Twist decomposition of Drell-Yan structure functions: phenomenological implications

Abstract

The forward Drell-Yan process in pp scattering at the LHC at √ S = 14 TeV is considered. We analyze the Drell-Yan structure functions assuming the dominance of a Compton-like emission of a virtual photon from a fast quark scattering off the small x gluons. The color dipole framework is applied to perform quantitatively the twist decomposition of all the Drell-Yan structure functions. Two models of the color dipole scattering are applied: the Golec-Biernat-Wüsthoff model and the dipole cross section obtained from the Balitsky-Fadin-Kuraev-Lipatov evolution equation. The two models have essentially different higher twist content and the gluon transverse momentum distribution and lead to different significant effects beyond the collinear leading twist description. It is found that the gluon transverse momentum effects are significant in the Drell-Yan structure functions for all Drell-Yan pair masses M , and the higher twist effects become important for M 10 GeV. It is found that the structure function W T T related to the A 2 angular coefficient and the Lam-Tung observable A 0 − A 2 are particularly sensitive to the gluon k T effects and to the higher twist effects. A procedure is suggested how to disentangle the higher twist effects from the gluon transverse momentum effects.

Nuclear modification of forward Drell-Yan production at the LHC

“…The study of the Drell-Yan process in the color dipole approach has been the subject of many theoretical and phenomenological works, see for example Refs. [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. In this formalism, the physical picture is the following: a collinear quark emitted by the projectile proton can radiate a virtual photon either before or after interacting with the dense color field of the target.…”

Drell–Yan production with the CCFM-K evolution

“…Also, unlike collinear factorization, it lacks formal proof. Despite these facts, many theoretical and phenomenological analyses of the DY process were made [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. The theoretical improvement was accompanied by many experimental results from fixed-target [38][39][40][41] and collider [42][43][44][45][46] experiments.…”

High-energy effects in forward inclusive dijet and hadron-jet production

“…The Balitsky-Fadin-Kuraev-Lipatov (BFKL) [1] approach represents the most effective mechanism to resum to all orders, both in the leading (LLA) and the next-to-leading (NLA) approximation, large energy logarithmic contributions rising in the Regge limit of QCD. With the aim of enhancing our knowledge of this high-energy regime, a wide range of semi-hard channels [2] (see [3] for some applications) has been suggested so far: the exclusive electroproduction of one [4][5][6] or two light vector mesons [7][8][9][10], the inclusive hadroproduction of two jets with large transverse momenta well separated in rapidity (Mueller-Navelet reaction [11]), for which a wealth of phenomenological analyses have been carried out so far [12][13][14][15][16][17][18][19][20][21][22][23][24][25], the inclusive emission of two charged light hadrons [26][27][28], multi-jet production [29][30][31][32][33][34][35], heavy-quark pair photo-and hadroproduction [36], J/Ψ-jet [37] correlations and forward Drell-Yan dilepton production [38][39][40] with a possible backward-jet emission [41,…”