1. SMI – STEFAN MEYER INSTITUTE
VIP2 at Gran Sasso – Test of the validity of the spin statistics theorem for electrons with X-ray spectroscopy
Johann Marton
for the VIP2 Collaboration
WWW:OEAW.AC.AT/SMI

2. VIP-2 Collaboration ITALY
INFN laboratori Nazionali di Frascati: C. Curceanu, S. Bartalucci, A. Clozza, L. de Paolis, A. d’Uffizi, C. Guaraldo, M. Iliescu, K. Piscicchia(*), E. Sbardella, A. Scordo, H. Shi, D. Sirghi, F. Sirghi, L.Sperandio  (*) and Museo torico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma
INFN Laboratori Nazionali del Gran Sasso: M. Laubenstein
Università and INFN Trieste: E. Milotti
AUSTRIA
SMI-Vienna: C. Berucci, M. Cargnelli, J. Marton, A. Pichler, J. Zmeskal
FRANCE
Univ. Rennes: S. di Matteo
GERMANY
TUM-Muenchen: O. Vazquez Doce
ROMANIA
IFIN-HH, Bucharest: M. Bragadireanu, D. Pietreanu, T. Ponta
SWITZERLAND
CERN: S. Bertolucci
Univ. Neuchatel: J.-P. Egger

3. SMI – STEFAN MEYER INSTITUTE
Motivation
If something in fundamental physics can be tested, then it absolutely must be tested (L. Okun)
PEP a solid rule of nature but no intuitive explanation (Pauli)
PEP connected with spin statistics
Spin statistics connection is a very robust feature of quantum field theory
Nature is divided in fermions and bosons
VIP/VIP-2 idea: testing PEP for electrons employing the method of Ramberg-Snow with detectors successfully used in kaonic atom spectroscopy (x-ray detector arrays, CCDs, SDDs)
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4. SMI – STEFAN MEYER INSTITUTE
1925
"In an atom there cannot be two or more equivalent electrons for which the values of all four quantum numbers coincide. If an electron exists in an atom for which all of these numbers have definite values, then the state is occupied."
W.Pauli, Über den Zusammenhang des Abschlusses der Elektronengruppen im Atom mit der Komplexstruktur der Spektren, Zeitschrift für Physik 31 (1925) 765.
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5. SMI – STEFAN MEYER INSTITUTE
Consequences
Some examples:
Periodic table of the elements
Stability of matter
Neutron stars
…… etc
So far no violation of the spin-statistics could be found
- but violations can arise in string theory
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6. SMI – STEFAN MEYER INSTITUTE
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7. SMI – STEFAN MEYER INSTITUTE
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8. Why the Special interest in the leptonic sector ?
Violation of the spin-statistics relation would have an important impact not only on microscopic atomic, nuclear, and particle physics scales, but also induce very interesting effects at astronomically large scales. In particular, it was argued that spin-statictics relation for neutrinos could be strongly violated, If so, neutrino may be the sole dark matter particle, contributing both to hot and cold dark matter.
There are speculations concerning a bosonic component of neutrinos with severe cosmological consequences (A. Dolgov et al.)

9. SMI – STEFAN MEYER INSTITUTE
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10. Best Limits for PEP Violation
SMI – STEFAN MEYER INSTITUTE
Best Limits for PEP Violation
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11. SMI – STEFAN MEYER INSTITUTE
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12. SMI – STEFAN MEYER INSTITUTE
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13. SMI – STEFAN MEYER INSTITUTE
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14. SMI – STEFAN MEYER INSTITUTE
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15. SMI – STEFAN MEYER INSTITUTE
VIP2 Experiment in LNGS
Running since 2016
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16. VIP2 Installation at LNGS

17. SMI – STEFAN MEYER INSTITUTE
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18. SMI – STEFAN MEYER INSTITUTE
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19. SMI – STEFAN MEYER INSTITUTE
VIP-2 Data taking in2016
I = 100 A
I = 0 A
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20. SMI – STEFAN MEYER INSTITUTE
Toward the final result
With first VIP2 data
taking 2016
same sensitivity
like VIP in
3 years
C. Curceanu et al.
arXiv: [quant-ph]
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21. SMI – STEFAN MEYER INSTITUTE
Future Research Plan
Installation of part of the passive shielding
New SDD detector system with new copper target
Optimized shielding with data taking of about 3 years (i.e. approx. 2020)
Goal after 3 years data taking with and without current  102 improvement of VIP limit
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22. Thank you for your attention
SMI – STEFAN MEYER INSTITUTE
"The special place enjoyed by the Pauli principle in modern theoretical physics does not mean that this principle does not require further and exhaustive experimental tests. On the contrary, it is specifically the fundamental nature of the Pauli principle which would make such tests, over the entire periodic table, of special interest."
Lev Okun
Thank you for your attention
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23. Spare