Diffraction driven steep rise of spin structure function gLT=g1+g2 at small x and DIS sum rules

Иванов, И. П.; Николаев, Н. Н.; Pronyaev, A. V.; Schäfer, Wolfgang

doi:10.1016/s0370-2693(99)00511-0

Cited by 6 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Evaluating the correction in α s to the structure function g 2 requires the introduction of threegluon operators G GG (see Eq. ( 4)) which enter through the quark loop coupling 3 [9] and might be responsible for the small-x Bj behaviour of g 2 (x Bj ), -the issue which is under debate [11].…”

mentioning

confidence: 99%

Renormalization of twist-three operators and integrable lattice models

2000

View full text Add to dashboard Cite

We address the problem of solution of the QCD three-particle evolution equations which govern the Q 2 -dependence of the chiral-even quark-gluon-quark and three-gluon correlators contributing to a number of asymmetries at leading order and the transversely polarized structure function g 2 (x Bj ). The quark-gluon-quark case is completely integrable in multicolour limit and corresponds to a spin chain with non-periodic boundary conditions, while the pure gluonic sector contains, apart from a piece in the Hamiltonian equivalent to XXX Heisenberg magnet of spin s = − 3 2, a non-integrable addendum which can be treated perturbatively for a bulk of the spectrum except for a few lowest energy levels. We construct a quasiclassical expansion with respect to the total conformal spin of the system and describe fairly well the energy spectra of quark-gluon-quark and three-gluon systems.

show abstract

mentioning

confidence: 99%

Renormalization of twist-three operators and integrable lattice models

2000

View full text Add to dashboard Cite

show abstract

“…If the order of integration cannot be interchanged because of the singular behevior of the parton distributions at small x and y, the above sum rule may be violated. Indeed some small x B study does indicate such singular behavior [20]. Finally, we consider the next-to-leading order correction to the non-singlet part of the x 2 moment of g T (x B , Q 2 ).…”

Section: Appendixmentioning

confidence: 94%

One-loop factorization of the nucleong2-structure function in the nonsinglet case

Wei²,

Osborne³

et al. 2000

Phys. Rev. D

View full text Add to dashboard Cite

We consider the one-loop factorization of the simplest twist-3 process: inclusive deep-inelastic scattering of longitudinally polarized leptons on a transversely polarized nucleon target. By studying the Compton amplitudes for certain quark and gluon states at one loop, we find the coefficient functions for the nonsinglet twist-3 distributions in the factorization formula of g 2 (x B ,Q 2 ). The result marks the first step towards a next-toleading order formalism for this transverse-spin-dependent structure function of the nucleon.PACS number͑s͒: 12.38. Bx, 13.88.ϩe, 14.20.Dh Deep-inelastic scattering ͑DIS͒ of leptons on the nucleon is a time-honored example of the success of perturbative quantum chromodynamics ͑PQCD͒ ͓1͔. The factorization formulas for the leading structure functions F 1 (x B ,Q 2 ) and g 1 (x B ,Q 2 ), augmented by the Dokshitzer-Gribov-LipatovAltarelli-Parisi ͑DGLAP͒ evolution equations for parton distributions ͓2͔, can describe the available DIS data collected over the last 30 years exceedingly well. Although the same formalism is believed to work for the so-called higher-twist structure functions ͓3͔, e.g., g 2 (x B ,Q 2 ) and F L (x B ,Q 2 ), which contribute to physical observables down by powers of the hard momentum Q, there are few detailed studies of them in the literature beyond the tree level. The QCD radiative corrections to g 2 (x B ,Q 2 ) need be investigated as accurate data have recently been taken ͓4͔ and more data will be available in the future ͓5͔.In this paper, we report a one-loop study of inclusive deep-inelastic scattering of longitudinally polarized leptons ͑e.g., electrons͒ on a transversely polarized nucleon target ͓6͔. The subject was first investigated in the context of single parton scattering in Ref. ͓7͔, and studies along the same line have continued in the literature ͓8͔. However, because of the subtlety of the twist-3 process ͓9-11͔, those results are sensitive to the treatment of quark masses and are incomplete in the context of QCD fatorization. Indeed, even at the tree level one must go beyond the single quark process to derive the correct g 2 (x B ,Q 2 ) expression in terms of the parton distributions ͓12-14͔. When loop corrections are included, one needs a general strategy to systematically calculate their contribution to higher-twist processes.For a transversely polarized nucleon of four-momentum P and polarization vector S Ќ , the hadron tensor W ϭ(1/4)͐e iq• ͗PS͉͓J (),J (0)͔ PS͘ can be expressed as W ϭϪi⑀ ␣␤ q ␣ S Ќ␤

show abstract

“…This vanishing of the pomeron dxg 2 (x, Q 2 ) = 0. Our recent discovery is that diffractive SCHNC destroys via unitarity the both WW relation and BC sum rule 6 . The unitarity diffractive contribution ( fig.…”

Section: Lt Interference and Schnc In Diffractive Dismentioning

confidence: 99%

“…The related QCD argument has been that quark helicity conservation entail the s-channel helicity conservation (SCHC) at small x, i.e., decoupling of QCD pomeron from helicity flip. Here I review the recent discovery 1,2,3,4,5,6 of substantial SCHNC in diffractive DIS into the both continuum and vector mesons. Furthermore, SCHNC diffractive DIS in conjunction with unitarity changes dramatically the small-x behaviour of spin structure function g 2 and leads to the demise of the Burkhardt-Cottingham sum rule and the departure from the Wandzura-Wilczek relation.…”

Section: Introductionmentioning

confidence: 99%