T2K makes the Top Ten !
Physics World, the magazine of the Institute of Physics in the U.K., has included one of T2K’s results in its top ten scientific breakthroughs of 2011. T2K was included for finding the first indications for oscillations from muon neutrinos to electron neutrinos as described here. Six electron-neutrino events were seen in Super Kamiokande (T2K’s far detector), whereas only 1.5 would have been expected if there were no such oscillations. This result is an indication that muon neutrinos may oscillate to electrons neutrinos, but is not yet conclusive. T2K will attempt to confirm that these oscillations do occur by taking more data during 2012.
First test run of beams in J-PARC proton accelerator since earthquake
The proton accelerator at J-PARC (Japan Proton Accelerator Research Complex) in Tokai, Japan was affected by the earthquake of March 2011, though not by the tsunami. The damage sustained during the earthquake has now been mostly repaired, and the first test run of proton beams since the earthquake was successfully conducted in the LINAC (linear accelerator) on 9th December 2011. This was an extremely important milestone for the J-PARC accelerator and the T2K experiment. For further information, see http://j-parc.jp/en/topics/2011/en.html#Test_operation1209 .
Status of recovery work since the earthquake
After several months of recovery work since the earthquake, we succeeded in taking the proton beam from Dec.24,2011 as scheduled and successfully confirmed the functionality of the beam line components and the reproducibility of neutrino production.
However, on Dec.22, during the final operation test, switching devices called IGBTs in the horn power supply were broken. The cause is being identified in detail.
Therefore, the beam operation during December was made without horn operation.
We are working to recover the power supply and aim to restart the full experiment with the horn operation from March.
During January we plan to take beam with the horn off in order to make beam studies for high power operation and various systematic studies using near neutrino detectors.
T2K statement on the OPERA anomaly (neutrinos travel faster than light)
Based on our initial assessment of our capability, at the moment T2K cannot make any definitive statement to verify the OPERA measurement of the speed of the neutrino (the OPERA anomaly).
We will assess a possibility to improve our experimental sensitivity for a measurement to cross-check the OPERA anomaly in the future. Such a measurement with an improved system, however, could take a while to achieve.
