Perturbative QCD effects and the search for a H->WW->l nu l nu signal at the Tevatron (2009)
Anastasiou, Charalampos, Dissertori, Guenther, Grazzini, Massimiliano, Stoeckli, Fabian, Webber, Bryan R.
The Tevatron experiments have recently excluded a Standard Model Higgs boson in the mass range 160 - 170 GeV at the 95% confidence level. This result is based on sophisticated analyses designed to...
Frost, James A., Gaunt, Jonathan R., Sampaio, Marco O. P., Casals, Marc, Dolan, Sam R., Parker, M. Andrew, ...
We present results of CHARYBDIS2, a new Monte Carlo simulation of black hole production and decay at hadron colliders in theories with large extra dimensions and TeV-scale gravity. The main new...
The MC@NLO 3.4 Event Generator (2008)
Frixione, Stefano, Webber, Bryan R.
This is the user's manual of MC@NLO 3.4. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
Single-top hadroproduction in association with a W boson (2008)
Frixione, Stefano, Laenen, E, Motylinski, P, Webber, Bryan R, White, C D
We present the calculation of the Wt single-top production channel to next-to-leading order in QCD, interfaced with parton showers within the MC@NLO formalism. This channel provides a complementary...
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...
QCD radiation effects on the H->WW->l nu l nu signal at the LHC (2008)
Anastasiou, Charalampos, Dissertori, Guenther, Stoeckli, Fabian, Webber, Bryan R.
The discovery of a Standard Model Higgs boson is possible when experimental cuts are applied which increase the ratio of signal and background cross-sections. In this paper we study the pp->H->WW...
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...
Implementation Of Supersymmetric, Stefano Moretti, Kosuke Odagiri, Peter Richardson, Michael H. Seymour, Bryan R. Webber
We describe the implementation of supersymmetric processes in the HERWIG Monte Carlo event generator. We de ne relevant parameter and mixing conventions and list the hard scattering matrix elements....
Herwig++ 2.0 Release Note (2006)
Gieseke, S, Grellscheid, D, Hamilton, K, Ribon, A, Richardson, P, Seymour, Michael 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...
Towards the European strategy for particle physics: the Briefing Book (2006)
Åkesson, T, Aleksan, R, Allanach, Benjamin C, Bertolucci, S, Blondel, A, Butterworth, J, ...
This document was prepared as part of the briefing material for the Workshop of the CERN Council Strategy Group, held in DESY Zeuthen from 2nd to 6th May 2006. It gives an overview of the physics...
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...
Addendum to "Distinguishing Spins in Decay Chains at the Large Hadron Collider" (2006)
Athanasiou, Christiana, Lester, Christopher G., Smillie, Jennifer M., Webber, Bryan R.
We extend our earlier study of spin correlations in the decay chain $D\to C q$, $C\to B l^{near}$, $B\to A l^{far}$, where $A,B,C,D$ are new particles with known masses but undetermined spins,...
Distinguishing Spins in Decay Chains at the Large Hadron Collider (2006)
Athanasiou, Christiana, Lester, Christopher G., Smillie, Jennifer M., Webber, Bryan R.
If new particles are discovered at the LHC, it will be important to determine their spins in as model-independent a way as possible. We consider the case, commonly encountered in models of physics...
Herwig++ 2.0$\beta$ Release Note (2006)
Gieseke, S, Grellscheid, D, Ribon, A, Richardson, P, Seymour, Michael 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...
Herwig++ 2.0$\beta$ Release Note (2006)
Gieseke, S, Grellscheid, D, Ribon, A, Richardson, P, Seymour, Michael 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...
The MC@NLO 3.2 Event Generator (2006)
Frixione, Stefano, Webber, Bryan R
This is the user's manual of MC@NLO 3.2. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
The MC@NLO 3.2 Event Generator (2006)
Frixione, Stefano, Webber, Bryan R
This is the user's manual of MC@NLO 3.2. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
New tests of multiparticle production models (2005)
The two quantities known in statistical theory as the median and modal multiplicities form a better basis than the multiplicity moments for tests of multiparticle production models, and distinguish...
Smillie, Jennifer M., Webber, Bryan R.
An interesting alternative to supersymmetry (SUSY) for extending physics beyond the Standard Model is a model with universal extra dimensions (UED), in which the SUSY superpartners are replaced by...
The MC@NLO 3.1 Event Generator (2005)
Frixione, Stefano, Webber, Bryan R.
This is the user's manual of MC@NLO 3.1. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
Exploring Higher Dimensional Black Holes at the Large Hadron Collider (2004)
Harris, C M, Palmer, M J, Parker, M A, Richardson, P, Sabetfakhri, A, Webber, Bryan R
In some extra dimension theories with a TeV fundamental Planck scale, black holes could be produced in future collider experiments. Although cross sections can be large, measuring the model...
Coalescence model for Theta_c pentaquark formation (2004)
Karliner, Marek, Webber, Bryan R.
We present a model for the formation of the charmed pentaquark Theta_c in hard scattering processes such as deep inelastic scattering, e^+e^- annihilation, and high-energy p pbar collisions. The...
Exploring Small Extra Dimensions at the Large Hadron Collider (2003)
Allanach, Benjamin C, Odagiri, K, Palmer, M J, Parker, M A, Sabetfakhri, A, Webber, Bryan R
Many models that include small extra space dimensions predict graviton states which are well separated in mass, and which can be detected as resonances in collider experiments. It has been shown that...
Herwig++ 1.0: An Event Generator for $e^{+}e^{-}$ Annihilation (2003)
Gieseke, S, Ribon, A, Seymour, Michael H, Stephens, P, Webber, Bryan R
Results from the new Monte Carlo event generator Herwig++ are presented. This first version simulates Hadron Emission Reactions With Interfering Gluons in electron-positron annihilation. The parton...
Measuring sparticle masses in non-universal string inspired models at the LHC (2003)
Allanach, Benjamin C, Lester, C G, Parker, M A, Webber, Bryan R
We demonstrate that some of the suggested five supergravity points for study at the LHC could be approximately derived from perturbative string theories or M-theory, but that charge and colour...
Searching for Narrow Graviton Resonances with the ATLAS Detector at the Large Hadron Collider (2003)
Allanach, Benjamin C, Odagiri, K, Parker, M A, Webber, Bryan R
A spectrum of massive graviton states is present in several recent theoretical models that include extra space dimensions. In some such models the graviton states are well separated in mass, and can...
New formalism for QCD parton showers (2003)
Gieseke, S, Stephens, P, Webber, Bryan R
We present a new formalism for parton shower simulation of QCD jets, which incorporates the following features: invariance under boosts along jet axes, improved treatment of heavy quark...
The MC@NLO 2.2 Event Generator (2003)
Frixione, Stefano, Webber, Bryan R
This is the user's manual of MC@NLO 2.2. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
The MC@NLO 2.2 Event Generator (2003)
Frixione, Stefano, Webber, Bryan R.
This is the user's manual of MC@NLO 2.2. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
CHARYBDIS: A Black Hole Event Generator (2003)
Harris, C M, Richardson, P, Webber, Bryan R
CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the...
The MC@NLO 2.0 Event Generator (2003)
Frixione, Stefano, Webber, Bryan R
This is the user's manual of MC@NLO 2.0. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
The MC@NLO 2.0 Event Generator (2003)
Frixione, Stefano, Webber, Bryan R
This is the user's manual of MC@NLO 2.0. This package is a practical implementation, based upon the HERWIG event generator, of the MC@NLO formalism, which allows one to incorporate NLO QCD matrix...
Matching NLO QCD and parton showers in heavy flavour production (2003)
Frixione, Stefano, Nason, P, Webber, Bryan R
We apply the MC@NLO approach to the process of heavy flavour hadroproduction. MC@NLO is a method for matching next-to-leading order (NLO) QCD calculations and parton shower Monte Carlo (MC)...
HERWIG 6.5 Release Note (2002)
Corcella, Gennaro, Knowles, I G, Marchesini, G, Moretti, S, Odagiri, K, Richardson, Peter, ...
A new release of the Monte Carlo program HERWIG (version 6.5) is now available. The main new features are: support for the Les Houches interface to matrix element generators; additional SM and MSSM...
Implementation of supersymmetric processes in the HERWIG event generator (2002)
Moretti, S, Odagiri, K, Richardson, Peter, Seymour, Michael H, Webber, Bryan 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....
HERWIG 6.4 Release Note (2002)
Corcella, Gennaro, Knowles, I G, Marchesini, G, Moretti, S, Odagiri, K, Richardson, Peter, ...
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...
QCD Matrix Elements + Parton Showers (2001)
Catani, S, Krauss, F, Kühn, R, Webber, Bryan R
We propose a method for combining QCD matrix elements and parton showers in Monte Carlo simulations of hadronic final states in $e^+e^-$ annihilation. The matrix element and parton shower domains are...
Detecting Exotic Heavy Leptons at the Large Hadron Collider (2001)
Allanach, Benjamin C, Harris, C M, Parker, M A, Richardson, Peter, Webber, Bryan R
New almost-degenerate charged and neutral heavy leptons are a feature of a number of theories of physics beyond the Standard Model. The prospects for detecting these at the Large Hadron Collider...
HERWIG 6.3 Release Note (2001)
Corcella, Gennaro, Knowles, I G, Marchesini, G, Moretti, S, Odagiri, K, Richardson, Peter, ...
A new release of the Monte Carlo program HERWIG (version 6.3) is now available. The main new features are new (MRS) built-in parton distribution functions, more SM gauge boson production processes, 2...
Tau Neutrinos from Astrophysical and Cosmological Sources (2001)
MacGibbon, Jane H., Wichoski, Ubi F., Webber, Bryan R.
Previous work on the neutrino spectra from high energy sources has not included the tau neutrinos directly produced by the decays in the source. Here we consider the tau neutrino component and...
Extracting the Flavour Structure of a Baryon-Number R-parity Violating Coupling at the LHC (2001)
Allanach, Benjamin C, Barr, A J, Parker, M A, Richardson, Peter, Webber, Bryan R
The detection of the flavour content of jets produced from R-parity violating neutralino decays is investigated in the case where one baryon-number violating coupling dominates. Simulations are...
Allanach, Benjamin C, Barr, A J, Drage, L M, Lester, C G, Morgan, D, Parker, M A, ...
The measurement of sparticle masses in the Minimal Supersymmetric Standard Model at the LHC is analysed, in the scenario where the lightest neutralino decays into three quarks. Such decays, occurring...
Corcella, Gennaro, Knowles, I G, Marchesini, G, Moretti, S, Odagiri, K, Richardson, Peter, ...
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...
Report of the QCD Working Group (2000)
Ballestrero, A, Bambade, P, Bravo, S, Cacciari, M, Costa, M, De Boer, Wim, ...
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...
Naturalness Reach of the Large Hadron Collider in Minimal Supergravity (2000)
Allanach, Benjamin C, Hetherington, J P J, Parker, M A, Webber, Bryan R
We re-analyse the prospects of discovering supersymmetry at the LHC, in order to re-express coverage in terms of a fine-tuning parameter and to extend the analysis to scalar masses (m_0) above 2 TeV....
Catani, S, Dittmar, Michael, Soper, Davison Eugene, Stirling, William James, Tapprogge, Stefan, Alekhin, S I, ...
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,...
Basic Properties of QCD: the Lagrangian, the running coupling, asymptotic freedom and colour confinement. Examples of perturbative calculations in electron- positron physics (total cross sections and...
Fragmentation and Hadronization (2000)
Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation...
Allanach, Benjamin C, Van Der Bij, Jochum J, Dedes, A, Djouadi, Abdelhak, Grosse-Knetter, J, Hetherington, J, ...
The Beyond the Standard Model Working Group discussed a variety of topics relating to exotic searches at current and future colliders, and the phenomenology of current models beyond the Standard...
BFKL dynamics at hadron colliders (1999)
Ewerz, Carlo, Orr, Lynne H., Stirling, W. James, Webber, Bryan R.
Hadron colliders can provide important tests of BFKL `small-x' dynamics. We discuss two examples of such tests, the inclusive dijet jet cross section at large rapidity separation and the number of...
BFKL dynamics at hadron colliders (1999)
Ewerz, C, Orr, L H, Stirling, William James, Webber, Bryan R
Hadron colliders can provide important tests of BFKL `small-x' dynamics. We discuss two examples of such tests, the inclusive dijet jet cross section at large rapidity separation and the number of...
Theoretical Aspects of Particle Production (1999)
These lectures describe some of the latest data on particle production in high-energy collisions and compare them with theoretical calculations and models based on QCD. The main topics covered are:...
Multiplicity of (Mini-)Jets at Small x (1999)
We derive closed expressions for the mean and variance of the (mini-)jet multiplicity distribution in hard scattering processes at low x. Here (mini-)jets are defined as those due to initial-state...
Multiplicity of (Mini-)Jets at Small x (1999)
Ewerz, Carlo, Webber, Bryan R.
We derive closed expressions for the mean and variance of the (mini-)jet multiplicity distribution in hard scattering processes at low x. Here (mini-)jets are defined as those due to initial-state...
Jet Rates at Small x to Single-Logarithmic Accuracy (1999)
Ewerz, Carlo, Webber, Bryan R.
We present predictions of jet rates in deep inelastic scattering at small x to leading-logarithmic order in x, including all sub-leading logarithms of Q^2/m_R^2 where m_R is the transverse momentum...
Two-loop enhancement factor for 1/Q corrections to event shapes in deep inelastic scattering (1998)
Dasgupta, Mrinal, Webber, Bryan R.
We compute the two-loop enhancement factors for our earlier one-loop calculations of leading (1/Q) power corrections to the mean values of some event shape variables in deep inelastic lepton...
Resummed $C$-Parameter Distribution in $e^+ e^-$ Annihilation (1998)
We give perturbative predictions for the distribution of the $C$-Parameter event shape variable in $e^+e^-$ annihilation, including resummation of large logarithms in the two-jet (small-$C$) region,...
Report of the Working Group on "W Mass and QCD" (1997)
Ballestrero, A, Charlton, D G, Cowan, G D, Dornan, Peter J, Edgecock, R, Ellis, Jonathan Richard, ...
The W Mass and QCD Working Group discussed a wide variety of topics relating to present and future measurements of M(W) at LEP2, including QCD backgrounds to W+W- production. Particular attention was...
Quantum chromodynamics (QCD) (1997)
An introduction to applied pertubative QCD with emphasis on the following topics; jet physics in e+ e- and hadron-hadron collisions: deep inelastic lepton scattering; heavy quark and electroweak...
Non-Perturbative Corrections to Heavy Quark Fragmentation in $e^+e^-$ Annihilation (1996)
We estimate the non-perturbative power-suppressed corrections to heavy flavour fragmentation and correlation functions in e^+e^- annihilation, using a model based on the analysis of one-loop Feynman...
Marchesini, G, Webber, Bryan R, Abbiendi, G, Knowles, I G, Seymour, Michael 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...
Marchesini, G, Webber, Bryan R, Abbiendi, G, Knowles, I G, Seymour, Michael 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...
Knowles, I G, Webber, Bryan R, Todorova, S, Thompson, J C, Seymour, Michael H, Sarkar, S, ...
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...
Knowles, I G, Sjöstrand, Torbjörn, Blondel, A, Böhrer, 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...
Nason, P, Khoze, V A, Dokshitzer, Yu L, Hautmann, F, Seymour, Michael H, Padilla, C, ...
We discuss QCD studies that will be possible at LEP2. We examine both experimental and theoretical aspects of jets, fragmentation functions, multiplicities and particle spectra.
Nason, P, Webber, Bryan R, Ward, D, Lanske, D, Del Pozo, L A, Fabbri, Franco Luigi, ...
We discuss QCD studies that will be possible at LEP2. We examine both experimental and theoretical aspects of jets, fragmentation functions, multiplicities and particle spectra.
Dispersive approach to power-behaved contributions in QCD hard processes (1995)
Dokshitzer, Yu L, Marchesini, G, Webber, Bryan R
We consider power-behaved contributions to hard processes in QCD arising from non-perturbative effects at low scales which can be described by introducing the notion of an infrared-finite effective...
Monte Carlo simulation of baryon and lepton number violating processes at high energies (1994)
Gibbs, M J, Ringwald, Andreas, Webber, Bryan R, Zadrozny, J
We report results obtained with the first complete event generator for electroweak baryon and lepton number violating interactions at supercolliders. We find that baryon number violation would be...
Fragmentation function method for charge asymmetry measurements in e+e- collisions (1994)
We propose a method for measuring the hadron charge asymmetry in \ee collisions which is based upon the fragmentation function formalism, and is largely independent of modelling of fragmentation...
Longitudinally-invariant k$_{\perp}$-clustering algorithms for hadron-hadron collisions (1993)
Catani, S, Dokshitzer, Yu L, Seymour, Michael H, Webber, Bryan R
Summary and theoretical basis (1991)
Reya, E, Zerwas, Peter M, Berends, F A, Bordes, G, Cavanna, F, Del Águila, F, ...
Measuring colour flows in hard processes via hadronic correlations (1990)
Dokshitzer, Yu L, Khoze, V A, Marchesini, G, Webber, Bryan R