Vacuum birefringence and dichroism signals in the PVLAS experimentUgo Gastaldi, INFN-LNL Legnaro on behalf of the PVLAS Collaboration

ICHEP’06 Moscow 27- 07- 2006

• IntroductionDYCHROISM PRL96,110406(2006) vacuum B induced rotationBIREFRINGENCE QCD-06 and ICHEP-06 vacuum B induced ellipticity

• Ellipticity measurementsPHASE and AMPLITUDE calibrations with gasesVACUUM Measurements

• OutcomeVACUUM BIREFRINGENCE has OPPOSITE SIGN of He, Ne,… Birefringencem=0.8-1.8meV M=1-7 10+5GeV 0++ boson responsible???

• ProspectsCONFIRM LIGHT BOSON INTERPRETATION by REGENERATION measurementsREDUCE NOISE INCREASE DUTY CYCLEPRECISE MEASUREMENTS OF m by changing magnet length

PVLAS Collaboration (Trieste, Pisa, Legnaro, Frascati, Ferrara): from left to right E.Polacco, E.Milotti, E.Zavattini, R.Cimino, G.Cantatore, S.Marigo, U.Gastaldi, G.Petrucci and A.Zanetti standing

G.Zavattini, M.Karuza, G.Ruoso, G.DiDomenico and F.DellaValle seated (S.Carusotto, G.Raiteri and P.Temnikov are not in the picture)

PVLAS EXPERIMENT

• SITE• MAGNET• ELLIPSOMETER• Fabry-Perot CAVITY• MODULATIONS• FINESSE • ELLIPTICITY• CONTROLS• OPERATIONS

PVLAS site:

two opposite walls of the square pit support the concrete beam (with turntable and

cryostat on top)

pit floor and pit walls rest on separate foundations

PVLAS top optical bench resting on 4 granite pillars thatsurround the (rotating) cryostat (with superconducting magnet inside)

Ne run1049_1

1.0E-6

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

1.0E-7

Frequency (Hz)507.568504.502 505.000 505.500 506.000 506.500 507.000

0.00E+0

2.00E-6

4.00E-6

6.00E-6

8.00E-6

1.00E-5

1.27E-590

180

270

N2 run1110_0 0.00E+0

2.00E-6

4.00E-6

6.00E-6

8.00E-69.33E-6

90

180

2701.0E-9

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

Frequency (Hz)507.537504.598 505.000 505.500 506.000 506.500 507.000

He run1161_00.00E+02.50E-65.00E-67.50E-61.00E-51.25E-51.50E-5

1.86E-590

180

270

1.0E-7

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

Frequency (Hz)507.474504.598 505.000 505.500 506.000 506.500 507.000

Ne run1187_0

1.0E-7

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

Frequency (Hz)507.599504.502 505.000 505.500 506.000 506.500 507.000

0.00E+0

5.00E-6

1.00E-5

1.50E-5

2.00E-5

2.67E-590

180

270

Run 807_1VacuumIR light

1.0E-6

1.0E-19

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

1.0E-7

Frequency (Hz)507.509504.514 505.000 505.500 506.000 506.500 507.000

0.00E+05.00E-81.00E-71.50E-72.00E-72.50E-73.00E-7

3.65E-790

180

270

run945_5VVacuumIR light

1.0E-5

1.0E-191.0E-18

1.0E-171.0E-161.0E-151.0E-14

1.0E-131.0E-121.0E-11

1.0E-101.0E-91.0E-81.0E-7

1.0E-6

Frequency (Hz)507.338504.647 505.000 505.500 506.000 506.500 507.000

0.00E+0

1.00E-7

2.00E-7

3.00E-7

4.00E-74.64E-7

90

180

270

Run 1101_0Vacuum

Green light

1.0E-7

1.0E-19

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

Frequency (Hz)507.504504.534 505.000 505.500 506.000 506.500 507.000

0.00E+01.00E-72.00E-73.00E-74.00E-75.00E-76.00E-7

7.98E-790

180

270

run1137_0Vacuum

Green light

1.0E-6

1.0E-19

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

1.0E-7

Frequency (Hz)507.441504.565 505.000 505.500 506.000 506.500 507.000

0.00E+02.00E-74.00E-76.00E-78.00E-71.00E-6

1.35E-690

180

270

Run 1166_0Vacuum

Green light

1.0E-6

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

1.0E-7

Frequency (Hz)507.535504.534 505.000 505.500 506.000 506.500 507.000

0.00E+02.00E-74.00E-76.00E-78.00E-71.00E-61.20E-61.40E-61.62E-6

90

180

270

1.0E-6

1.0E-19

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

1.0E-8

1.0E-7

Frequency (Hz)506.872505.197 505.400 505.600 505.800 506.000 506.200 506.400 506.600

run1167_0VacuumGreen light

0.00E+0

5.00E-7

1.00E-6

1.50E-6

2.00E-6

2.50E-6

2.99E-690

180

270

November 2005:N2+Ne + Vacuum

November 2005:N2+He + Vacuum

PVLAS: Vacuum, N2 and Ne ellipticity phases of 2004-2005 runs

PVLAS 1064nm light ISOELLIPTICITY and

ISOROTATION curves in (m,M) plane

Physics outcome

DICHROISM(IR) amplitude circa 4 10-12 (published in PRL2006) ELLIPTICITY(IR) amplitude circa 2-5 10-12, phase opposite to CME(He, Ne)

ELLIPTICITY(Gr) amplitude amplitude circa 3-15 10-12, phase opposite to CME(He, Ne)

If effects observed truly generated mostly by quantum vacuum effects and not by apparatus

If microscopic interpretation in terms of existence of ultralight bosons coupled to two photons valid

If ultralight bosons have spin zero and only one sort present

Phase opposite to CME(noble gases) tells bosons are scalars 0++m=0.8-1.8 meV M=0.1-0.7 10+5 GeV

PVLAS oasis in desert of (m,1/M)

plane

main question:oasis or mirage???

PROSPECTSConfirm LIGHT BOSON interpretation regeneration measurements (in parallel to polarization measur.s)with permanent magnet (beeing purchased to be installed below ellipsometer)

Reduce NOISEAMAGNETIC ACCESS STRUCTURE beeing installedPERMANENT MAGNETS planned in place of superconducting m.(no rotating stray field on FP mirrors and other optics elements)

Improve SIGNALIncrease DUTY CICLE with permanent magnets (no cryo. constraints)

Measure m accurately by changing length L of magnetized volume (in polarization and regeneration measurements)

PVLASafter June 2006 removal

of Fe access structure around the vertical granite support

of the top optical bench,that surrounds the cryostat

W=20 mwatt out of FP N=5 10+4 in FP, give 5 10+21 photons sec-1passing through PVLAS

magnet

C=16 10-12conversion probability

in PVLAS magnet 1m long 5.5 Tesla

8 10+10 bosons sec-1boson beams

R=16/(4x7.5) 10-12reconversion prob.

in permanent magnet0.5m long 2 Tesla

expect4 10-2 photons sec-1

regenerated in perm. mag

PVLAS superconducting Morpurgo magnet

(assembled with vertical bore)

before insertion into warm bore cryostat

Run 1092_0_2SOM 90Vacuum

B=01.0E-8

1.0E-18

1.0E-17

1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-9

Frequency (Hz)507.756504.439 505.000 505.500 506.000 506.500 507.000

0.00E+0

2.00E-7

4.00E-7

6.00E-7

8.00E-7

1.00E-6

1.19E-690

180

270

Run 1091_1VacuumSOM 90B=4.35 Tesla

0.00E+0

2.00E-7

4.00E-7

6.00E-7

8.00E-7

1.00E-6

1.19E-690

180

270

0.00E+02.00E-74.00E-76.00E-78.00E-71.00E-6

1.36E-690

180

270

Run 1092_0_2VacuumSOM 90B=0 Tesla

B2 dependance of 2omegam signal

Run1091_0SOM 90

0.00E+0

2.00E-7

4.00E-7

6.00E-7

8.00E-7

1.00E-6

1.23E-690

180

270

Run1084_0SOM 0

0.00E+02.00E-74.00E-76.00E-78.00E-71.00E-6

1.36E-690

180

270

November 2005 , 1ωM peak :N2+Ne + Vacuum

November 2005 , 1ωM peak :N2+He + Vacuum

References

Iacopini and Zavattini PL85B(1979)151

Maiani, Petronzio and Zavattini PL B175(1986)359

Raffelt and Stodolsky PR D37 (1988)1237

Cameron et al. (BFST Collab.) PR D47(1993)3707

Rizzo et al. IRPC 16 (1997) 81 and refs. therein

Zavattini et al (PVLAS Collab.) PRL 96(2006)110406

Gastaldi arXiv:hep-ex/0605072 (2006) and refs. therein

October 2004:Ne + Vacuum

December 2004:Ne + Vacuum

May 2005:Ne + Vacuum

October 2004, 1ωM peak:Ne + Vacuum

December 2004 , 1ωM peak :Ne + Vacuum

May 2005 , 1ωM peak :Ne + Vacuum

B dependence:Oct. 2004, Ne 18mbar

2 ωM peak 1 ωM peak

B2

B2

B4

B dependence:Dec. 2004, Vacuum

B2

B4

PVLAS532nm and 1024nm light

ISOELLIPTICITY curves

in (m,M) plane

PVLAS 532 nmlight ISOELLIPTICITY and ISOROTATION curves

in (m,M) plane

PVLAS532nm and 1024nm light ISOROTATION curves

in (m,M) plane

---

Regeneration scheme with TWO identical OPPOSITE GOING boson beams

Regeneration scheme with TWO identical OPPOSITE GOING boson beams

Yoke of Morpurgo superconducting magnet

PVLAS Morpurgo magnet :winding of superconducting coils

PVLAS Morpurgo superconducting magnet

PVLASsuperconducting

Morpurgo magnetbefore insertion

into (liquid He) cryostat

PVLAS superconducting magnet parked in vertical assembly stand

PVLAS cryostat ( with the Morpurgo superconducting magnet inside )lowered onto the rotating table which rests onto a reinforced concrete beam

supported at its extremities by the walls of the square pit of the PVLAS site at INFN-LNL in Legnaro

Top of PVLAS cryostat parked on the floor of the pit in the PVLAS site

PVLASCRYOSTAT

PVLAScryostat

PVLAS optical bench below magnet

PVLAS optical bench

above magnet

PVLASinstallation of amagnetic

access structure (Al)to the top optical bench

and to the cryostat(July2006)

PVLAS amagnetic access structure