LHCb VELO Cluster Hit Analysis


All Hits N.B. (x,y) Global Co-ordinates

After bug fix

Plots of all cluster (x,y) per sensor by module

Plot cluster (x,y) per sensor, but weighted by the residual per point.
To normalise, this is then divided by the first set of plots above.
The plot then contains the average residual per (x,y) bin, each bin is 1mm x 1mm.
The colour scale is ±20μm. See here

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all R sensors

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all Phi sensors

Mean residuals vs R and Phi by module

Plot cluster size vs strip by module

cluster size projections by module

I have extracted the numbers of clusters of different types per strip for every sensor from the above plots and
I can list the strips which have an occupancy < limit. The default it limit=1, but if you change this number in
the url directly on your browser, then the page will regenerate and show more strips. In addition I also show
all strips that were flagged as bad (negative code) and noisy or low gain (positive code) in the Liverpool DB.

Low occupancy/Bad channels by module


Original pre-bugfix

Plots of all cluster (x,y) per sensor by module

Plot cluster (x,y) per sensor, but weighted by the residual per point.
To normalise, this is then divided by the first set of plots above.
The plot then contains the average residual per (x,y) bin, each bin is 1mm x 1mm.
The colour scale is ±20μm. See here

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all R sensors

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all Phi sensors

Mean residuals vs R and Phi by module

Tight Selection Hits

Plots of all cluster (x,y) per sensor by module

Plots of <residual> per (x,y) per sensor by module

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all R sensors

Plot radius, weighted radius and normalised weighted radius
and phi, weighted phi and normalised phi for all Phi sensors

After bug fix

Plots of all cluster (x,y) per sensor by module

Plot cluster (x,y) per sensor, but weighted by the residual per point.
To normalise, this is then divided by the first set of plots above.
The plot then contains the average residual per (x,y) bin, each bin is 1mm x 1mm.
The colour scale is ±20μm. See here

Plots of residual RMS scaled by pitch/sqrt(12) per (x,y) bin per sensor by module


All tracks after bug fix

Plots of all cluster (x,y) per sensor by module

Plot cluster (x,y) per sensor, but weighted by the residual per point.
To normalise, this is then divided by the first set of plots above.
The plot then contains the average residual per (x,y) bin, each bin is 1mm x 1mm.
The colour scale is ±20μm. See here