Jet Modification in the RHIC and LHC era Workshop
Wayne State University, August 20-23, 2012.
Wayne State University was host of an important scientific workshop in high energy nuclear physics gathering experts on “Jet Physics” from all around the world. This 3-½ day workshop, held at Science Hall on August 20-23, 2012, featured a review of the most important new experimental measurements and theoretical breakthroughs presented a week earlier at the International Quark Matter 2012 Conference held in Washington DC. The purpose of this targeted workshop was to assess whether a consistent picture of the jet quenching occurring in heavy ions collisions at ultra-relativistic energies has emerged.
More than forty experts of this subfield of heavy ion physics gathered from all around the world to discuss their results and views. The workshop was slow paced by design and featured intense and exciting discussions on the recent advances of the field. Slides from the various talks presented at the meeting are available online at the Workshop website (http://rhig.physics.wayne.edu/jetmeeting/).
A paper summarizing the conclusions of the workshop will be published by the organizers in the prestigious Comments in Nuclear and Particle Physics journal.
The workshop was organized by members of the Wayne State University heavy ion physics group consisting of Professors Thomas Cormier, Sean Gavin, Abhijit Majumder, Joern Putchke, Claude Pruneau, and Sergei Voloshin, in concert with the JET Collaboration. The organizers acknowledge generous financial support from the Wayne State heavy ion group, the Physics Department, the College of Sciences and Liberal Arts, the WSU Office of the Vice President Research, and the Jet Collaboration.
Mars is incontestably the most popular planet of our solar system. It is the planet most written about in both fiction and non-fiction books. It has been the subject or the basis for countless movies. And it is by far the most explored planet – beside earth of course. Why such a popularity?
Perhaps we will never know for sure. But one man can be credited for popularizing Mars and the notion that intelligent beings might have once inhabited the planet. His name is Percival Lowell.
Percival Lowell (1855-1916) was born of a rich Massachusetts family. He had a successful career as businessman and counsellor for the United State government. He travelled extensively in the far east and wrote about his observations of the Japanese society. He became enamored with Mars after reading the book by Camille Flammarion’s La planète Mars. The canals of Mars, as drawn by Italian astronomer Giovanni Schiaparelli, particularly attracted his interest.
His interest in Mars became so strong, he actually abandoned all prior activities and devoted the rest of his life towards the study of Astronomy. In 1894, he invested his fortune in the construction of an observatory in Flagstaff, Arizona. A pioneer of his time, he was the first to choose an observatory site based on its seeing qualities: at an altitude of 2100 meters, with few cloudy nights, and far from city lights, the Flagstaff site was an excellent site for astronomical observations.
Lowell spent the next fifteen years in the study of Mars. He observed Mars night after night to map out its surface. He made detailed and intricate drawings of structures he saw on Mars surface through the eyepiece of his telescope. He saw long canals crossing the surface of the planet. He imagined oases at the intersections of canals. He imagined beings building these canals and living off them. He wrote about his observations and his thoughts in three books: Mars (1895), Mars and Its Canals (1906), and Mars As the Abode of Life (1908). He was convinced these canals were the product of an advanced civilization struggling to survive and using canals to carry water from the icy polar caps to irrigate the Martian surface.
Astronomers of his time were at odds with both his observations and ideas. They did not see the same structures and canals, and they could not embrace his conclusions about the presence of a civilization on Mars. Lowell and his observatory were largely ostracized. But Lowell was a true enthusiast. He persisted in his work, and the popularization of his ideas. He is in fact credited for providing inspiration for H. G. Wells’ very influential book The War of the Worlds which logically inferred that inhabitants of a dying world might seek to invade Earth.
The matter of canals finally came to rest when the NASA Mariner 4 and Mariner 9 missions took the first close-up pictures of Mars in 1965 and 1972. Mars was then seen for what it really is, a rocky barren desolated planet, with no liquid water on its surface.
Yet, till this day, we humans continue to wonder. What if?
Given the preeminent polar caps, was there ever liquid on Mars’ surface? Pictures taken by recent missions in orbit around Mars suggest water flows aside mountains and the existence of large lakes in a distant past. What if?
Water is a precious ingredient for life as we know it. If there was once abundant liquid water on Mars, perhaps the conditions were ripe for the emergence of simple forms of life.
A hundred years after Lowell’s observations of the Martian’s surface, we now know for sure there are no canals on Mars. We also know the soil of Mars is laden with super oxides which readily destroy organic molecules. Yet, we still do not know if Mars ever hosted life. Perhaps even today are there hidden crevasses where liquid water flows. Maybe organic molecules, the basic ingredients of life, were once abundant on the surface. Perhaps one can find traces of such molecules in places where there was once abundant liquid water.
Tonight, with a little bit of luck, and an amazing load of sophisticated technology, the Mars Space Laboratory (MSL) will deliver the Curiosity Robotic Rover on the Martian surface. Curiosity will not the first rover to roam the planet. But it will be the largest and most sophisticated of them all. Weighing about a ton, it is the size of a jeep. Its delivery mechanism to the planet surface is by far the most sophisticated ever built. Curiosity is packed with sophisticated instruments designed to explore and poke the surface, study its chemistry and search for organic molecules. It will not be searching for life but for life’s ingredients. Was Mars once hospitable to life? Could it be colonized?
Percival Lowell was dead wrong about Martian canals. Yet he has inspired generations of astronomers and engineers in the pursuit of a dream: exploring Mars and ever pushing the boundaries of human knowledge. I bet that if Lowell was still alive today, he would be quite excited about the mission and would not go to sleep tonight before NASA receives Curiosity’s signal that it is safe and sound on the Martian surface.
The landing is scheduled at 10:31 PM PDT tonight (Aug 5, 2012). That’s 1:31 AM EDT, Aug 6 for us on the east coast.
For more information, visit: http://mars.jpl.nasa.gov/msl/participate/
Director of Wayne State Planetarium
At ~1:30 am EST on August 6th, Mars will have a new invader. The Mars Science Laboratory, or Curiosity, will begin its mission of analyzing Martian soil and rocks. According to the mission website, “the rover’s onboard laboratory will study rocks, soils, and the local geologic setting in order to detect chemical building blocks of life (e.g., forms of carbon) on Mars and will assess what the martian environment was like in the past.” Curiosity will be an adventurer compared to its previous rover associates. During its mission, which will last 687 days (or one Martian year), Curiosity will move 3 to 12 miles from its landing site. So if, during its mission, Curiosity travels 3 miles from its landing site it will be traveling at an average speed of .00018 miles per hour. If it travels 12 miles from its landing site, the average speed will be .00073 miles per hour. While blazing across the Martian surface, Curiosity will do 70 soil/rock samples. On board, Curiosity has 3 cameras, 4 spectrometers, 2 radiation detectors, and environmental and atmospheric sensors. Mars Science Laboratory indeed!
The landing process is understandably stressful (lots of time, planning, and money go into these missions) and the landing of Curiosity is being referred to as “Seven Minutes of Terror”. Missions to Mars have a bad habit of failing. Out of the 49 missions sent to Mars, 26 failed to launch, failed en route, or failed to land. The Curiosity landing is additionally stressful because it will be testing out new equipment. Here is an image of the landing process:
The small insert in lower left hand corner shows the end portion of the landing, which uses the sky crane! Previously, airbags were used to land the rovers safely on Mars, but Curiosity is too large. Once the parachute is detached, the sky crane will use rockets to decrease velocity (from 13,000 mph at entry to 1.7 mph at landing) and then will lower Curiosity to the surface, placing it on its wheels. Once Curiosity senses touchdown, the cables connecting it to the sky crane will be severed, the crane will fly away, and Curiosity will begin roving.
Curiosity is going to be doing some great science. The information gained by this mission, both scientific (understanding Mars’ past) and engineering (sky cranes!), will lead to even better rover mission in the future and will hopefully lay the ground work for manned missions to Mars! And if Curiosity does a really good job, it might be immortalized by xkcd like Spirit was:
For updates and more information, follow Curiosity on twitter!
Curiosity images credit: NASA/JPL-Caltech
Spirit comic credit: xkcd
Article written by WSU Physicist, Dr. Gavin Lawes
Although chemotherapy is one of the most potent tools developed for treating cancer, the toxicity of the chemotherapy drugs often leads to undesirable side effects, which can significantly impact a patient’s quality-of-life. In order to limit the toxic effects of these drugs, there is considerable interest in establishing techniques to selectively control their release in the body.
In a paper recently appearing on-line in the Journal of Materials Chemistry, researchers from Wayne State University and Kettering University present a study showing that the anti-cancer drug mitroxantrone can be released from a temperature responsive polymer by the application of an external magnetic field. The key to developing this response was to incorporate magnetic nanoparticles in the polymer, which produce a strong response to the magnetic field. While similar effects have been observed previously over long timescales, this particular system exhibited a large release of the anti-cancer drug in only a few minutes, potentially making this approach compatible with other treatment modalities. Although these results were obtained on samples measured in vitro, the research team is planning to pursue in vitro studies on animal models to test the applicability of this technique.
The senior researchers associated with this project are Gavin Lawes and Ratna Naik from the Department of Physics and Astronomy and David Oupicky from the College of Pharmacy and Health Sciences at Wayne State University, together with Prem Vaishnava from Kettering University. Graduate students Rajesh Regmi from Physics and Amit Wani from Pharmacy were primarily responsible for the laboratory work.
To view the abstract of this paper, go to: http://dx.doi.org/10.1039/c0jm00844c
Article written by WSU Physicist, Dr. Peter Hoffmann (16 Jul 2010)
In our cells, water is stuck between molecules with only a few nanometers to spare. Such ‘nanoconfined’ water has long been suspected of having unique properties. Now a team of physicists at Wayne State University has measured the mechanical properties of water squeezed down to just a few molecules, and found that water can be switched from being a liquid to a bouncy solid by small changes in external conditions. Using a new Atomic Force Microscope technique developed at Wayne State, the team probed the mechanical properties of confined water layers without disturbing them. Oscillating a tiny probe, immersed in the liquid, with amplitudes the size of a hydrogen atom (0.1 nm), they recorded the response as the probe squeezed the water at extremely low speeds. Once squeezed to a layer four molecules thick or less, the water behaved like honey: more viscous than in bulk, but still liquid. However, at squeeze speeds of 0.8 nm/s and above, water became elastic. This speed is so slow, it would take 12 years to move one foot, yet it is enough to change the behavior of water drastically.
The paper describing the research, “Dynamic Solidication in Nanoconned Water Films” has been accepted for publication in Physical Review Letters. A preprint is available at http://arxiv.org/abs/1006.3320 .
On March 30, the largest particle accelerator ever built, LHC (Large Hadron Collider), achieved record-collision energies when the combined energy of two proton beams reached 7 Tev (tera electron volts). This is only “half” our targeted energy and the goal is to eventually reach the LHC’s design energy of 14 Tev! The current plan is to use 7 Tev another year after which time the LHC will be shutdown for maintenance and upgrades. Operations will resume later next year with proton collisions, and possibly, lead-ion collisions.
The LHC was, in large part, built and designed to achieve one thing: establish the existence of a particle named the Higgs boson. Theory predicts the Higgs boson, and discovery of the Higgs, may help to explain the rise of mass in the universe. The LHC will also permit, with the acceleration of heavy nuclear beams of lead, the study of primordial matter, i.e. matter that existed for a period of one micro-second immediately after the Big Bang.
The LHC is the premier accelerator in the world. The level of complexity of its design is unprecedented. Perhaps no single project, including the Apollo missions that brought men on the Moon, have had the technological scope of the LHC. In short, the LHC is a technological wonder. Having our Wayne State faculty and students participate in this endeavor brings great prestige to our University and plenty of opportunities for our students to get advanced degrees in Science.
At Wayne State, there are two groups involved in research at the LHC:
The first group to join the LHC is the heavy ion physics (nuclear physics) group composed of Professors Rene Bellwied, Thomas Cormier, Sergei Voloshin, and myself. We have three post-doctoral researchers involved in this effort: Drs. Bourisov, Pavlinov, and Timmins as well as several graduate students. Our goal is to study the matter produced in lead-on-lead nuclear collisions at an energy of 5.5 TeV per nucleon.(This is expected to happen in 2011). These collisions are so violent that they produce nuggets of matter with temperatures reaching one trillion (i.e. a million million) degrees. That is about one million times the temperature in the Sun’s core. At such tremendous temperatures, matter as we know it, essentially dissolves into its elementary constituents called quarks and gluons. Quarks and gluons are the stuff that permeated the Universe right after the Big Bang for a duration of about one micro-second. The goal of our research is to study the properties of this matter, such as the density and temperature achieved, the matter’s equation of state, its viscosity, and many other fundamental properties. Our group joined the ALICE (A Large Ion Collider Experiment) collaboration over six years ago for this single purpose. Our contribution to the ALICEexperiment amounts to the construction of a large detector called EMCal in the basement of the Physics building. EMCal is an electromagnetic calorimeter designed to make precise measurements of the energy of particles produced in nuclear collisions. The ALICE experiment will provide wonderful opportunities for our students and post-doctoral researchers to become specialists in advanced detector and accelerator technologies, sophisticated data analysis techniques, as well as discover new physics.
The second group to join the LHC from our Department is the group of Professors Robert Harr, Paul Karchin, Mark Mattson, and Caroline Milstene. They also have postdocs and graduate students involved in their research. This group is involved in the experiment called CMS (Compact Muon Solenoid experiment). The primary goal of the CMS collaboration, i.e. the reason they designed and built this truly gigantic detector, is to search for the Higgs boson I mentioned above. The Higgs boson is required in the framework of the so called Standard Model of Particle Physics to explain why all particles, and consequently, everything around us – including ourselves – have mass. In the context of the standard model, essentially all known properties of matter and the four fundamental forces (gravity, electromagnetism, weak and strong nuclear forces) can be described and understood. The standard model is, in fact, extremely successful and permits predictions with astounding precision. But unfortunately, it is incomplete. Indeed, the standard model alone cannot explain why particles (e.g. electrons, protons, neutrons – the stuff we are made of) have a non-zero mass. Sound weird? Well, perhaps it is. However, a physicist by the name of Peter Higgs (in truth, there were a few others involved) discovered that a certain theoretical construction could explain mass. This theoreticalconstruction is called Higgs mechanism. It requires the existence of a new particle which physicists have now taken to call the Higgs boson. Discovering this new particle is one of the most important goals of the CMS experiment. CMS also has many other goals such as the search for particles predicted in the context of other theories, including particles of dark matter – the stuff that makes up 25% of matter in our Universe, but as of yet, nobody knows what it is. As for the ALICE experiment, Wayne State students involved in the CMS experiment will get to learn about new technologies, new physics, and hopefully discover the Higgs boson or the nature of Dark Matter.
While the physics studied at the LHC will not have immediate consequences in our daily lives, it will provide for new insight into the fundamental understanding of matter, fundamental forces, and in fact, the whole universe. March 30th was an important step toward accomplishing the goals and dreams of the LHC and more is yet to come!!!!
Who would have guessed, that the discovery of radioactivity and the element Polonium by Marie Curie at the end of the 19th century, would lead to nuclear power, nuclear magnetic resonance imaging (used every day to diagnose illnesses and save lives), and many other applications that enrich and better our lives. And today we can only speculate what futureresearch at the LHC will bring to mankind over the next 10, 20 or 50 years. Surely the past does not warrant the future, but I believe we can expect great things to come out of this research. At the very least, the LHC will bring a new understanding of the fundamental properties of our Universe, the stuff from which all matter emerged 13.7 billion years (+ or – 1%, as measured by the WMAP experiment) ago and evolved to create solar systems, planets, life and consciousness. Surely, that’s worth a great deal!!!