Elodie Resseguie | Searcharxiv

arXiv2019

Search for chargino-neutralino production using an emulated recursive jigsaw reconstruction technique in three-lepton final states with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos is presented in a three-lepton final state. The analyzed proton-proton collision data taken at a centre-of-mass energy of $\sqrt{s} = 13$ TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of $139$ fb$^{-1}$. The search emulates the recursive jigsaw reconstruction technique using conventional analysis variables, searching for low-mass chargino-neutralino pair production that decays to on-shell $W$ and $Z$ bosons. The technique is validated and the excess seen previously in 2015 and 2016 data is studied while incorporating new data.

hep-ex↗

arXiv2015

Mapping charge transport effects in thick CCDs with a dithered array of 40,000 stars

We characterize the astrometric distortion at the edges of thick, fully-depleted CCDs in the lab using a bench-top simulation of LSST observing. By illuminating an array of forty thousand pinholes (30mu m diameter) at the object plane of a f/1.2 optical reimager, thousands of PSFs can be imaged over a 4Kx4K pixel CCD. Each high purity silicon pixel, 10mu m square by 100mu m deep, can then be individually characterized through a series of sub-pixel dithers in the X/Y plane. The unique character [response, position, shape] of each pixel as a function of flux, wavelength, back side bias, etc. can be investigated. We measure the magnitude and onset of astrometric error at the edges of the detector as a test of the experimental setup, using a LSST prototype CCD. We show that this astrometric error at the edge is sourced from non-uniformities in the electric field lines that define pixel boundaries. This edge distortion must be corrected in order to optimize the science output of weak gravitational lensing and large scale structure measurements for the LSST.

astro-ph.IM↗