1. C++ and the Higgs 17 years of Bjarne in High Energy Physics Festschrift for Bjarne Stroustrup Ren é Brun, Axel Naumann/CERN Geneva

2. The HEP Context High Energy Physics: “what is mass”, “why is the universe so heavy”, “now show me that Higgs!” CERN: international lab in Geneva / Switzerland, with 10’000 users Large Hadron Collider (LHC) with 4 major experiments provides highest energy LHC simulatio n LHC simulatio n LHC approval LHC approval LHC start LHC start LHC End??? LHC End???

3. LHC Large Hadron Collider 28 km ring Mont Blanc Jura Geneva lake

4. C++ in HEP C++ has 20’000 HEP users 50 MLOC C++ at CERN All experiments rely on C++ The 4 LHC experiments have today more than 100 Petabytes of data in the form of C++ objects managed by the ROOT software.

5. The Consumer Age HEP used FORTRAN. Everywhere. Does it scale to 10’000 users? Future? Educating students? And that OO thing... Bjarne helped right at the start in 1995, e.g. with ROOT (CERN’s data analysis tool) Shared his expertise, encouraged us

6. The Expert Age Importance of C++ in HEP grew Bjarne’s visits transformed from consulting to main attraction C++ forced to be self-sustained at CERN Success: novices + experts all work on the same code!

7. The Contributor Age Slowly realizing (also thanks to Bjarne!) that our experience is relevant Contribute with software, e.g. ROOT: insurances, banking, aerospace... Contribute to software, e.g. GCC Contribute to C++: Fermilab / Chicago @ C++ standards committee

8. Summary Hard to imagine CERN or HEP without C++ Bjarne continues to be a fantastic mentor Whatever we find at CERN: Bjarne has contributed his share!