We present an update of the Binoth Les Houches Accord (BLHA) to standardise the interface between Monte Carlo programs and codes providing one-loop matrix elements.
A
bstract
We calculate the process
pp
→
W
+
W
−
→
e
+
ν
e
μ
−
ν
¯
μ
at NLO QCD, including also effective field theory (EFT) operators mediating the
ggW
+
W
−
interaction, which first occur at ...dimension eight. We further combine the NLO and EFT matrix elements produced by G
o
S
am
with the H
erwig
7/M
atchbox
framework, which offers the possibility to study the impact of a parton shower. We assess the effects of the anomalous couplings by comparing them to top-mass effects as well as uncertainties related to variations of the renormalisation, factorisation and hard shower scales.
A new model of color reconnection in the Monte Carlo generator Herwig 7 is presented. It is based on the minimization of a boost-invariant distance of the parton system, where all partons have ...momentum as well as spacetime position assigned. We test the influence of both types of variables, namely the rapidity span and transverse distance, on the actual need to reconnect the system to better describe soft physics measurements. We find reasonable agreement with the data and conclude that spacetime topology of the event can be useful for hadron collision modeling.
Herwig 7 is a general-purpose Monte Carlo generator of particle collisions comprising both hard perturbative as well as soft phenomenological physics. Herwig is therefore capable to describe the ...entire final state of hadronized particles in a collision event. A spacetime topology of a parton system entering hadronization is fully described and tested for the first time. A combination of information from particles momenta and spacetime positions is utilized to minimize a boost-invariant distance measure of the parton system. We present a reasonable agreement of the model with a selection of experimental data and conclude that spacetime event topology can be meaningfully used in the further development.
We evaluated the Boehringer Mannheim (B.M.) Reflotron Total Cholesterol "dry-chemistry" method after its recalibration in 1987. Reports in the literature up to 1986-1987 of a negative bias (up to ...-10%) in the method prompted a revision of the factory-set calibration of the Reflotron. For this, B.M. prepared a new set of calibrators with 12 different concentrations of cholesterol. We checked in two ways whether accuracy had been achieved: (a) The values assigned to the calibrators by B.M. were checked with the manual Abell-Kendall Reference Method (MAK) performed in an official Reference Center. These were shown to be correct. (b) Concurrently, a direct comparison was made by analyzing 200 fresh samples of human serum. Reflotron cholesterol values obtained for these samples proved to be accurate, meeting the current World Health Organization/Centers for Disease Control criterion of maximum bias less than or equal to 5%. Orthogonal regression analysis yielded the following correlation: Reflotron = 0.985 MAK + 0.238 mmol/L (y = ax + b). Reflotron mean = 6.26 mmol/L; MAK mean = 6.09 mmol/L. SDa = 0.015 mmol/L; SDb = 0.120 mmol/L, and r = 0.989.
This Report summarizes the proceedings of the 2017 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, ...(II) theoretical uncertainties and dataset dependence of parton distribution functions, (III) new developments in jet substructure techniques, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (V) phenomenological studies essential for comparing LHC data from Run II with theoretical predictions and projections for future measurements, and (VI) new developments in Monte Carlo event generators.
This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of ...Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.
A new release of the Monte Carlo event generator Herwig++ (version 2.7) is now available. This version comes with a number of improvements including: an interface to the Universal FeynRules Output ...(UFO) format allowing the simulation of a wide range of new-physics models; developments of the Matchbox framework for next-to-leading order (NLO) simulations; better treatment of QCD radiation in heavy particle decays in new-physics models; a new tune of underlying event and colour connection parameters that allows a good simultaneous description of both Tevatron and LHC underlying event data and the effective cross-section parameter for double-parton scattering.
This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, ...(II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phenomenological studies essential for comparing LHC data from Run I with theoretical predictions and projections for future measurements in Run II, and (V) new developments in Monte Carlo event generators.
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