Neutron Interferometry Search for Strongly- Coupled Chameleons W.M. - - PowerPoint PPT Presentation

Neutron Interferometry Search for Strongly- Coupled Chameleons

W.M. Snow (Indiana University)

• M. Arif, M. Huber, D.L. Jacobson (NIST)
• D. Pushkin (Institute for Quantum Computing)

What is a neutron interferometer? Use for chameleon search: recent developments Thanks to G. Pignol, P. Brax

Perfect Crystal Neutron Interferometer

5 - 15 cm in length and 2 - 10 cm in width

Blades are typically 0.5 to 3 mm thick Dimensional tolerance: A few micro-meters Typical neutron transit is time 50-100 micro-sec

Contrast > 90% Phase Stability: 0.25o / day (best value) Monochromator: PG (002), Parallel double crystal geometry Beam Intensity: 2.10 5 n/cm2 .sec (at the interferometer) Vibration : < 10-7 g Stability: < 2 micro-meter (linear) < 1 micro-rad (rotation) Temperature: < 0.1o C Polarizer: Super mirror transmission type Polarization: > 98 %

Neutron Interferometer and Optics Facility (NIOF)

How a neutron interferometer works

Neutron b e a m Interferometer O

• b

e a m H-beam Phase shifter Sample Δε δ

Phase Shifter Angle (deg)

1000 500

• 2
• 1

2 1 Visibility Δφ

Outgoing wave front Incident wave front

• pt

V

Δφ Sample λ λ λ/ n λ λ λ D

Only neutron optics device which can directly measure the phase shift. Visibility > 90%

Sample Top View Neutron wave function coherently split by Bragg diffraction.

Δφ = − λΝbD

Setup for measuring scattering length of gas samples

1 cm n - beam phase shifter Si (111) vacuum cell cell out Temp B

3He detectors

Temp A cell in gas cell quartz alignment flag

Neutron interferometry

One of the beams traverses a chamber where the chameleon leads to a change of the phase Chameleon bubble

vacuum Chameleon bubble Brax-Pignol, to appear.

Interferometry vs GRANIT

Interferometry is competitive with current bouncing neutron experiments.

CHASE constraints on V (φ) = M4

Λ(1 + MΛ/φ)

Amol Upadhye Testing gravity in the laboratory 16

matter coupling βm photon coupling βγ torsion pendulum qBounce GRANIT helioscope gγ = βγ / MPl [GeV-1] 1e-10 1e-9 1e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2 1e-1 1 10000 1e+08 1e+12 1e+16 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 1e+16 1e+17 1e+18 neutrons (Grenoble) colliders (CLEO, precision EW) afterglow (GammeV-CHASE) matter coupling βm photon coupling βγ torsion pendulum qBounce GRANIT helioscope gγ = βγ / MPl [GeV-1] 1e-10 1e-9 1e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2 1e-1 1 10000 1e+08 1e+12 1e+16 1e+08 1e+09 1e+10 1e+11 1e+12 1e+13 1e+14 1e+15 1e+16 1e+17 1e+18 neutrons (Grenoble) colliders (CLEO, precision EW) afterglow (GammeV-CHASE)

Theory: AU, Steffen, Chou, PRD 86:035006(2012)[arXiv:1204.5476],

AU, Steffen, Weltman, PRD 81:015013(2010)[arXiv:0911.3906]

Experiment: Steffen, AU, Baumbaugh, Chou, Mazur, Tomlin, Weltman,

Wester, PRL 105:261803(2010)[arXiv:1010.0988]

Future neutron interferometry experiments for Chameleons

Repeat with dedicated experiment: straightforward, can get

~1 order of magnitude improvement Sensitivity can be improved significantly using neutron Fabry-Perot cavities and larger-area interferometers Technical developments also of interest for quantum computing research