by Sparsh Navin. Published: 16 October 2011

My journey into particle physics – it started way back when I was still an undergraduate at Warwick university. I was in my second year doing a bachelor’s degree in Maths and Physics when I was offered a 10-week summer placement to work with York Ramachers on a Warwick-based experiment. The work and department were so good that within a few weeks of the placement, I had decided to apply for a PhD a year later, and had three offers to choose from. It was one of the most difficult decisions I took. In the end, it was the prospect of working at CERN that made me choose Birmingham. However, there was one more choice to make – which experiment? It took me two whole weeks to decide to work on ALICE, and I haven’t regretted my decision since.


ALICE's Sparsh Navin

The first few months sped past very quickly with learning new software, lectures, getting to know my supervisors, Roman Lietava and Cristina Lazzeroni, teaching and adapting to a postgraduate way of life. My first trip to CERN was in November 2007 along with the other PhD students (coincidentally, we were all female). Ironically, I started reading “Angels and Demons” on my way to CERN, and was very excited when I first saw the “globe”. The trip to CERN was short – with the help of the head of our group, David Evans, we got our registrations done, keys and permits made, and tried not to explode with excitement when we knew we eating on the same table as a Nobel prize winner in restaurant 1 (R1). We stayed at the CERN hostel and had our noses buried in a map to navigate around CERN. But of course, the highlight of the visit was a trip underground to see the detector. It was like nothing I’d ever seen or felt before. That was when I realised just how large the project I started working on was.

My next trip to CERN was to train for shifts. I was training with David on a night shift, one of many more to follow. Shifts were scary at first as I was responsible for the trigger for 8 hours. Once I got used to them, learnt more about the trigger and knew where to find help, I began enjoying them and managed to make some friends. By now, I had visited the detector again and one day it was time to have my own hat and boots (necessary accessories to go underground). That was another exciting day as the friendly staff at the CERN stores allowed me to ride in their cart to pick up goods from a 2-storied aisle. Eventually, I was lucky enough to get a closer look at ALICE, walking around the TOF and TPC. Thanks Alex!

A few more short visits for meetings and a few presentations followed. On one such trip I discovered that Karel plays badminton. So after a meeting one day, we were a group of 4 that booked a court in Segny and played for a couple of hours. It was this short game that later led to Karel introducing me to the Prevessin badminton club, where I found my husband.

Before I knew it, my short visits to CERN stopped and I was on a long-term attachment at CERN, living in Saint Genis. By this time, I was done with graduate lectures and had started working on trigger efficiencies for the first physics group. Living so close to CERN made a huge difference to my work as I could take part in and contribute to day-to-day first physics meetings. Then came the first beam - I was at the RAL summer school in the UK. Unfortunately, the accident delayed first collisions. However, to my advantage, it gave me enough time to apply for a placement with MCnet in Lund. I spent 4 months working with Torbjorn Sjostrand on including hard diffraction in Pythia 8. This period not only taught me more about PYTHIA and phenomenology, but also gave me many opportunities starting with a talk at the low-x conference in Ischia. The work done in those four months would fill nearly a whole chapter of my thesis.

Once back at CERN, it was time for first collisions. The atmosphere was tense and work took over everything else. Eventually, ALICE published the first LHC paper with data. A few more months at CERN and it was time for me to head back to the UK to write my thesis. As expected, the move was hard. Living around CERN was great - the place is beautiful and offered so much to do including skiing and badminton. Back in the UK, there was more analysis to do. I was comparing uncorrected data from ALICE, using an offline trigger to enhance diffractive events, with different event generators. Working out the systematic uncertainties on the results took a few months. Writing my thesis demanded a lot of discipline as I always found something I could do instead. Planning a wedding in India during this time didn’t help much. In the end, after writing, editing, making plots and remaking plots, my supervisors spending their evenings and weekends proof-reading, my thesis was finally ready and submitted.

The second scariest part (see later for the first) of finishing your PhD is the viva – the long oral examination, with 2 examiners trying to determine if the student is good enough to be awarded a PhD. I had more than a month in between submitting my thesis and having my viva in which I had a second wedding in Saint Genis (my husband is French). Closer to my viva, my supervisors spent many hours preparing me for the day. However, nothing can really prepare you for the questions you will be asked, you can only try to gain some confidence in having a few mock viva beforehand. My examiners were experts in diffraction and had many topics to ask me questions on. Some questions I had anticipated and was prepared to answer well, however, I struggled to answer some others. Eventually, 3 hours and 45 minutes after we started, I was told that the viva had ended. I had passed subject to minor corrections to my thesis!

Today, after completing those corrections and waiting for the final copy to be bound, the (first) scariest part of finishing my PhD is ahead of me – I now need to find a job.

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