# Rivet for heavy ions

There is a new talk on the talks page. It is about a project which I have spent a large part of the past two years working on, called Rivet for heavy ions.

The project is based on the Rivet project, which is an analysis toolkit for high energy Monte Carlo simulations. The idea is that experimental papers are implemented in code, and one can then with the press of a button compare any Monte Carlo simulation to the results obtained in the paper. This is pretty valuable stuff, especially as Rivet has more than 400 analyses implemented.

What we have done in this project, is to extend the analysis toolkit to also handle heavy ion collisions. Time will tell if the toolkit will be as well received in the heavy ion community as in the pp community, but already now the initial investment is paying off in form of easy validation of our models.

# The Glauber model

One of the staples of modeling of heavy ion collisions, is the Glauber model. It is one of the things all students have to go through starting out. The most remarkable thing about the Glauber model is its simplicity. It imposes a view of a proton-ion or ion-ion collisions, as the separate sub-collisions of several black disks. Some of the disks will interact, and some will not. This allows for a very inituitive understanding of a complicated system, as depicted below.

In the figure, a simulation of a proton-lead collision at LHC is depicted. The picture is taken from real simulation, that anyone with some introduction to Python programming can do. One of the other neat features of this model, is that it lends itself easily to computer implementation. If you are interesting in learning about this, I have written a small tutorial. that takes you through the most important steps of simulating the Glauber model, and using that simulation for an analysis.

To do the tutorial, simply download the pdf above and follow the steps, or you can pull the tutorial code directly using git, by doing:

git clone http://bierlich.net/git/glauber-tutorial.git

If you find any errors or misprints in the tutorial, I will appreciate it if you drop me a line.

# PhD thesis

The PhD thesis. The crown on years of hard work. Also a document you seldom look at again after it
is out. Should you, however, want to take a look in my thesis entitles **Rope Hadronization, Geometry and Particle Production
in pp and pA collisions**, you can download it from the Lund University research portal.

# Electrodynamics

The book **Classical Electrodynamics** by John David Jackson (3rd ed. Wiley) is one of the few true classics of theoretical physics, no matter what field you specialize in. And the problems in the book are interesting, but often quite difficult.

There are many people posting solutions to subsets of this book online - I only think mine are better, because I believe them to be correct. I hope they can prove useful to someone else, that's why I have compiled them into a solutions compendium.

# Statistical physics

Statistical physics is fun, although I rarely get to use what I learned as a student. Once I calculated a bunch of the typical exercises, and took the time to write them up nicely. It is pretty standard stuff, entropy of a rubber band, van der Waals equation, and some more advanced stuff like RG equations, simple lattice spin model etc. It can be downloaded here.