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The extended version provides SamplerBase objects which can be used alternatively to the default ACDCSampler. ** New BSM models *** New colour sextet diquark model A colour sextet diquark model has been included, as described in Richardson and Winn (arXiv:1108.6154). *** Models reproducing the CDF t-tbar asymmetry Four models that can reproduce the reported t-tbar asymmetry have been included. *** Zprime A simple standard model extension by one additional heavy neutral vector boson. ** Interface to AlpGen, with MLM merging The Contrib directory contains a new interface to the AlpGen matrix element generator. AlpGen events must be preprocessed with the provided AlpGenToLH.exe tool before they can be used. More information can be found in the Herwig++ 2.6 release note. ** HiggsVBF Powheg Higgs boson production by vector boson fusion is available at NLO in the POWHEG scheme, as described in d'Errico, Richardson (arXiv:1106.2983). The Powheg DIS processes were available in Herwig++-2.5.2 already. ** Statistical colour reconnection Alternative mechanisms to minimize the colour length Sum(m_clu) before the hadronization stage, based on Metropolis and annealing algorithms. ** Energy extrapolation of underlying-event tunes To describe underlying-event data at different c.m. energies, the energy-dependent parameter pT_min will now be adjusted automatically, following a power-law. The new tune parameters are the value at 7000 GeV "MPIHandler:pTmin0", and MPIHandler:Power. ** Ticket #239: Reporting of minimum-bias cross-section When simulating minimum-bias events using the MEMinBias matrix element, the correct unitarized cross section can now be reported via the standard facilities; it is no longer necessary to extract it from the .log file of the run. The corresponding functionality is enabled by inserting a MPIXSecReweighter object as a post-subprocess handler: create Herwig::MPIXSecReweighter MPIXSecReweighter insert LHCHandler:PostSubProcessHandlers 0 MPIXSecReweighter ** Dependency on 'boost' Herwig++ now requires the boost headers to build; if not detected in standard locations, specify with the --with-boost configure option. ** Tests directory The Tests directory now contains input cards for almost all Rivet analyses. A full comparison run can be initiated with 'make tests'. ** Minor changes *** Default LHC energy now 8 TeV All LHC-based defaults have now been updated to use 8 TeV as the center-of-mass energy. *** Herwig::ExtraParticleID -> ThePEG::ParticleID The namespace for additional particles has been unified into ThePEG::ParticleID *** MEee2VectorMeson The e+e- -> vector meson matrix element has moved from Contrib into HwMELepton.so *** SUSY numerics fixes Better handling of rare numerical instabilities. *** YODA output for Rivet The built-in histogramming handler can now output data in the YODA format used by Rivet. *** Consistency checks in SLHA file reader Better warnings for inconsistent SusyLHA files *** better colour flow checking for development ** Bug fixes *** Extremely offshell W from top decay Numerical improvements for very off-shell W bosons coming from top decays. *** Ticket #367: problems in using SUSY + LHE Susy events from Les Houches event files are now handled better. *** Infinite loop in remnant decayer The remnant decayer will now abort after 100 tries. *** Fix to HiggsVBF LO diagrams The diagram structure of HiggsVBF LO matrix elements has been fixed. *** LEP thrust fix The calculation of the transverse momentum of a branching from the evolution variable in final-state radiation can now be changed. While formally a sub-leading choice this enables a better description of the thrust distribution in e+e- collisions at small values of the thrust. Currently the default behaviour, where the cut-off masses are used in the calculation, remains the same as previous versions. * Herwig++-2.5.2 release: 2011-11-01 (tagged at SVN r6928) ** Optional new jet vetoing model The jet vetoing model by Schofield and Seymour (arXiv:1103.4811) is available via Evolver:ColourEvolutionMethod, PartnerFinder:PartnerMethod and SplittingFunction:SplittingColourMethod. The default behaviour is unchanged. ** MPI tune Version 3 of the MPI tunes is now the default. Please note that the pT parameter is energy-dependent and needs to be modified when an LHC run is not at 7 TeV. The latest tunes are always available at http://projects.hepforge.org/herwig/trac/wiki/MB_UE_tunes ** MPI PDFs MPI PDFs can now be controlled independently. ** Initialization time speedup A new BSMModel base class was introduced between StandardModel and the BSM model classes. Together with a restructured decay mode initialization, this offers significantly faster startup times for BSM runs. ThreeBodyDecays can now always be switched on without a large speed penalty. ** Decay mode file Decay mode files in the SLHA format can now be read separately in any BSM model with 'set Model:DecayFileName filename' ** Powheg DIS Charged- and neutral-current DIS processes implementing the POWHEG method are now available. ** Diffraction models Xi cut implemented in PomeronFlux ** Ticket #352: Colour reconnection fixed in DIS ** Ticket #353: Improved numerical stability in chargino decays ** Ticket #358: Infinite loop in top events with pT cut in shower ** Ticket #361: Problem with duplicate 2-body modes in BSM ** Tickets #362 / #363: Crashes with baryon number violating models Particle decays in SUSY models with RPV now work correctly in the colour 8 -> 3,3,3 case. Colour reshuffling now works for RPV clusters. ** Improved Fastjet detection The configure step uses fastjet-config to make sure all header file paths are seen. ** Darwin 11 / OS X Lion A configure bug was fixed which prevented 'make check' from succeeding on OS X Lion. ** Vertex classes The specification of QED / QCD orders has been moved to the vertex constructors, to allow ThePEG consistency checks. WWHH vertices in MSSM and NMSSM were fixed. Some Leptoquark and UED vertices fixed. ** Hadronization Cleanup of obsolete code. * Herwig++-2.5.1 release: 2011-06-24 (tagged at SVN r6609) ** Example input files at 7 TeV All our example input files for LHC now have their beam energy set to 7 TeV instead of 14 TeV. ** Colour reconnection on by default The colour reconnection tunes are now the default setup. Version 2 of the tunes replaces the *-1 tunes, which had a problem with LEP event shapes. ** Run name tags Aded possibility to add a tag to the run name when running with the '-t' option. One run file can thus be run with different seeds and results stored in different output files. ** Floating point exceptions The new command line option -D enables floating point error checking. ** General improvements to WeakCurrent decays ** Remnant decayer Hardwired gluon mass was removed. ** WeakCurrentDecayConstructor Instead of specifying separate Particle1...Particle5 vectors for the decay modes, the new interface DecayModes can be filled with decay tags in the standard syntax. ** BSM: improvements to handling of vertex and model initialisation ** Powheg Higgs Option to use pT or mT as the scale in alphaS and for the factorization scale in the PDFs ** Ticket #337: Tau polarization wrong in charged Higgs decay ** Ticket #339: Colour flows in GeneralThreeBody Decayers for 3bar -> 8 3bar 1 ** Ticket #340: Crash for resonant zero-width particles ** Ticket #341: Varying scale for BSM processes The scale used is now ResonantProcessConstructor:ScaleFactor or TwoToTwoProcessConstructor:ScaleFactor multiplied by sHat. ** Ticket #346: Chargino decays Chargino decayers now automatically switch between the mesonic decays for mass differences less than 2 GeV and the normal partonic decays above 2 GeV. ** Ticket #349: Stop by default on input file errors The '--exitonerror' flag is now the default behaviour for the Herwig++ binary. To switch back to the old behaviour, '--noexitonerror' is required. ** Ticket #351: Four-body stop decays ** Tested with gcc-4.6 * Herwig++-2.5.0 release: 2011-02-08 (tagged at SVN r6274) ** Uses ThePEG-1.7.0 Herwig++ 2.5.0 requires ThePEG 1.7.0 to benefit from various improvements, particularly: handling of diffractive processes; respecting LD_LIBRARY_PATH when loading dynamic libraries, including LHAPDF; improvements to repository commands for decay modes. See ThePEG's NEWS file for more details. ** POWHEG improvements *** New POWHEG processes Simulation at NLO accuracy using the POWHEG method is now available for hadronic diboson production (pp to WW,WZ,ZZ), Higgs decays to heavy quarks, and e+e- to two jets or ttbar, including full mass dependence. *** Input file changes The input files for setting up POWHEG process simulation have been simplified. See the example files LHC-Powheg.in and TVT-Powheg.in for the improved command list. *** Structural changes The POWHEG backend in the shower code has been restructured to make future additions easier: PowhegEvolver has merged with Evolver; both the matrix element corrections and real corrections in the POWHEG scheme are implemented directly in the ME or Decayer classes. ** New processes at leading order *** Photon initiated processes We have added a matrix element for dijet production in gamma hadron collisions. *** Bottom and charm in heavy quark ME The option of bottom and charm quarks is now supported for heavy quark production in MEHeavyQuark. ** Colour reconnection The cluster hadronization model has been extended by an option to reconnect coloured constituents between clusters with a given probability. This new model is different from the colour reconnection model used in FORTRAN HERWIG, and improves the description of minimum bias and underlying event data. ** Diffractive Processes Both single and double diffractive processes are now supported in Herwig++. The Pomeron PDF is implemented using a fit to HERA data, and a pion PDF can be used to model reggeon flux. ** BSM physics *** New models We have added new BSM models, particularly ADD-type extra dimension models and the next-to-minimal supersymmetric standard model (NMSSM). Effects of leptoquarks can as well be simulated. *** Vertex additions We have added flavour changing stop interactions (stop - neutralino - charm) and gravitino interactions with particular emphasis on numerical stability for very light gravitinos. Tri-linear Higgs and Higgs-Higgs/Vector-Vector four-vertices are available as well. *** Input file changes The SUSY model can now also extract the SLHA information from the header of a Les Houches event file: replace the SLHA file name in the example input files with the LH file name. *** Structure The backend structure of the HardProcessConstructor has changed, to allow easier inclusion of new process constructors. Some 2->3 BSM scattering processes involving neutral higgs bosons are now included. The spin handling has been improved in the background. ** Shower splitting code reorganized The selection of spin structures has been decoupled from the choice of colour structure. This gives more flexibility in implementing new splittings. Selected splittings can be disabled in the input files. ** B mixing B mixing, and indirect CP violation in the B meson system are included now. ** Looptools The Looptools directory has been updated to reflect T.Hahn's Looptools 2.6. ** Contrib changes The ROOT interface has been removed as deprecated. The MCPWNLO code has temporarily been removed from the Contrib directory as a major review of this code is required. Additionally, there are various fixes to all other codes shipped in Contrib. ** DIS improvements The momentum reshuffling in DIS events has been improved. ** mu and nu beams mu, nu_e and nu_mu and their antiparticles are now available as beam particles. They are all supported in the DIS matrix elements. mu+ mu- collisions are supported in the general matrix element code for BSM models, but not yet in the hard-coded matrix elements for lepton-lepton scattering. ** Structural changes *** Inline code Inline code has been merged into the header files, .icc files were removed. *** Silent build By default, Herwig++ now builds with silent build rules. To get the old behaviour, run 'make V=1'. *** Debug level The debug level on the command line will now always have priority. *** Event counter The event counter has been simplified. *** Interpolator persistency Interpolators can now be written persistently. ** Ticket #307: Momentum violation check in BasicConsistency Added parameters AbsoluteMomentumTolerance and RelativeMomentumTolerance ** Example POWHEG input files The example input files for Powheg processes now set the NLO alpha_S correctly, and are run as part of 'make check'. ** Truncated shower A problem which lead to the truncated shower not being applied in some cases has been fixed. ** Fixes to numerical problems Minor problems with values close to zero were fixed in several locations. ** Remove duplicated calculation of event shapes An accidental duplication in the calculation of event shapes was removed, they are now only calculated once per event. Several other minor issues in the event shape calculations have also been fixed. ** MRST PDFs fixed An initialization problem in the internal MRST PDFs was fixed. ** Vertex scale choice The scale in the Vertex classes can now be zero where possible. ** Treatment of -N flag The Herwig++ main program now correctly treats the -N flag as optional. ** Numerical stability improved The numerical stability in the 'RunningMass' and 'QTildeReconstructor' classes has been improved. The stability of the boosts in the SOPTHY code for the simulation of QED radiation has been improved. The accuracy of boosts in the z-direction has been improved to fix problems with extremely high p_T partons. ** Bugfix in initial state splittings A bug in the implementation of the PDF weight in initial-state qbar -> qbar g splittings has been fixed. ** Bugfix in chargino neutralino vertices A bug in the 'chi+- chi0 W-+' and charged Higgs-sfermions vertices has been fixed. ** Remove uninitialized variables written to repository A number of uninitialised variables which were written to the repository have been initialised to zero to avoid problems on some systems. ** Fix to QED radiation in hadronic collisions The longitudinal boost of the centre-of-mass frame in hadronic collisions is correctly accounted for now in the generation of QED radiation. ** Fix to numerical problems in two-body decays Numerical problems have been fixed, which appeared in the rare case that the three-momenta of the decay products in two-body decays are zero in the rest frame of the decay particle. ** A problem with forced splittings in the Remnant was fixed. ** ME correction for W+- decays applied properly The matrix element correction for QCD radiation in W+- decays which was not being applied is now correctly used. ** Top quark decays from SLHA file The presence of top quark decay modes in SLHA files is now handled correctly. ** Exceptional shower reconstruction kinematics Additional protection against problems due to the shower reconstruction leading to partons with x>1 has been added. ** Ordering of particles in BSM processes Changes have been made to allow arbitrary ordering of the outgoing particles in BSM processes. ** Bugfixes in tau decays Two bugs involving tau decays have been fixed. The wrong masses were used in the 'KPiCurrent' class for the scalar form factors and a mistake in the selection of decay products lead to tau- --> pi0 K- being generated instead of tau- --> eta K-. ** Avoid crashes in baryon number violating processes. To avoid crashes, better protection has been introduced for the case where diquarks cannot be formed from the quarks in a baryon-number violating process. In addition, the parents of the baryon-number violating clusters have been changed to avoid problems with the conversion of the events to HepMC. ** QED radiation in W- decays A bug in the 'QEDRadiationHandler' class which resulted in no QED radiation being generated in W- decays has been fixed. ** A number of minor fixes to the SUSY models have been made. ** Partial width calculations in BSM models A fix for the direction of the incoming particle in the calculation of two-body partial widths in BSM models has been made. ** LoopTools improvements The LoopTools cache is now cleared more frequently to reduce the amount of memory used by the particle. ** Negative gluino masses are now correctly handled. ** A problem with mixing matrices which are not square has been fixed. ** Removed duplicate diagram The 'MEee2gZ2ll' class has been fixed to only include the photon exchange diagram once rather than twice as previously. ** Fix for duplicate particles in DecayConstructor A problem has been fixed which occurred if the same particle was included in the list of DecayConstructor:DecayParticles. ** Fixes for UED model vertices A number of minor problems in the vertices for the UED model have been fixed. ** Include missing symmetry factor The missing identical-particle symmetry factor in 'MEPP2GammaGamma' has been included. ** Fix floating point problem in top decays A floating point problem in the matrix element correction for top decays has been fixed. * Herwig++-2.4.2 release: 2009-12-11 (tagged at SVN r5022) ** Ticket #292: Tau decay numerical instability The momentum assignment in tau decays contained numerical instabilities which have been fixed by postponing the tau decay until after the parton shower. A new interface setting DecayHandler:Excluded is available to prevent decays in the shower step. This is enabled by default for tau only. ** Ticket #290: Missing MSSM colour structure The missing colour structure for gluino -> gluon neutralino was added. ** Ticket #294: Zero momentum in some decays Some rare phase space points lead to zero momentum in two-body decays. This has been fixed. ** Ticket #295: Stability of QED radiation for lepton collider processes The numerical stability of QED radiation momenta was improved further. ** Ticket #296: K0 oscillation vertex was wrong The oscillation from K0 to K0_L/S now takes place at the production vertex of K0. ** Ticket #289: Undefined variables in repository On some system configurations, undefined variables were written to the repository. These have been fixed. ** Fixed QED radiation for hadron processes The longitudinal boost of the centre-of-mass frame in hadronic collisions is correctly accounted for now. ** Numerical stability fixes Small fixes in RunningMass and QTildeReconstructor. ** Powheg example input files The example input files for Powheg processes now set the NLO alpha_S correctly, and are run as part of 'make check'. ** OS X builds for Snow Leopard Snow Leopard machines will now be recognized as a 64bit architecture. * Herwig++-2.4.1 release: 2009-11-19 (tagged at SVN r4932) ** Uses ThePEG-1.6.0 Herwig++ now requires ThePEG-1.6.0 to benefit from the improved helicity code there. If you have self-written vertex classes, see ThePEG's NEWS file for conversion instructions. ** Vertex improvements ThePEG's new helicity code allowed major simplification of the vertex implementations for all Standard Model and BSM physics models. ** New Transplanckian scattering model An example configuration is in LHC-TRP.in ** BSM ModelGenerator as branching ratio calculator The BSM ModelGenerator has a new switch to output the branching ratios for a given SLHA file in SLHA format, which can then be used elsewhere. ** BSM debugging: HardProcessConstructor New interface 'Excluded' to exclude certain particles from intermediate lines. ** Chargino-Neutralino-W vertex fixed ** Spin correlations are now switched on by default for all perturbative decays. ** Ticket #276: Scale choice in BSM models' HardProcessConstructor New interface 'ScaleChoice' to choose process scale between - sHat (default for colour neutral intermediates) and - transverse mass (default for all other processes). ** Ticket #287: Powheg process scale choice The default choice is now the mass of the colour-singlet system. ** Ticket #278: QED radiation for BSM Soft QED radiation is now enabled in BSM decays and all perturbative decays by default. ** Ticket #279: Full 1-loop QED radiation for Z decays Soft QED radiation in Z decays is now fully 1-loop by default. ** Ticket #280: Redirect all files to stdout This is now implemented globally. The files previously ending in -UE.out and -BSMinfo.out are now appended to the log file. They now also obey the EventGenerator:UseStdout flag. ** Ticket #270: LaTeX output updated After each run, a LaTeX file is produced that contains the full list of citations. Please include the relevant ones in publications. ** Ticket #256: Mac OS X problems An initialization problem that affected only some configurations has been identified and fixed. ** Tests directory added This contains many .in files, to exercise most matrix elements. ** Minor fixes *** Prevent rare x>1 partons in shower reconstruction. *** SUSY-LHA parameter EXTPAR can be used to set tan beta *** Improved Fastjet detection at configure time * Herwig++-2.4.0 release: 2009-09-01 (tagged at SVN r4616) ** New matrix elements We have added a built-in implementation of several new matrix elements: PP --> WW / WZ / ZZ PP --> W gamma / Z gamma PP --> VBF Higgs PP --> Higgs tt / Higgs bb e+e- --> WW / ZZ gamma gamma --> ff / WW ** Base code improvements *** Ticket #257: Remnant handling A problem with forced splittings in the Remnant was fixed. *** Ticket #264: Soft matrix element correction A problem with emissions form antiquarks was fixed. ** PDF sets *** New default set MRST LO** is the new default PDF set. LO* is also available built-in. *** Shower PDFs can be set separately from the hard process Use the 'ShowerHandler:PDF' interface. ** Parameter tunes Shower, hadronization and underlying event parameters were retuned against LEP and Tevatron data respectively. ** BSM module improvements *** Ticket #259: read error for some UED models Arbitrary ordering of outgoing lines in the process description is now possible. *** Ticket #266: branching ratio sums The warning threshold for branching ratios not summing to 1 has been relaxed. It is now a user interface parameter. *** Ticket #267: Top decay modes Top decay modes listed in SLHA files are now handled correctly. ** QED radiation *** Ticket #241: Soft QED radiation is now enabled by default *** Ticket #265: Radiation off W+ and W- is now handled correctly ** Interfaces *** Ticket #243: Fastjet Fastjet is now the only supported jet finder code. All example analyses have been converted to use Fastjet. *** KtJet and CLHEP interfaces have been removed. *** New interfaces to AcerDet and PGS available in Contrib *** MCPWnlo distributed in Contrib *** HepMC and Rivet interfaces moved to ThePEG ** Ticket #239: Inelastic cross-section for MinBias This information is now available in the ...-UE.out files. ** Technical changes *** Ticket #186 Configure now looks for ThePEG in the --prefix location first. *** Configure information Important configuration information is listed at the end of the 'configure' run and in the file 'config.thepeg'. Please provide this file in any bug reports. *** New ZERO object The ZERO object can be used to set any dimensionful quantity to zero. This avoids explicit constructs like 0.0*GeV. *** Exception specifiers removed Client code changes are needed in doinit() etc., simply remove the exception specifier after the function name. *** Ticket #263: Tau polarizations can be forced in TauDecayer * Herwig++-2.3.2 release: 2009-05-08 (tagged at SVN r4249) ** SUSY enhancements *** Ticket #245: Select inclusive / exclusive production Using the new 'HardProcessConstructor:Processes' switch options 'SingleParticleInclusive', 'TwoParticleInclusive' or 'Exclusive' *** Improved three-body decay generation Several problems were fixed, incl. tickets #249 #250 #251 Thanks to J.Tattersall and K.Rolbiecki for the stress-testing! *** Looptools fix Release 2.3.1 had broken the Looptools initialization. *** Improved warning message texts ** Ticket #237: Values of q2last can now be zero where possible. ** Ticket #240: The Herwig++ main program now correctly treats the -N flag as optional. ** Ticket #246: Extreme pT partons fixed by improving accuracy of z boosts. ** DIS Improved parton shower momentum reshuffling. ** Minimum Bias events The zero-momentum interacting particle used for bookkeeping is now labelled as a pomeron. ** User Makefile Makefile-UserModules does not enable -pedantic anymore. User's ROOT code will not compile otherwise. ** Build system Small fixes in the build system. * Herwig++-2.3.1 release: 2009-03-31 (tagged at SVN r4140) ** Initial state showers The PDF veto was wrongly applied to qbar->qbar g splittings. ** User interaction The Makefile-UserModules now includes the Herwig version number. The -N flag to 'Herwig++ run' is optional now, as was always intended. ** Contrib The contrib directory is now included in the tarball. The omission was accidental. ** Numerical accuracy Minor problems with values close to zero were fixed in several locations. ** LEP event shapes An accidental duplication was removed, they are now only calculated once per event. ** MRST PDF code Initialization problem fixed. ** Mac OS X The configure script was improved to detect libraries better. ** Libtool Updated to version 2.2.6 * Herwig++-2.3.0 release: 2008-12-02 (tagged at SVN r3939) ** Major release, with many new features and bug fixes ** Extension to lepton-hadron collisions ** Inclusion of several processes accurate at next-to-leading order in the POsitive Weight Hardest Emission Generator (POWHEG) scheme ** Inclusion of three-body decays and finite-width effects in BSM processes ** New procedure for reconstructing kinematics of the parton shower based on the colour structure of the hard scattering process ** New model for baryon decays including excited baryon multiplets ** Addition of a soft component to the multiple scattering model of the underlying event and the option to choose more than one hard scattering explicitly ** New matrix elements for DIS and e+e- processes ** New /Contrib directory added containing external modules that will hopefully be of use to some users but are not expected to be needed by most users and are not supported at the same level as the main Herwig++ code ** Minor changes to improve the physics simulation: *** IncomingPhotonEvolver added to allow the simulation of partonic processes with incoming photons in hadron collisions *** KTRapidityCut added to allow cuts on the p_T and rapidity, rather than just the p_T and pseudorapidity used in SimpleKTCut. This is now used by default for cuts on massive particles such as the $W^\pm$, $Z^0$ and Higgs bosons and the top quark *** Several changes to the decayers of B mesons both to resolve problems with the modelling of partonic decays and improve agreement with $\Upsilon(4s)$ data *** Changes to allow values other than transverse mass of final-state particles as maximum transverse momentum for radiation in parton shower either SCALUP for Les Houches events or the scale of the hard process for internally generated hard processes *** Changed defaults for intrinsic transverse momentum in hadron collisions to 1.9GeV, 2.1GeV and 2.2GeV for the Tevatron and LHC at 10 TeV and 14 TeV, respectively *** Pdfinfo object is now created in the HepMC interface However in order to support all versions of HepMC containing this feature the PDF set is not specified as not all versions contain this information *** New option of only decaying particles with lifetimes below user specified value *** New options for the cut-off in the shower and some obsolete parameters removed *** Added option of switching off certain decay modes in BSM models *** Added a Matcher for Higgs boson to allow cuts to be placed on it *** Diffractive particles deleted from default input files they were not previously used ** Technical changes: *** Some AnalysisHandler classes comparing to LEP data have been renamed e.g. MultiplicityCount becomes LEPMultiplicityCount to avoid confusion with those supplied in /Contrib for observables at the Upsilon(4s) resonance *** Reorganisation to remove the majority of the .icc files by moving inlined functions to headers in an effort to improve compile time *** Restructured the decay libraries to reduce the amount of memory allocation and de-allocation which improves run-time performance *** The switch to turn off LoopTools has been removed because LoopTools is now used by several core modules. As LoopTools does not work on 64-bit platforms with g77 this build option is not supported *** Removed support for obsolete version of HepMC supplied with CLHEP and improved the support for different units options with HepMC *** EvtGen interface has been removed until it is more stable *** Support for ROOT has been removed it was not previously used *** CKKW infrastructure has been removed from the release until a concrete implementation is available *** Default optimisation has been increased from -O2 to -O3 *** Handling of the fortran compiler has been improved mainly due to improvements in the autotools *** Use of FixedAllocator for Particle objects in ThePEG has been removed as it had no performance benefits ** Bugs fixed: *** Problems with the mother/daughter relations in the hard process and diagram selection in W+- and Z0 production in association with a hard jet *** In general matrix element code for fermion-vector to fermion-scalar where the outgoing fermion is coloured and the scalar neutral *** In the selection of diagrams in some associated squark gaugino processes *** h0->mu+mu- was being generated when h0->tau+tau- *** Normalisation in the Histogram class for non unit-weight events *** Protection against negative PDF values has been improved these can occur when using NLO PDF sets *** Lifetime for BSM particles is now automatically calculated at the same time as the width *** Hadrons containing a top quark now treated like hadrons containing BSM particles in order to support this possibility *** Several ambiguous uses of unsigned int *** Several variables that may have been used undefined *** Several memory leaks at initialisation *** The configuration now aborts if no fortran compiler is found as this is required to compile Looptools *** Several minor floating point errors that did not affect results * Herwig++-2.2.1 release: 2008-07-09 (tagged at SVN r3434) ** Ticket #181: BSM shower with a decay close to threshold Now fixed. ** Ticket #191: Split SUSY crash Improved error message. ** Ticket #192: using SCALUP as the pT veto in the shower Now implemented. ** Ticket #194: production processes of ~chi_1(2)- Fixed bug in the diagram creation. ** Removed unused particles DiffractiveParticles.in was removed, they were never produced. ** Hadronization Top quark clusters now possible, handled as 'exotic' clusters. ** Improved handling of decay modes See ThePEG-1.3.0. 'defaultparticle' command is now obsolete. ** Multi-Parton interactions Increased phase space sampling to have less than 1% uncertainty on average multiplicity. ** New libtool version gfortran is now used as default if it is available. Set FC=g77 to override this. ** Fixed several memory leaks ** Memory allocation Now using plain 'new' and 'delete'. * Herwig++-2.2.0 release: 2008-04-18 (tagged at SVN r3195) ** Major release: now as stand-alone library Herwig++ is now a stand-alone dlopen() plugin to ThePEG. No compile-time linking to Herwig code is required. The Herwig++ binary is a simple executable steering ThePEG, which can be replaced by other frontends (such as setupThePEG / runThePEG). ** New matrix elements p p -> W + jet / Z + jet / W + higgs / Z + higgs e+ e- -> Z + higgs ** Looptools Updated to version 2.2. ** Ticket #141: segfault from using 'run' command Fixed by using default allocators in Herwig++, and the Repository::cleanup() method in ThePEG 1.2.0. ** Ticket #157: broken gsl library path on some 64bit systems Paths with lib64 are correctly identified now. ** Ticket #159: p_t spectrum of ttbar pair Fixed identical particle multiplier in Sudakov form factor. ** Ticket #161: glibc segfault Rare segfault in MPI handler fixed. ** Ticket #165: rare infinite loop in four-body decay All 4-body decays without dedicated decayers now use the Mambo algorithm. A loop guard has been introduced to 3-body decays to avoid infinite retries. ** Ticket #166: rare infinite loop in top ME correction These very rare events (O(1) in 10^7) close to mass threshold now are discarded. ** Higgs width fixes ** SatPDF Optionally, the PDF extrapolation behaviour outside a given range can now be specified. ** gcc 4.3 Herwig++-2.2 compiles cleanly with the new gcc 4.3 series. * Herwig++-2.1.4 release: 2008-03-03 (tagged at SVN r3024) ** Ticket #152: Vertex positions All vertex positions of unphysical particles are set to zero until a fix for the previous nonsensical values can be implemented. * Herwig++-2.1.3 release: 2008-02-25 (tagged at SVN r2957) ** Ticket #129: Baryon decays Fix for baryon decay modes. ** Ticket #131: HepMC Check if IO_GenEvent exists ** Ticket #134: Hadronization Smearing of hadron directions in cluster decay fixed. ** Ticket #137: HepMC HepMC conversion allows specification of energy and length units to be used. ** Ticket #139: Neutral kaons Ratio K_L / K_S corrected. ** Ticket #140 / #141: Crash on shutdown Event generation from the 'read' stage or an interface now shuts down cleanly. Fixes a crash bug introduced in 2.1.1 which affected external APIs to ThePEG / Herwig. ** Ticket #146: BSM models can be disabled To save build time, some or all of the BSM models can be disabled using the '--enable-models' configure switch. ** Reorganised .model files The .model files now include the model-specific particles, too. ** Re-tune Re-tuned hadronization parameters to LEP data. ** Other fixes in QSPAC implementation in Shower; Multi-parton interaction tuning; MRST initialization * Herwig++-2.1.2 release: 2008-01-05 (tagged at SVN r2694) ** Ticket #127 Thanks to a patch submitted by Fred Stober, HepMCFile now can output event files in all supported formats. ** Ticket #128 Fixed incorrect value of pi in histogram limits. ** Other fixes in CKKW Qtilde clusterers, BSM width cut, SUSY mixing matrices. * Herwig++-2.1.1 release: 2007-12-08 (tagged at SVN r2589) ** Bug #123 Fixed a bug with particle lifetimes which resulted in nan for some vertex positions. ** Secondary scatters Fixed bug which gave intrinsic pT to secondary scatters. ** gcc abs bug detection configure now checks for and works around http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34130 ** CKKW reweighting Fixed wrong check for top quarks. ** MPIHandler Fixed call order ambiguity. * Herwig++-2.1.0 release: 2007-11-20 (tagged at SVN r2542) ** Major new release Herwig++-2.1 includes significant improvements, including multi-parton interactions, BSM physics and a new hadronic decay model, tuned to LEP data. For an overview of the changes, please see the release note arXiv:0711.3137 * Herwig++-2.0.3 release: 2007-08-21 (tagged at SVN r2101) ** Bug #90 nan in top decay ME corrections fixed. ** unlisted Colour flow fix in LightClusterDecayer ** unlisted Updated version of MultiplicityCount analysis handler. * Herwig++-2.0.2 release: 2007-07-06 (tagged at SVN r1716) ** Bug #80 Separation of HepMC from CLHEP is handled properly now. ** Bug #83 Workaround for OS X header problem ** unlisted Veto on very hard emissions from Shower. ** unlisted Detailed documentation in .in files * Herwig++-2.0.1 release: 2006-12-05 (tagged at SVN r1195) ** Bug #54 ClusterFissioner vertex calculation fixed. ** Bug #57 Crash when showering W+jet events supplied by Les Houches interface. ** Bug #59 Fix for #57 applied to LHC events. ** Bug #60 Segfault when PDF is set to NoPDF. ** Bug #61 Missing weight factor for I=0 mesons ** Bug #62 Spinor vertex calculations broken when spinor rep is not default rep. ** Bug #63 Top decay never produces tau. ** Bug #69 TTbar and HiggsJet analysis handlers fixed. ** unlisted Reorganization of Hadronization module gives 30% speedup. Thanks to Vincenzo Innocente at CMS for his profiling work! ** unlisted cleaner automake files in include/ and src/ ** unlisted Hw64 hadron selection algorithm 'abortnow' fixed. ** unlisted Top/LeptonDalitzAnalysis removed (only worked with modified code). ** unlisted removed f'_0 from particle list, decays were not handled * Herwig++-2.0.0 release: 2006-09-28 (tagged at SVN r1066) ** Full simulation of hadron collisions