Edinburgh nuclear physicist Daria Sokhan has been awarded the 2009 Thomas Jefferson National Accelerator Facility (Jefferson Lab) thesis prize.
Daria wins a $2000 prize, a commemorative plaque to be placed in Jefferson Lab and the opportunity to present her thesis results at the annual Jefferson Lab user meeting. She shares this year’s award with Andrew Puckett from MIT.
The work by Daria which the award recognises will be a crucial part of the measurement programme aiming to accurately determine the properties of the excited states of the neutron and proton. These are complicated composite quantum systems comprising quarks and gluons interacting with each other and the vacuum.
Daria’s thesis work used the intense transversely polarised high-energy photon beam at Jefferson Lab to excite target neutrons into various excited states. A superconducting magnetic toroidal spectrometer (CLAS) was used to detect the decay products from the subsequent decay of the excited states a few trillion-trillionths of a second later.
As with any composite system, the excitation spectrum gives a window to test our understanding of the interactions and dynamics of its constituents. The energy associated with the interactions of the constituents of the proton and neutron are responsible for over 95 per cent of their mass (E=mc2) and therefore most of the mass of the visible universe.
Daria said: "I was delighted to receive the prize. It's in large part due to the great opportunity Edinburgh offered to work at such a fantastic facility abroad and of course the excellent supervision and support I received back here. Drinks all round!”
Her PhD supervisor Dan Watts said, “It’s great to see Daria’s work recognised in this way. Her results are a crucial missing piece in obtaining a better understanding of the dynamics of the nucleon. I would expect her to take the nuclear group out on the town using that generous award!"
Thomas Jefferson National Accelerator Facility
Jefferson Lab provides a continuous electron beam with energy up to 6 GeV. An upgrade to 12 GeV will start in 2011. The Lab is in Virginia, a few hours south of Washington DC, and it caters for around 1000 outside users per year.
About the award
The Thesis Prize is awarded to a graduate student who has carried out research related to Jefferson Lab science. It is awarded for the best graduate student thesis and includes a prize of $2,000 and a commemorative plaque placed at the lab. Four areas are considered in rating the submitted theses: the quality of the written dissertation; the student's contribution to the research; the work's impact on the field of physics; and service (how the work benefits Jefferson Lab or other experiments).
Image gallery
The CLAS detector used by Daria at Jefferson Lab.
Physicists from the School of Physics & Astronomy have announced the first results from data produced by the Large Hadron Collider (LHC). This comes just weeks after the LHC started operating at a new beam energy of a record 7 trillion electron volts (TeV).
Speaking at the RICH10 conference, the University of Edinburgh’s Prof. Franz Muheim presented the first results from the Ring Imaging Cherenkov (RICH) Detectors of the LHCb Experiment with data taken at the LHC.
The RICH detectors are built to distinguish between different types of charged particles known as pions, kaons and protons. Their proper identification is crucial for measuring differences between particles and antiparticles. The detectors were built by a collaboration of 10 institutes from the UK, Italy and CERN.
The results represent an immense achievement – and a lot of hard work – over the last decade by the LHCb collaboration.
The Edinburgh team has made major contributions to the LHCb RICH detectors. Also to the development of distributed analyses techniques for the large LHC dataset on the Grid, including using ScotGrid and ECDF. The group has pioneered new ideas for searching for new physics beyond the Standard Model and have now commenced analysing LHCb data.
Prof. Franz Muheim says: “We are all thrilled to observe such an excellent RICH detector performance from day one.
“The LHCb experiment is located in the forward region, close to the beam pipe of a hadron collider, which is a very harsh environment and this makes these initial results a great achievement. We are all looking forward to the large data rates that the LHC will produce as it gradually increases the collision rate over the year."
“With the LHCb experiment at the LHC, we will explore uncharted territory and hopefully find something new, possibly unexpected."
“This is a fantastic time for science. Particle physics is one of the disciplines that excites school kids and motivates them to study physics, and we need a more scientifically literate workforce to tackle the challenges of the 21th century.”
The LHCb group in the School of Physics & Astronomy comprises: Prof. Franz Muheim, Prof. Pete Clarke, Prof. Steve Playfer, Dr. Stephan Eisenhardt, Dr. Greig Cowan, Dr. Yuehong Xie and Ph.D Students Rob Currie, Gemma Fardell, Conor Fitzpatrick, Young Min Kim, Ailsa Sparkes, Nick Styles, Ross Young and technician Andrew Main.
The results were presented at the 7th International Workshop on Ring Imaging Cherenkov detectors (RICH 2010), which runs from 3–7 May in Cassis , South of France. RICH2010 focuses on the present state of the art and the future developments in Cherenkov light imaging techniques for applications in High Energy Physics, Nuclear Physics and Astroparticle Physics.
See below for an explanation of the LHCb experiment and some first-hand accounts of the University’s involvement in LHCb and the RICH detectors.
The Hybrid Photon Detectors
Here some of the members of the LHCb group in the School of Physics & Astronomy describe their involvement with the experiment.
Ross Young
Ross Young is a PhD student who, at the RICH2010 conference, gave a presentation on results from operating the Hybrid Photon Detectors (HPDs) in the LHCb RICH counters.
“I was very fortunate that as part of my PhD studies I started a placement at CERN in October 2008, just after the installation of the HPDs into the RICH1 detector. Part of my work has been with the performance studies of HPDs - the light sensitive detectors of the RICH system.
“During the installation, columns of HPDs were mounted side-by-side to form 'bee-hive' arrays of HPDs (see Figure 2, below). Since then, we have been testing the performance of these arrays under a variety of different environments.
“As an example, we shine a continuous-wave laser on to the arrays to test the HPD response to light. Looking at the pixel hitmap of RICH1 (see Figure 1, above) you can notice, for every HPD under such illumination from laser, the projection of the circular photocathode image onto the pixel chip, in addition to other features such as shadowing. As well as carrying out analysis of the results, I have had the opportunity to carry out the runs myself in the control room.”
“The principle of a Ring Imaging Cherenkov detector is as follows: when a highly relativistic particle traverses through a medium at a very large speed exceeding the speed of light in the radiator, Cherenkov light is emitted at an angle which depends only on the speed of the particle and the refractive index of the medium.
“The Cherenkov photons are focused by spherical mirrors onto a ring on the photon detector arrays. The RICH detectors have recorded the first Cherenkov photon rings from collisions of the LHC beams.
“Figure 3 (below) shows a typical event. Each orange point depicts a single photon recorded by the HPDs. The sets of blue rings correspond to different particle hypotheses. One observes that photons lying typically on the ring with the largest radius identifies them as coming from a pion. Cherenkov photons from kaons or protons would lie on the smaller circles.”
Stephan Eisenhardt
Dr. Stephan Eisenhardt is coordinator of the University’s photodetector laboratory and he has been leading the testing of the HPDs in Edinburgh.
“The fully operational Ring Imaging Cherenkov Detectors of LHCb are a great achievement. The HPDs are a new technology. From idea and concept via design and development to commissioning they are a brain child of LHCb physicists.
“The HPDs provide an unprecedented noise-free sensitivity to enable particle identification. Never before has a detector been built which provides particle identification over such a wide momentum range.
“New concepts had to be developed for many aspects of it. Yet it is working from day one at a very high efficiency. This is testimony of the spirit of dedication and collaboration of so many people."
Ailsa Sparkes and Conor Fitzpatrick
Ailsa Sparkes and Conor Fitzpatrick are currently on a placement at CERN and take part in the day-to-day running of the RICH detectors.
Ailsa: “It is extremely exciting to be contributing to such an important experiment as LHCb at this pivotal time in particle physics.
“I didn't expect to be given direct control over the RICH detectors so soon into arriving here at CERN and it's a great experience. The atmosphere at CERN makes it a fun and lively place to work with potentially ground-breaking discoveries just around the corner.”
Conor: “This is very exciting. As a RICH Piquet I am responsible for the safe and reliable running of these detectors, a role I share with a number of physicists from universities and institutes throughout the world.
“It is humbling to be part of such a dedicated collaborative effort, and to share in the continued successes of our work."
Young Min Kim
Young Min Kim will present a poster at the RICH2010 conference, and explain his simulation studies of the performance expected from improved RICH photon detectors which will allow the LHCb experiment to operate at a ten times greater collision rate in the second half of the decade.
"It is a great honour to see my work on the HPDs integrated with that of everyone else to give fruit to the LHCb RICH detector system. A mix of fascination and pride swims in me knowing I'm contributing to detective work using the smallest traces of light as our clues."
The LHCb Experiment
The LHCb experiment aims to understand the matter-antimatter asymmetry in the Universe.
It is a real puzzle why the observable Universe consists almost entirely of matter. When the Universe was created in the Big Bang the amounts of matter and antimatter were identical, so the question is: “Where has all the antimatter gone?”
The Standard Model of Particle Physics provides a partial answer. The BaBar experiment at SLAC, Stanford, observed a large asymmetry between the decay rate of a neutral B meson (a particle containing a b-quark), which oscillates (transmutates) at a high frequency into its antiparticle and back, compared to the corresponding decay rate of the antiparticle into the same final state.
This phenomenon is known as CP violation in the interference between mixing and decay of B mesons, but the observed magnitude of CP violation is too low by a large factor of 1000 millions to explain the observed asymmetry.
The University of Edinburgh is a member of the BaBar experiment and the physicists proposing this mechanism as the origin of CP violation within the Standard Model were recognised with the Physics Nobel prize in 2008. By recreating at the LHC the conditions that existed a millionth of a millionth of a second after the Big Bang, the LHCb experiment is aiming to shed light on the cause of this matter-antimatter asymmetry which is at the basis of our existence.
Image gallery
Prof. Peter Higgs, the Emeritus Professor whose theory of particle physics has dominated the discipline for decades, met Professor Rolf-Dieter Heuer, Director General of the European Organisation for Nuclear Research (Cern), and Dr Charles Jencks, landscape architect, at Dr Jencks' home, Portrack House, near Dumfries.
Cosmic garden
While at Portrack House, the guests enjoyed a tour of Dr Jencks’ Garden of Cosmic Speculation, which includes a sculpture of the standard model of physics.
The standard model is a theory which brings together fundamental elements of the science of physics. It includes the Higgs boson particle, which was first postulated by Professor Higgs when he was a researcher at the University in the 1960s.
Cern project
Dr Jencks is in discussions to design a garden at Cern, the physics laboratory near Geneva that is expected to uncover evidence of the theoretical particle.
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Prof. Peter Higgs and the sculpture of the standard model of physics.
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New nuclear build, both fusion and fission, now seems inevitable in many countries. Crucial to the safety and lifetime of reactors is the degradation of the steels from which they are made due to radiation. The ability of a material to resist radiation damage is determined by how well the microstructure can remove vacancies and interstitial defects in equal numbers. In this week's Science, Prof Graeme Ackland proposes that nanomaterials can be used as catalysts for healing damage, or as nanodustbins for storing embrittling byproducts such as Helium.
The School of Physics & Astronomy is part of today’s significant developments at the European Organisation for Nuclear Research (CERN).
Physicists from the University of Edinburgh are working at the Large Hadron Collider (LHC) as it starts to smash sub-atomic particles together with a record level of energy – 7 trillion electron-volts (TeV).
The powerful particle collisions mark the beginning of LHC’s first high-energy activity.
Experiments at the LHC will collect data that may provide evidence of the Higgs boson. The existence of this theoretical particle was first postulated by Professor Peter Higgs when he was a researcher at the University in the 1960s. It will be a remarkable achievement for physics if his predictions are correct.
About 20 physicists from the University perform research at CERN, working on the ATLAS and LHCb detectors which analyse collision data from the LHC as it recreates the conditions of the Big Bang.
The researchers’ work on ATLAS involves modelling and simulating the particle collision process to help understand the detector’s response and the complex data produced by the experiments. They also contribute to the operation of the ATLAS detector itself and provide software to manage the data produced.
Dr Philip Clark, School of Physics and Astronomy, said, “We are delighted to be involved with CERN as the new high-energy run gets under way. The Large Hadron Collider is expected to advance significantly our knowledge of physics and as such represents an enormously important development.”
The Edinburgh group works on the Ring Imaging Cherenkov (RICH) detectors for the LHCb experiment. The RICH detectors are built to distinguish between kaons and pions, which are different types of charged particles. Their proper identification is crucial for measuring differences between particles and antiparticles. The LHCb experiment aims to understand the matter-antimatter asymmetry in the Universe.
Prof. Franz Muheim, School of Physics and Astronomy, states: “Today is the start of a new era for particle physics. We have worked hard over more than a decade to design, build and commission the LHCb experiment. Thus we are very excited to have started data-taking at the LHC. This is a giant step into unknown territory and the LHC will hopefully reveal a few secrets of Nature.”
The LHC research may shed light on other important unsolved questions in physics. These include furthering scientists’ knowledge of dark matter and explaining why the Universe is made from matter, not anti-matter.
Physics exhibition
To mark today’s CERN milestone, the School is holding an exhibition in the forum of the University’s Main Library. This will be followed by a presence at the Science Festival.
The display, which is run by Alan Walker of the Particle Physics Experiment group, features a series of experiments relating to particle physics and the search for the Higgs boson.
Picture gallery
An LHCb event recorded at 7 TeV
Happy researchers in the LHCb control room, including Conor Fitzpatrick (foreground), a 2nd year PhD student, who is involved in calibrating the RICH detectors.
COSMIC is a collaboration between the University's schools of Physics & Astronomy, Chemistry, Biology and Medicine. It has pioneered the use of spectroscopy and imaging techniques to study how viral infections affect cells. The cover image of the latest issue of the Journal of Biophotonics shows one of COSMIC's images of cells under viral attack.
Dr Davide Marenduzzo has been awarded the 2010 Young Scientist Prize by the C3 Commission on Statistical Physics of the International Union of Pure and Applied Physics (IUPAP).
The citation for the prize recognizes Davide's contributions to the statistical mechanics of biomolecular and soft matter systems, in particular his groundbreaking simulations of DNA organization, liquid crystals and active gels.
Davide will receive his prize at the StatPhys24 conference in Cairns, Australia in July. The Young Scientist Prize in Statistical Physics recognises outstanding achievements by scientists in the early stages of their career working in the broad field of Statistical Physics.
Software was highlighted as a key facility needed for high quality research by a recent Engineering and Physical Sciences Research Council (EPSRC) consultation. A sustained future for this valuable resource has now been assured thanks to a £4.2 million grant from EPSRC, which will establish the UK’s Software Sustainability Institute (SSI).
EPCC at the University of Edinburgh will lead a team of academics and software engineers based at the University of Southampton’s School of Electronics and Computer Science and the Department of Computer Science at the University of Manchester. The groups will work in partnership with the research community to manage software beyond the lifetime of its original funding, so that it is strengthened, adapted and customised to maximise its value to future generations of researchers.
“The issue at the moment is that there are no co-ordinated ways of sustaining important research software once it comes to the end of its funding,” said Neil Chue Hong, Director of the SSI and OMII-UK. “Some software gets abandoned when the project ends. Some systems are maintained in pockets on very much a best-effort basis rather than on the basis of any longer term strategy.”
Mr Chue Hong and his collaborators will work with 30-40 groups across the UK, providing the expertise needed to create self-sustaining communities of researchers around important software. It is these communities that will ensure the software’s future by keeping it up-to-date and developing it to meet new requirements. A wide range of disciplines are set to benefit from the SSI’s work, with early projects encompassing climate change, nuclear fusion and medical imaging.
The SSI will collaborate with key researchers to identify and shape the software which is considered by its community to be the most important for research. Strategies for sustaining software will be optimised, and the best methods will be communicated to researchers through SSI consultancy. This work will help to stop the decay of software. “The creation of the SSI will ensure that important software is sustained so that it can continue to contribute towards high quality research” said Mr Chue Hong.
Further Information
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Dr Mark Parsons, EPCC Commercial Director.
+44 (0)131 650 5022
m.parsons [at] epcc.ed.ac.uk -
Neil Chue Hong, Director of SSI and OMII-UK,
+44 023 8059 8862,
N.ChueHong [at] omii.ac.uk
Dr Richard Blythe, member of the Institute for Condensed Matter and Complex Systems, has been recognised by the publisher of top physics journal "Physical Review Letters" as an "Outstanding Referee". This award, bestowed by the American Physical Society, is in appreciation of the care he has taken in reviewing papers submitted to APS journals to help ensure that those that are eventually published meet the highest scientific standards.
Dr Blythe is one of about 150 physicists from 35 countries selected to appear on the 2010 roll of honour for the quality, number and timeliness of reports on articles submitted to APS journals. He joins Prof Mike Cates FRS as the second Edinburgh physicist to receive this award.
Galaxies which are likely to be the most distant yet seen have been identified by two teams of UK astronomers using the recently updated Hubble Space Telescope (HST).
The UK teams, one led by Andrew Bunker and Stephen Wilkins at the University of Oxford and the other by Ross McLure and Jim Dunlop at the University of Edinburgh, analysed infrared images from the new Wide Field Camera 3 (WFC3) instrument on HST, installed during the most recent Space Shuttle servicing mission in May 2009.
Infrared light is light invisible to the human eye, with wavelengths about twice as long as visible light – beyond those of red light.
"The expansion of the Universe causes the light from very distant galaxies to appear redder, so having a new camera on Hubble which is very sensitive in the infrared means we can identify galaxies at much greater distances than was previously possible," said Stephen Wilkins, a postdoctoral researcher in astrophysics at Oxford University.
In a series of papers, to appear in the Monthly Notices of the Royal Astronomical Society, the UK teams present their analysis of the most sensitive images of the Universe yet taken in the infrared.
"The unique infrared sensitivity of Wide Field Camera 3 means that these are the best images yet for providing detailed information about the first galaxies as they formed in the early Universe", said Dr Ross McLure of the Institute for Astronomy in Edinburgh.
The new images from Hubble include the region of sky known as the Hubble Ultra Deep Field, which Bunker and colleagues were the first to analyse five years ago using visible light images taken with Hubble's Advanced Camera for Surveys (ACS).
"Hubble has now revisited the Ultra Deep Field which we first studied five years ago, taking infrared images which are more sensitive than anything obtained before. We can now look even further back in time, identifying galaxies when the Universe was only five per cent of its current age – within 1 billion years of the Big Bang," said Dr Daniel Stark, a postdoctoral researcher at the Institute of Astronomy in Cambridge who was involved in the work of both UK teams.
As well as identifying potentially the most distant objects yet, these new HST observations present an intriguing puzzle.
"We know the gas between galaxies in the Universe was ionised (where electrons are removed from their host atomic nuclei) early in the history of the cosmos, but the total light from these new galaxies may not be sufficient to achieve this," said Andrew Bunker, a researcher at the University of Oxford.
The researchers are now looking forward to seeing these intriguing objects more clearly in the years ahead.
"These new observations from HST are likely to be the most sensitive images Hubble will ever take, but the very distant galaxies we have now discovered will be studied in detail by Hubble's successor, the James Webb Space Telescope, which will be launched in 2014," commented Professor Jim Dunlop at the University of Edinburgh.
Further Information
The results are included in three separate papers in the journal Monthly Notices of the Royal Astronomical Society:
R.J. McLure, J.S. Dunlop, M. Cirasuolo, A.M. Koekemoer, E. Sabbi, D.P. Stark, T.A. Targett, R.S. Ellis, Accepted in the Monthly Notices of the Royal Astronomy Society.
Stephen M. Wilkins, Andrew J. Bunker, Richard S. Ellis, Daniel Stark, Elizabeth R. Stanway, Kuenley Chiu, Silvio Lorenzoni, Matt J. Jarvis, Accepted in the Monthly Notices of the Royal Astronomy Society.
Bunker, Andrew; Wilkins, Stephen; Ellis, Richard; Stark, Daniel; Lorenzoni, Silvio; Chiu, Kuenley; Lacy, Mark; Jarvis, Matt; Hickey, Samantha, Submitted to the Monthly Notices of the Royal Astronomy Society.