Neutrino mass hierarchy,status of the flavor problem(discussion session)

Invisibles 2013July 15-19, 2013

Durham, United Kingdom

Walter Winter

Universität Würzburg

2

Mass hierarchy?

There is a new kidin town!

3

Mass hierarchy: PINGU?W. Winter,

arXiv:1305.5539, PRD(~20 string version, full three flavor,

full parameter degeneracy, GLoBES)

PINGU official, arXiv:1306.5846

(similar sensitivity obtainedby Blennow, Schwetz, 1306.3988;

Choubey confirms …)

4

Mass hierarchy: Summary?

Option Timescale (3)

Addl. cost Risk/challenge

Existing experiments

>> 2025 Operation Exposure

PINGU/ORCA

~ 2020-2022

Low+

predictable

Detector perf., 23

LBNE > 2022 High CP

Daya Bay-II ~ 2025? Moderate Energy resolution

Supernova 2013-2113?

None Model; no warranty

5

Impact of “newcomers“?

Elisa Resconi: "How would the beam strategy change if the mass hierarchy came from PINGU/ORCA?"

Looked into that, in particular, in LBNE reconfiguration report (T2HK: no effect)http://www.fnal.gov/directorate/lbne_reconfiguration/files/LBNE-Reconfiguration-Steering-Committee-Report-August2012.pdf

Conclusions (if MH dropped): In phase I, Fermilab Soudan (underground) clearly

preferred (“broadest phase I physics program“, astrophysics)

But: no upgrade beyond 1.1 MW Preferance of FNAL-Homestake unchanged!?

6

A theorist‘s dream?

Beam to South Pole (PINGU) L ~ 11800 km from FNAL,

CERN, JHF etc to South Pole

Flux x param. resonance x Megaton detector = Mass hierarchy with short pipe beam

Core

W. W

inter,

arXiv:1305.5539, P

RD

7

13: impact on theory of flavor?

Structure:A4 TBM, S4, …

Anarchy:Random

draw of matrix?

13 very small very large

Different flavor symmetry?

Fixes:Corrections?CL sector?

RGR running?

Some structure + randomness:

Froggatt-Nielsen?

vs.

Quark-leptoncomplementarity:

13 ~ C?

Tri-bimaximal mixings:Dead or alive?

What are the minimalrequirements for a

successful state-of-the-artflavor model?

8

CP phase Measurement requires (most probably) new long-baseline

experiment How much precision does one actually need?

Consequences of measurement for … Leptogenesis? Flavor models? Lepton flavor violation, other observables? Sum rules: charged lepton vs neutrino mixing matrix?

There seems to be increasing awareness in theory/model community (13 known reduces the d.o.f. …) to describe origin: “Geometric“? Random O(1) complex Yukawa? From SSB? …

However: my impression in many models: phases just “mess up things“! Transition of awareness needed?