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Beauty and charm quarks are ideal probes of pertubative Quantum Chromodymanics in proton–proton collisions, owing to their large masses. In this paper the role of multi-parton interactions in the production of doubly-heavy hadrons is studied using simulation samples generated with Pythia, a Monte Carlo event generator. Comparisons are made to the stand-alone generators BcVegPy and GenXicc. New methods of speeding up Pythia simulations for events containing heavy quarks are described, enabling the production of large samples with multiple heavy-quark pairs. We show that significantly higher production rates of doubly-heavy hadrons are predicted in models that allow heavy quarks originating from different parton–parton interactions (within the same hadron–hadron collision) to combine to form such hadrons. Quantitative predictions are sensitive to the modelling of colour reconnections. We suggest a set of experimental measurements capable of differentiating these additional contributions.

Weak decays of the vector D∗0 and B(s)∗0 mesons to the μ+μ- final state provide novel potential to test the Standard Model of particle physics. Such processes have extremely small branching fractions as the vector mesons are able to decay through electromagnetic and (for the D∗0 meson) strong interactions. Nonetheless, the production of copious quantities of these particles in LHC collisions, and the ability to exploit experimental techniques that can suppress background to low levels, provides good potential to reach interesting sensitivity. The possibility to reconstruct these processes as part of the decay chain of B- or Bc+ mesons appears particularly attractive due to the clean experimental signature of the displaced vertex. Indeed, published LHCb data on B-→π-μ+μ- decays already implies a stringent limit on the branching fraction of D∗0→μ+μ-. Estimates are made on the achievable sensitivity to D∗0→μ+μ- and B(s)∗0→μ+μ- decays with the LHCb experiment.

A method for analysing the hadronic resonance contributions in B¯0→K¯∗0μ+μ- decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving JPC=1-- resonances, relative to the short-distance component, across the full dimuon mass spectrum of B¯0→K¯∗0μ+μ- transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the q2 spectrum provide a dramatic enhancement to CP-violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, RK(∗), in the presence of new physics is presented.

This paper reports world averages of measurements of b-hadron, c-hadron, and τ-lepton properties obtained by the Heavy Flavour Averaging Group using results available through September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays, and Cabibbo–Kobayashi–Maskawa matrix elements.

This document presents the result of recent developments within Ganga[1] project to support users from new communities outside of HEP. In particular I will examine the case of users from the Large Scale Survey Telescope (LSST) group looking to use resources provided by the UK based GridPP[2][3] DIRAC[4][5] instance. An example use case is work performed with users from the LSST Virtual Organisation (VO) to distribute the workflow used for galaxy shape identification analyses. This work highlighted some LSST specific challenges which could be well solved by common tools within the HEP community. As a result of this work the LSST community was able to take advantage of GridPP[2][3] resources to perform large computing tasks within the UK.

The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2–100 GeV/ c . The operation and control, software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types ( π , K, p) is achieved.

A job submission and management tool is one of the necessary components in any distributed computing system. Such a tool should provide a user-friendly interface for physics production groups and ordinary analysis users to access heterogeneous computing resources, without requiring knowledge of the underlying grid middleware. Ganga, with its common framework and customizable plug-in structure is such a tool. This paper will describe how experiment-specific job management tools for BESIII and SuperB were developed as Ganga plug-ins to meet their own unique requirements, discuss and contrast their challenges met and lessons learned.

Ganga is the main end-user distributed analysis tool for the ATLAS and LHCb experiments and provides the foundation layer for the HammerCloud system, used by the LHC experiments for validation and stress testing of their numerous distributed computing facilities. Here we illustrate recent developments and demonstrate how tools that were initially developed for a specific user community have been migrated into the Ganga core, and so can be exploited by a wider user-base. Similarly, examples will be given where Ganga components have been adapted for use by communities in their custom analysis packages.

Ganga has been widely used for several years in ATLAS, LHCb and a handful of other communities. Ganga provides a simple yet powerful interface for submitting and managing jobs to a variety of computing backends. The tool helps users configuring applications and keeping track of their work. With the major release of version 5 in summer 2008, Ganga's main user-friendly features have been strengthened. Examples include a new configuration interface, enhanced support for job collections, bulk operations and easier access to subjobs. In addition to the traditional batch and Grid backends such as Condor, LSF, PBS, gLite/EDG a point-to-point job execution via ssh on remote machines is now supported. Ganga is used as an interactive job submission interface for end-users, and also as a job submission component for higher-level tools. For example GangaRobot is used to perform automated, end-to-end testing of distributed data analysis. Ganga comes with an extensive test suite covering more than 350 test cases. The development model involves all active developers in the release management shifts which is an important and novel approach for the distributed software collaborations. Ganga 5 is a mature, stable and widely-used tool with long-term support from the HEP community.