Search for particle superpartners gathers pace at the Large Hadron Collider

Researchers at the University of Southampton are expanding understanding of the supersymmetric universe by analysing the latest data from the Large Hadron Collider.

Particle physicist Dr Harri Waltari is searching for neutrino superpartners, known as sneutrinos, to help explain scientific mysteries including how the subatomic particles get their masses.

He is advancing the research through a new one-year postdoctoral fellowship from The Finnish Academy of Sciences and Letters, representing a third funding success for Southampton’s NExT Institute in the past three years.

One of the challenges of the Standard Model of particle physics is that states that neutrinos are massless. However, neutrino oscillation experiments have found that these subatomic particles do have small masses that can be generated through interactions between the Higgs boson, neutrinos and the new supersymmetric particles.

Southampton physicists are exploiting the connection between supersymmetry and neutrino physics to help answer these inconsistencies.

“We have recently demonstrated that there are some cases where you can probe neutrino dynamics through their superpartners in the Large Hadron Collider (LHC) experiments,” Harri says. “This new fellowship will allow us to study further signatures coming from the mechanism that generates neutrino masses and then extend the searching strategies for new particles into the third run of the LHC and beyond.”

Supersymmetry predicts that all particles have superpartners, which have the same charge but a different spin to their known particles. While neutrinos fly through high energy particle detectors, their superpartners can decay and leave visible tracks in detectors. Researchers are investigating these decay products and then translating these to the properties of their related neutrinos.

Professor Stefano Moretti, Director of the NExT Institute, says: “This completely novel work of probing neutrinos indirectly from the study of their supersymmetric counterparts has no precedent. In fact, traditional approaches, including within supersymmetry, have pursued direct searches for neutrinos, which are notoriously difficult as these particles are never really captured by detectors.”

Harri’s latest funding from The Finnish Academy of Sciences and Letters follows awards in 2018 and 2019 from the Magnus Ehrnrooth Foundation and The Finnish Foundations Postdoc Pool.