The second moment of the pion light cone wave function

Abstract

We present a preliminary result for second moment of the light cone wave function of the pion. This parameter is the subject of a discrepancy between theoretical predictions (coming from lattice and sum rules) and a recent experimental result (that remarkably agrees with purely perturbative predictions). In this work we exploit lattice hypercubic symmetries to remove power divergences and, moreover, implement a full 1-loop matching for all the contributing operators.

Revisiting the pion leading-twist distribution amplitude within the QCD background field theory

“…It shows that our present estimation of a π 2 agrees with most of the estimations within errors derived in the literature. Especially, our central value is close to the Lattice QCD estimations [16,17]. Following the idea of Ref.…”

“…Theoretically, the Gegenbauer moments have been calculated by QCD * Electronic address: zhongtao@ihep.ac.cn † Electronic address: wuxg@cqu.edu.cn ‡ Electronic address: zgwang@aliyun.com § Electronic address: huangtao@ihep.ac.cn sum rules [9][10][11][12][13] and the lattice gauge theory [14][15][16][17]. Phenomenologically, the Gegenbauer moments have also been estimated from the pion-photon transition form factor [18][19][20][21], the pion electromagnetic form factor [22,23], the B → π TFFs [24,25], and etc.…”

Moments of pseudoscalar meson distribution amplitudes from the lattice

“…The authors of Ref. [55], on the other hand, performed a simulation in quenched QCD and renormalised their results perturbatively to the MS scheme at µ 2 = 7.1289 GeV 2 , ξ 2 MS π (µ 2 = 7.1289 GeV 2 ) = 0.280 (49) +0.030 −0.013 . This paper is organised as follows.…”

Second moment of the pion's distribution amplitude

“…Although the first lattice calculations of ξ 2 appeared almost 20 years ago [3], there has been surprisingly little activity in this area in recent times [4][5][6] to complement other theoretical investigations, e.g. [7][8][9][10][11][12][13][14][15][16][17][18].…”