TY  - JOUR
AU  - Alexandrou, Constantia
AU  - Bacchio, Simone
AU  - De Santis, Alessandro
AU  - Dimopoulos, Petros
AU  - Finkenrath, Jacob
AU  - Frezzotti, Roberto
AU  - Gagliardi, Giuseppe
AU  - Garofalo, Marco
AU  - Hadjiyiannakou, Kyriakos
AU  - Kostrzewa, Bartosz
AU  - Jansen, Karl
AU  - Lubicz, Vittorio
AU  - Petschlies, Marcus
AU  - Sanfilippo, Francesco
AU  - Simula, Silvano
AU  - Tantalo, Nazario
AU  - Urbach, Carsten
AU  - Wenger, Urs
TI  - Probing the Energy-Smeared R Ratio Using Lattice QCD
JO  - Physical review letters
VL  - 130
IS  - 24
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PUBDB-2023-03985
M1  - arXiv:2212.08467
SP  - 241901
PY  - 2023
N1  - Version accepted for publication on PRL. Results unchanged
AB  - We present a first-principles lattice QCD investigation of the R ratio between the e<sup>+</sup>e<sup>−</sup> cross section into hadrons and into muons. By using the method of Ref. [1], that allows one to extract smeared spectral densities from Euclidean correlators, we compute the R ratio convoluted with Gaussian smearing kernels of widths of about 600 MeV and central energies from 220 MeV up to 2.5 GeV. Our theoretical results are compared with the corresponding quantities obtained by smearing the KNT19 compilation [2] of R-ratio experimental measurements with the same kernels and, by centering the Gaussians in the region around the ρ-resonance peak, a tension of about 3 standard deviations is observed. From the phenomenological perspective, we have not included yet in our calculation QED and strong isospin-breaking corrections, and this might affect the observed tension. From the methodological perspective, our calculation demonstrates that it is possible to study the R ratio in Gaussian energy bins on the lattice at the level of accuracy required in order to perform precision tests of the standard model.
KW  - density: spectral (INSPIRE)
KW  - correlation function: Euclidean (INSPIRE)
KW  - muon (INSPIRE)
KW  - GeV (INSPIRE)
KW  - lattice (INSPIRE)
KW  - lattice field theory (INSPIRE)
KW  - quantum chromodynamics (INSPIRE)
KW  - tension (INSPIRE)
KW  - hadron (INSPIRE)
LB  - PUB:(DE-HGF)16
C6  - 37390427
UR  - <Go to ISI:>//WOS:001025958700005
DO  - DOI:10.1103/PhysRevLett.130.241901
UR  - https://bib-pubdb1.desy.de/record/586747
ER  -