Related papers: Small-$x$ resummation from HELL
We propose the formulation of a dihadron fragmentation function in terms of parton matrix elements. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at…
We demonstrate that theoretical predictions using current resummation techniques for the lepton pair production (LPP) rapidity and $x_F$ distributions can be inconsistent with data in high rapidity and $x_F$ kinematic regions by observing…
A survey is given of recent developments on the resummed small-$x$ evolution, in a framework based on the renormalization group equation, of non--singlet and singlet structure functions in both unpolarized and polarized deep--inelastic…
Using parton density functions (PDFs) with threshold-resummation improvement, we consistently calculate higgsino/gaugino and slepton pair production at next-to-leading order and next-to-leading logarithmic accuracy at the LHC. The smaller…
The status of the resummation of small x contributions to the unpolarized and polarized deep inelastic structure functions is reviewed.
In calculations of (semi-) inclusive events within perturbative Quantum Chromodynamics, large logarithmic corrections arise from certain kinematic regions of interest which need to be resummed. When resumming soft gluon effects one…
The off-diagonal parton-scattering channels $g+\gamma^*$ and $q+\phi^*$ in deep-inelastic scattering are power-suppressed near threshold $x\to 1$. We address the next-to-leading power (NLP) resummation of large double logarithms of $1-x$ to…
We present all-order expressions for the leading double-logarithmic threshold contributions to the quark-gluon coefficient functions for inclusive Higgs-boson production in the heavy top-quark limit and for Drell-Yan lepton-pair production.…
The small $x$ behaviour of polarized parton distributions is related to non-leading reggeons in the framework of the high-energy effective action. Double-logarithmic contributions to the reggeon interaction beyond the ones included in the…
Low-x physics is reviewed, with particular emphasis on searches for deviations from GLAP evolution of the parton densities. Although there are several intriguing indications, both in HERA and Tevatron data, as yet there is no unambiguous…
We present HEJ 2, a new implementation of the High Energy Jets formalism for high-energy resummation in hadron-collider processes as a flexible Monte Carlo event generator. In combination with a conventional fixed-order event generator, HEJ…
We present the coefficient functions for deep-inelastic scattering (DIS) via the exchange of a scalar phi directly coupling only to gluons, such as the Higgs boson in the limit of a very heavy top quark and n_f effectively massless light…
We consider the region of small transverse momenta in the production of high-mass systems in hadronic collisions. By using the current knowledge on the infrared behaviour of tree-level and one-loop QCD amplitudes at O(alpha_s^2), we…
Direct photon production is an important process at hadron colliders, being relevant both for precision measurement of the gluon density, and as background to Higgs and other new physics searches. Here we explore the implications of…
We present a method for identifying $H\rightarrow WW^* \rightarrow \ell \nu j j$ in the presence of large Standard Model backgrounds and illustrate how this decay mode may be applied to the study of Bell-type Inequalities. Our findings…
I discuss the motivation for resummation of the effects of initial-state soft gluon radiation, to all orders in the strong coupling strength, for processes in which the near-threshold region in the partonic subenergy is important. I…
We investigate small$-x$ resummation effects in QCD coefficient functions for $Z_0g$ and $Wg$ fusion processes, and we compare them with the known ones of $\gamma g$ type. We find a strong process dependence, that we argue to be due to the…
Processes involving heavy quarks are a crucial component of the LHC physics program, both by themselves and as backgrounds for Higgs physics and new physics searches. In this work, we critically reconsider the validity of the widely-adopted…
We investigate the production of highly energetic top-quark pairs at hadron colliders, focusing on the case where the invariant mass of the pair is much larger than the mass of the top quark. In particular, we set up a factorization…
Experiments at the LHC are collecting a wealth of data with an unprecedented level of precision. As a consequence, the theoretical error is now starting to lag behind the experimental one, and a ceaseless effort is required to reduce the…