Twist expansion of differential cross-sections of forward Drell-Yan process

Forward Drell-Yan process at the LHC is a sensitive tool for investigating higher twist effects in QCD. The expansion of all Drell-Yan structure functions is performed assuming GBW saturation model and the saturation scale plays the role of the hadronic scale of OPE. We show that the Lam-Tung relation is broken at twist 4. The results open the way for a forthcoming analysis of multiple scattering and higher twist effects.Comment: 4 pages, 2 figures, talk presented at the International Workshop on Diffraction in High-Energy Physics Primosten (Croatia), September 10 - 16, 201

Twist expansion of forward Drell-Yan process

We present a twist expansion of differential cross-sections of the forward Drell-Yan process at the high energies. The expansion of all invariant form-factors is performed assuming GBW saturation model and the saturation scale plays the role of the hadronic scale of OPE. Some expilicit predictions for LHC experiments are given. It is shown also how the Lam-Tung relation is broken at twist 4 what provides a sensitive probe for searching of higher twists.Comment: 6 pages, 6 figures, talk presented at EDS Blois 2015 conference in Borgo, France, 29 Jun - 4 Jul, 2015. arXiv admin note: substantial text overlap with arXiv:1412.228

Forward Drell-Yan and backward jet production as a probe of the BFKL dynamics

We propose a new process which probes the BFKL dynamics in the high energy proton-proton scattering, namely the forward Drell-Yan (DY) production accompanied by a backward jet, separated from the DY lepton pair by a large rapidity interval. The proposed process probes higher rapidity differences and smaller transverse momenta than in the Mueller-Navelet jet production. It also offers a possibility of measuring new observables like leptons angular distribution coefficients in the DY lepton pair plus jet production.Comment: 23 pages, 8 figure

Improving predictions for associated ttˉHt\bar{t} H production at the LHC : soft gluon resummation through NNLL accuracy

In the following we present our recent results on the resummation of soft gluon corrections to the $pp\rightarrow t\bar{t}H$ cross section at the LHC. The resummation was carried out at next-to-next-to-leading-logarithmic (NNLL) accuracy using the Mellin space technique. Obtained results were matched to the NLO cross section. We show that the resummation leads to reduction of scale-variation uncertainty of the total $pp\rightarrow t\bar{t}H$ cross section.Comment: 6 pages, 1 figure, 1 table, proceedings prepared for the European Physical Society Conference on High Energy Physics (EPS-HEP 2017), 5-12 July 2017, Venice, Ital

Associated ttˉHt \bar{t} H production at the LHC: theoretical predictions at NLO+NNLL accuracy

We perform threshold resummation of soft gluon corrections to the total cross section and the invariant mass distribution for the process $pp \to t\bar{t}H$. The resummation is carried out at next-to-next-to-leading-logarithmic (NNLL) accuracy using the direct QCD Mellin space technique in the three-particle invariant mass kinematics. After presenting analytical expressions we discuss the impact of resummation on the numerical predictions for the associated Higgs boson production with top quarks at the LHC. We find that NLO+NNLL resummation leads to predictions for which the central values are remarkably stable with respect to scale variation and for which theoretical uncertainties are reduced in comparison to NLO predictions.Comment: 21 pages, 9 figures; NNLL results accounting now for color decomposition of the one-loop hard function, discussion of the literature added, typos correcte

Soft gluon resummation for associated ttˉHt \bar{t} H production at the LHC

We perform resummation of soft gluon corrections to the total cross section for the process $pp \to t\bar{t}H$. The resummation is carried out at next-to-leading-logarithmic (NLL) accuracy using the Mellin space technique, extending its application to the class of $2 \to 3$ processes. We present an analytical result for the soft anomalous dimension for a hadronic production of two coloured massive particles in association with a colour singlet. We discuss the impact of resummation on the numerical prediction for the associated Higgs boson production with top quarks at the LHC.Comment: 11 pages, 4 figure

Soft gluon resummation for the associated production of a top quark pair with a W boson at the LHC

We present our results on soft gluon resummation in the invariant mass threshold applied to the associated production of a top quark pair with a W boson at the LHC in the Mellin space formalism.Comment: 6 pages, 4 figures, 1 table, proceedings prepared for the European Physical Society Conference on High Energy Physics (EPS-HEP 2017), 5-12 July 2017, Venice, Ital

Associated top-pair production with a heavy boson production through NLO+NNLL accuracy at the LHC

In this talk we present results of our recent calculations of cross sections and distributions for the associate production of top-antitop quark pairs with a heavy boson (Higgs, W, Z) at the LHC, obtained using threshold resummation in direct QCD, i.e. in the Mellin-space approach.Comment: 4 pages, 6 figures, contribution to the 2019 QCD session of the 54th Rencontres de Morion

Twist expansion of Drell-Yan structure functions in color dipole approach

The forward Drell-Yan process at the LHC probes the proton structure at a very small Bjorken-x and moderate hard scales. In this kinematical domain higher twist effects may be significant and introduce sizeable corrections to the standard leading twist description. We study the forward Drell-Yan process beyond the leading twist approximation within the color dipole model framework that incorporates multiple scattering effects. We derive the Mellin representation of the forward Drell-Yan impact factors for fully differential cross-sections. These results combined with the color dipole cross-section of the saturation model are used to perform the twist expansion of the Drell-Yan structure functions at arbitrary transverse momentum q T of the Drell-Yan pair and also of the structure functions integrated over q_{T}. We also investigate the Lam-Tung relation, find that it is broken at twist 4 and provide explicit estimates for the breaking term