Investigation of EC/${\beta }^{+}$-decays with the COBRA experiment

Besides the very commonly investigated ${\beta }^{-}{\beta }^{-}$-decay also ${\beta }^{+}{\beta }^{+}$-decay modes can be of great interest. However, they are more difficult to observe than their ${\beta }^{-}{\beta }^{-}$-counterpart - only the EC/EC of ${}^{78}$Kr has been managed to be observed, yet. Of the three ${\beta }^{+}{\beta }^{+}$-decay modes also the EC/${\beta }^{+}$-decay is promising to be detected, though. It has a lower half-life than the ${\beta }^{+}{\beta }^{+}$-decay and creates a more characteristic signature in the detector array than the EC/EC. Measuring the half-life of 2$\nu$EC/${\beta }^{+}$-events would help to probe models used to calculate nuclear matrix elements, while 0$\nu$EC/${\beta }^{+}$-events are especially sensitive to the involvement of right-handed currents in the decay mechanism, thus, could help to gain a deeper understanding of the general physics involved. The COBRA demonstrator, consisting of 4$\times$4$\times$4 CdZnTe semiconductor detectors, provides three different isotopes capable of EC/${\beta }^{+}$-decays. Additionally, the experiment's granularity greatly improves the probability to recognize the events' characteristic decay structures. This talk's topic will be the investigation of double beta-decay modes with the COBRA experiment and focus on EC/${\beta }^{+}$-decays. First investigations of the prospects and feasibility of the EC/${\beta }^{+}$-decays' investigation in general as well as with the COBRA experiment in particular and the current status of the data analysis will be discussed.