PhD in theoretical physics: good or bad for engineering jobs? I'm a student who is currently undertaking a Master of Physics (coursework &amp; research) at the University of Western Australia. I have also previously completed two Bachelor's degrees: one in physics and one in electrical engineering (with honours). Next year, I am hoping to start a PhD in high-energy physics (HEP) somewhere in Australia, doing a highly theoretical topic (such as supersymmetry, string theory, etc.) with the long term goal of following an academic path in this area of research.

From my understanding though, it is VERY hard finding academic jobs relevant to this particular field. I've heard through the grapevine that you have more chance of becoming a professional athlete than becoming a professor in theoretical HEP which is honestly quite dejecting.

However, understanding physics beyond the standard model is undoubtedly my passion so I would really like to pursue a PhD in it to determine whether or not it can become more than just a hobby. I've heard of theoretical HEP PhD's going into finance, etc. when finding an academic position proved fruitless, but if I'm being honest, that doesn't sound all that appealing to me. If the academic path didn't work out, I have always had a super keen interest in areas such as signal processing, control theory and data analysis. Which leads me to my main question:

In case I can't find an academic position in theoretical HEP, do you think my EE degree and MPhys (both of which involved experimental research projects highly focused on signal processing and data analysis) would be sufficient credentials to land a job in engineering/signal processing/data analysis? Or perhaps if I'm lucky, even some area of industry research (if so, what areas)?

Further, do you think having a PhD in theoretical HEP, in addition to my other credentials, would be a benefit or a hindrance in securing these types of jobs?

Some potentially relevant information:

I have 3 months of work experience at an electrical engineering company

My EE research project involved analyzing audio signals using a DSP to achieve desired acoustic properties

My MPhys research project is about detecting gravitational waves which involves heavy signal processing and manipulating large sets of data (100GB+) using python

By the end of this year my MPhys research should produce at least 1 or 2 papers in the Physical Review Letters journal
I would say that strongly depends on what you do in the HEP PhD. 

If it is more like pen and paper theory I would say this is not very interesting for industry. Perhaps even in the contrary as you might seem too "academic". Pen and paper theory jobs do not really exist in industry.

It is more the big data processing and computer simulation related skills what is relevant. The tools (python and methods) you use in your MPhys research sounds exactly what some companies are also using internally. 

Industry considers hiring people from adjacent fields, when demand is much higher than the supply for certain jobs. Currently I see that this is the case for "data scientists". So I would say now your chances are good to find a job there as many companies are now exploring big data applications. They are scared by the success of Google, Facebook, etc.. and do not want them to take over an important part of their business. So many are investing here. Industry also has these jobs so it is not just finance. It is very diverse. One gains some feeling for it when one looks at current job offers (which is what I did, so I have no deeper experience than that). However, you have to keep in mind that the situation may be different is in a few years when you might have to give up your academic career (hopefully not). 

A PhD is liked for certain types of jobs even in industry. As the PhD is teaching more a generic mindset (-> how to work scientifically,/thoroughly, know how to tackle big, unsolved problems) this is considered useful in some industrial jobs. Appropriate job descriptions would perhaps have names with "scientist" in it, like "data scientist", "research scientist" and so, not so much the "engineer" type of jobs. Sometimes PhDs are also found in sales/marketing, when a product needs deep explanation, training (and the customers are themselves PhDs) or must be customized to the users needs (and this is not straightforward).

Note: Even though I have worked in the US, I a most familiar with the German system. Nevertheless I hope the answer helps somehow.