Sökresultat

Event generators play a crucial role in the exploration of LHC physics. This presentation summarizes news and plans for the three general-purpose pp generators HERWIG, PYTHIA and SHERPA, as well as briefer notes on a few other generators. Common themes, such as the matching and merging between matrix elements and parton showers, are highlighted. Other topics include a historical introduction, from

In this contribution we analyse double vector meson production in photon - hadron (γh) interactions at pp/pA/AA collisions and present predictions for ρρ, J/ψJ/ψ and ρJ/ψ production considering the double scattering mechanism. We estimate the total cross sections and compare our results with the predictions for double vector meson production in γγ interactions at hadronic c olliders. Our results d

We present a trinification-based grand unified theory incorporating a global SU(3)F family symmetry, that after spontaneous symmetry breaking leads to a left-right symmetric model. In addition to unification of gauge couplings, the model unifies Yukawa interactions and contains equivalent representations in the scalar and fermion sectors at high energy scales. Considering the minimal low-energy sc

We demonstrate that current experimental data on γ/Z0 and heavy quarkonium production in pp collisions at RHIC and LHC energies can be described by the color dipole formalism. Three different phenomenological models based on saturation physics are used to estimate the Drell-Yan (DY) dilepton spectra in such processes. In order to further constrain QCD dynamics we suggest to measure the azimuthal c

The Large Hadron Electron Collider (LHeC) project is the proposal to use the existing LHC proton/ion beams and construct a new electron beam line to perform high-energy electron-proton/ion collisions. In this talk, we consider some of the physics topics that could be studied in the electronion mode. In particular, we estimate how much the current nuclear parton distribution fits could be improved

As the current nuclear PDF analyses are mainly constrained by fixed-target Drell-Yan and deeply inelastic scattering data only the quark nuclear modifications at fairly large x values are in a good control. Inclusive pion production in d+Au collisions at RHIC provides some constraints for gluons but due to the limited kinematic reach of the data the gluon modifications remain uncertain especially

This talk describes the work done in calculating leading logarithms in massive effective field theories. We discuss shortly leading logarithms in renormalizable theories and how they can be calculated using only one-loop calculations in effective field theories. The remainder of the talk discusses masses, decay constants, condensates and anomalous processes in mesonic effective field theories like

We discuss some of the effects of twisted boundary conditions in finite volume using continuum SU(3) Chiral Perturbation Theory. We point out how broken cubic symmetry affects the definitions of quantities such as form-factors. Using the π+ as an example, we give one loop results for the mass, decay constants and electromagnetic form-factor and illustrate how the relevant Ward identities are satis

Recent progress on colour reconnection within the Pythia framework is presented. A new model is introduced, based on the SU(3) structure of QCD and a minimization of the potential string energy. The inclusion of the epsilon structure of SU(3) gives a new baryon production mechanism and makes it possible simultaneously to describe hyperon production at both e+e- and pp colliders. Finally, predictio

We discuss finite volume effects and partial quenching for Chiral Perturbation Theory in the mesonic sector. The effects are computed in terms of analytical expressions for masses, decay constants and vacuum expectation values (VEVs) to two-loop order. Numerical examples are presented for a number of interesting and relevant cases. All numerical programs are publically available, the prospects of

We present an overview of the options for diffraction implemented in the general-purpose event generator PYTHIA8. We review the existing model for low- and high-mass soft diffraction and present a new model for hard diffraction in pp and pp¯ collisions. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a

In this work, we analyse the all-orders resummation structure of the momentum sharing fraction, zg, opening angle, θg, and relative transverse momentum, kt,g, of the splitting tagged by the Dynamical Grooming procedure in hadronic collisions. We demonstrate that their resummation does non-exponentiate and it is free of clustering logarithms. Then, we analytically compute the probability distributi

The program HiggsSignals confronts the predictions of models with arbitrary Higgs sectors with the available Higgs signal rate and mass measurements, resulting in a likelihood estimate. A new version of the program, HiggsSignals-2, is presented that contains various improvements in its functionality and applicability. In particular, the new features comprise improvements in the theoretical input f

In this work we compute for the first time the so-called Complete-NLO predictions for top-quark pair hadroproduction in association with at least one isolated photon (tt¯ γ). We also compute NLO QCD+EW predictions for the similar case with at least two isolated photons (tt¯ γγ) and for single-top hadroproduction in association with at least one isolated photon. In addition, we complement our resul

We study fully differential quarkonia photoproduction observables in ultraperipheral collisions as functions of momentum transfer squared. We employ the dipole picture of the QCD part of the scattering with proton and nucleus targets, with the projectile being a quasireal photon flux emitted by an incoming hadron. We analyze such observables for ground J/ψ, (1S) and excited ψ′, (2S) states whose l

In this review, we provide a short outlook of some of the current most popular pictures and promising approaches to non-perturbative physics and confinement in gauge theories. A qualitative and by no means exhaustive discussion presented here covers such key topics as the phases of QCD matter, the order parameters for confinement, the central vortex and monopole pictures of the QCD vacuum structur

We provide a statistically significant observation of the elusive Odderon exchange, based on novel and model-independent analysis of the scaling properties of the differential cross sections of elastic pp and pp scattering in the TeV energy range. We report the statistical significance of the observed Odderon signal at the level of 6.26 σ.