The PVLAS experiment: detecting vacuum magnetic birefringence

6th International Workshop DICE2012 Spacetime – Matter – Quantum Mechanics: From the Planck Scale to Emergent Phenomena

物理学;力学

Zavattini, G.^3 ; Valle, F. Della^1 ; Gastaldi, U.^2 ; Messineo, G.^3 ; Milotti, E.^1 ; Pengo, R.^2 ; Piemontese, L.^4 ; Ruoso, G.^2

INFN, Sez. di Trieste and Dip. di Fisica, Università di Trieste, via A. Valerio 2, I-34127 Trieste, Italy^1

INFN, Lab. Naz. di Legnaro, viale dell'Università 2, I-35020 Legnaro, Italy^2

INFN, Sez. di Ferrara and Dip. di Fisica e di Scienze della Terra, Università di Ferrara, via Saragat 1, Edificio C, I-44122 Ferrara, Italy^3

INFN, Sez. di Ferrara, via Saragat 1, Edificio C, I-44122 Ferrara, Italy^4

关键词: Effective Lagrangian;    Ellipsometers;    Fabry-Perot cavity;    High sensitivity;    Magnetic birefringence;    Nonlinear terms;    Permanent dipoles;    Strong magnetic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/442/1/012057/pdf
DOI  :  10.1088/1742-6596/442/1/012057

学科分类：力学，机械学

来源: IOP

【 摘 要 】

The PVLAS collaboration is presently assembling a new apparatus to detect vacuum magnetic birefringence. This property is related to the structure of the QED vacuum and is predicted by the Euler-Heisenberg-Weisskopf effective Lagrangian. It can be detected by measuring the ellipticity acquired by a linearly polarised light beam propagating through a strong magnetic field. Here we report results of a scaled-down test setup and briefly describe the new PVLAS apparatus. This latter one is in construction and is based on a high-sensitivity ellipsometer with a high-finesse Fabry-Perot cavity (> 4×105) and two 0.8 m long 2.5 T rotating permanent dipole magnets. Measurements with the test setup have improved by a factor 2 the previous upper bound on the parameter Ae, which determines the strength of the nonlinear terms in the QED Lagrangian: Ae(PVLAS)-21T-295% c.l.