The Line of Beauty
Departments Research impact and institutes 25th October 2022
Last time, in our mini series about the work Manchester scientists are carrying out on the Large Hadron Collider (LHC) at CERN, we talked about the equipment that was built right here at the University. However, what about the experiments themselves? What activities are taking place that are improving our understanding of the fundamental nature of the universe, and how, exactly, are our scientists involved?
Professor Chris Parkes is an experimental particle physicist working in the Department of Physics. He is also the spokesperson – or leader – of one of the four large experiments at the LHC: namely, the “Large Hadron Collider beauty” experiment, or LHCb.
As we said last time, the LHC accelerates particles to almost the speed of light before colliding them together with astonishing accuracy – equivalent to firing two needles from a distance of 10km apart and hitting the points. These collisions take place at four points on the 27-kilometre circumference of the LHC, and it’s at those points that the four experiments take place. The experiments are called Atlas, CMS (Compact Muon Solenoid), Alice and LHCb. We’ll be looking at some of those other experiments in future articles, but today we’re going to talk about LHCb.
We recently spoke to Chris, and he told us that the LHCb experiment has around 1,500 collaborators from 20 different countries. He added “some of what we’re doing is really searches for new phenomena, which is beyond what we know in our current physics. If we were able to discover such a thing, that would be of course, tremendous, would be a real paradigm shift. But also a lot of things that we do are testing inside our current knowledge of physics and expanding what we know within the theoretical framework that we have, to learn more about it.”
Professor Chris Parkes
We asked Chris about the way his work, and the work of his colleagues at CERN, often gets reported in the media over here, and the fact that it’s often reduced to scare stories about black holes and the end of the world. However, he said “I’m quite pleased with the fact that the kinds of fundamental physics that we’re doing now is much better known in the general public now than it used to be. There’s been a lot more media coverage over the last ten years with the LHC, with some of the breakthroughs that we’ve made. And I think people are much more educated about what we do. I mean, you’re right that the actual ‘we’re going to destroy everybody in a black hole’ is clearly something which you need to reassure people (about) – you need to explain the science behind what we’re doing. You need to explain that … while we’ve never done the (experiments) on earth before, what we’re really doing is creating the same kind of conditions that would have existed in the early universe. And by doing these experiments, you’re trying to find out about this fundamental physics, but that what we’re doing is not dangerous.”
Earlier this year, there was great excitement when Chris’s team were able to announce what were described as new “exotic” configurations of quarks. Chris told us “we announced the discovery of what’s called a pair of tetraquarks and a pentaquark. The particles of which the atomic nucleus are made up, are the proton and the neutron. And the proton and the neutron consist of three quarks that are bound together. There are also particles that contain two quarks, that are bound together. And during the 1960s and 1970s there became this ‘zoo’ of these particles that we found containing two particles bound together and three particles bound together. Collectively, these particles containing quarks are called hadrons. Now, it was speculated already from very early on when people started to understand that particles like the proton and the neutron were made out of these more fundamental particles called quarks, that there could be more exotic hadrons, which could contain four quarks or five quarks. So a particle containing four quarks is known as a tetraquark and a particle containing five quarks is known as a pentaquark. And over the last years at LHCb, we’ve discovered a number of these tetra quarks and pentaquarks. And what we’ve just announced is the discovery of four more.”
People are much more educated about what we do. You need to explain that while we’ve never done the experiments on earth before, what we’re really doing is creating the same kind of conditions that would have existed in the early universe, and that what we’re doing is not dangerous
And what of the future? There’s talk about building a new collider, many degrees of magnitude larger than the current LHC. Chris said “these projects are extremely large scale and therefore they also have large time horizons. With the LHC experiment alone, we’re already plotting out what we want to do into the 2040s. But we’re also starting to look at what could come after the LHC. There’s a five year design study for what’s called the Future Circular Collider at the moment, which would be a collider with an energy about seven times that of the current LHC located in roughly the same area as CERN, on the French-Swiss border near Geneva.
“You have to think about the civil engineering for it, the local area, the political support – and all these elements are going together at the moment into this design study that’s going to report in, I think, 2026 to see whether this is a project that could potentially go ahead. I think it’s extremely exciting and I think it could really be the next big machine for our field.”
In terms of the UK’s contribution to the work on the LHC, Chris said that it had recently been announced that the UK government had agreed funding for the next version of the LHCb experiment, to take the team into the 2030s. He gave more detail about the importance of such funding. “These projects are extremely long scale, and we’ve been having ideas about the version of the project of the LHCb experiment that will operate in the 2030s. We recently issued a document which lays out the plans for what it is we’d like to build and what science we’d like to do with this project, in the 2030s. And just a few weeks ago the UK has announced that it wishes to fund this project and is giving a grant of £50 million for its construction.”
So it seems that the future of the science that’s taking place on the LHC is secured for the relatively long term. And given what we’ve learnt already, it’s exciting to think about what might come next. One thing’s for certain, though – University of Manchester scientists will be at the forefront.
And if you want more from Chris, including more detail about the work he does on the LHCb experiment, and the major discoveries his team are making, you can listen to the full audio of our interview with him below:
Transcript of the audio discussion with Chris Parkes (PDF document)
If you’ve enjoyed reading about what our scientists are doing at CERN, then watch this space for the next instalment, when we’ll be talking to Will Bertsch, who works on the Alpha experiment.
