Posted: 28 August 2008
Tests Show Big Bang Experiment on Track
The largest piece of scientific apparatus in the world has moved one step closer to its launch on 10 September thanks to a team of researchers, led by Dr Ronan McNulty, from UCD’s School of Physics.
The €6 billion giant particle collider - the Large Hadron Collider (LHC) - at CERN (the European Organisation for Nuclear Research) is housed in a 27km long tunnel 100m underground in the Swiss city of Geneva. Described as the world's largest particle physics laboratory, this September, it will carry out its first collisions in a bid to recreate a fireball of energy similar to the energy conditions of the universe one billionth of a second after the Big Bang.
Pictured far right: Particle tracks seen in the LHCb vertex detector (VELO) and triggered by the experiment's calorimeter during synchronization tests last weekend
This will necessitate accelerating protons in opposite directions at almost the speed of light and colliding them at four points on the 27km ring. The research scientists involved hope that this will, in time, deliver new data which will shed light on fundamental questions about our universe such as: what is mass?, what makes up dark matter?, and is there a new ‘supersymmetric’ form of matter? According to UCD physicist, Dr Ronan McNulty, answers to these questions will likely result in a Nobel Prize.
The successful test which the UCD team carried out on 22 August involved firing particles down the transfer line from the Super Proton Synchrotron (SPS) accelerator to the LHC over a 3km section. The clock-wise and anti-clockwise tests went off successfully, an indication that the 10 September launch is on track. However, in the course of making these tests, the very first interactions from the LHC were also observed in the VELO subdetector of the LHCb experiment, which the UCD School of Physics helped build, test and install.
UCD has the only experimental particle physics research programme in Ireland and the university’s research team has been involved with CERN since 2003. Speaking of last Friday’s success, Dr McNulty said, “I am very excited about this. For UCD and the School of Physics, it is very important. We are at the start of a very large programme of research in which scientists from across the world have collaborated. It is cutting edge scientific research comparable to the Hubble Telescope or even the moon landing.”
LHCb is one of four large experiments at the LHC. The experiment is dedicated to the study of subtle differences between matter and antimatter and to the searches for new physics through the ultra-fast decays of particles produced in high energy proton-proton collisions.
The Vertex Location (VELO) is the part of the detector closest to the collisions at the LHC and it can locate the position of particles and allows researchers to measure subatomic particles that live for less than one millionth of one millionth of a second. It will capture and analyse the debris at one of the collision points. The primary goal of LHCb is to shed light on why the universe is so full of matter and contains hardly any anti-matter.
Dr McNulty, who is a former Young Scientist of the Year, believes that the really important scientific findings will begin to emerge in about three years’ time. “It will need up to 20,000 connected computers to analyse the data emerging and UCD’s Department of Computer Science will play an important role in grid linking these computers around the world.” Recording and analysing this data requires sophisticated algorithms and new computing paradigms. The DGET project, undertaken jointly between the Schools of Physics and Computer Science at UCD and CERN, is developing tools for the management and data-mining of distributed data-sets.
Paying credit to the role of UCD’s technical staff and research students in this project, Dr McNulty said that a large team of people had contributed to UCD’s success on LHCb. “The mechanical workshop constructed parts of VELO while post-graduate students spent long hours in Dublin, Liverpool and Geneva testing nearly 200,000 readout channels. Without this collaborative effort we would not now be celebrating being the first experiment to reconstruct LHC interactions.”
Dr McNulty graduated with a BSc from UCD in 1989 and he later continued his studies in particle physics overseas because there was nowhere in Ireland at the time offering the facilities to do research in this field. However, with an active research team now established at the School of Physics in UCD, students and researchers can once again perform investigations into the ‘heart of matter.’
Discovering the answers to “questions which have been asked since ancient Greece – such as what is the world made from and what is at the root of everything has as much a philosophical dimension as a scientific one,” Dr McNulty said. “They are very simple and yet very profound questions.”
Further information: www.ucd.ie/physics/lhcb
