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Neacsu, Andrei

Publications and source records attributed to Neacsu, Andrei.

Shell Model Studies of Competing Mechanisms to the Neutrinoless Double-Beta Decay in 124 Sn, 130 Te, and 136 Xe

Neutrinoless double-beta decay is a predicted beyond Standard Model process that could clarify some of the not yet known neutrino properties, such as the mass scale, the mass hierarchy, and its nature as a Dirac or Majorana fermion. Should this transition be observed, there are still challenges in understanding the underlying contributing mechanisms. We perform a detailed shell model investigation of several beyond Standard Model mechanisms that consider the existence of right-handed currents. Our analysis presents different venues that can be used to identify the dominant mechanisms for nuclei of experimental interest in the mass A ~ 130 region ( 124 Sn, 130 Te, and 136 Xe). In conclusion, it requires accurate knowledge of nine nuclear matrix elements that we calculate in addition to the associated energy-dependent phase space factors.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

An Effective Method to Accurately Calculate the Phase Space Factors for β - β - Decay

Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates and for the analysis of the associated electron angular and energy distributions. We present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet it allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Efficient double beta decay nuclear matrix elements computations

We have developed a shell model code for the accurate computation of the two-body matrix elements of the transition operators involved in the neutrinoless double beta decay. This code features coupled cluster method short-range correlations with Jastrow-like functions, finite nucleon size effect and higher order nucleon current corrections. We present the results obtained for {sup 48}Ca and {sup 82}Se, then we compare them with other results in the literature. In the case of {sup 48}Ca, we also study the contributions of the included effects and find good agreement with other published results.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗