Jung, H., De Roeck, A., Ajaltouni, Z. J., Albino, S., Altarelli, G., Ambroglini, F., ...
2nd workshop on the implications of HERA for LHC physics. Working groups: Parton Density Functions Multi-jet final states and energy flows Heavy quarks (charm and beauty) Diffraction Cosmic Rays...
Soft gluons and superleading logarithms in QCD (2009)
After a brief introduction to the physics of soft gluons in QCD we present a surprising prediction. Dijet production in hadron-hadron collisions provides the paradigm, i.e. h_1 +h_2 \to jj+X. In...
Soft gluons and superleading logarithms in QCD (2009)
Forshaw, J. R., Seymour, M. H.
After a brief introduction to the physics of soft gluons in QCD we present a surprising prediction. Dijet production in hadron-hadron collisions provides the paradigm, i.e. h_1 +h_2 \to jj+X. In...
Introduction to Monte Carlo Tools (2008)
V. Lendermann, A. Nikitenko, E. Richter-was, P. Robbe, M. H. Seymour
Herwig++ 2.3 Release Note (2008)
Bähr, M, Gieseke, S, Gigg, M, Grellscheid, D, Hamilton, K, Plätzer, S, ...
A new release of the Monte Carlo program Herwig++ (version 2.3) is now available. This version includes a number of improvements including: the extension of the program to lepton-hadron collisions;...
Herwig++ 2.3 Release Note (2008)
Bahr, M., Gieseke, S., Gigg, M., Grellscheid, D., Hamilton, K., Platzer, S., ...
A new release of the Monte Carlo program Herwig++ (version 2.3) is now available. This version includes a number of improvements including: the extension of the program to lepton-hadron collisions;...
Bahr, M., Gieseke, S., Gigg, M. A., Grellscheid, D., Hamilton, K., Latunde-Dada, O., ...
Herwig++ is the successor of the event generator HERWIG. In its present version 2.2.1 it provides a program for full LHC event generation which is superior to the previous program in many respects....
Forshaw, J R, Kyrieleis, A, Seymour, M H
In a previous paper we reported the discovery of super-leading logarithmic terms in a non-global QCD observable. In this short update we recalculate the first super-leading logarithmic contribution...
Forshaw, J. R., Kyrieleis, A., Seymour, M. H.
In a previous paper we reported the discovery of super-leading logarithmic terms in a non-global QCD observable. In this short update we recalculate the first super-leading logarithmic contribution...
Herwig++ 2.2 Release Note (2008)
Bahr, M, Gieseke, S, Gigg, M, Grellscheid, D, Hamilton, K, Latunde-Dada, O, ...
A new release of the Monte Carlo program Herwig++ (version 2.2) is now available. This version includes a number of improvements including: matrix elements for the production of an electroweak gauge...
Herwig++ 2.2 Release Note (2008)
Bahr, M., Gieseke, S., Gigg, M., Grellscheid, D., Hamilton, K., Latunde-Dada, O., ...
A new release of the Monte Carlo program Herwig++ (version 2.2) is now available. This version includes a number of improvements including: matrix elements for the production of an electroweak gauge...
Herwig++ Physics and Manual (2008)
Bahr, M, Gieseke, S, Gigg, M A, Grellscheid, D, Hamilton, K, Latunde-Dada, O, ...
In this paper we describe Herwig++ version 2.1, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton and hadron-hadron collisions. A number of important hard...
Herwig++ Physics and Manual (2008)
Bahr, M., Gieseke, S., Gigg, M. A., Grellscheid, D., Hamilton, K., Latunde-Dada, O., ...
In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of...
Tuning MC Models To Fit DIS ... Scattering Events (2007)
J.A. Lauber, L. Lönnblad, M. H. Seymour
62> 1 10 10 2 10 3 0 2 4 6 8 10 12 14 16 18 20 0.3 < x vis < 1.0 E t,out [GeV] HERWIG PYTHIA F2GEN pointlike Data minus Background Figure 1: Transverse energy out of the tag plane. Because...
Multiparton Interactions in Photoproduction at HERA (2007)
J. M. Butterworth, J. R. Forshaw, M. H. Seymour
The high energy photoproduction of jets is being observed at the ep collider, HERA. It may be that the HERA centre-of-mass energy is sufficiently large that the production of more than one pair of...
Soft Isolated Photon Production as a Probe of the Parton Shower Mechanism (2007)
We discuss the rate of low-energy well-isolated photons in e + e \Gamma annihilation into hadrons, which is highly sensitive to the differences in scale-ordering used in parton shower models. We show...
Bahr, M, Gieseke, S, Gigg, M, Grellscheid, D, Hamilton, K, Latunde-Dada, O, ...
A new release of the Monte Carlo program Herwig++ (version 2.1) is now available. This version includes a number of significant improvements including: an eikonal multiple parton-parton scattering...
Herwig++ 2.1 Release Note (2007)
Bahr, M., Gieseke, S., Gigg, M., Grellscheid, D., Hamilton, K., Latunde-Dada, O., ...
A new release of the Monte Carlo program Herwig++ (version 2.1) is now available. This version includes a number of significant improvements including: an eikonal multiple parton-parton scattering...
Breakdown of QCD coherence? (2006)
Kyrieleis, A, Forshaw, J R, Seymour, M H
We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a...
Breakdown of QCD coherence ? (2006)
Kyrieleis, A., Forshaw, J. R., Seymour, M. H.
We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a...
Herwig++ 2.0 Release Note (2006)
Gieseke, S., Grellscheid, D., Hamilton, K., Ribon, A., Richardson, P., Seymour, M. H., ...
A new release of the Monte Carlo program Herwig++ (version 2.0) is now available. This is the first version of the program which can be used for hadron-hadron physics and includes the full simulation...
Alekhin, S., Altarelli, G., Amapane, N., Andersen, J., Andreev, V., Arneodo, M., ...
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to...
Alekhin, S., Altarelli, G., Amapane, N., Andersen, J., Andreev, V., Arneodo, M., ...
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to...
A standard format for Les Houches Event Files (2006)
Alwall, J., Ballestrero, A., Bartalini, P., Belov, S., Boos, E., Buckley, A., ...
A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is...
Super-leading logarithms in non-global observables in QCD? (2006)
Forshaw, J. R., Kyrieleis, A., Seymour, M. H.
We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a...
Herwig++ 2.0beta Release Note (2006)
Gieseke, S., Grellscheid, D., Ribon, A., Richardson, P., Seymour, M. H., Stephens, P., ...
A new release of the Monte Carlo program Herwig++ (version 2.0beta) is now available. The main new feature is the extension of the program to include simple hadron-hadron processes including the...
Alekhin, S., Altarelli, G., Amapane, N., Andersen, J., Andreev, V., Arneodo, M., ...
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to...
Alekhin, S., Altarelli, G., Amapane, N., Andersen, J., Andreev, V., Arneodo, M., ...
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to...
HERA and the LHC - A workshop on the implications of HERA for LHC physics: Proceedings Part A (2006)
S. Alekhin, DESY Forschung Hochenergiephysik, G. Altarelli, N. Amapane, J. Andersen, V. Andreev, ...
Internal report | Preprint
S. Alekhin, DESY Forschung Hochenergiephysik, G. Altarelli, N. Amapane, J. Andersen, V. Andreev, ...
Internal report | Preprint
The colour evolution of the process q q -> q q g (2005)
We calculate the soft anomalous dimension matrix for a five-parton process, qq -> qqg. Considering different bases we unveil some interesting properties of this matrix.
Gaps between Jets in the High Energy Limit (2005)
Forshaw, J. R., Kyrieleis, A., Seymour, M. H.
We use perturbative QCD to calculate the parton level cross section for the production of two jets that are far apart in rapidity, subject to a limitation on the total transverse momentum Q0 in the...
The Les Houches Accord PDFs (LHAPDF) and LHAGLUE 575 (2005)
G. Altarelli (cern, J. Blümlein (desy, M. Botje (nikhef, J. Butterworth (ucl, K. Eggert (cern, M. Mangano (cern, ...
The resummation of inter-jet energy flow for gaps-between-jets processes at HERA (2003)
Appleby, R. B., Seymour, M. H.
We calculate resummed perturbative predictions for gaps-between-jets processes and compare to HERA data. Our calculation of this non-global observable needs to include the effects of primary gluon...
Non-global logarithms in inter-jet energy flow with kt clustering requirement (2002)
Appleby, R. B., Seymour, M. H.
Recent work in inter-jet energy flow has identified a class of leading logarithms previously not considered in the literature. These so-called non-global logarithms have been shown to have...
An eikonal model for multiparticle production in hadron-hadron interactions (2002)
We introduce an eikonal Monte Carlo model (running in conjunction with HERWIG) for simulating multiparticle production in hadron-hadron interactions. We compare our simulated data to the CDF Tevatron...
Implementation of supersymmetric processes in the HERWIG event generator (2002)
Moretti, S., Odagiri, K., Richardson, P., Seymour, M. H., Webber, B. R.
We describe the implementation of supersymmetric processes in the HERWIG Monte Carlo event generator. We define relevant parameter and mixing conventions and list the hard scattering matrix elements....
Small x Phenomenology: Summary and Status (2002)
Baranov, S., Bartels, J., Ciafaloni, M., Collins, J., Davidsson, M., ...
The aim of this paper is to summarize the general status of our understanding of small x physics. It is based on presentations and discussions at an informal meeting on this topic held in Lund,...
HERWIG 6.4 Release Note (2002)
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
A new release of the Monte Carlo program HERWIG (version 6.4) is now available. The main new features are: spin correlations between the production and decay of heavy fermions, i.e. top quarks, tau...
HERWIG 6.3 Release Note (2001)
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
A new release of the Monte Carlo program HERWIG (version 6.3) is now available. The main new features are new (MRST) built-in parton distribution functions, more SM gauge boson production processes,...
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
HERWIG is a general-purpose Monte Carlo event generator, which includes the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron scattering and soft hadron-hadron collisions in one...
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
HERWIG is a general-purpose Monte Carlo event generator, which includes the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron scattering and soft hadron-hadron collisions in one...
Summary of the SUSY Working Group (2000)
Abdullin, S., Drees, M., Martyn, H U., Ambrosanio, S., Dreiner, H., Godbole, R M., ...
The results obtained by the Working Group on Supersymmetry at the 1999 Les Houches Workshop on Collider Physics are summarized. Separate chapters treat "general" supersymmetry, R-parity violation,...
Jets in Hadron Collisions (2000)
We discuss recent progress and open questions in QCD jet physics, with particular emphasis on two areas: jet definitions and jet substructure.
Report of the QCD Working Group (2000)
Ballestrero, A., Bambade, P., Bravo, S., Cacciari, M., Costa, M., DeBoer, W., ...
The activities of the QCD working group concentrated on improving the understanding and Monte Carlo simulation of multi-jet final states due to hard QCD processes at LEP, i.e. quark-antiquark plus...
Summary of the SUSY Working Group of the 1999 Les Houches Workshop (2000)
Abdullin, S., Drees, M., Polesello, G., Ambrosanio, S., Dreiner, H., ...
The results obtained by the Working Group on Supersymmetry at the 1999 Les Houches Workshop on Collider Physics are summarized. Separate chapters treat "general" supersymmetry, R-parity violation,...
Catani, S., Dittmar, M., Soper, D., Stirling, W. J., Tapprogge, S., Alekhin, S., ...
We discuss issues of QCD at the LHC including parton distributions, Monte Carlo event generators, the available next-to-leading order calculations, resummation, photon production, small x physics,...
Jet Activity in t-tbar Events and Top Mass Reconstruction at Hadron Colliders (2000)
Corcella, G., Mangano, M. L., Seymour, M. H.
We analyse the impact of matrix-element corrections to top decays in HERWIG on several observables related to the jet activity in t-tbar events at the Tevatron and at the LHC. In particular, we study...
Beneke, M., Efthymiopoulos, I., Mangano, M. L., Womersley, J., Ahmadov, A., Azuelos, G., ...
We review the prospects for studies of the top quark at the LHC.
Report of the QCD working group (2000)
Ballestrero, A, Bambade, P, Bravo, S, Cacciari, M, Costa, M, De Boer, W, ...
HERWIG 6.1 Release Note (1999)
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
A new version of the Monte Carlo program HERWIG (version 6.1) is now available. This note gives brief details of the new features relative to the previous version (5.9). A fully updated manual will...
PYTHIA and HERWIG for Linear Collider Physics (1999)
An overview is given of general-purpose event generators, especially PYTHIA and HERWIG. The current status is summarized, some recent physics improvements are described, and planned future projects...
Subjet Rates in Hadron Collider Jets (1999)
Forshaw, J. R., Seymour, M. H.
We calculate the subjet rates for jets produced in hadron collisions. The kt algorithm is used to define the jets and allows the theoretical calculation to sum both the leading and next-to-leading...
Searching for R-Parity Violation at Run-II of the Tevatron (1999)
Allanach, B., Baer, H., Banerjee, S., Berger, E. L., Chertok, M., De Campos, F., ...
We present an outlook for possible discovery of supersymmetry with broken R-parity at Run II of the Tevatron. We first present a review of the literature and an update of the experimental bounds. In...
Searching for R parity violation at Run II of the Tevatron (1998)
Allanach, BC, Baer, H, Banerjee, S, Berger, EL, Chertok, MB, Cheung, King-man, ...
Tuning MC Models to Fit DIS e-gamma Scattering Events (1997)
Lauber, J. A., Lonnblad, L., Seymour, M. H.
Monte Carlo models of DIS e-gamma scattering must describe hard emissions as well as the soft and collinear limits. Comparison with the observed experimental hadronic energy flow has shown that...
Rapidity Gaps Between Jets (1996)
Butterworth, J. M., Hayes, M. E., Seymour, M. H., Sinclair, L. E.
An excess of events with a rapidity gap between jets, over what would be expected from non-diffractive processes, has been observed at HERA. A process based on a perturbative QCD calculation of...
Marchesini, G., Webber, B. R., Abbiendi, G., Knowles, I. G., Seymour, M. H., Stanco, L.
HERWIG (Hadron Emission Reactions With Interfering Gluons) is a multipurpose Monte Carlo event generator for the simulation of hard collisions between hadrons, leptons and photons. This note...
Multiparton Interactions in Photoproduction at HERA (1996)
Butterworth, J. M., Forshaw, J. R., Seymour, M. H.
The high energy photoproduction of jets is being observed at the ep collider, HERA. It may be that the HERA centre-of-mass energy is sufficiently large that the production of more than one pair of...
Gamma-Gamma Physics at LEP2 (1996)
Aurenche, P., Schuler, G. A., Bawa, A., Boudinov, E., Buijs, A., Cacciari, M., ...
This report is an overview of the gamma-gamma physics capabilities of LEP2, and covers the following topics: structure functions, equivalent photon approximation, tagging conditions etc, soft and...
Knowles, I. G., Sjostrand, T., Blondel, A., Boehrer, A., Buchanan, C. D., Charlton, D. G., ...
This report is a survey on QCD Event Generator issues of relevance for LEP 2. It contains four main sections: a summary of experience from LEP 1, extrapolations to LEP 2 energies, Monte Carlo...
Infrared Renormalons and Power Suppressed Effects in $e^+e^-$ Jet Events (1995)
We study the effect of infrared renormalons upon shape variables that are commonly used to determine the strong coupling constant in $e^+e^-$ annihilation into hadronic jets. We consider the model of...
Multiple Hard Interactions in Gamma-Gamma and Gamma-P Physics at LEP and HERA (1995)
Butterworth, J. M., Forshaw, J. R., Seymour, M. H., Storrow, J. K., Walker, R.
At $e^+e^-$ and $ep$ colliders, the large fluxes of almost on-shell photons accompanying the lepton beams lead to the photoproduction of jets. As the centre-of-mass energy is increased, regions of...
THE STRUCTURE FUNCTION F_2^{\gamma}(x,Q^2) AT LEP2 (1995)
Forshaw, J. R., Seymour, M. H.
The unique nature of the photon can be investigated in hitherto unexplored kinematic regions at LEP2. We discuss the theoretical significance of deep inelastic measurements and present a prescription...
Heavy Quark Pair Multiplicity in. . . (1994)
We calculate the multiplicity of heavy quark pairs in e + e \Gamma annihilation events, which arises from perturbative gluon splitting. Our result is exact to leading order in ff s ; and resums large...
P. Aurenche, Conveners P. Aurenche, G. A. Schuler, E. Boudinov, A. Buijs, M. Cacciari, ...
this report to extrapolate the published results to a total charm cross section. Some caution is in order however when comparing theory and the results of different experiments in this way. This...
Thesis (B.Sc.-Quantity Surveying)-University of Natal, 1984.
Corcella, G., Knowles, I. G., Marchesini, G., Moretti, S., Odagiri, K., Richardson, P., ...
A new release of the Monte Carlo program HERWIG (version 6.4) is now available. The main new features are: spin correlations between the production and decay of heavy fermions, i.e. top quarks, tau...