Development of a timing chip prototype in 110 nm CMOS technology

We present a readout chip prototype for future pixel detectors with timing capabilities. The prototype is intended for characterizing 4D pixel arrays with a pixel size of $100\times100~\mu \text{m}^2$, where the sensors are Low Gain Avalanche Diodes (LGADs). The long-term focus is towards a possible replacement of disks in the extended forward pixel system (TEPX) of the CMS experiment during the High Luminosity LHC (HL-LHC). The requirements for this ASIC are the incorporation of a Time to Digital Converter (TDC) within each pixel, low power consumption, and radiation tolerance up to $5\times10^{15}~n_\text{eq}\text{~cm}^{-2}$ to withstand the radiation levels in the innermost detector modules for $3000 \text{fb}^{-1}$ of the HL-LHC (in the TEPX). A prototype has been designed and produced in 110~nm CMOS technology at LFoundry and UMC with different versions of TDC structures, together with a front end circuitry to interface with the sensors. The design of the TDC will be discussed, with the test set-up for the measurements, and the first results comparing the performance of the different structures

Characterization of timing and spacial resolution of novel TI-LGAD structures before and after irradiation

The characterization of spacial and timing resolution of the novel Trench Isolated LGAD (TI-LGAD) technology is presented. This technology has been developed at FBK with the goal of achieving 4D pixels, where an accurate position resolution is combined in a single device with the precise timing determination for Minimum Ionizing Particles (MIPs). In the TI-LGAD technology, the pixelated LGAD pads are separated by physical trenches etched in the silicon. This technology can reduce the interpixel dead area, mitigating the fill factor problem. The TI-RD50 production studied in this work is the first one of pixelated TI-LGADs. The characterization was performed using a scanning TCT setup with an infrared laser and a $^90$Sr source setup

Characterization of timing and spacial resolution of novel TI-LGAD structures before and after irradiation

The characterization of spacial and timing resolution of the novel Trench Isolated LGAD (TI-LGAD) technology is presented. This technology has been developed at FBK with the goal of achieving 4D pixels, where an accurate position resolution is combined in a single device with the precise timing determination for Minimum Ionizing Particles (MIPs). In the TI-LGAD technology, the pixelated LGAD pads are separated by physical trenches etched in the silicon. This technology can reduce the interpixel dead area, mitigating the fill factor problem. The TI-RD50 production studied in this work is the first one of pixelated TI-LGADs. The characterization was performed using a scanning TCT setup with an infrared laser and a $^{90}$Sr source setup

Fragmentation of jets containing a prompt J/ΨJ/\Psi meson in PbPb and pp collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

Jets containing a prompt meson are studied in lead-lead collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using the CMS detector at the LHC. Jets are selected to be in the transverse momentum range of . The yield in these jets is evaluated as a function of the jet fragmentation variable z, the ratio of the to the jet . The nuclear modification factor, , is then derived by comparing the yield in lead-lead collisions to the corresponding expectation based on proton-proton data, at the same nucleon-nucleon center-of-mass energy. The suppression of the yield shows a dependence on z, indicating that the interaction of the with the quark-gluon plasma formed in heavy ion collisions depends on the fragmentation that gives rise to the meson