J-PARC Particle and Nuclear Physics Seminar

(J-PARC 素粒子原子核セミナー)


DATE: Dec. 2, 2019. 15:00-16:30

VENUE:
   Room 115, Tokai Building #1, Tokai-campus

TITLE: The Knowledge on Theta13: Implication from CP-Violation to Unitarity.


LANGUAGE: English

SPEAKER: Anatael Cabrera (CNRS-IN2P3)
    FLUO/LAL (Orsay) / LNCA (Chooz) Laboratories
    Double Chooz spokesperson


HOST: S. Mihara

CONTACT: S. Mihara, O. Morimatsu, K. Aoki (j-parc-pn-seminar-(AT)-ml.post.kek.jp)



Abstract:

The establishment of the "neutrino oscillation" phenomenon provides full explanation to both solar (driven by “Theta12") and atmospheric (driven by “Theta23”) anomalies and one critical prediction: a new neutrino oscillation (driven by “Theta13”). This new oscillation was expected to be small thanks mainly to the CHOOZ (based in France) experiment data. The observation of this new oscillation was first made within 2011-2012 by the experiments Daya Bay (based in China), Double Chooz (based in France) and RENO (based in South Korea). A non-zero Theta13 was of critical knowledge to the field since the mixing behind neutrino oscillations could imply a measurable manifestation of CP-violation (CPV) whose amplitude is proportional to the size of Theta13. This way the neutrino mixing matrix (PMNS) ― equivalent to the quark (CKM) ― allows for CPV manifestation upon mixing. CPV is key to our understanding of the Universe since we observed an effective dominance of matter, relative to anti-matter, upon the Big Bang. The cause behind is not understood. As of today, our ability to challenge the Standard Model of Particle Physics via neutrino oscillations is tightly linked to the overall precision we can characterise the the PMNS matrix composition and structure. A novel detection technique, called LiquidO ― born within Double Chooz ― has been proposed as possible technique allowing unprecedented further precision. In addition to the unknown CPV, one of the key goals is to experimentally test the unitarity of the PMNS matrix ― so far assumed. This scenario might have direct sensitivity to the possible discovery of new neutrino states or interactions, should any significant deviation be found. The exploration of this scenario ― under preliminary study ― will be described as well as the possible role of LiquidO technology might have within.