CPPM PhD days 4 : ANTARES/KM3NeT
Amphithéâtre
CPPM
14:00 - 14:45 ANTARES/KM3Net Phd Day
Muon Track Reconstruction with ORCA
Quinn Liam
In order to determine the neutrino mass hierarchy, it is important to have a good reconstruction of energy and direction in the range 1-30GeV. The current status of the muon channel reconstruction will be presented, as well future plans to improve the mass hierarchy sensitivity further. This requires a more precise measurement of inelasticity of muon neutrino charged current interactions, by identifying and measuring the light yielded by hadronic showers in the seawater.
STUDY OF OM EFFICIENCY AND NEUTRINO OSCILLATIONS WITH ANTARES
Salvadori Ilénia
ANTARES is a neutrino telescope situated at the bottom of the sea at 40 km from the coast of Toulon (France). It has been completed in 2008. It is composed of 12 detection lines, each one of them equipped with 25 floors of three optical modules (OMs). Its main goal is, at high energies, the study of energetic astrophysical objects. However, at lower energies, neutrino oscillations can be measured by analyzing distortions in the energy/angular spectrum of upward-going atmospheric neutrinos.
In this first year of my research, I focused first on the ANTARES OMs efficiency study through the 40K trigger method. In the sea water there are radioactive isotopes, and among them, 40K is the most abundant. Its decay products produce Cherenkov light very similar to the signal we are interested in. For this reason 40K decays constitute one of the main sources of background. Nevertheless, we can also exploit its signal in order to calibrate our OMs. If a 40K decays near a storey (a group of three OMs), its signal can be registered by two OMs simultaneously. From such coincidence hits we can estimate the OMs sensitivity.
The second part of my research is devoted to the neutrino oscillations study. A previous analysis of neutrino oscillation parameters with ANTARES data from 2007 to 2010 has already been done, but now data between 2007 to 2015 are available, thus a more precise analysis is possible. The first step is to develop a new energy reconstruction algorithm, suitable for energies below 100 GeV, where the sensitivity to neutrino oscillations reaches its maximum. The goal is to obtain an improved measurement of the atmospheric neutrino oscillation parameters, complemented with limits for a sterile neutrino.
14:45 - 15:00 ATLAS
Combinatorial likelihood discriminant method for ttH(H->bb) search with the ATLAS detector at the LHC
Yulia RODINA
Search for the Higgs boson produced in association with a pair of top quarks is an important channel at the LHC as it gives access to the direct measurement of the Higgs coupling with the top quark. This talk is covering the work on the combinatorial likelihood discriminant method towards observation of the ttH(bb) process with the LHC Run 2 data. This method is exploiting kinematic reconstruction and btagging information in order to construct a high-performance discriminating variable between signal and background.