Publications (28)
Interpretation of electron-proton scattering at low Q^2
Johan Alwall, Gunnar Ingelman
Low-Q^2 photons do not resolve partons in the proton, which gives problems when applying the deep inelastic scattering formalism, such as an unphysical, negative gluon density extr…
Quark Asymmetries in Nucleons
Johan Alwall
We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations o…
B's with Direct Decays: Tevatron and LHC Discovery Prospects in the b\bar{b}+MET Channel
Johan Alwall, Jonathan L. Feng, Jason Kumar +1
We explore the discovery prospects for B'\bar{B}' pair production followed by direct decays B'->bX, where B' is a new quark and X is a long-lived neutral particle. We develop optim…
New Developments in MadGraph/MadEvent
Johan Alwall, Pierre Artoisenet, Simon de Visscher +4
We here present some recent developments of MadGraph/MadEvent since the latest published version, 4.0. These developments include: Jet matching with Pythia parton showers for both…
Generalized VDM and F_2 data at low Q^2
Johan Alwall, Gunnar Ingelman
The generalised vector meson dominance model (GVDM) gives a good description of F_2 data at very low Q^2. At intermediate Q^2 a GVDM component avoids problems when applying the lar…
The SysCalc code: A tool to derive theoretical systematic uncertainties
Alexis Kalogeropoulos, Johan Alwall
Undisputedly, derivation of theoretical systematic uncertainties is an inseparable ingredient of any robust analysis dealing with experimental data. However, it is not uncommon, ev…