Sökresultat

Higgs boson production in association with a high pT photon at the CERN Large Hadron Collider is analyzed, in the framework of the MSSM model, for the heavier neutral Higgs bosons. The request of an additional photon in the exclusive Higgs boson final state selects b-quark pairs among the possible initial partonic states, since gluon-gluon initial states are not allowed by C-parity conservation. H

We report on detailed Monte Carlo comparisons of selection variables to separate tbH± signal events from the standard model tt background using an iterative discriminant analysis (IDA) method. While kinematic differences exist between the two processes whenever m_{Hpm≠}m_Wpm , the exploration of the spin difference between the charged Higgs and the W± gauge boson becomes crucial in the particularl

We investigate the viability of observing charged Higgs bosons ( H± ) produced in association with W bosons at the CERN large hadron collider, using the leptonic decay H+ → + ν τ and hadronic W decay, within different scenarios of the minimal supersymmetric standard model (MSSM) with both real and complex parameters. Performing a parton level study we show how the irreducible standard model backgr

At the Large Hadron Collider, we prove the feasibility to detect pair production of the lightest CP-even Higgs boson h of Type II 2-Higgs Doublet Models through qq (′) qq (′)hh (vector-boson fusion). We also show that, through the hh 4b decay channel in presence of heavy-flavour tagging, further exploiting forward/backward jet sampling, one has direct access to the λ Hhh triple Higgs coupling - wh

We show that partons traversing a quark-gluon plasma can lose substantial amounts of energy also by scatterings, and not only through medium-induced radiation as mainly considered previously. Results from Monte Carlo simulations of soft interactions of partons, emerging from a hard scattering, through multiple elastic scatterings on gluons in an expanding relativistic plasma show a sizeable jet qu

Charged Higgs boson production in association with a top quark could be the first indication of the existence of Higgs particles. The Tevatron Run-II started data-taking in April 2001 at √s = 1960 GeV and could probe the existence of a charged Higgs boson beyond the current mass limit. We study the pp̄ → tbH± production process with Monte Carlo simulations in HERWIG and PYTHIA, comparing expected

We study the process gg → bb̄H+H- at large tanβ, where it represents the dominant production mode of charged Higgs boson pairs in a Type II 2-Higgs doublet model, including the minimal supersymmetric standard model. The ability to select this signal would in principle enable the measurements of some triple-Higgs couplings, which in turn would help understanding the structure of the extended Higgs

The interaction potential V(Q2) between static test charges can be used to define an effective charge αv(Q2) and a physically based renormalization scheme for quantum chromodynamics and other gauge theories. In this paper we use recent results for finite-mass fermionic corrections to the heavy-quark potential at two loops to derive the next-to-Ieading order term for the Gell-Mann-Low function of t

A new model for hadronic string reinteractions based on a generalised area law is presented. The model describes both the hadronic final states in e+ e- annihilation and the diffractive structure function in deep inelastic scattering. The model also predicts a shift in the W-mass reconstructed from hadronic decays of W-pairs of the order 65 MeV.

We show that the asymmetry in the fractional energy of charm versus anticharm jets produced in high energy diffractive photoproduction is sensitive to the interference of the Odderon (C=-) and Pomeron (C=+) exchange amplitudes in QCD. We predict the dynamical shape of the asymmetry in a simple model and estimate its magnitude to be of the order 15% using an Odderon coupling to the proton which sat

The conventional definition of the running coupling (Formula presented) in quantum chromodynamics is based on a solution to the renormalization group equations which treats quarks as either completely massless at a renormalization scale μ above their thresholds or infinitely massive at a scale below them. The coupling is thus nonanalytic at these thresholds. In this paper we present an analytic ex

Membrane processes are often competing directly with conventional separation processes. The aim of this study is to highlight the potentials of combinations of membrane processes and conventional separation processes by the means of hybrid processes and process synergies. The concepts of hybrid processes and process synergies will be introduced and defined supported by industrial examples, e.g. th

Physics and programming aspects are discussed for a Fortran 77 Monte Carlo program to simulate complete events in deep inelastic lepton-nucleon scattering. The parton level interaction is based on the standard model electroweak cross sections, which are fully implemented in leading order for any lepton of arbitrary polarization, and different parametrizations of parton density functions can be use

In the last half of the twelfth century, canon law established the rule that a marriage could be declared invalid if the consent had been given through force or fear. This ruling was a natural consequence of the insistence on free consent as the only requirement for a valid marriage. It did, however, entail a number of both practical and theoretical problems. It could be difficult to prove force a

The differences between two standard Monte Carlo models, LEPTO and ARIADNE, for deep inelastic scattering at small-χ is analysed in detail. It is shown that the difference arises from a 'unorthodox' suppression factor used in ARIADNE which replaces the normal ratio of parton densities. This gives rise to a factor that qualitatively is similar to what one would expect from BFKL dynamics for some ob

A program to simulate the production of heavy quarks through the boson-gluon fusion process in e±p collisions is presented. The full electroweak structure of the electron-gluon interaction is taken into account as well as the masses of the produced heavy quarks. Higher order QCD radiation is treated using initial and final state parton showers, and hadronization is performed using the Lund string