Welcome

Dr. Eirini Tziaferi is a Post-doctoral researcher at the Department of Physics, National and Kapodistrian University of Athens specializing in Experimental High-Energy Physics.

Research Interests

The field of research of Dr. Eirini Tziaferi is Experimental High Energy Physics. She studies the properties and interactions of elementary particles in collider experiments (pp) at the LHC accelerator at CERN. She focuses on searches for new physics in multi-jet topologies, exploring a variety of new physics models from Extra Dimensions to Dark Matter.

Short Bio

Dr. Eirini Tziaferi received her BSc degree in physics (2003) from the Aristotle University of Thessaloniki and her PhD degree (2007) from the Department of Physics & Astronomy of the University of Sheffield, UK, working on the DRIFT-II experiment at the Boulby mine (UK). This experiment was built for the direct detection of dark matter. In 2007 she moved to Aachen (Germany) and afterwards to Zurich (Switzerland) to work as a postdoctoral research associate in the XENON100 dark matter experiment in the underground laboratoty of Gran Sasso in Italy. This experiment set the most stringent limit in the spin-independent WIMP-nucleon elastic scattering cross sections at that time. In 2012 she joined the CMS experiment at CERN (Geneva, Switzerland) as a postdoctoral researcher at the University of Ioannina and since 2015 as a member of the group of Ass. Prof. Saoulidou at the University of Athens.

As a member of the CMS experiment of the Large Hadron Collider (LHC) at CERN Dr. Tziaferi searches for new physics utilizing events with hadronic jets in the final states. Since 2014 she is one of the key analyzers of the Dijet Resonance Search with the 13 TeV data. She worked on the analysis optimization, and since data taking started, on detailed data-quality studies comparing real with simulated events, on data-stability studies examining the behavior of physics quantities as a function of time and on the development of a robust data-driven QCD background prediction method that can significantly reduce systematic uncertainties. The Dijet Resonance Search is among the roughly ten High Priority Analyses of the CMS Exotica Group. She also studies the quality of reconstruction and selection of the hadronic jets (PF Jet Identification criteira). She led the careful study and documentation of the PF JetID selection criteria for the 8 TeV data, and in their improvement for the 13 TeV data, which are recommended (mandatory) for all CMS analyses. It is important to note that these criteria, which are used by all CMS analyses, made possible the first searches of dark matter utilizing mono-jets events. She was appointed as a co-convener for the Jet+X group for the period 9/2021-9/2023. This subgroup oversees analyses with final states dominated by jets, such as di-jet, multi-jet, or topologies with leptons and jets, searching for narrow and broad resonances from a variety of new physics models (including DM mediators), leptoquarks, heavy neutral leptons etc.

Selected Publications

• CMS Collaboration, “Search for dijet resonances in proton-proton collisions at √s = 13 TeV with the full Run II data”, EXO-19-012 (2019)
• CMS Collaboration, “Pileup mitigation at CMS in 13 TeV data”, JME-18-001 (2019)
• CMS Collaboration, J. High Energy Phys. (2018) 130, “Search for narrow and broad dijet resonances in proton-proton collisions at √s = 13 TeV and constraints on dark matter mediators and other new particles”
• CMS Collaboration, PLB 769 (2017) 520542, “Search for dijet resonances in proton-proton collisions at √s = 13 TeV and constraints on dark matter and other models”
• CMS Collaboration, PLB 770 (2017) 256-267, “Search for new phenomena in events with high jet multiplicity and low missing transverse momentum in proton-proton collisions at √s= 8 TeV”
• CMS Collaboration, PRL 116, 071801 (2016), “Search for Narrow Resonances Decaying to Dijets in Proton-Proton Collisions at 13 TeV”
• CMS Collaboration, “Jet Algorithm Performance in 13 TeV data”, CMS PAS JME-16-003 (2016).
• E.Aprile et al., J. Phy. G40 (2013) 115201, “The neutron background of the XENON100 dark matter search experiment”
• E.Aprile et al, Astroparticle Physics 35 (2012), 573-590, “The XENON100 dark matter experiment”
• Ε.Aprile et al., Astroparticle Physics 35 (2011) 43-49, “Material screening and selection for XENON100”
• Ε.Aprile et al. Physical Review D 84, 052003 (2011), “Likelihood approach to the first dark matter results from XENON100”
• E.Aprile et al, Physical Review D 83, 082001 (2011): “A study of the electromagnetic background in the XENON100 experiment”
• E.Aprile et al, Physics Review Letter 105, 131302 (2010): “First Dark Matter Results from the XENON100 Experiment”
• D.Snowden-Ifft et al, NIM A 600 (2009) 417-423: “Measurements of the range component directional signature in DRIFT-II detector using 252Cf neutrons”
• T.B.Lawson et al, NIM A 584 (2008) 114-128 “Track reconstruction and performance of DRIFT directional dark matter detectors using alpha particles”
• E.Tziaferi et al, Astroparticle Physics 27 (2007) 326-338: “First measurement of low intensity fast neutron background from rock at the Boulby Underground Laboratory”
• D.Snowden-Ifft et al., Astroparticle Physics 28 (2007) 409-421: "Studies of neutron detection and backgrounds with the DRIFT-IIa dark matter detector”
• G.J.Alner et al, Astroparticle Physics 28 (2007) 287-302 “First limits on WIMP nuclear recoil signal in ZEPLIN-II: A two phase xenon detector for dark matter detection”
• M.Carson et al, NIM A 546 (2005) 509-522: “Simulations of neutron background in a time projection chamber relevant to dark matter searches”