Alexandrou, Constantia; Bacchio, Simone; De Santis, Alessandro; Dimopoulos, Petros; Finkenrath, Jacob; Frezzotti, Roberto; Gagliardi, Giuseppe; Garofalo, Marco; Hadjiyiannakou, Kyriakos; Kostrzewa, Bartosz; Jansen, Karl; Lubicz, Vittorio; Petschlies, Marcus; Sanfilippo, Francesco; Simula, Silvano; Tantalo, Nazario; Urbach, Carsten; Wenger, Urs (2023). Probing the Energy-Smeared R Ratio Using Lattice QCD. Physical review letters, 130(24), p. 241901. American Physical Society 10.1103/PhysRevLett.130.241901
|
Text
PhysRevLett.130.241901.pdf - Published Version Available under License Creative Commons: Attribution (CC-BY). Download (1MB) | Preview |
We present a first-principles lattice QCD investigation of the R ratio between the e^{+}e^{-} 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.
Item Type: |
Journal Article (Original Article) |
|---|---|
Division/Institute: |
08 Faculty of Science > Institute of Theoretical Physics 10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC) |
UniBE Contributor: |
Wenger, Urs |
Subjects: |
500 Science > 530 Physics |
ISSN: |
0031-9007 |
Publisher: |
American Physical Society |
Language: |
English |
Submitter: |
Pubmed Import |
Date Deposited: |
03 Jul 2023 09:57 |
Last Modified: |
16 Jul 2023 02:26 |
Publisher DOI: |
10.1103/PhysRevLett.130.241901 |
PubMed ID: |
37390427 |
BORIS DOI: |
10.48350/184290 |
URI: |
https://boris.unibe.ch/id/eprint/184290 |
Actions (login required)
 |
Edit item |