Tracker alignment in CMS::interplay with pixel local reconstruction

The CMS silicon tracking system measures the trajectories of charged particles with a hit resolution of the order of microns in the pixel detector and tens of microns in the strip detector. One of the most important inputs for track reconstruction is the precision with which the tracker geometry is known. Therefore the position, orientation, and curvature of each tracker sensor must be precisely determined. Changes in the operating conditions can cause movements in the different substructures and also in the sensors. For maintaining the targeted precision, frequent corrections are needed, and the procedure to determine these corrections is commonly referred to as tracker alignment. Due to accumulated radiation during data taking, the response of the sensors changes over time. This affects the local reconstruction of pixel hits and consequently the result of the alignment procedure. In this contribution, the alignment procedure in CMS is introduced, as well as the dedicated calibration for the pixel local reconstruction. The effect of the change in the local reconstruction due to aging of the sensors on the alignment procedure is discussed.Comment: 8 pages, 4 figures, conference report for Pixel2022, to be published in PoS(Pixel2022

Characterisation of a Silicon Photomultiplier of 64 channels

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2018, Tutor: Ricardo Graciani DiazThis work presents the study of a 64 channel silicon photomultiplier (3.2 x 3.2 mm2 each channel) built by Hammamatsu. From the experimental data, the values of the gain at four different voltages (68V, 68.5V, 69V, 69.5V) are measured for each channel and, the breakdown voltage and the gain per voltage, for each channel, have been determined. Also measurements at 70V have been preformed but rejected because of the amount of noise

Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

Tracker Alignment in CMS: interplay with pixel local reconstruction

The CMS silicon tracking system measures the trajectory of charged particles with a hit resolution of the order of microns in the pixel detector and tens of microns in the strip detectors. One of the most important inputs for track reconstruction is the precision with which the tracker geometry is known. Therefore the position, orientation, and curvature of each tracker sensor must be precisely determined. Changes in the operating conditions can cause movements in the different substructures and also in the sensors. For maintaining the targeted precision, frequent corrections are needed, and the procedure to determine these corrections is commonly referred to as tracker alignment. Due to accumulated radiation during data taking, the response of sensors changes over time. This affects the pixel local reconstruction and consequently the result of the alignment procedure. In this talk, the alignment procedure in CMS is introduced, as well as the dedicated calibration for the pixel local reconstruction. We discuss the change in the local reconstruction due to the ageing of the sensors on the alignment procedure

Commissioning of a Burn-In Setup for PS and 2S Detector Modules for the Upgrade of the CMS Outer Tracker

The high luminosity LHC Upgrade will increase the instantaneous lu- minosity by a factor of five. The CMS detector will be upgraded in the so called Phase-2 Upgrade in order to meet the new requirements, among others the level of radiation tolerance and coping with larger pileup and thus higher data rates, as well as to add triggering capa- bilities. The entire silicon tracker will be replaced. The Outer Tracker (OT), consisting of macro-pixel and strip detectors, will be based on silicon modules that must operate at low temperatures (−33∘ C) due to the exposition at high radiation levels. The probability for defec- tive electronic components to fail is higher after few hours of operation. Moreover, temperature cycles can induce mechanical stress. Therefore a burn-in procedure as well as thorough quality control is needed to ensure the correct operation of each of the OT modules before instal- lation. For this, a burn-in system is being commissioned at DESY. This setup will perform thermal cycles from room to operation temperature and key measurements to ensure the good performance of the modules. In this talk, the status of the DESY burn-in setup as well as first tests will be presented

Uranium- decay chain

The main objective of this article is to modelize the process of decay of Uranium within the framework of Membrane Computing, so the evolution of great numbers of particles can be progressively followed and the results of the desintegrations (nuclei coming from and − decays) can be counted. In order to model the process in an accurate manner, exploiting the properties of maximal parallelism and non-determinism of Membrane Computing, a Population Dynamic P system (or PDP for short) restricted to one environment and a P system conformed by only the skin have been selected. The difficulty in the characterisation of this reactions lays in the simultaneity of the different decays, since the number of desintegrations of nucleous of each specie depend on the number of atoms of the initial population. In order to solve this problem and keep their attachment, the characteristic time of production of each decay has been translated into probabilities of deintregration of a nucleous using the decay constant