Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fermilab experiments narrow allowed mass range for Higgs boson

27.07.2010
New constraints on the elusive Higgs particle are more stringent than ever before. Scientists of the CDF and DZero collider experiments at the U.S. Department of Energy’s Fermilab revealed their latest Higgs search results today (July 26) at the International Conference on High Energy Physics, held in Paris from July 22-28. Their results rule out a significant fraction of the allowed mass range established by earlier experiments.

The Fermilab experiments now exclude a Higgs particle with a mass between 158 and 175 GeV/c2. Searches by previous experiments and constraints due to the Standard Model of Particles and Forces indicate that the Higgs particle should have a mass between 114 and 185 GeV/c2. (For comparison: 100 GeV/c2 is equivalent to 107 times the mass of a proton.) The new Fermilab result rules out about a quarter of the expected Higgs mass range.

“Fermilab has pushed the productivity of the Tevatron collider to new heights,” said Dennis Kovar, DOE Associate Director of Science for High Energy Physics. “Thanks to the extraordinary performance of Fermilab’s Tevatron collider, CDF and DZero collaborators from around the world are producing exciting results and are making immense progress on the search for the Higgs particle.”

At the ICHEP conference, CDF and DZero scientists are giving more than 40 talks on searches for exotic particles and dark matter candidates, discoveries of new decay channels of known particles and precision measurements of numerous particle properties. Together, the two collaborations present about 150 results.

The Higgs particle is the last not-yet-observed piece of the theoretical framework known as the Standard Model of Particles and Forces. According to the Standard Model, the Higgs boson explains why some particles have mass and others do not.

“We are close to completely ruling out a Higgs boson with a large mass,” said DZero co-spokesperson Dmitri Denisov, one of 500 scientists from 19 countries working on the DZero experiment. “Three years ago, we would not have thought that this would be possible. With more data coming in, our experiments are beginning to be sensitive to a low-mass Higgs boson.”

Robert Roser, co-spokesperson for the 550 physicists from 13 countries of the CDF collaboration, also credited the great work of the CDF and DZero analysis groups for the stringent Higgs exclusion results.

“The new Higgs search results benefited from the wealth of Tevatron collision data and the smart search algorithms developed by lots of bright people, including hundreds of graduate students,” Roser said. “The CDF and DZero analysis groups have gained a better understanding of collisions that can mimic a Higgs signal; improved the sensitivity of their detectors to particle signals; and included new Higgs decay channels in the overall analysis.”

To obtain the latest Higgs search result, the CDF and DZero analysis groups separately sifted through more than 500,000 billion proton-antiproton collisions that the Tevatron has delivered to each experiment since 2001. After the two groups obtained their independent Higgs search results, they combined their results to produce the joint exclusion limits.

“Our latest result is based on about twice as much data as a year and a half ago,” said DZero co-spokesperson Stefan Söldner-Rembold, of the University of Manchester. “As we continue to collect and analyze data, the Tevatron experiments will either exclude the Standard Model Higgs boson in the entire allowed mass range or see first hints of its existence.”

The observation of the Higgs particle is also one of the goals of the Large Hadron Collider experiments at the European laboratory CERN, which record proton-proton collisions that have 3.5 times the energy of Tevatron collisions. But for rare subatomic processes such as the production of a Higgs particle with a low mass, extra energy is less important than a large number of collisions produced.

“With the Tevatron cranking out more and more collisions, we have a good chance of catching a glimpse of the Higgs boson,” said CDF co-spokesperson Giovanni Punzi, of the University of Pisa and the National Institute of Nuclear Physics (INFN) in Italy. “It will be fascinating to see what Mother Nature has in her cards for us. We might find out that the Higgs properties are different from what we expect, revealing new insights into the origin of matter.”

Kurt Riesselmann | EurekAlert!
Further information:
http://www.fnal.gov

Further reports about: CDF DZero Fermilab GeV/c2 Higgs boson Higgs particle Large Hadron Collider Physic Tevatron

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>