• CMS
• LHC
• High Energy Phyisics
• Track Trigger

The increased instantaneous luminosity of 5 × 1034 cm−2s−1
to be provided by the upgrade of the LHC (High Luminosity LHC)
by 2028, will open unprecedented opportunities for the high
precision study of the Standard Model of particle physics and for
searches of physics beyond the Standard Model. To exploit such
an opportunity, and to address the challenges of an increased
pile up condition of 200 events per bunch crossing , the CMS
experiment will upgrade most of its subdetectors. In particular,
a completely new tracker detector is being developed. One of
the most innovative designs consists of a new sensor concept
called 𝑝𝑇 module. The module filters out hits produced by low
transverse momentum tracks directly on the front end electronics.
In such a way the data rate is brought to a manageable level to
allow online track reconstruction at the collision rate of 40 MHz
within a latency of only 5 𝜇s, with dedicated processors based
on FPGA. The online reconstructed tracks will be sent to the
Level 1 trigger boards, where high level objects will be formed,
such as vertices, and, together with the information from other
subdetectors, more complex objects, such as muons, electrons,
jets, missing energy etc.
This thesis deals with the measurement of some of the key
aspects that must be fulfilled in order to achieve the desired on-
line track reconstruction efficiency, and that I had the possibility
to perform. The first part is devoted to the measurement of the
latency of several blocks of the online tracking system: the one
coming from the optical fibre length, as measured by an ad-hoc
developed setup, and the one from the track finding algorithm
run on the FPGA. The second part is devoted to measure the per-
formances of the 𝑝𝑇 modules in terms of efficiencies and tracking
precision, after having developed an alignment algorithm in a
test beam with 160 GeV muons performed at CERN, which I took
part during the Fall of 2022.