"Reactor θ13: the Ultimate Measurement?"
講演者 ： Dr. Anatael Cabrera
（Dr Staff / Permanent Researcher of CNRS/IN2P3, APC Laboratory CNRS/IN2P3 Universite Paris）
日時 ： 2012/12/5（Wed.）16：30 〜 18：00
場所 ： 素粒子物理国際研究センター会議室（理学部１号館１０階１０１７号室）
A new neutrino oscillation mode has been observed in around 2011-2012 by
reactor neutrino experiments. This oscillation mode was expected under
the 3 neutrino oscillations model characterised by the PMNS mixing
leptonic flavour matrix , where the so-called "solar" and "atmospheric"
modes are modulated by the the mixing angles θ12 and θ23, respectively.
The new oscillation is modulated by θ13. Amazing progress has been
obtained thanks to the precise contributions of the reactor neutrino
experiments (alphabetically ordered: Daya Bay, Double Chooz, RENO).
Consistent evidence towards θ13 oscillations had been obtained from
electron neutrino appearance by T2K and MINOS experiments and the
tension between combined Solar experiments and KamLAND results. sin^2(2θ
13) is now known to be around 0.1 -as large as the CHOOZ limit allowed
it to be- while the current precision is around 15%, dominated by the
Daya Bay measurements. In this seminar, the global reactor θ13
measurement situation will be reviewed. The final best reactor θ13
measurement (full statistics envisaged by end of ~2015) will dominate
our knowledge on this parameter for a long time. No other technique,
with current technologies, is expected to offer cleaner input on the
value of θ13. We will cover discussion on the experimental progress to
ensure a precise but also the most accurate measurement of θ13. The
impact of the accuracy on the knowledge of θ13 will be highlighted
within the phenomenological context of a coherent 3-neutrino oscillation
講演資料 ： [ ]