Related papers: Resummation and Shower Studies
When parton distributions are falling steeply as the momentum fractions of the partons increases, there are effects that occur at each order in $\alpha_s$ that combine to affect hard scattering cross sections and need to be summed. We show…
The perturbation series for electroweak vector boson production at small transverse momentum is dominated by large double logarithms at each order in perturbation theory. An accurate theoretical prediction therefore requires a resummation…
We consider the simultaneous measurement of the Higgs ($p_t^{\tiny{\mbox{H}}}$) and the leading jet ($p_t^{\tiny{\mbox{J}}}$) transverse momentum in hadronic Higgs-boson production, and perform the resummation of the large logarithmic…
The transverse momentum distribution of W+/- bosons at hadron colliders is well described by a parton-shower model for small pT values, but not for large ones. This article is an attempt to give a better description of the distribution by…
This paper presents the studies of the background contribution to the $H \rightarrow 4l$ searches originating from the processes of off-shell (virtual) photon emissions and their conversions into lepton pairs accompanying the production of…
We perform a precise calculation of the transverse momentum ($\vec{q}_T$) distribution of the boson+jet system in boson production events. The boson can be either a photon, $W$, $Z$ or Higgs boson with mass $m_V$, and $\vec{q}_T$ is the sum…
We consider the transverse-momentum distribution of colourless high-mass systems (lepton pairs, vector bosons, Higgs particles...) produced in hadronic collisions. We briefly review a formalism for the all-order resummation of the…
We present a study of the transverse momentum spectra and their evolution in function of the position of the azimuthal of the particles associated to the leading particle. Additionally, the behavior of the spherocity distribution in the…
The accuracy of parton-shower simulations is often a limiting factor in the interpretation of data from high-energy colliders. We present the first formulation of parton showers with accuracy one order beyond state-of-the-art…
Hadronic cross sections at ultra-high energy have a significant impact on the development of extensive air shower cascades. Therefore the interpretation of air shower data depends critically on hadronic interaction models that extrapolate…
Over the last two decades, various experiments have measured muon densities in extensive air showers over several orders of magnitude in primary energy. While some experiments observed differences in the muon densities between simulated and…
Ultra-relativistic heavy-ion collisions are a window of opportunity to study QCD matter under extreme conditions of temperature and density, such as the quark-gluon plasma. Among the several possibilities, the study of jet quenching -…
Analysis of small-x semi-inclusive DIS hadroproduction suggests that multiple parton radiation leads to a broadening of transverse momentum distributions beyond that predicted by a straightforward calculation in the Collins-Soper-Sterman…
We observe that at the Large Hadron Collider, using forward + central detectors, it becomes possible for the first time to carry out calorimetric measurements of the transverse energy flow due to "minijets" accompanying production of two…
The transverse momentum ($p_T$) distribution of Higgs bosons at hadron colliders enables a detailed probe of its production dynamics and is a key ingredient to precision studies of Higgs boson properties, but receives very large QCD…
We discuss collective effects like percolation, quark gluon plasma, or string fusion and their effect on the longitudinal development of high energy showers in air. It is shown that iron-air showers could develop more slowly than expected…
Uncertainties in the simulation of Higgs boson production with up to two jets at next-to leading order accuracy are investigated. Traditional uncertainty estimates based on scale variations are extended employing different functional forms…
Predictions from the GR@PPA event generator concerning the transverse-momentum ($p_{T}$) spectrum of $Z$ bosons are compared with recent measurements at LHC and Tevatron. The simulation results are in reasonable agreement with the…
We consider the transverse-momentum (q_T) distribution of generic high-mass systems (lepton pairs, vector bosons, Higgs particles, ....) produced in hadron collisions. At small q_T, we concentrate on the all-order resummation of the…
We discuss the transverse momentum distribution of $Z^0$ and $W^\pm$ gauge bosons at the LHC with $\sqrt s=14$ TeV for pp collisions and with $\sqrt s=5.5$ TeV for Pb+Pb collisions. Effects of power corrections and shadowing are also…