Constraints on light neutrino parameters derived from the study of neutrinoless double beta decay

The study of the neutrinoless double beta ($0 \beta\beta$) decay mode can provide us with important information on the neutrino properties, particularly on the electron neutrino absolute mass. In this work we revise the present constraints on the neutrino mass parameters derived from the $0 \beta\beta$ decay analysis of the experimentally interesting nuclei. We use the latest results for the phase space factors (PSFs) and nuclear matrix elements (NMEs), as well as for the experimental lifetimes limits. For the PSFs we use values computed with an improved method reported very recently. For the NMEs we use values chosen from literature on a case-by-case basis, taking advantage of the consensus reached by the community on several nuclear ingredients used in their calculation. Thus, we try to restrict the range of spread of the NME values calculated with different methods and, hence, to reduce the uncertainty in deriving limits for the Majorana neutrino mass parameter. Our results may be useful to have an up-date image on the present neutrino mass sensitivities associated with $0 \beta\beta$ measurements for different isotopes and to better estimate the range of values of the neutrino masses that can be explored in the future double beta decay (DBD) experiments.Comment: 11 page

Fast, Efficient Calculations of the Two-Body Matrix Elements of the Transition Operators for Neutrinoless Double Beta Decay

To extract information about the neutrino properties from the study of neutrinoless double-beta (0\nu\beta\beta) decay one needs a precise computation of the nuclear matrix elements (NMEs) associated with this process. Approaches based on the Shell Model (ShM) are among the nuclear structure methods used for their computation. ShM better incorporates the nucleon correlations, but have to face the problem of the large model spaces and computational resources. The goal is to develop a new, fast algorithm and the associated computing code for efficient calculation of the two-body matrix elements (TBMEs) of the 0\nu\beta{\beta} decay transition operator, which are necessary to calculate the NMEs. This would allow us to extend the ShM calculations for double-beta decays to larger model spaces, of about 9-10 major harmonic oscillator shells. The improvement of our code consists in a faster calculation of the radial matrix elements. Their computation normally requires the numerical evaluation of two-dimensional integrals: one over the coordinate space and the other over the momentum space. By rearranging the expressions of the radial matrix elements, the integration over the coordinate space can be performed analytically, thus the computation reduces to sum up a small number of integrals over momentum. Our results for the NMEs are in a good agreement with similar results from literature, while we find a significant reduction of the computation time for TBMEs, by a factor of about 30, as compared with our previous code that uses two-dimensional integrals.Comment: 6 pages, one figur

Constraints on Heavy Neutrino and SUSY Parameters Derived from the Study of Neutrinoless Double Beta Decay

New constraints on the lepton number violating (LNV) parameters are derived from the analysis of the neutrinoless double beta (0νββ) decay in the hypothesis that this process would occur through the exchange of heavy neutrinos and/or SUSY particles. For derivation, we use new values of both phase space factors (PSFs) and nuclear matrix elements (NMEs) calculated with numerical codes developed recently, as well as the most recent experimental lifetimes. The NMEs are computed with a shell model (ShM) code for  48Ca,  76Ge, and  82Se nuclei, while at present similar ShM results are available only for the first nucleus. We compare our results with similar ones from literature, obtained with ShM, QRPA, and IBM-2 methods, and conclude that more results are needed for a relevant analysis on the validity of NMEs associated with these decay mechanisms

A note on the QFT randomness spectral test a new approach of DST

Quantum computers provide a new way of solving problems even in cryptography in which digital signature make an important role. In this paper, we describe a comparison between the spectral test in classical mode and quantum mode through Fourier Transform. A comparison of the results in the two cases was made. Applications of the proposed techniques are from the field of statistical testing of the pseudorandom bit generators used for cryptographic applications. The proposed statistical test is an extension of the Discrete Fourier Transform statistical test proposed in NIST SP 800-22

Radio-induced brain lesions

Introduction: Radiotherapy, an important tool in multimodal oncologic treatment, can cause radio-induced brain lesion development after a long period of time following irradiation.Material and method: We report 4 cases with radio-induced brain lesions, admitted into the Fourth Department of Neurosurgery, Emergency Clinical Hospital Bagdasar-Arseni, during a 4 years period of time.Results: Two patients had meningiomas and two had unruptured cavernomas. Other side effects of radiotherapy, such as diffuse brain atrophy, leukoencephalopathy, optic atrophy, panhypopituitarism were also noted. The two patients with large meningiomas underwent surgery, with good outcome. Observation was the choice for the two asymptomatic cavernomas. Panhypopituitarism needed synthetic hormonal replacement therapy.Conclusions: Radiotherapy can cause long-term complications and can induce development of new brain lesions into previous radiation area. Meningiomas and cavernomas can be radio-induced brain lesions. Meningiomas can grow to large size, requiring surgery. Unruptured asymptomatic cavernomas can be left in place and patients are followed clinical and with serial imaging. Other findings after radiotherapy are diffuse brain atrophy, leukoencephalopathy, optic atrophy and panhypopituitarism