixing as well as the additional four
B
parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for
m
c
and
m
b
as well as those for the decay constants, form factors, and mixing parameters of charmed and bottom mesons and baryons. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant
α
s
. We consider nucleon matrix elements, and review the determinations of the axial, scalar and tensor bilinears, both isovector and flavor diagonal. Finally, in this review we have added a new section reviewing determinations of scale-setting quantities.
In this work we apply the Dispersive Matrix (DM) method of Di Carlo et al. (Phys Rev D 104:054502, 2021) and Martinelli et al. (Phys Rev D 105:034503, 2022) to the lattice computations of the Form ...Factors (FFs) entering the semileptonic
B
→
D
∗
ℓ
ν
ℓ
decays, recently produced by the FNAL/MILC Collaborations (Fermilab Lattice, MILC collaboration, Semileptonic form factors for
B
→
D
∗
ℓ
ν
at nonzero recoil from 2 + 1-flavor lattice QCD.
arXiv:2105.14019
) at small, but non-vanishing values of the recoil variable (
w
-
1
). Thanks to the DM method we obtain the FFs in the whole kinematical range accessible to the decay in a completely model-independent and non-perturbative way, implementing exactly both unitarity and kinematical constraints. Using our theoretical bands of the FFs we extract
|
V
cb
|
from the experimental data and compute the theoretical value of
R
(
D
∗
)
. Our final result for
|
V
cb
|
reads
|
V
cb
|
=
(
41.3
±
1.7
)
·
10
-
3
, compatible with the most recent inclusive estimate at the
0.5
σ
level. Moreover, we obtain the pure theoretical value
R
(
D
∗
)
=
0.275
±
0.008
, which is compatible with the experimental world average at the
∼
1.3
σ
level.
FLAG Review 2019 Aoki, S; Aoki, Y; Bečirević, D ...
European physical journal. C, Particles and fields,
02/2020, Letnik:
80, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More ...specifically, we report on the determination of the light-quark masses, the form factor f+(0) arising in the semileptonic K→π transition at zero momentum transfer, as well as the decay constant ratio fK/fπ and its consequences for the CKM matrix elements Vus and Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)L×SU(2)R and SU(3)L×SU(3)R Chiral Perturbation Theory. We review the determination of the BK parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for mc and mb as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant αs. Finally, in this review we have added a new section reviewing results for nucleon matrix elements of the axial, scalar and tensor bilinears, both isovector and flavor diagonal.
A
bstract
We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon including leading-order ...electromagnetic corrections. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with
N
f
= 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (
a
≃ 0
.
062
,
0
.
082
,
0
.
089 fm) with pion masses in the range
M
π
≃ 210-450 MeV. The strange and charm quark masses are tuned at their physical values. Neglecting disconnected diagrams and after the extrapolations to the physical pion mass and to the continuum limit we obtain:
a
μ
s
(
α
em
2
) = (53.1 ± 2.5) · 10
− 10
,
a
μ
s
(
α
em
3
) = (−0.018 ± 0.011) · 10
− 10
and
a
μ
c
(
α
em
2
) = (14.75 ± 0.56) · 10
− 10
,
a
μ
c
(
α
em
3
) = (−0.030 ± 0.013) · 10
− 10
for the strange and charm contributions, respectively.
We present an updated determination of the values of
|
V
cb
|
,
R
(
D
∗
)
and
|
V
ub
|
/
|
V
cb
|
based on the new data on semileptonic
B
→
D
∗
ℓ
ν
ℓ
decays by the Belle and Belle-II Collaborations ...and on the recent theoretical progress in the calculation of the form factors relevant for semileptonic
B
→
D
∗
ℓ
ν
ℓ
and
B
s
→
K
ℓ
ν
ℓ
decays. In particular we present results derived by applying either the Dispersive Matrix (DM) method of Di Carlo et al. (Phys Rev D 104:054502, 2021), Martinelli et al. (Phys Rev D 104:094512, 2021), Martinelli et al. (Phys Rev D 105:034503, 2022), Martinelli et al. (Eur Phys J C 82:1083, 2022), Martinelli et al. (JHEP 08:022, 2022) and Martinelli et al. (Phys Rev D 106:093002, 2022) or the more standard Boyd–Grinstein–Lebed (BGL) (Boyd et al. in Phys Rev D 56:6895, 1997) approach to the most recent values of the form factors determined in lattice QCD. Using all the available lattice results for the form factors from the DM method we get the theoretical value
R
th
(
D
∗
)
=
0.262
±
0.009
and we extract from a bin-per-bin analysis of the experimental data the value
|
V
cb
|
=
(
39.92
±
0.64
)
·
10
-
3
.
Our result for
R
(
D
∗
)
is consistent with the latest experimental world average
R
exp
(
D
∗
)
=
0.284
±
0.012
(HFLAV Collaboration in Preliminary average of
R
(
D
) and
R
(
D
∗
)
as for Summer 2023. See
https://hflav-eos.web.cern.ch/hflav-eos/semi/summer23/html/RDsDsstar/RDRDs.html
) at the
≃
1.5
σ
level. Our value for
|
V
cb
|
is compatible with the latest inclusive determinations
|
V
cb
|
incl
=
(
41.97
±
0.48
)
·
10
-
3
(Finauri and Gambino in The
q
2
moments in inclusive semileptonic
B
decays.
arXiv:2310.20324
) and
|
V
cb
|
incl
=
(
41.69
±
0.63
)
·
10
-
3
(Bernlochner et al. in JHEP 10:068, 2022) within
≃
2.6
and
≃
2.0
standard deviations, respectively. From a reappraisal of the calculations of
|
V
ub
|
/
|
V
cb
|
,
we also obtain
|
V
ub
|
/
|
V
cb
|
=
0.087
±
0.009
in good agreement with the result
|
V
ub
|
/
|
V
cb
|
=
0.0844
±
0.0056
from the latest FLAG review (Flavour Lattice Averaging Group (FLAG) Collaboration in Phys J C 82:869, 2022).
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