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Main Authors: Bacchio, S., Bečirević, D., Gagliardi, G., Sanfilippo, F.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2404.10644
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author Bacchio, S.
Bečirević, D.
Gagliardi, G.
Sanfilippo, F.
author_facet Bacchio, S.
Bečirević, D.
Gagliardi, G.
Sanfilippo, F.
contents The normalization of the leading-twist photon distribution amplitude (DA), $f_γ^{\perp}$, is an important ingredient in the study of exclusive processes involving the photon emission by means of QCD sum-rules. In this paper we determine the up- , down- and strange-quark contribution to $f_γ^{\perp}$ by exploiting its relation to the zero-momentum two-point correlation function of the electromagnetic current $J_{\rm em}^μ$ and the electric component of the tensor current $T^{μν}$. To that end we employ the gauge ensembles obtained by using $N_{f}=2+1+1$ Wilson-Clover twisted-mass quark flavors, generated by the Extended Twisted Mass (ETM) Collaboration, and after adding all sources of systematic uncertainties, we obtain a total error of $1.5\%$ and $3.5\%$, respectively, for the light- ($u$ and $d$) and strange-quark contribution to $f_γ^{\perp}(2~{\rm GeV})$ in the $\overline{\mathrm{MS}}$ scheme, thus improving their accuracy by a factor of $2.3$ and $2.8$, respectively. For the strange-quark contribution $f_{γ,s}^{\perp}(2~{\rm GeV})$, we observe a discrepancy with respect to previous lattice calculations. By combining our result with the world average lattice value of the chiral condensate, we obtain for the susceptibility of the quark condensate $χ_d^{\overline{\mathrm{MS}}} (2\, {\rm GeV}) \simeq χ_u^{\overline{\mathrm{MS}}} (2\, {\rm GeV}) =2.17(12)~{\rm GeV^{-2}}$.
format Preprint
id arxiv_https___arxiv_org_abs_2404_10644
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Lattice QCD determination of the normalization of the leading-twist photon distribution amplitude and susceptibility of the quark condensate
Bacchio, S.
Bečirević, D.
Gagliardi, G.
Sanfilippo, F.
High Energy Physics - Lattice
High Energy Physics - Phenomenology
The normalization of the leading-twist photon distribution amplitude (DA), $f_γ^{\perp}$, is an important ingredient in the study of exclusive processes involving the photon emission by means of QCD sum-rules. In this paper we determine the up- , down- and strange-quark contribution to $f_γ^{\perp}$ by exploiting its relation to the zero-momentum two-point correlation function of the electromagnetic current $J_{\rm em}^μ$ and the electric component of the tensor current $T^{μν}$. To that end we employ the gauge ensembles obtained by using $N_{f}=2+1+1$ Wilson-Clover twisted-mass quark flavors, generated by the Extended Twisted Mass (ETM) Collaboration, and after adding all sources of systematic uncertainties, we obtain a total error of $1.5\%$ and $3.5\%$, respectively, for the light- ($u$ and $d$) and strange-quark contribution to $f_γ^{\perp}(2~{\rm GeV})$ in the $\overline{\mathrm{MS}}$ scheme, thus improving their accuracy by a factor of $2.3$ and $2.8$, respectively. For the strange-quark contribution $f_{γ,s}^{\perp}(2~{\rm GeV})$, we observe a discrepancy with respect to previous lattice calculations. By combining our result with the world average lattice value of the chiral condensate, we obtain for the susceptibility of the quark condensate $χ_d^{\overline{\mathrm{MS}}} (2\, {\rm GeV}) \simeq χ_u^{\overline{\mathrm{MS}}} (2\, {\rm GeV}) =2.17(12)~{\rm GeV^{-2}}$.
title Lattice QCD determination of the normalization of the leading-twist photon distribution amplitude and susceptibility of the quark condensate
topic High Energy Physics - Lattice
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2404.10644