Pile-up Mitigation: Straw Picker
Table of Contents
Using all particles
Strategy to determine ρ:- Identify centers of hard-scatter jets by clustering all particles in the event.
- Order clustered jets by P_{T} and take jets with P_{T} higher than P_{T min}, but no more than N_{max} = 12.
- Subtract areas of the jets from detector area and remove all tracks associated with the jets.
- Divide sum of P_{T} left in the event by the area.
Plots
Parameter | Value |
---|---|
Grid spacing | 0.5 |
Jet R | 0.7 |
Jet min p_{T} | 5.0 GeV |
Resolution
4 Tops
Dijets
Z'
Bias
4 Tops
Dijets
Z'
ρ Difference
4 Tops
Dijets
Z'
Using neutral particles
Strategy to determine ρ:- Identify centers of hard-scatter jets by clustering neutral particles in the event.
- Order clustered jets by P_{T} and take jets with P_{T} higher than P_{T min}, but no more than N_{max} = 12.
- Subtract areas of the jets from detector area and remove all tracks associated with the jets.
- Divide sum of P_{T} left in the event by the area.
Plots
Parameter | Value |
---|---|
Grid spacing | 0.5 |
Jet R | 0.7 |
Jet min p_{T} | 5.0 GeV |
Resolution
4 Tops
Dijets
Z'
Bias
4 Tops
Dijets
Z'
ρ Difference
4 Tops
Dijets
Z'
Using charged signal particles
Strategy
Strategy to determine $\rho_\mathrm{straw}$:- Identify centers of hard-scatter by jet clustering charged signal particles in the event.
- Discard clustered jets with $p_\mathrm{T}$ smaller than $p_\mathrm{T}^{\min}$. Remaining jets order by $p_\mathrm{T}$ and keep at most $N^{\max}$.
- Tag all tiles which centers are closer to the centers of the jets than jet radius $R$.
- In every tile sum $p_\mathrm{T}$ of all deposits, excluding tagged ones. Tagged tiles exclude from the list of tiles.
- Determine median $p_\mathrm{T}^\mathrm{median}$ and divide it by tile area to obtain $\rho_\mathrm{straw}$
Settings
- Grid spacing: 0.5
- jet $R = 0.7$
- $p_\mathrm{T}^{\min} = 5$ GeV
- $N^{\max} = 12$