B-Meson Decay – Toying with LHCb Data

Particle physics is kind of a hobby of mine and since some time it is even possible to get access to some of the data generated with the LHC accelerator at CERN.
One such dataset is from the LHCb experiment, which gives you access to data about decays of B-mesons to three hadrons. The largest file is some 636MB (B2HHH_MagnetDown.root) which I chose to start exploring.

Exploring means that at the start I do not know exactly what kind of data is in there. So I had to do some exploring and decided to start with just reading out some data and drawing graphs with it. For starters, I am not primarily interested in the physics, but in how to work with the data and what I can use it for. So I study the toosl and the programming, but it is clear that at the same time I analyse the data, I will have to study the physics behind it, otherwise it is not possible to make useful evaluations.

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3rd FCC Workshop at CERN

I was lucky enough to be able to participate in the 3rd FCC Workshop from January 13 to 17, 2020 and got I first hand look behind the scenes of the planning of the Future Circular Collider (FCC) which is supposed to come after the current Large Hadron Collider (LHC) has gone through its High Luminosity (HL) upgrades and needs to be replace somewhere in the beginning of the 2040s.
That sounds like a long time, but as was pointed out, there is a lot of civil engineering work to be done – namely digging the 100 km circumference tunnels – and this needs to be started soon.

FCC is actually several colliders all of which are refereed to as FCC-INT. The first to be implemented is the FCC-ee collider, which is a electron-positron collider. Here, there is some competition between the circular FCC-ee (in CERN), the linear ILC (in Japan) and CLIC (in CERN) designs.

If you’re new to this subject I recommend reading Circular and Linear e+e− Colliders: Another Story of Complementarity by Alain Blondel and Partick Janot (arxiv.org:1912.11871).
In a nutshell, FCC-ee is the front-runner if you plan to do more than just Higgs physics. Namely EW, Flavour and Top physics as well as Beyond Standard Model physics (BSM) and if you want to keep the road open to a proton-proton (a hadron collider) called FCC-hh.
Current thinking seems to be that FCC-ee is favoured but with synergies of either ILC (or even CLIC) being built in Japan.

What I profited most in these 5 intense days, was to get some points drawn which I can now connect. Especially in QCD and EFT, BSM physics, but also collider technologies, software used to do particle physics and data acquisition (DAQ) process.

I now have a much better general understanding about the actual data which is being collected. Unfortunately, with my Windows 10 notebook, I couldn’t really participate in the software workshop – this is corrected now. It’s running Fedora 31 – which turns out to be noticeably faster…

I enjoyed my stay at CERN. Nice international atmosphere. Some buildings could use a make-over, though :-).

RTL-SDR and ADS-B Messages

Currently working with my RTL-SDR device to catch ADS-B messages from nearby airplanes.
Luckily, there’s an app for that called dump1090 that works with my device out of the box.
I run it on FreeBSD 12.1 and it catches the messages well. Unfortunately, it is a bit behind and I am not sure the app is still maintained. In any case, the problem is with the way the app produces json files, and uses Google maps to visualize the data captured. So I am currently rewriting part of it to produce a GeoJson formatted output file and a Webpage that uses Mapbox (OpenStreeMaps) instead of Google.
The C-code currently compiles on Linux but not (yet) on FreeBSD, but I am confident I can have a working base version by the end of next week (depending of schedule of course).

Here’s a sneak peak at the current layout (which will be improved once the backend and data-display works well enough)

The goal of this project is to learn and demonstrate how to visualise real-time data and to learn how to work with signals from antennas – but that will be another project…