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Abstract
Abstract.
The Pauli exclusion principle (PEP) has been tested for nucleons (n,p) in \({}^{12}{\rm C}\) and \({}^{16}{\rm O}\) nuclei, using the results of background measurements with the prototype of the Borexino detector, the Counting Test Facility (CTF). The approach consisted of a search for \(\gamma\), n, p and/or \(\alpha\)’s emitted in a non-Paulian transition of 1P- shell nucleons to the filled 1S1/2 shell in nuclei. Similarly, the Pauli-forbidden \(\beta^{\pm}\) decay processes were searched for. Due to the extremely low background and the large mass (4.2 tons) of the CTF detector, the following most stringent up-to-date experimental bounds on PEP violating transitions of nucleons have been established: \(\tau({}^{12}{\rm C} \rightarrow {}^{12}{\rm\widetilde C} + \gamma) > 2.1\cdot10^{27} \mathrm y\), \(\tau({}^{12}{\rm C} \rightarrow {}^{11}{\rm\widetilde B} + p) > 5.0\cdot10^{26} {\mathrm{y}}\), \(\tau({}^{12}{\rm C} ({}^{16}{\rm O}) \rightarrow {}^{11}{\rm\widetilde C} ({}^{15}{\rm\widetilde O} ) + n) > 3.7 \cdot 10^{26} {\mathrm{y}}\), \(\tau({}^{12}{\rm C} \rightarrow {}^{8}{\rm\widetilde{Be}} + \alpha) > 6.1 \cdot 10^{23} \mathrm y\), \(\tau({}^{12}{\rm C} \rightarrow {}^{12}{\rm\widetilde N} + e^- + \widetilde{\nu_e}) > 7.6 \cdot 10^{27} \mathrm y\) and \(\tau({}^{12}{\rm C} \rightarrow {}^{12}{\rm\widetilde B} + e^ + + \nu_e) > 7.7 \cdot 10^{27} \mathrm y\), all at \(90 \%\) C.L.
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1 Physics Department, Virginia Polytechnic Institute and State University, Blacksburg, USA
2 I.N.F.N Laboratori Nazionali del Gran Sasso, Assergi(AQ), Italy
3 Dipartimento di Fisica Nucleare e Teorica Universita’ and I.N.F.N., Pavia, Italy
4 Laboratoire de Physique Corpusculaire et Cosmologie, Paris Cedex 05, France
5 Dipartimento di Fisica Universitá and I.N.F.N., Milano, Italy
6 Dept. of Physics, Princeton University, Princeton, USA
7 Max-Planck-Institut fuer Kernphysik, Heidelberg, Germany
8 Dept. of Physics, Queen’s University Stirling Hall, Kingston, Ontario, Canada
9 Technische Universitaet Muenchen, Garching, Germany
10 Joint Institute for Nuclear Research, Dubna, Russia
11 Dept. of Physics Massachusetts Institute of Technology, Cambridge, USA
12 RRC Kurchatov Institute, Moscow, Russia
13 KFKI-RMKI, Budapest, Hungary
14 Dipartimento di Fisica Universitá and I.N.F.N., Genova, Genova, Italy
15 Dipartimento di Chimica, Universitá, Perugia, Perugia, Italy
16 Bell Laboratories, Lucent Technologies, Murray Hill, USA
17 M .Smoluchowski Institute of Physics, Jagellonian University, Krakow, Poland