Workshop on Sampling Particles on the Cooper-Frye Transition Surface (2013)

Goal of the Workshop

The topic of the workshop is our present understanding of sampling particles on a fluid-Cooper Frye hypersurface. There are a lot of different algorithms on the market with different features concerning e.g. conservation laws in a local or global fashion. There are also still open issues concerning the viscous corrections to the distribution functions, the applicability of a hybrid framework to anisotropic hydrodynamics and how to preserve momentum correlations in the context of event-by-event fluctuations. The goal of the workshop is to define the status and potentially set up a taskforce to put together a community wide standard on how to perform the particle sampling in the most efficient way.  


  • H. Petersen 
  • P. Huovinen
  • M. Bleicher
  • E. Bratkovskaya

Questions to be addressed

  • How is the hypersurface determined? Which switching criterion is used and why?
  • which EoS are you using? To which hadron transport model are you matching?
  • Do you first sample momentum space and then coordinate space or the other way round? 
  • How are the momentum distributions sampled and in which frame? 
  • What criterion stops the sampling, i.e. how the number of sampled particles is fixed, how the chemical composition of the sampled ensemble is fixed?
  • Are conservation laws obeyed? Which and how? Conservation of momentum in particular?
  • How do you cope with negative contributions? 
  • How are viscous corrections to distribution function treated? 
  • Which programming language and why? 

Location and Accommodation

The workshop will be held from July 18-20th 2013 at Martin-Niemoeller-Haus in Schmitten, Germany. It is located roughly 35 minutes by car from Frankfurt airport in the Taunus. Surrounded by smaller mountains like the Feldberg and nice forest we expect a great working atmosphere.  

Cost for accommodation in single rooms is: ~50 EUR per night

The hotel can be paid by VISA or Mastercard (no American Express). 

We will take care of booking the rooms for you according to the arrival/departure information provided in the registration. 


How to get there

Information in german by the Martin-Niemöller-Haus can be found here.

Public Transport: 

From the airport: 

1) S- Bahn S8/9 direction Frankfurt City to 'Hauptwache' ~15 minutes

2) U-Bahn (subway) U3 from 'Hauptwache' to the end station 'Oberursel Hohemark' ~45 minutes

3) Bus number 50 direction 'Graevenwiesbach' to the stop 'Schmitten-Arnoldshain Forsthaus' ~15 minutes

From the main train station ('Hauptbahnhof'): 

1) Any S-Bahn direction south or east Frankfurt to the station 'Hauptwache' ~3 minutes

Steps 2) and 3) as mentioned above. 

You can check timetables for the route from 'Flughafen Regionalbahnhof' to 'Arnoldshain-Forsthaus' here

If you arrive late in the evening or need to catch a flight in the early morning or public transport is inconvenient for any other reason, please send us an email to with your arrival and departure details (flight/train number and time). According to your needs, we will arrange transportation from the airport, train station or 'Oberursel Hohemark'.  


By Car: 

Address: Am Eichwaldsfeld 3, 61389 Schmitten


By Taxi: 

If you plan to take a taxi from the airport, there is the option to get a flat rate of 70 EUR per ride, if we organise it ahead via the Martin-Niemöller-Haus.

Please contact the taxi company 'Albert' directly via phone +49-6082-4444 and mention the workshop at the Martin-Niemöller-Haus, if you want to reserve one. 



Conference Fee

The fee covers all local expenses and is: 150 EUR

The fee has to be paid by bank transfer before the meeting (deadline July 10th 2013) to this account: 

Account holder name: FIAS

Account number: 0444224 00

Routing number: 50070010

IBAN: DE86500700100044422400


Please make sure to indicate your name and the workshop identifier 'TRASA' on the transfer. 

If you do not have a bank account in Europe, it will be possible to pay the fee in cash at the conference site to avoid large bank transfer fees. 

Program Outline

The program will consist of 2 1/2 days starting on Thursday morning and ending on Saturday afternoon. For each talk 30 minutes are allocated +15 minutes for discussion. Two additional discussion sessions of 2 hours length are foreseen.  The schedule for the workshop can be found here. The presentation slides are available here

Participant List

A list of participants can be found here.


Adjacent Workshop

A second workshop dedicated to transport theory in heavy ion collisions will be held from July 15th-17th 2013 at the same location. Please adjust the arrival dates in your registration email accordingly, if you plan to attend the second workshop as well.

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