Semi-Analytical Monte Carlo Method to Simulate the Signal of the VIP-2 Experiment

E Milotti ,L De Paolis ,H Shi ,K Piscicchia ,J Márton ,M Miliucci ,M Bragadireanu ,C Guaraldo ,M Cargnelli ,M Iliescu ,D Sirghi ,R Del Grande ,M Bazzi ,A Clozza ,S Bartalucci ,F Napolitano ,M Laubenstein ,O Vázquez Doce ,L Sperandio ,F Sirghi ,S Bertolucci ,A Scordo ,C Curceanu ,J Zmeskal

doi:10.3390/sym13010006

Abstract

The VIP-2 collaboration runs an apparatus in the Gran Sasso underground laboratories of the Italian Institute for Nuclear Physics (INFN) designed to search for anomalous X-rays from electron-atom interactions due to violations of the fundamental antisymmetry of multi-electron wavefunctions. The experiment implements the scheme first proposed by Ramberg and Snow, where a current source injects electrons into a metal strip (the experiment’s target). In this paper we describe the structure of a Monte Carlo program to simulate a new upgrade of the experiment, where the anomalous X-ray emission is modulated by an arbitrary time-varying input current. A novel feature of the simulation algorithm is that the Monte Carlo program is based on a mixture of analytical and numerical methods. We report preliminary, exploratory results on the expected detection rate for different modulations of the injected current; these results are a starting point on the way to optimize the modulation scheme and indicate a large potential improvement of the detection sensitivity.

Highlights

IntroductionTo the existence of neutron stars [2]
Since our aim is the estimate of the average signal, we adopt techniques that minimize the fluctuations of the Monte Carlo runs and boost computational efficiency
We detect a violation when we find that there is a statistically significant spectral peak that corresponds to a harmonic of the current modulation frequency

Summary

Introduction

To the existence of neutron stars [2] As is it was clearly shown by Pauli [3], the principle lies at the crossroads of our most important theories, relativity and quantum physics, it is a very robust feature of relativistic Quantum Field Theory [4], and it is important to test its validity [5]. The VIP-2 experiment [6,7] (a followup of the VIP experiment [8]) tests the validity of the Pauli Exclusion Principle (PEP) for electrons—and the fundamental antisymmetry of the multi-electron wavefunctions—with the same conceptual setup first introduced by Ramberg and Snow in 1990 [9]. The final electron transitions in the electromagnetic cascade emit X-rays with energies that differ from those of the characteristic X-rays of the target material and provide a unique signature of the non-Paulian capture process (see [13] for a recent and precise theoretical determination of the energies of the characteristic X-rays of Cu)

Objectives

Discussion

Conclusion