Thesis

Development of data processing and analysis tools for the LZ Dark Matter direct search experiment

• Call:

  IDPASC Portugal - PHD Programme 2015

• Academic Year:

  2015 / 2016

• Domains:

  Experimental Particle Physics | Astroparticle Physics

• Supervisor:

  Francisco Neves

• Co-Supervisor:

  Alexandre Lindote

• Institution:

  Universidade de Coimbra

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  The observational evidence for the existence of a non-baryonic, non-luminous and non-relativistic component of the universe, accounting for ~80% of its total mass, has been strengthened in recent years [Cal09, Ber05, Ber10]. However, the nature and origin of this dark matter are still unknown. One of the strongest candidates are Weakly Interacting Massive Particles (WIMPs) [Ber05, Fen10], expected to be detectable by looking at nuclear recoils from their scattering with nuclei. 2-phase (liquid/gas) xenon detectors are the leading technology in direct WIMP search, and are used by the most sensitive experiments in the world. Merging two teams with wide experience and an history of leadership in the field (LUX [Ake14] and ZEPLIN [Aki12]), the LZ collaboration is developing a 7-ton dual-phase xenon detector, the biggest ever built using this technology. With the shielding offered by the outer xenon layer, the 5 tonnes of the inner region of LZ will be an extraordinarily low background place, allowing this detector to improve the current best sensitivity to WIMPs (established by the LUX detector) by a factor of ~1000. The set of tasks foreseen for this project evolve naturally from the participation of the student in the development of the LZ data analysis chain, starting with the characterization of the acquired pulses, their identification and filtering, and finally the determination of the sensitivity of the experiment to WIMP-nucleon scatters. The LIP-Coimbra team joined the LZ collaboration in 2012 after working in the ZEPLIN (since 2005) and LUX collaborations (2011). In this project, the student will be integrated in an international collaboration and work in a state-of-the-art detector. He/she will be supported by the LIP team, largely experienced in all aspects of this type of experiment. While most of the tasks can be performed in the LIP-Coimbra facilities, the student is also expected to work on site, in the Sanford Laboratory (USA), for periods of up to 1 month, during the commissioning and data acquisition periods of the detector. References: [Ake14] D.S. Akerib et al. (LUX Collaboration), “First results from the LUX dark matter experiment at the Sanford Underground Research Facility”, Phys. Rev. Lett. 112, 091303 (2014), DOI:10.1103/PhysRevLett.112.091303, arXiv:1310.8214. [Aki12] D. Yu. Akimov et al. (ZEPLIN-III Collaboration), “WIMP-nucleon cross-section results from the second science run of ZEPLIN-III”, Phys. Lett. B 709 (2012), pp. 14-20, DOI:10.1016/j.physletb.2012.01.064, arXiv:1110.4769v2. [Ber05] G. Bertone, D. Hooper, J. Silk, “Particle Dark Matter: Evidence, Candidates and Constraints”, Phys.Rep. 405 (2005), 279-390, DOI:10.1016/j.physrep.2004.08.031, arXiv:hep-ph/0404175. [Ber10] G. Bertone, “Particle Dark Matter – Observations, Models and Searches”, Cambridge University Press, 2010. [Cal09] R. Caldwell and M. Kamionkowski, “Cosmology: Dark matter and dark energy”, Nature 458 (2009), doi:10.1038/458587a. [Fen10] J. L. Feng, “Dark Matter Candidates from Particle Physics and Methods of Detection”, Annual Review of Astronomy and Astrophysics, 48 (2010), 495-545, DOI:10.1146/annurev-astro-082708-101659, arXiv:1003.0904.