Featured Research

from universities, journals, and other organizations

Indication of a new type of neutrino oscillation at the T2K experiment

Date:
June 16, 2011
Source:
Louisiana State University
Summary:
Scientists have been working for several years on an experiment in Japan called T2K, or Tokai to Kamioka Long Baseline Neutrino Oscillation Experiment, which studies the most elusive of fundamental subatomic particles -- the neutrino. The team announced they have an indication of a new type of neutrino transformation or oscillation from a muon neutrino to an electron neutrino.

LSU Department of Physics Professors Thomas Kutter and Martin Tzanov, and Professor Emeritus William Metcalf, along with graduate and undergraduate students, have been working for several years on an experiment in Japan called T2K, or Tokai to Kamioka Long Baseline Neutrino Oscillation Experiment, which studies the most elusive of fundamental subatomic particles -- the neutrino. The team announced they have an indication of a new type of neutrino transformation or oscillation from a muon neutrino to an electron neutrino.

In the T2K experiment in Japan, a beam of muon neutrinos -- one of the three types of neutrinos, which also include the electron and tau -- was produced in the Japan Proton

Accelerator Research Complex, or J-PARC, located in Tokai village, Ibaraki prefecture, on the east coast of Japan. The beam was aimed at the gigantic Super-Kamiokande underground detector in Kamioka, near the west coast of Japan, 295 km, or 185 miles away from Tokai. An analysis of the detected neutrino-induced events in the Super-Kamiokande detector indicated that a small number of muon neutrinos traveling from Tokai to Kamioka transformed themselves into electron neutrinos.

As part of the experiment, high energy protons were directed onto a carbon target, where their collisions produced charged particles called pions, which travelled through a helium-filled volume where they decayed to produce a beam of the elusive neutrinos. These neutrinos then flew about 200 meters through Earth to a sophisticated detector system capable of making detailed measurements of their energy, direction and type.

"It took the international collaboration about ten years to realize the project and bring it from first idea to first results," said Kutter, leader of the T2K project at LSU. "The entire LSU team is honored to be part of the collaboration and proud to contribute to the experiment. We expect many more results in the near future and look forward to the new research opportunities which are likely to arise from the tantalizing indication of this new neutrino oscillation."

LSU physicists have been part of a number of measurements over the last decade, which include Super Kamiokande, SNO, KamLAND that have shown that neutrinos possess the strange property of neutrino oscillations -- one flavor of neutrino can transform into another as it travels through space. This is significant because neutrinos were first predicted theoretically in 1930, first actually detected in 1956 and for 50 years were assumed to have zero mass. But neutrino oscillations require mass.

With mysterious linkage between the three types, neutrinos challenge the understanding of the fundamental forces and basic constituents of matter. They may be related to the mystery of why there is more matter than anti-matter in the universe, and are the focus of intense study worldwide.

Precision measurements of neutrino oscillations can be made using artificial neutrino beams. This was pioneered in Japan by the K2K neutrino experiment in which neutrinos were produced at the KEK accelerator laboratory near Tokyo and were detected using the Super-Kamiokande neutrino detector, a 50,000 ton tank of ultra-pure water located more than half a mile underground in a laboratory 183 miles away near Toyama.

T2K is a more powerful and sophisticated version of the K2K experiment, with a more intense neutrino beam derived from the newly-built main ring synchrotron at the J-PARC accelerator laboratory. The beam was built by physicists from KEK in cooperation with other Japanese institutions and with assistance from American, Canadian, UK and French T2K institutes. The beam is aimed once again at Super-Kamiokande, which has been upgraded for this experiment with new electronics and software.

Before the neutrinos leave the J-PARC facility, their properties are determined by a sophisticated "near" detector, partly based on a huge magnet donated from the CERN accelerator laboratory in Geneva. The CERN magnet was earlier used for the UA1 experiment, which won the Nobel Prize for the discovery of the W and Z bosons which are the basis of neutrino interactions. The LSU team was responsible for building major components of the "near" detector, which provided an important ingredient to the oscillation analysis.

During the next several years, the search will be improved, with the hope that the three-mode oscillation will allow a comparison of the oscillations of neutrinos and anti-neutrinos, probing the asymmetry between matter and anti-matter in the universe.


Story Source:

The above story is based on materials provided by Louisiana State University. Note: Materials may be edited for content and length.


Journal References:

  1. The TK Collaboration. Indication of Electron Neutrino Appearance from an Accelerator-produced O -axis Muon Neutrino Beam. Physical Review Letters, 2011; (submitted)
  2. The T2K Collaboration. The T2K Experiment. arXiv.org, 2011; [link]

Cite This Page:

Louisiana State University. "Indication of a new type of neutrino oscillation at the T2K experiment." ScienceDaily. ScienceDaily, 16 June 2011. <www.sciencedaily.com/releases/2011/06/110616193858.htm>.
Louisiana State University. (2011, June 16). Indication of a new type of neutrino oscillation at the T2K experiment. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/06/110616193858.htm
Louisiana State University. "Indication of a new type of neutrino oscillation at the T2K experiment." ScienceDaily. www.sciencedaily.com/releases/2011/06/110616193858.htm (accessed August 1, 2014).

Share This




More Matter & Energy News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) — Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) — A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) — Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins