Skip to main content

Particle Physics Seminar: A Search for Relic Axions and Their Frequency Modulation

Particle Physics Seminar: A Search for Relic Axions and Their Frequency Modulation

  • Date 13 Jan 2021
  • Time 3.30pm - 4.30pm
  • Category Seminar

Dr Shriram Jois (RHUL)

The axion was hypothesized to explain the invariance of strong interactions under the transformations P and CP. The theory predicts that a large number of relic axions could have been produced in the big bang. If discovered, it could account for the majority of the dark matter in the Milky Way galaxy. This hypothetical particle is being searched in a microwave cavity in the ADMX collaboration. The experiment includes a high Q microwave cavity inside the bore of an 8-T solenoid magnet. The whole setup is cooled down to cryogenic temperatures. The application of a strong magnetic field provides an alternate path for axions to decay into photons in a process called Sikivie conversion. Because the mass of the axion is unknown, the cavity is slowly tuned. The Run 1B of the ADMX run covered a frequency range of 680 – 800 MHz.

The data from the experiment are recorded in two channels: a medium resolution and a high-resolution channel. While the medium resolution channel searches for virialized axion flow, the high-resolution channel searches for unvirialized axion flow. Due to motions of the Earth in the Milky Way galaxy relative to the axion flow, the signal is expected to undergo a diurnal and annual frequency modulation. This frequency modulation is expected to be around 10 mHz per 100 sec scan at a cavity frequency of 1 GHz. The high-resolution data are sensitive to such modulations and therefore must be considered in the analysis. The analysis includes various cuts to identify and remove the synthetic axion injections, identify and remove the non-persistent triggers and investigate the frequency modulation of the axion signal. In this talk, I present the results of the high-resolution data analysis of Run 1B of the ADMX run.

2021-01-13-PPSeminar-Jois.jpg

A microwave cavity on a test bench

Related topics

Explore Royal Holloway

Get help paying for your studies at Royal Holloway through a range of scholarships and bursaries.

There are lots of exciting ways to get involved at Royal Holloway. Discover new interests and enjoy existing ones

Heading to university is exciting. Finding the right place to live will get you off to a good start

Whether you need support with your health or practical advice on budgeting or finding part-time work, we can help

Discover more about our 21 departments and schools

Find out why Royal Holloway is in the top 25% of UK universities for research rated ‘world-leading’ or ‘internationally excellent’

Royal Holloway is a research intensive university and our academics collaborate across disciplines to achieve excellence.

Discover world-class research at Royal Holloway

Discover more about who we are today, and our vision for the future

Royal Holloway began as two pioneering colleges for the education of women in the 19th century, and their spirit lives on today

We’ve played a role in thousands of careers, some of them particularly remarkable

Find about our decision-making processes and the people who lead and manage Royal Holloway today