Heeger theta13, May 8 2003

A Neutrino Project at Diablo Canyon

Heeger theta13, May 8 2003

Underground Neutrino Detectors and Locations

Solar (SNO)

Reactor (KamLAND)

Accelerator (LSND)

Atmospheric (Super-K)

at national laboratories

in an old mine in Japan

in a nickel mine in Canada

Heeger theta13, May 8 2003

Sudbury Neutrino Observatory

• 1,000 t ultrapure heavy water in clean room environment

• 6800 ft underground

• 9500 photomultipliers

Heeger theta13, May 8 2003

KamLAND

Balloon

Steel Sphere

Calibration Deck

• 1,000 t of liquid scintillator

• Flammable and toxic

Heeger theta13, May 8 2003

Diablo Canyon Site

Heeger theta13, May 8 2003

Location

Diablo Canyon powerplant in San Luis Obispo county

Heeger theta13, May 8 2003

Diablo Canyon

From South East

From North East

Heeger theta13, May 8 2003

Diablo Canyon

From South East

Heeger theta13, May 8 2003

• Powerful: Two reactors (3.1+3.1 GW Eth) on the California coast• Overburden: Horizontal tunnel could give 800 mwe shielding!• Infrastructure: Roads built for heavy machinery. Controlled access. • Scientific Collaborations: existing collaborations between PG&E and marine scientists, biologists, and geologists with site access.

Diablo Canyon Site

1500 ft

600 ft

Heeger theta13, May 8 2003

Possible Locations for Near Detector

• Space constrained by hills and infrastructure• Best overburden to the North East of the powerplant

Distances of near detector: > 0.4 km

Heeger theta13, May 8 2003

Possible Locations for Near Detector

• Space constrained by hills and infrastructure• Best overburden to the North East of the powerplant

Distances of near detector: > 0.4 km

Heeger theta13, May 8 2003

Far Detector

Possible location

Crowbar Canyon Parallel to Diablo Canyon

Existing road access

Possibility for good overburden

Tunnels in radial direction

from reactor

Heeger theta13, May 8 2003

~ 600-800 mwe

FAR II: distance 2-2.5 km

FAR I: distance 1.5-2 km

NEAR: distance~ 0.5 km

tunnels

~ 400 mwe

A Reactor Neutrino Oscillation Experiment with Fixed Detectors or Variable Baseline

Excavation required

Heeger theta13, May 8 2003

Possible Movable Detector for Diablo Canyon

• Modular, movable liquid scintillator detector

• active muon veto

• Vfiducial ~ 80-100 t

Heeger theta13, May 8 2003

Diablo Canyon Project

Some Detector Issues

Excavation required

Hazardous materials

Some Site Issues

Environmental impact (statepark and conservation area nearby)

Indian burial grounds on PG&E site

Status

Negotiations with PG&E are underway

What are the issues? What is unique to Diablo Canyon?

What is the process for environmental impact studies?

Heeger theta13, May 8 2003

Heeger theta13, May 8 2003

Sensitivity and Complementarity of 13 Experiments

Reactor 13 experiment

No matter effect

Correlations are small, no degeneracies

Independent of solar osc. parameters 12,m212

sin2213 sensitivity limit

m213 dependence

Tru

e va

lue

of

m2

31

(eV

2)

Sensitivity to sin2213

10-110-3 10-2

Ref: Huber et al., hep-ph/0303232

13 sensitivity of reactor experiments comparable to JHF-SK

Heeger theta13, May 8 2003

Reactor Neutrino Measurement of 13

Detector 1

Detector 2

Searching for Subdominant Oscillations in e ,

to measure the last yet undetermined

neutrino mixing angle, 13

P νe → νe( )≈sin4θ13+cos4θ13 1−sin2(2θ12) ⋅sin2 Δm122 L

4Eν

⎛

⎝ ⎜

⎞

⎠ ⎟

⎧ ⎨ ⎩

⎫ ⎬ ⎭

13 oscillation signature

Heeger theta13, May 8 2003

13 and CP Violation

?

Neutrino Mixing Matrix

13 is key parameter for oscillation phenomenology since 12 and 23 are both large

13 determines whether CP violation is accessible

CP proportional to 13

13 is key parameter for oscillation phenomenology since 12 and 23 are both large

13 determines whether CP violation is accessible

CP proportional to 13

€

U =

Ue1 Ue2 Ue3

Uμ1 Uμ 2 U μ 3

Uτ1 Uτ 2 Uτ 3

⎛

⎝

⎜ ⎜ ⎜

⎞

⎠

⎟ ⎟ ⎟

=

cosθ12 sinθ12 0

−sinθ12 cosθ12 0

0 0 1

⎛

⎝

⎜ ⎜ ⎜

⎞

⎠

⎟ ⎟ ⎟×

cosθ13 0 e−iδ CP sinθ13

0 1 0

−e iδCP sinθ13 0 cosθ13

⎛

⎝

⎜ ⎜ ⎜

⎞

⎠

⎟ ⎟ ⎟×

1 0 0

0 cosθ23 sinθ23

0 −sinθ23 cosθ23

⎛

⎝

⎜ ⎜ ⎜

⎞

⎠

⎟ ⎟ ⎟×

1 0 0

0 e iα / 2 0

0 0 e iα / 2+iβ

⎛

⎝

⎜ ⎜ ⎜

⎞

⎠

⎟ ⎟ ⎟

atmospheric present

solar present

reactor and accelerator future

0 experimentsfuture

Heeger theta13, May 8 2003

Movable detectors?

Does a site like this exist?

Site Requirements

1. A reactor, or multiple-reactor complex

2. Sites for 2-3 detectors at distances of 1-5 km from reactor

3. Detector overburden for reduction of cosmic ray background• Man-made overburden or• Underground site in a mine (good overburden)• Underground site in tunnels (movable detectors)

A 13 Reactor Experiment in the US ?