/ 96 05 46 6 v 1 3 J un 1 99 6 QCD Analysis of Twist - 4 Contributions to the g 1 Structure Functions
نویسنده
چکیده
We analyze the twist-4 contributions to Bjorken and Ellis-Jaffe sum rules for spin-dependent structure function g1(x,Q ). We investigate the anomalous dimensions of the twist-4 operators which determine the logarithmic correction to the 1/Q behavior of the twist-4 contribution by evaluating off-shell Green’s functions in both flavor non-singlet and singlet case. It is shown that the EOM operators play an important role to extract the anomalous dimensions of physical operators. The calculations to solve the operator mixing of higher-twist operators are given in detail. KUCP-96 June, 1996
منابع مشابه
ar X iv : h ep - p h / 96 04 26 4 v 1 8 A pr 1 99 6 Polarized Structure Function g 2 in the CM bag model
The spin-dependent structure functions g 1 (x), g 2 (x), g W W 2 (x) and ¯ g 2 (x) and their moments are studied in the CM bag model. The results show that (i) 1 0 g 2 (x)dx = 0, i.e. the Burkhardt-Cottingham sum rule holds, hence g 2 (x) must have at least one non-trivial zero besides x = 0 and x = 1. 1 0 x 2 g 2 (x)dx is negative for the proton, neutron and deuteron. (iii) 1 0 x 2 g 2 (x)dx i...
متن کاملar X iv : h ep - p h / 04 11 19 1 v 1 1 5 N ov 2 00 4 POLARIZED STRUCTURE FUNCTIONS AND THE GDH INTEGRAL FROM LATTICE QCD
The Gerasimov-Drell-Hearn integral I GDH (Q 2), and its relation to polarized nu-cleon structure functions, is discussed from the lattice perspective. Of particular interest is the variation of I GDH (Q 2) with Q 2 , and what it may teach us about the origin and magnitude of higher-twist contributions.
متن کاملar X iv : h ep - p h / 99 12 37 6 v 1 1 6 D ec 1 99 9 On the twist - 3 contribution to h L in the instanton vacuum
We show that the instanton model of the QCD vacuum indicates the parametric smallness of the twist-3 contributions to the polarized structure function h L. This smallness is related to the diluteness of the QCD instanton vacuum. 1. Among higher twist parton distributions the twist-3 distributions play a special role. In many physical observables the twist-3 distributions enter not suppressed by...
متن کاملar X iv : h ep - p h / 96 04 37 7 v 1 2 1 A pr 1 99 6 WIS - 96 / 17 / Apr . - PH Scaling approach to higher - twist corrections
Bjorken scaling is violetd. At large x-values (0.7 < ∼ x ≤ 1) the violation is mainly attributed to ∝ 1/Q 2 (higher-twist) corrections. We discuss how to incorporate such corrections by using a new scaling variable ¯ x(x, Q 2) which accounts for the non-perturbative effects due to the confining parton interaction in the final state. The approach can accomodate also the remaining QCD logarithmic...
متن کاملar X iv : h ep - p h / 96 05 31 0 v 1 1 5 M ay 1 99 6 O ( α 2 G F m 2 t ) Contributions to H → γγ
The rare decay H → γγ is a promising detection channel for an intermediate mass Higgs boson. We compute its two-loop O(αGFm 2 t ) correction in the standard model and find that it is much smaller than the corresponding QCD correction. The analogous correction to the amplitude for gg → H is recovered as a special case. The generalization of our result to other models is also briefly indicated.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1996