rx-data 0.1.4

Project with lists of LFNs and utilities needed to download filteres ntuples

$R_X$ data

This repository contains:

• Versioned lists of LFNs
• Utilities to download them and link them into a tree structure

for all the $R_X$ like analyses.

Installation

To install this project run:

pip install rx_data

# The line below will upgrade it, in case new samples are available, the list of LFNs is part of the
# project itself
pip install --upgrade rx_data

The download would require a grid proxy, which can be made with:

. /cvmfs/lhcb.cern.ch/lib/LbEnv

# This will create a 100 hours long proxy
lhcb-proxy-init -v 100:00

Listing available triggers

In order to see what triggers are present in the current version of the ntuples do:

list_triggers -v v1

# And this will save them to a yaml file
list_triggers -v v1 -o triggers.yaml

Downloading the ntuples

For this, run:

download_rx_data -m 5 -p /path/to/downloaded/.data -v v1 -d -t triggers.yaml

which will use 5 threads to download the ntuples associated to the triggers in triggers.yaml and version v1 to the specified path.

IMPORTANT:

• In order to prevent deleting the data, save it in a hiden folder, e.g. one starting with a period. Above it is .data.
• This path is optional, one can export DOWNLOAD_NTUPPATH and the path will be picked up

Potential problems: The download happens through XROOTD, which will try to pick a kerberos token. If authentication problems happen, do:

which kinit

and make sure that your kinit does not come from a virtual environment but it is the one in the LHCb stack or the native one.

Building directory structure

All the ntuples will be downloaded in a single directory. In order to group them by sample and trigger run:

make_tree_structure -i /path/to/downloaded/.data/v1 -o /path/to/directory/structure

this will not make a copy of the ntuples, it will only create symbolic links to them.

Samples naming

The samples were named after the DecFiles names for the samples and:

• Replacing certain special charactes as shown here
• Adding a _SS suffix for split sim samples. I.e. samples where the photon converts into an electron pair.

A useful guide showing the correspondence between event type and name is here