Subscribe free to our newsletters via your
. 24/7 Space News .




TIME AND SPACE
One Step Closer To Finding The Higgs Boson
by Staff Writers
Bloomington IN (SPX) Mar 17, 2009


The DZero detector, pictured above, records particles emerging from high-energy proton-antiproton collisions produced by the Tevatron. Tracing the particles back to the center of the collision, Indiana University physicists and other researchers from around the world were able to search for the tiny fraction of collisions that might have produced single top quarks. Photo Credit: Fermilab.

Six Indiana University physicists collaborating with researchers from around the world have helped move mankind one step closer to finding the Higgs boson, the still unidentified particle predicted by the Standard Model to be the origin of mass for all elementary particles.

Former graduate student Leah Welty-Rieger, post-doctoral fellow Nirmalya Parua, research scientist Daria Zieminska, assistant professor Sabine Lammers, associate professor Harold Evans and Physics Department Chair Rick Van Kooten, with scientists from 80 other institutions working as part of the DZero collaboration, say they have observed particle collisions that produce single top quarks. The work was submitted March 4 to Physical Review Letters for publication.

"Discovering single top quark production presents challenges similar to the Higgs boson search in the need to extract an extremely small signal from a very large background," Van Kooten explained. "And the techniques mastered for single top quark discovery are now being used for the Higgs boson search."

"In particular, Lammers works on an analysis with essentially the same background to this single top quark channel and tunes simulations to get good agreement between data and background simulation," he added. "Her analysis will then be extended for application to data from the Large Hadron Collider to search for the Higgs boson using the ATLAS detector."

The work was conducted by scientists in two collaborative teams at the Department of Energy's Fermi National Accelerator near Chicago using the Tevatron, the world's highest-energy particle collider now operating, to send protons through a magnetic course and then smash them into one another at high energies.

Previously, top quarks had only been observed in pairs when produced by the strong nuclear interaction between tiny elementary particles.

The production of single top quarks, which involves the weak nuclear force and is harder to identify experimentally, is observed only once in every 20 billion proton-antiproton collisions. Making identification trickier is the fact that the signal of these rare occurrences is easily mimicked by other background processes that occur at much higher rates.

"Observation of the single top quark production is an important milestone for the Tevatron program," said Dennis Kovar, Associate Director of the Office of Science for High Energy Physics at the U.S. Department of Energy. "Furthermore, the highly sensitive and successful analysis is an important step in the search for the Higgs."

To make the single-top discovery, physicists of the Collider Detector at Fermilab and DZero collaborations spent years combing independently through the results of proton-antiproton collisions. Each team identified several thousand collisions that looked the way experimenters expect single top events to appear.

Sophisticated statistical analysis and detailed background modeling showed that a few hundred collision events produced the real thing.

The two collaborations earlier had reported preliminary results on the search for the single top. Since then, experimenters have more than doubled the amount of data analyzed, and sharpened selection and analysis techniques, making the discovery possible.

For each experiment, the probability that background events have faked the signal is now only one in nearly four million, allowing both collaborations to claim a bona fide discovery that paves the way to more discoveries.

Davis, who was the physical coordinator for the experiments that led to the original announcement in 2007 of the evidence for production of single top quarks and their first direct measurement, said that while Tevatron now stands a good chance of beating Europe's still-idle Large Hadron Collider to measuring the Higgs boson, the facility will still be needed to confirm the particle's properties.

LHC, located at CERN, the European Organization for Nuclear Research near Geneva, is expected to be back on line in late 2009.

"With the delays at LHC the chance that Fermilab could identify the Higgs boson first becomes greater," he said. "But to pin it down, to confirm the properties that Tevatron might observe, we will need LHC."

.


Related Links
Indiana University
Understanding Time and Space






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








TIME AND SPACE
Cluster's Insight Into Space Turbulence
Paris, France (ESA) Mar 27, 2009
The four satellites of ESA's Cluster mission have revealed, for the first time, how turbulence develops in space just outside the Earth's magnetic environment. This result improves the understanding of turbulence, a key physical process by which energy throughout the Universe is transported from large scales at which it is input, to all scales where it is dissipated. Turbulence is a ... read more


TIME AND SPACE
Third Meeting Of ISECG

China To Land Probe On Moon At Latest In 2013

Help To Define A Lunar Lander

What Is The Story Behind The Dark Side Of The Moon

TIME AND SPACE
Opportunity's New Software Working Fine - sol 1811-1817

Spirit Makes Slight Progress on New Route - sol 1831-1837

HiRISE Camera Captures Subtle Colors of Mars' Tiny Moon Deimos

Mars Odyssey Reboots Successfully

TIME AND SPACE
Forum To Explore Why We Should Go To Moon And Mars

Iranian President Declares His Country A Space And Nuclear Power

Ares Super-Chute

North Korea Joins Space Treaty And Convention

TIME AND SPACE
China Able To Send Man To Moon Around 2020

China To Launch 15 To 16 Satellites In 2009

Macao Donates 14 Million Yuan To Mainland Space Program

Scholarships Established For Aerospace Research

TIME AND SPACE
ISS Partners Rule Out Turning Life On Orbiter Into Reality Show

Station Spacewalkers Install Experiments And Probe

US, Russian spacemen take spacewalk: mission control

Space junk sparks crew scare on ISS

TIME AND SPACE
Four Launches From Esrange Space Center In Four Days

Herschel And Planck Launch Postponed

LRO Launch Update

45th Space Wing Set To Launch MilComms Satellite

TIME AND SPACE
Starlight, Star Bright

Keck Teaming Up With Kepler To Find Other Earths

Kepler Mission Rockets To Space In Search Of Other Earths

Texas Astronomer To Aid Search For Earth-like Planets

TIME AND SPACE
NEWSKY Communication Network Presented For The First Time

CombiMatrix Receives New Contract From NASA

Engineers Crack Ceramics Production Obstacle

SES To Move ASTRA 2C Satellite To 31.5 Degrees East




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement