Studies of Non-Standard Neutrino Interactions in Coherent Elastic Neutrino-Nucleus Scattering

Sevgi Karadag^1,2*, Shuvadeep Karmakar^2,3, Muhammed Deniz⁴

¹Department of Physics Engineering, Istanbul Technical University, Istanbul, Turkey
²Institute of Physics, Academia Sinica, Taipei, Taiwan
³Department of Physics, GLA University, Mathura, India
⁴Department of Physics, Dokuz Eylül University, Izmir, Turkey

* Presenter:Sevgi Karadag, email:sevgik@gate.sinica.edu.tw

Coherent elastic neutrino-nucleus scattering (CEνNS) is one of the most fundamental neutrino interactions. The first observation of CEνNS was carried out by the COHERENT Collaboration in 2017. After the first detection of CEνNS, many attempts have been made to comprehend this phenomenon. The TEXONO Collaboration is also currently conducting experimental studies on these fundamental interactions.
The standard model (SM) describes neutrinos interacting via weak interactions, which occur through the exchange of W± and Z bosons. Non-standard interactions (NSI) of neutrinos refer to hypothetical interactions between neutrinos and nucleus that deviate from the predictions of the SM and go beyond the standard model (BSM). NSI propose additional mechanisms or new particles that allow neutrinos to interact differently with the nucleus.
In this work, a simplified model that allows us to link the theoretical predictions with the experimental data is used. This model helps us to extend our SM calculations to BSM studies by suggesting new mediator particles and new neutrino interactions such as scalar, pseudoscalar, vectorial, axial-vector, and tensorial. This model allows us to test the SM and put some limits on the masses of new mediators and coupling constant parameters that arise in NSI. Additionally, in some NSI scenarios, neutrino flavors can also change during interactions with the nucleus. These interactions are considered in a model-independent approach described as a four-Fermi point-like interaction. In this scenario, a modified weak charge, which has different epsilon parameters corresponding to each quark and neutrino type, is in consideration instead of new mediators.
To test our model, first, the SM calculations are compared with the theoretical results published by the COHERENT collaboration. Then, the 90% upper limits and allowed regions are derived for new mediators and new coupling constant parameters of NSI. Similarly, 90% upper limits both flavor conservating and violating epsilon parameters are studied.

Keywords: Neutrino Physics, Beyond Standard Model, Non-standard Interactions