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We consider the effect of general neutrino interactions (scalar, vector, pseudoscalar, axial vector, and tensor) in neutrino-electron scattering at the DUNE near detector. Those interactions can be associated with heavy new physics and their effect is to cause distortions in the recoil spectrum of the electrons. We show that for some cases energy scales up to 9 TeV are accessible after a 5 year run and that current bounds on interaction parameters can be improved by up to an order of magnitude. The full set of general interactions includes the usually considered neutrino-electron nonstandard matter interactions, and the near detector will give limits comparable but complementary to the ones from the analysis of neutrino oscillations in the far detector.

As neutrino physics parameters are pinned down with ever more precision, windows to potential new physics are opened. The phenomenologically interesting neutrino nonstandard interactions (NSI) (see e.g.,

A potent future experiment to address precision measurements in neutrino physics is the Deep Underground Neutrino Experiment (DUNE) which will observe neutrino oscillations at a 1300 km long baseline

Other future possibilities to probe neutrino-electron scattering also exist, for instance IsoDAR

This document is structured as follows. In Sec.

The Lagrangian of the most general

Coupling constants and operators appearing in the general

In the case of Dirac neutrinos, all the above parameters are

Considering all possible flavor combinations, in the general case there are 90 real degrees of freedom, which are reduced to 48 in the Majorana case. Further details on this statement are reserved for future work.

In this work we take an agnostic position towards mass models,

It is common to translate the

To investigate the sensitivity of DUNE ND towards new physics effects in neutrino-electron scattering, one needs to discuss both the neutrino beam and the ND design. Neutrino beams can be produced in two channels, neutrino and antineutrino. The composition of the two beam channels is shown in Fig.

Simulated neutrino fluxes from the optimized design in

The ND conceptual design is yet undetermined; however, from recent reports

In this section we discuss the relevant differential cross sections. In principle, when considering

The differential cross sections for

Let us discuss which parameters are accessible independently after summing over all final neutrino flavors. The exotic interactions

Parameters that influence the scattering of electrons with muon (anti)neutrinos (first line) and the fundamental new interaction parameters that can be constrained from the respective measurements (second line).

To make use of the spectral information, we consider event numbers within energy bins of the recoil electron of size

Expected electron event numbers from neutrino-electron scattering in neutrino channel (blue) and antineutrino channel (red) at each 2.5 years of exposure assuming SM parameters.

Deviation of the expected event number spectrum in the neutrino channel for different new physics parameters tuned away from their SM values. The sample values are of the order of magnitude of current bounds, see Table

To project the sensitivities towards new physics, we apply a standard

Concerning single-parameter bounds, namely, tuning only one parameter away from its SM value at a time we obtain the expected bounds shown in Table

Recall that matter NSI equal electron NSI if we assume quark NSI to vanish

For comparison, we note that the current bounds on general neutrino-quark interactions from the COHERENT experiment

Expected bounds (90% C.L.) on new-physics neutrino-electron interaction parameters after

Considering two parameters nonvanishing at the same time, we obtain the exclusion plots given in Fig.

Two-parameter exclusion plots after

Let us discuss if one could solidly distinguish the different new physics effects. To this end we consider the spectra generated by one parameter tuned away from the SM and fit the result to the other parameters [assuming configuration B defined in

Now we briefly discuss the advantages of the differential cross section analysis and thereby explain how our analysis extends the discussion in

Here we have only considered flux uncertainties, but other, in particular energy-dependent systematics, could readily be included in the actual fit.

The second major advantage, as we already discussed, is that different new physics effects can potentially be distinguished much better. This is because an increase of total cross sections can, in principle, originate from any of the parameters, while their effect on differential cross sections will be distinct.We have investigated prospects of the planned DUNE near-detector facility to find or constrain new physics in the lepton sector. Namely, from neutrino-electron scattering events, one can expect to probe general effective

It will be interesting to investigate if the inclusion of bounds on new neutrino-quark interactions from scattering data can be combined to sufficient bounds on nonstandard interactions in matter to notably improve the sensitivity of oscillation experiments towards the fundamental parameters of neutrino physics. Neutrino-electron scattering will in the future also be studied by other experiments, which will allow for further exploration of the parameter spaces. In addition, other processes like coherent neutrino-nucleus scattering can also probe general neutrino interactions, which still remains a field with few analyses.

We thank Xun-Jie Xu for helpful discussions. I. B. is supported by the International Max Planck research school for precision tests of fundamental symmetries (IMPRS-PTFS) and enrolled at Heidelberg University. W. R. is supported by the DFG with Grant No. RO 2516/7-1 in the Heisenberg program.

In this section, we discuss the possible origin of new physics, parametrized in terms of

At the dimension-six level, a nonredundant set of operators is the Warsaw basis

It is more intricate to generate the (pseudo)scalar and tensor interactions. In fact all dimension-6 operators involving four leptons, including two neutrinos can be reformulated in terms of

Here we discuss the mapping between the parametrization of general neutrino-electron interactions in

We employ the convention of

Here we derive the differential cross sections of neutrino-electron scattering for a generic interaction Lagrangian

The amplitudes of the scattering