Tag Archives: standard model

Nobels explained

UD faculty members discuss 2013 prize-winners at annual symposium

Today’s chemists might work at a computer as often as in a laboratory, medical researchers studying conditions such as diabetes rely on understanding how cells carry and deposit materials within the body, and average investors in the market increasingly buy index funds to average out the short-term ups and downs of individual stocks.

The discoveries that led to these changes are among the work that was honored by this year’s Nobel Prizes. (more…)

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Nobel in Physics: A long time in the making

Nearly 50 years of experiments and billions of dollars in equipment followed the prediction of the Higgs mechanism by theoretical physicists in 1964. Ulrich Heintz and Meenakshi Narain, two of the particle physicists at Brown University who worked on experiments at Fermilab and at CERN, note that the successful search for the Higgs was caried on by thousands of researchers.

The Nobel Prize awarded today to Francois Englert and Peter Higgs was a long time in the making. The Higgs mechanism was invented almost 50 years ago, and ever since the standard model emerged as the explanation of everything in particle physics that we have observed so far. The search for the Higgs boson was a quest that heated up for particle physics experimenters with every new facility that came online. Some of us (Heintz, Narain) looked for it in their thesis experiment at the Cornell Electron Storage Ring in the 1980s. Then the search moved to European Organization for Nuclear Research (CERN) to the Large Electron Positron Collider, and back again to the Tevatron at Fermilab near Chicago, where we (Cutts, Heintz, Landsberg, Narain) were part of the discovery of the top quark in 1995 with the D-Zero experiment. (more…)

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Planck Mission Brings Universe into Sharp Focus

PASADENA, Calif. — The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe, revealing new information about its age, contents and origins.

Planck is a European Space Agency mission. NASA contributed mission-enabling technology for both of Planck’s science instruments, and U.S., European and Canadian scientists work together to analyze the Planck data. (more…)

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Forcing the Molecular Bond Issue

New and Improved Model of Molecular Bonding from Researchers at Berkeley Lab’s Molecular Foundry

Material properties and interactions are largely determined by the binding and unbinding of their constituent molecules, but the standard model used to interpret data on the formation and rupturing of molecular bonds suffers from inconsistencies. A collaboration of researchers led by a scientist at the U.S Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has developed a first-of-its-kind model for providing a comprehensive description of the way in which molecular bonds form and rupture. This model enables researchers to predict the “binding free energy” of a given molecular system, which is key to predicting how that molecule will interact with other molecules.

“Molecular binding and unbinding events are much simpler than we have been led to believe from the standard model over the past decade,” says Jim DeYoreo, a scientist with the Molecular Foundry, a DOE nanoscience center at Berkeley Lab who was one of the leaders of this research. “With our new model, we now have a clear means for measuring one of the most important parameters governing how materials and molecules bind together.” (more…)

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Greg Landsberg: Seeking the Higgs boson

Greg Landsberg, professor of physics at Brown, is the physics coordinator for the Compact Muon Solenoid (CMS) at CERN in Switzerland, part of a Brown team that includes professors David Cutts, Ultich Heintz, and Meenakshi Narain. The giant instrument’s primary mission is finding the Higgs boson, a particle whose existence would confirm the best guess physicists have made about why things have mass.

On July 4, Landsberg and his colleagues will reveal the latest results of their search. Anything could happen when Greg Landsberg and, including an announcement that the Higgs has been found or that it has been ruled out, sending theorists back to the whiteboard. Landsberg spoke by Skype with science news officer David Orenstein on June 26 as CERN physicists were preparing for their press conference. (more…)

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What’s Happening with the Higgs Boson

Berkeley Lab scientists, major contributors to the ATLAS experiment at the Large Hadron Collider, explain what the excitement is about

CERN, the European Organization for Nuclear Research headquartered in Geneva, Switzerland, will hold a seminar early in the morning on July 4 to announce the latest results from ATLAS and CMS, two major experiments at the Large Hadron Collider (LHC) that are searching for the Higgs boson. Both experimental teams are working down to the wire to finish analyzing their data, and to determine exactly what can be said about what they’ve found.

“We do not yet know what will be shown on July 4th,” says Ian Hinchliffe, a theoretical physicist in the Physics Division at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), who heads the Lab’s participation in the ATLAS experiment. “I have seen many conjectures on the blogs about what will be shown: these are idle speculation. Things are moving very fast this week, and it’s an exciting time at CERN. Many years of hard work are coming to fruition.” (more…)

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New Take on Impacts of Low Dose Radiation

*Berkeley Lab Researchers Find Evidence Suggesting Risk May Not Be Proportional to Dose at Low Dose Levels*

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation – the linear-no-threshold hypothesis or LNT – which holds that risk is directly proportional to dose at all levels of irradiation.

“Our data show that at lower doses of ionizing radiation, DNA repair mechanisms work much better than at higher doses,” says Mina Bissell, a world-renowned breast cancer researcher with Berkeley Lab’s Life Sciences Division. “This non-linear DNA damage response casts doubt on the general assumption that any amount of ionizing radiation is harmful and additive.” (more…)

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