A new timing detector for the CT-PPS project

R Arcidiacono

doi:10.1016/j.nima.2016.05.114

Abstract

The CT-PPS detector will be installed close to the beam line on both sides of CMS, 200m downstream the interaction point. This detector will measure forward scattered protons, allowing detailed studies of diffractive hadron physics and Central Exclusive Production. The main components of the CT-PPS detector are a silicon tracking system and a timing system. In this contribution we present the proposal of an innovative solution for the timing system, based on Ultra-Fast Silicon Detectors (UFSD). UFSD are a novel concept of silicon detectors potentially able to obtain the necessary time resolution (∼20ps on the proton arrival time). The use of UFSD has also other attractive features as its material budget is small and the pixel geometries can be tailored to the precise physics distribution of protons. UFSD prototypes for CT-PPS have been designed by CNM (Barcelona) and FBK (Trento): we will present the status of the sensor productions and of the low-noise front-end electronics currently under development and test.

Highlights

The main physics goal of the CT-PPS project (CMS-TOTEM Precision Proton Spectrometer) is the study of Central Exclusive Production pp → pXp (CEP) at the LHC
25 we will describe the requirements of the timing system and present in detail the new proposal based on a novel type of silicon sensors (UFSD)
An alternative solution for the timing system of CT-PPS has been presented. It is based on the recently conceived Ultra-Fast Silicon Detectors (UFSD) detectors, LGAD sensors optimized for time measurements, in rapid development phase

Summary

Introduction

The main physics goal of the CT-PPS project (CMS-TOTEM Precision Proton Spectrometer) is the study of Central Exclusive Production pp → pXp (CEP) at the LHC. The distinctive signature of CEP events is to have, concur rently to the hard process seen in the CMS detector, two protons in the final state, scattered at very small angles with respect to the beam lines. Preprint submitted to Nuclear Instruments and Methods A shows, as an example, the Feyman diagram for the CEP of di-lepton events. To distinguish this category of events, one needs to detect the outgoing protons, measuring with high precision their momentum, direction and timing. The CT-PPS project plans to be completed and start collecting physics data in normal CMS runs in 2017 (possibly already during 2016). 25 we will describe the requirements of the timing system and present in detail the new proposal based on a novel type of silicon sensors (UFSD)

Requirements of the timing system

Status of the signal processing chain

Conclusions and outlook

155 References