A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » News
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

MINOS experiment sheds light on mystery of neutrino disappearance(Forwarded)



 
 
Thread Tools Display Modes
  #1  
Old March 31st 06, 05:44 AM posted to sci.space.news
external usenet poster
 
Posts: n/a
Default MINOS experiment sheds light on mystery of neutrino disappearance(Forwarded)

Public Affairs
Fermi National Accelerator Laboratory

Press contact:
Kurt Riesselmann, Fermilab Public Affairs
630-840-3351

Additional media contacts are listed at the end of the press release.

March 30, 2006

06-08

MINOS experiment sheds light on mystery of neutrino disappearance

BATAVIA, Illinois -- An international collaboration of scientists at the
Department of Energy's Fermi National Accelerator Laboratory announced
today (March 30, 2006) the first results of a new neutrino experiment.
Sending a high-intensity beam of muon neutrinos from the lab's site in
Batavia, Illinois, to a particle detector in Soudan, Minnesota, scientists
observed the disappearance of a significant fraction of these neutrinos.
The observation is consistent with an effect known as neutrino
oscillation, in which neutrinos change from one kind to another. The Main
Injector Neutrino Oscillation Search (MINOS) experiment found a value of
delta m2 = 0.0031 eV2, a quantity that plays a crucial role in neutrino
oscillations and hence the role of neutrinos in the evolution of the
universe.

"Only a year ago we launched the MINOS experiment," said Fermilab Director
Pier Oddone. "It is great to see that the experiment is already producing
important results, shedding new light on the mysteries of the neutrino."

Nature provides for three types of neutrinos, yet scientists know very
little about these "ghost particles," which can traverse the entire Earth
without interacting with matter. But the abundance of neutrinos in the
universe, produced by stars and nuclear processes, may explain how
galaxies formed and why antimatter has disappeared. Ultimately, these
elusive particles may explain the origin of the neutrons, protons and
electrons that make up all the matter in the world around us.

"Using a man-made beam of neutrinos, MINOS is a great tool to study the
properties of neutrinos in a laboratory-controlled environment," said
Stanford University professor Stan Wojcicki, spokesperson of the
experiment. "Our first result corroborates earlier observations of muon
neutrino disappearance, made by the Japanese Super-Kamiokande and K2K
experiments. Over the next few years, we will collect about fifteen times
more data, yielding more results with higher precision, paving the way to
better understanding this phenomenon. Our current results already rival
the Super-Kamiokande and K2K results in precision."

Neutrinos are hard to detect, and most of the neutrinos traveling the 450
miles from Fermilab to Soudan -- straight through the earth, no tunnel
needed -- leave no signal in the MINOS detector. If neutrinos had no mass,
the particles would not change as they traverse the Earth and the MINOS
detector in Soudan would have recorded 177 +/- 11 muon neutrinos. Instead,
the MINOS collaboration found only 92 muon neutrino events -- a clear
observation of muon neutrino disappearance and hence neutrino mass. The
deficit as a function of energy is consistent with the hypothesis of
neutrino oscilations and yields a value of delta m2, the square of the
mass difference between two different types of neutrinos, equal to 0.0031
eV2 +/- 0.0006 eV2 (statistical uncertainty) +/- 0.0001 eV2 (systematic
uncertainty). In this scenario, muon neutrinos can transform into electron
neutrinos or tau neutrinos, but alternative models -- such as neutrino
decay and extra dimensions -- are not yet excluded. It will take the
recording of much more data by the MINOS collaboration to test more
precisely the exact nature of the disappearance process.

Details of the current MINOS results will be presented by David Petyt of
the University of Minnesota at a special seminar at Fermilab on March 30,
2006, at 4:00 p.m. A day later, the MINOS collaboration will commemorate
MINOS co-spokesperson Doug Michael at a memorial service at Fermilab.
Michael, senior research associate at Caltech, died at age 45 on December
25, 2005, after a year-long battle with cancer.

The MINOS experiment includes about 150 scientists, engineers, technical
specialists and students from 32 institutions in 6 countries, including
Brazil, France, Greece, Russia, the United Kingdom and the United States.
The institutions include universities as well as national laboratories.
The U.S. Department of Energy provides the major share of the funding,
with additional funding from the U.S. National Science Foundation and from
the United Kingdom's Particle Physics and Astronomy Research Council.

"The MINOS experiment is a hugely important step in our quest to
understand neutrinos -- we have created neutrinos in the controlled
environment of an accelerator and watched how they behave over very long
distances," said Professor Keith Mason, CEO of PPARC. "This has told us
that they are not totally massless as was once thought, and opens the way
for a detailed study of their properties. UK scientists have taken key
roles in developing the experiment and in exploiting the data from it, the
results of which will shape the future of this branch of physics."

The Fermilab side of the MINOS experiment consists of a beam line in a
4,000-foot-long tunnel pointing from Fermilab to Soudan. The tunnel holds
the carbon target and beam focusing elements that generate the neutrinos
from protons accelerated by Fermilab's Main Injector accelerator. A
neutrino detector, the MINOS "near detector" located 350 feet below the
surface of the Fermilab site, measures the composition and intensity of
the neutrino beam as it leaves the lab. The Soudan side of the experiment
features a huge 6,000-ton particle detector that measures the properties
of the neutrinos after their 450-mile trip to northern Minnesota. The
cavern housing the detector is located half a mile underground in a former
iron mine.

The MINOS neutrino experiment follows up on the K2K long-baseline neutrino
experiment in Japan. From 1999-2001 and 2003-2004, the K2K experiment in
Japan sent neutrinos from an accelerator at the KEK laboratory to a
particle detector in Kamioka, a distance of about 150 miles. Compared to
K2K, the MINOS experiment uses a three times longer distance, and the
intensity and the energy of the MINOS neutrino beam are higher than the
K2K beam. These advantages have enabled the MINOS experiment to observe in
less than one year about three times more neutrinos than the K2K
experiment did in about four years.

"It is a great gift for me to hear this news," said Yoji Totsuka, former
spokesperson of the Super-Kamiokande experiment and now Director General
of KEK. "Neutrino oscillation was first established in 1998, with
cosmic-ray data taken by Super-Kamiokande. The phenomenon was then
corroborated by the K2K experiment with a neutrino beam from KEK. Now
MINOS gives firm results in a totally independent experiment. I really
congratulate their great effort to obtain the first result in such a short
time scale."

Fermi National Accelerator Laboratory, founded in 1967, is a Department of
Energy National Laboratory in Batavia, Illinois, about 40 miles west of
Chicago. Fermilab operates the world's highest-energy particle
accelerator, the Tevatron, on its 6,800-acre campus. About 2,300
physicists from universities and laboratories around the world conduct
physics experiments using Fermilab's accelerators to discover what the
universe is made of and how it works. Discoveries at Fermilab have
resulted in remarkable new insights into the nature of the world around
us. Fermilab is operated by Universities Research Association, Inc., a
consortium of 90 research universities, for the United States Department
of Energy, which owns the laboratory.

More information on the MINOS experiment is at
http://www-numi.fnal.gov

MINOS Institutions:

Argonne National Laboratory
University of Athens (Greece)
Benedictine University
Brookhaven National Laboratory
Cal Tech
University of Cambridge (U.K.)
College de France
Harvard University
Illinois Institute of Technology
Indiana University
ITEP-Moscow
Lebedev Physical Institute
Lawrence Livermore National Laboratory
University College, London (U.K.)
University of Minnesota
University of Minnesota-Duluth
Oxford University (U.K.)
University of Pittsburgh
IHEP-Protvino
Rutherford Appleton Lab (U.K.)
University of Sao Paulo (Brazil)
Soudan Underground Laboratory
University of South Carolina
Stanford University
University of Sussex (U.K.)
Texas A&M University
University of Texas at Austin
Tufts University
UNICAMP (Brazil)
Western Washington University
University of Wisconsin
College of William and Mary

Media contacts of other InterAction collaboration members available for
comment:

Argonne National Laboratory, U.S.A.:
Suraiya Farukhi
Communications and Public Affairs
+ 1 630 2525581

Brookhaven National Laboratory, U.S.A.:
Mona S. Rowe
Media and Communications Office
+ 1 631 3445056

KEK, Japan:
Dr. Youhei Morita
Public Relations Office
+ 81 29 879 6046

Particle Physics and Astronomy Research Council (PPARC), United Kingdom
Peter Barratt
Press and Media Centre
+ 44 1793 442025

For more information on the InterAction collaboration, visit
http://www.interactions.org

Photos are available at:
http://www.fnal.gov/pub/presspass/pr...es/NuMI_photos

A 12-minute streaming video on the MINOS experiment is at:
http://vmsstreamer1.fnal.gov/VMS_Sit...INOS/MINOS.htm

Two scientific graphics summarizing the results are at:
http://www.fnal.gov/pub/presspass/pr...sPictures.html


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Teleportation knowledge analizer of the internet matirx! IT's a Roger wilco History 4 July 8th 05 06:11 PM
Beyond Linear Cosmology and Hypnotic Theology Yoda Misc 0 June 30th 04 07:33 PM
Milky Way's Big Bang Giovanni Astronomy Misc 30 January 6th 04 11:32 AM
UFO Activities from Biblical Times (Long Text) Kazmer Ujvarosy UK Astronomy 3 December 25th 03 11:41 PM


All times are GMT +1. The time now is 10:06 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.