Riasat Sheikh 🐈‍⬛

シェイク リアサト Riasat Sheikh

PhD Researcher

Theory of Elementary Particles Lab

Kyushu University Fukuoka, Japan

About Me

I am a PhD researcher in elementary particle theory at Kyushu University, with research interests in dark matter, Higgs physics, and particle phenomenology beyond the Standard Model.

Education

  • PhD Physics

    Kyushu University, Japan

    2024 – Present

  • MSc Physics

    Banaras Hindu University, India

    2020 – 2022

  • BSc Physics

    Cotton University, India

    2016 – 2019

Interests

Dark Matter Higgs Physics Particle Phenomenology Model Building

Research Impact

4

Publications

11

Citations

3

h-index

Data from INSPIRE-HEP, October 2026

Latest News
Aug 7 – 13, 2026 Fuji Calm, Japan

Poster presentation at SI2026 in Fuji Yoshida

Presented a poster on two-component pseudo-Nambu-Goldstone boson dark matter at the 30th International Summer Institute on Phenomenology of Elementary Particle Physics and Cosmology.

Recent Publications
Exothermic nuclear recoils from thermal quasi-pNGB dark matter featured image

hep-ph

Exothermic nuclear recoils from thermal quasi-pNGB dark matter

Two nearly identical dark matter particles, one of which drops to the lighter state when it hits a nucleus and gives it an extra kick. We use this to interpret LZ's high-energy event at 248 keV.

Preprint •
Two component pseudo-Nambu-Goldstone-boson dark matter featured image

hep-ph

Two component pseudo-Nambu-Goldstone-boson dark matter

A dark sector with two stable pNGB dark matter particles, where the heavier one converts into the lighter one and produces fast-moving “boosted” dark matter.

Preprint •
Pseudo-Nambu-Goldstone-boson Dark Matter from Three Complex Scalars featured image

hep-ph

Pseudo-Nambu-Goldstone-boson Dark Matter from Three Complex Scalars

pNGB dark matter kept stable by a ℤ₃ symmetry, which naturally escapes direct-detection limits and opens new “semi-annihilation” channels.

INSPIRE4
JHEP •

Current Research

About 26% of the energy density of the universe is dark matter, yet everything we know about it comes from its gravity. My research is driven by a single question: what is dark matter? This means understanding what keeps it stable, whether it is a single particle or a whole dark sector, how it acquired its abundance in the early universe, how it communicates with ordinary matter, however faintly, and how we can probe it. The continued null results of direct detection experiments do not close these questions. They sharpen them, and point toward signals that conventional searches are not designed to see.

Symmetry as a guide. Much of my work builds dark sectors in which symmetry does the heavy lifting. In pseudo-Nambu-Goldstone boson (pNGB) dark matter, the dark matter is the Goldstone mode of a spontaneously broken global symmetry, which suppresses its scattering off nuclei while keeping annihilation efficient; a soft explicit breaking gives it mass, and residual symmetries make it stable. Richer symmetry structures lead to multi-component dark matter with semi-annihilation, conversion between species, and long-lived excited states. These dynamics can produce boosted dark matter and exothermic nuclear recoils, signatures testable at neutrino and direct detection experiments.

New ways to look. I am also working on unconventional probes of dark matter’s properties. Even electrically neutral dark matter could carry electromagnetic moments, and the damage tracks it would leave in billion-year-old minerals turn paleo-detection into a kiloton-year experiment. On the cosmological side, I study how hidden sectors can leave imprints on the universe, for example by amplifying cosmic magnetic fields through an oscillating non-Abelian condensate. Together, these directions aim to connect model building with measurable properties, and ultimately to pin down what dark matter is.

Recent Posts