We propose new solutions to accommodate both the MiniBooNE electron-like and MicroBooNE photon low-energy excesses, based on interactions involving light dark matter and/or neutrinos. The novelty of our proposal lies in the utilization of a photon arising from 2-to-3 scattering processes between a nucleus/nucleon and a neutrino and/or dark matter via exchanges of light mediators. We find that viable regions exist in the coupling and mass parameter space of the mediators and light dark matter that can simultaneously explain the observed excesses and remain consistent with current experimental constraints. We further highlight that these scenarios can be tested with upcoming data from various ongoing experiments.
A new generation of neutrino experiments is testing the $4.8σ$ anomalous excess of electron-like events observed in MiniBooNE. This is of huge importance for particle physics, astrophysics, and cosmology, not only because of the potential discovery of physics beyond the Standard Model, but also because the lessons we will learn about neutrino-nucleus interactions will be crucial for the worldwide neutrino program. MicroBooNE has recently released results that appear to disfavor several explanations of the MiniBooNE anomaly. Here, we show quantitatively that MicroBooNE results, while a promisin…
The MiniBooNE experiment reported results from the analysis of $ν_e$ and $\overlineν_e$ appearance searches, which showed an excess of signal-like events at low reconstructed neutrino energies with respect to the expected background. A proposed explanation for this anomaly is based on the existence of a heavy ($\sim 50$~MeV) sterile neutrino. These $ν_h$ would be produced by $ν_μ$ electromagnetic and neutral current interactions. A fraction of them decays radiatively inside the detector. The emitted photon is misidentified as an electron or positron in MiniBooNE. We have investigated the $ν_h$…
This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone, and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combi…
The strong statistical significance of an observed electron-like event excess in the MiniBooNE (MB) experiment, along with an earlier similar excess seen in the Liquid Scintillator Neutrino Detector (LSND), when interpreted in conjunction with recent MicroBooNE results may have brought us to the cusp of new physics discoveries. This has led to many attempts to understand these observations, both for each experiment individually and in conjunction, via physics beyond the Standard Model (SM). We provide an overview of the current situation, and discuss three major categories under which the many…
Implications for new physics solutions to the LSND and MiniBooNE anomalies after MicroBooNE results
Cairo University（开罗大学）；Harish-Chandra Research Institute（哈里什-昌德拉研究所）；Amity School of Engineering and Technology, Amity University Hyderabad（海德拉巴阿米蒂大学工程与技术学院）；School of Physics, University of Hyderabad（海德拉巴大学物理学院）
Flux-integrated inclusive and pionless cross sections for charged-current neutrino scattering off ${}^{40}\text{Ar}$ at energies available in the MicroBooNE experiment
Institute for Nuclear Research, Russian Academy of Sciences（俄罗斯科学院核物理研究所）
The MiniBooNE low-energy excess is a longstanding problem which has received further confirmation recently with a reanalysis using newly collected data, with the anomaly now at the $4.8σ$ level. In this letter we propose a novel explanation which advocates a low-energy sector containing $Z^\prime$ bosons with GeV-scale masses and sterile neutrinos with masses around $100$-$500$ MeV. We show that this scenario can provide an excellent spectral agreement with the MiniBooNE low-energy excess in the form of $Z^\prime$-mediated neutral current production of heavy sterile states, a fraction of whose…
The MiniBooNE experiment is a $ν_μ\toν_e$ and $\barν_μ\to\barν_e$ appearance neutrino oscillation experiment at Fermilab. The neutrino mode oscillation analysis shows an excess of $ν_e$ candidate events in the low-energy region. These events are analyzed under the SME formalism, utilizing the short baseline approximation. The preliminary result shows the time independent solution is favored. The relationship with the SME parameters extracted from the LSND experiment is discussed. The systematic error analysis and antineutrino mode analysis are outlined.
The MiniBooNE experiment has recently reported an anomalous 4.5$σ$ excess of electron-like events consistent with $ν_e$ appearance from a $ν_μ$ beam at short-baseline. Given the lack of corresponding $ν_μ$ disappearance observations, required in the case of oscillations involving a sterile flavor, there is strong motivation for alternative explanations of this anomaly. We consider the possibility that the observed electron-like signal may actually be due to hypothetical new particles,which do not involve new sources of neutrino production or oscillations. We find that the electron-like event e…
We consider a simple extension of the Standard Model (SM) by a complex scalar doublet and a singlet along with three sterile neutrinos. The sterile neutrinos mix with the SM neutrinos to produce three light neutrino states consistent with the oscillation data and three heavy sterile states. The lightest sterile neutrino has lifetime longer than the age of the Universe and can provide correct dark matter relic abundance. Utilizing tree-level flavor changing interactions of a light scalar with mass~$\sim\mathcal{O}(100)$~MeV along with sterile neutrinos, we can explain the anomalous magnetic mom…
The MiniBooNE collaboration has reported an excess of $460.5\pm 95.8$ electron-like events ($4.8σ$). We propose an explanation of these events in terms of a sterile neutrino decaying into a photon and a light neutrino. The sterile neutrino has a mass around 250 MeV and it is produced from kaon decays in the proton beam target via mixing with the muon or the electron in the range $10^{-11} \lesssim |U_{\ell 4}|^2 \lesssim 10^{-7}$ ($\ell = e,μ$). The model can be tested by considering the time distribution of the events in MiniBooNE and by looking for single-photon events in running or upcoming…
Heavy neutral leptons ($N$) below the kaon mass are severely constrained by cosmology and lab-based searches for their decays in flight. If $N$ interacts via an additional force, $N\toνe^+e^-$ decays are enhanced and cosmological limits can be avoided. We show that the T2K and MicroBooNE neutrino experiments provide the best limits on the mixing of $N$ with muon-neutrinos, outperforming past-generation experiments, previously thought to dominate. We constrain models with electromagnetically-decaying and long-lived $N$, such as in a transition-magnetic-moment portal and in a leptophilic axion-l…
Neglected single photon processes are fit to an excess of electron-like events observed in a predominantly nu_mu beam at MiniBooNE. Predictions are given for analogous events in antineutrino mode.
Recently, the MiniBooNE experiment at Fermilab has updated the results with increased data and reported an excess of $560.6 \pm 119.6$ electronlike events ($4.7σ$) in the neutrino operation mode. In this paper, we propose a scenario to account for the excess where a Dirac-type sterile neutrino, produced by a charged kaon decay through the neutrino mixing, decays into a leptophilic axionlike particle ($\ell$ALP) and a muon neutrino. The electron-positron pairs produced from the $\ell$ALP decays can be interpreted as electronlike events provided that their opening angle is sufficiently small. In…
The MiniBooNE Experiment has contributed substantially to beyond standard model searches in the neutrino sector. The experiment was originally designed to test the $Δm^2$~1 eV$^2$ region of the sterile neutrino hypothesis by observing $ν_e$ ($\barν_e$) charged current quasi-elastic signals from a $ν_μ$ ($\barν_μ$) beam. MiniBooNE observed excesses of $ν_e$ and $\barν_e$-candidate events in neutrino and anti-neutrino mode, respectively. To date, these excesses have not been explained within the neutrino Standard Model ($ν$SM), the Standard Model extended for three massive neutrinos. Confirmatio…
We study the dependence of neutral current (NC) neutrino-induced $π^0$/photon production ($ν_μ+ A \to ν_μ+1π^0 / γ+ X$) on the atomic number of the target nucleus, A, at 4-momentum transfers relevant to the MiniBooNE experiment: $Δ$ resonance mass region. Our conclusion is based on experimental data for photon-nucleus interactions from the A2 collaboration at the Mainz MAMI accelerator. We work in the approximation that decays of $Δ$ resonance unaffected by its production channel, via photon or Z boson. $1π^0+X$ production scales as A$^{2/3}$, the surface area of the nucleus. Meanwhile the pho…
We present a novel framework that provides an explanation to the long-standing excess of electron-like events in the MiniBooNE experiment at Fermilab. We suggest a new dark sector containing a dark neutrino and a dark gauge boson, both with masses between a few tens and a few hundreds of MeV. Dark neutrinos are produced via neutrino-nucleus scattering, followed by their decay to the dark gauge boson, which in turn gives rise to electron-like events. This mechanism provides an excellent fit to MiniBooNE energy spectra and angular distributions.
We revisit models of heavy neutral leptons (neutrissimos) with transition magnetic moments as explanations of the $4.8σ$ excess of electron-like events at MiniBooNE. We perform a detailed Monte Carlo-based analysis to re-examine the preferred regions in the model parameter space to explain MiniBooNE, considering also potential contributions from oscillations due to an eV-scale sterile neutrino. We then derive robust constraints on the model using neutrino-electron elastic scattering data from MINERvA. We find that MINERvA rules out a large region of parameter space, but allowed solutions exist…
We point out that the excess of electron-like neutrino events recently observed by the T2K collaboration may have a common origin with the similar excess events previously reported by the LSND and MiniBooNE experiments and interpreted as a signal from the radiative decays of a sterile neutrino ν_h with the mass around 50 MeV produced in muon neutrino neutral current (NC) interactions. In this work we assumed that the ν_h can also be produced in tau neutrino NC reactions.
We present the results of a new analysis of the data of the MiniBooNE experiment taking into account the additional background of photons from $Δ^{+/0}$ decay proposed in arXiv:1909.08571 and additional contributions due to coherent photon emission, incoherent production of higher mass resonances, and incoherent non-resonant nucleon production. We show that the new background can explain part of the MiniBooNE low-energy excess and the statistical significance of the MiniBooNE indication in favor of short-baseline neutrino oscillation decreases from $5.1σ$ to $3.6σ$. We also consider the implic…
Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck-scale physics. Various types of data are analyzed to search for Lorentz violation under the Standard-Model Extension (SME) framework, including neutrino oscillation data. MiniBooNE is a short-baseline neutrino oscillation experiment at Fermilab. The measured excesses from MiniBooNE cannot be reconciled within the neutrino Standard Model; thus it might be a signal of new physics, such as Lorentz violation. We have analyzed the sidereal time dependence of MiniBooNE data for signals of the possible breakdown of L…
We consider the non-oscillatory explanations of the low energy excess of events detected by MiniBooNE. We present a systematic search for phenomenological scenarios based on new physics which can produce the excess. We define scenarios as series of transitions and processes which connect interactions of accelerated protons in target with single shower events in the MiniBooNE detector. The key elements of the scenarios are production and decay of new light $\mathcal{O}(\text{keV}-100\,\text{MeV})$ particles (fermions or/and bosons). We find about $20$ scenarios with minimal possible number of n…
New MiniBooNE excess interpretation using Pseudo-Hermitian neutrino oscillation
Sciences Departement, Teacher Education College of Setif（塞提夫师范学院科学系）；Laboratoire de Physique Mathematique et Subatomique, Universite Freres Mentouri Constantine 1（康斯坦丁1兄弟门图里大学数学与亚原子物理实验室）
The electron-like excess observed by the MiniBooNE experiment is explained with a model comprising a new low mass state ($\mathcal{O}(1)$ eV) participating in neutrino oscillations and a new high mass state ($\mathcal{O}(100)$ MeV) that decays to $ν+γ$. Short-baseline oscillation data sets are used to predict the oscillation parameters. Fitting the MiniBooNE energy and scattering angle data, there is a narrow joint allowed region for the decay contribution at 95% CL. The result is a substantial improvement over the single sterile neutrino oscillation model, with $Δχ^2/dof$ = 19.3/2 for a decay…
A sensitive search for anomalous LSND-like nu_mu to nu_e oscillations has been performed by the ICARUS Collaboration exposing the T600 LAr-TPC to the CERN to Gran Sasso (CNGS) neutrino beam. The result is compatible with the absence of additional anomalous contributions giving a limit to oscillation probability of 3.4E-3 and 7.6E-3 at 90% and 99% confidence levels respectively showing a tension between these new limits and the low-energy event excess (200 < E_nu QE < 475 MeV) reported by MiniBooNE Collaboration. A more detailed comparison of the ICARUS data with the MiniBooNE low-energy excess…
Heavy neutrinos with additional interactions have recently been proposed as an explanation to the MiniBooNE excess. These scenarios often rely on marginally boosted particles to explain the excess angular spectrum, thus predicting large rates at higher-energy neutrino-electron scattering experiments. We place new constraints on this class of models based on neutrino-electron scattering sideband measurements performed at MINER$ν$A and CHARM-II. A simultaneous explanation of the angular and energy distributions of the MiniBooNE excess in terms of heavy neutrinos with light mediators is severely …
This report summarizes our study of Neutral Current (NC)-induced photon production in MiniBooNE, as motivated by the low energy excess in this experiment [A. A. Aquilar-Arevalo et al. (MiniBooNE Collaboration), Phys. Rev. Lett. 98, 231801 (2007); 103, 111801 (2009)]. It was proposed that NC photon production with two anomalous photon-$Z$ boson-vector meson couplings might explain the excess. However, our computed event numbers in both neutrino and antineutrino runs are consistent with the previous MiniBooNE estimate that is based on their pion production measurement. Various nuclear effects di…
It has been recently shown that puzzling excess events observed by the LSND and MiniBooNE neutrino experiments could be interpreted as a signal from the radiative decay of a heavy sterile neutrino ($ν_h$) of the mass from 40 to 80 MeV, with a muonic mixing strength $\mix \simeq 10^{-3} - 10^{-2}$, and the lifetime $10^{-11} < τ_h < 10^{-9}$ s. We discuss bounds on $\mix$ obtained from the recent precision measurements with muons and show that they are consistent with the above limits. If the $ν_h$ exists its admixture in the ordinary muon or kaon decay would result in the decay chain $\muhd$ o…
We present the results of a new analysis of the data of the MiniBooNE experiment taking into account the additional background of photons. MiniBooNE normalises the rate of photon production to the measured $π^0$ production rate. We study neutral current (NC) neutrino-induced $π^0$/photon production ($ν_μ+ A \to ν_μ+1π^0 / γ+ X$) on carbon nucleus (A=12). Our conclusion is based on experimental data for photon-nucleus interactions from the A2 collaboration at the Mainz MAMI accelerator. We work in the approximation that decays of the intermediate states (non-resonant N, $Δ$ resonance, higher re…
We point out that production of new bosons by charged meson decays can greatly enhance the sensitivity of beam-focused accelerator-based experiments to new physics signals. This enhancement arises since the charged mesons are focused and their three-body decays do not suffer from helicity suppression in the same way as their usual two-body decays. As a realistic application, we attempt to explain the MiniBooNE low energy excess utilizing this overlooked mechanism, uniquely realizing dark-sector interpretations as plausible solutions to the excess. As proof of the principle, we consider two wel…
The MiniBooNE experiment at Fermilab reports results from an analysis of $ν_e$ appearance data from $12.84 \times 10^{20}$ protons on target in neutrino mode, an increase of approximately a factor of two over previously reported results. A $ν_e$ charged-current quasielastic event excess of $381.2 \pm 85.2$ events ($4.5 σ$) is observed in the energy range $200<E_ν^{QE}<1250$~MeV. Combining these data with the $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, a total $ν_e$ plus $\bar ν_e$ charged-current quasielastic event excess of $460.5 \pm 99.0$ e…
The MiniBooNE experiment has reported results from the analysis of $ν_e$ and $\bar ν_e$ appearance searches, which show an excess of signal-like events at low reconstructed neutrino energies, with respect to the expected background. A significant component of this background comes from photon emission induced by (anti)neutrino neutral current interactions with nucleons and nuclei. With an improved microscopic model for these reactions, we predict the number and distributions of photon events at the MiniBooNE detector. Our results are compared to the MiniBooNE in situ estimate and to other theo…
A recent update from MiniBooNE has strengthened the observed $4.8σ$ excess of $e$-like events. Motivated by this and other notable deviations from standard model predictions, such as the muon $(g-2)$, we propose a solution to low energy anomalies through a dark neutrino sector. The model is renormalizable and can also explain light neutrino masses with an anomaly-free and dark $U(1)^\prime$ gauge symmetry broken at the GeV scale. Large kinetic mixing leads to s-channel production of heavy neutral leptons at $e^+e^-$ colliders, where we point out and explain a $\gtrsim 2σ$ excess observed in th…
We construct a neutrino model of three twin neutrinos in light of the neutrino appearance excesses at LSND and MiniBooNE. The model, which includes a twin parity, naturally predicts identical lepton Yukawa structures in the Standard Model and the twin sectors. As a result, a universal mixing angle controls all three twin neutrino couplings to the Standard Model charged leptons. This mixing angle is predicted to be the ratio of the electroweak scale over the composite scale of the Higgs boson and has the right order of magnitude to fit the data. The heavy twin neutrinos decay within the experim…
We consider a model of neutrino oscillations with three additional sterile neutrinos and a gauged B-L interaction. We find allowed values of the model parameters which can reconcile the results of the evidence for antimuon neutrino to antielectron neutrino conversion seen at the LSND neutrino oscillation experiment with the null results of the MiniBooNE experiment. A portion of the low energy excess of electron neutrino events seen at MiniBooNE can arise naturally, and we make a quantitative prediction for the forthcoming anti-neutrino oscillation results at MiniBooNE.
In view of the recent results from the MiniBooNE experiment we revisit the global neutrino oscillation fit to short-baseline neutrino data by adding one or two sterile neutrinos with eV-scale masses to the three Standard Model neutrinos, and for the first time we consider also the global fit with three sterile neutrinos. Four-neutrino oscillations of the (3+1) type have been only marginally allowed before the recent MiniBooNE results, and become even more disfavored with the new data (at the level of $4σ$). In the framework of so-called (3+2) five-neutrino mass schemes we find severe tension b…
The MiniBooNE experiment at Fermilab reports results from a search for $\bar ν_μ\rightarrow \bar ν_e$ oscillations, using a data sample corresponding to $5.66 \times 10^{20}$ protons on target. An excess of $20.9 \pm 14.0$ events is observed in the energy range $475<E_ν^{QE}<1250$ MeV, which, when constrained by the observed $\bar ν_μ$ events, has a probability for consistency with the background-only hypothesis of 0.5\%. On the other hand, fitting for $\barν_μ\rightarrow\barν_e$ oscillations, the best-fit point has a $χ^2$-probability of 8.7\%. The data are consistent with $\bar ν_μ\rightarro…
In a new measurement on neutrino oscillation $ν_μ\toν_e$, the MiniBooNE Collaboration observes an excess of electron-like events at low energy and the phenomenon may demand an explanation which obviously is beyond the oscillation picuture. We propose that heavier neutrino $ν_2$ decaying into a lighter one $ν_1$ via the transition process $ν_μ\to ν_e+X$ where $X$ denotes any light products, could be a natural mechanism. The theoretical model we employ here is the unparticle scenario established by Georgi. We have studied two particular modes $ν_μ\to ν_e+\Un$ and $ν_μ\to ν_e+\barν_e+ν_e$. Unfort…
Over the last two decades, several experiments have reported anomalous results that could be hinting at the exciting possibility of sterile neutrino states in the $eV^{2}$ mass scale. Liquid Argon Time Projection Chambers (LArTPCs) are a particularly promising technology to explore this physics due to their fine-grained tracking and exceptional calorimetric capabilities. The MicroBooNE experiment, a 170 ton LArTPC scheduled to start taking data very soon with Fermilab's Booster Neutrino Beam (BNB), will combine LArTPC development with the main physics goal of understanding the low-energy elect…
While the low-energy excess observed at MiniBooNE remains unchallenged, it has become increasingly difficult to reconcile it with the results from other sterile neutrino searches and cosmology. Recently, it has been shown that non-minimal models with new particles in a hidden sector could provide a better fit to the data. As their main ingredients they require a GeV-scale $Z'$, kinetically mixed with the photon, and an unstable heavy neutrino with a mass in the 150 MeV range that mixes with the light neutrinos. In this letter we point out that atmospheric neutrino experiments (and, in particul…
It has been recently suggested that the anomalous excess of low-energy electron-like events observed by the MiniBooNE experiment, could be explained by the radiative decay of a heavy sterile neutrino nu_h of the mass around 500 MeV with a muonic mixing strength in the range |U_{μh}|^2 \simeq (1-4)\times 10^{-3}. If such nu_h exists its admixtures in the decay Ds -> mu+nu would result in the decay Ds -> mu+nu_h with the branching fraction \simeq (1.2-5.5)\times 10^{-4}, which is in the experimentally accessible range. Interestingly, the existence of the Ds -> mu+nu_h decay at this level may als…
We discuss the possibility that a sterile neutrino of mass around 50 MeV slightly mixed with the muon flavor may be the origin of the MiniBooNE anomaly. We show that its production in the atmosphere in a fraction of kaon decays would imply an excess of contained showers at IceCube from down-going and near-horizontal directions.
The anomaly in the low energy distribution of quasi-elastic neutrino events reported by the MiniBooNE collaboration is discussed. We show that the observed excess of electron-like events could originate from the production and decay of a heavy neutrino ($ν_h$) in the MiniBooNE detector. The $ν_h$ is created by mixing in $ν_μ$ neutral-current interactions and decays radiatively into $ νγ$ due to a transition magnetic moment between the $ν_h$ and a light neutrino $ν$. The energy measured in the detector arises from the subsequent conversion of the decay photon into a $\pair$ pair within the dete…
This work has attempted to reconcile puzzling neutrino oscillation results from the LSND, KARMEN and MiniBooNE experiments. We show that the LSND evidence for $\barν_μ\to \barν_e$ oscillations, its long-standing disagreement with the results from KARMEN, and the anomalous event excess observed by MiniBooNE in $ν_μ$ and $\barν_μ$ data could all be explained by the existence of a heavy sterile neutrino ($ν_h$). All these results are found to be consistent with each other assuming that the $ν_h$ is created in $ν_μ$ neutral-current interactions and decays radiatively into a photon and a light neut…
The MiniBooNE experiment at Fermilab reports a total excess of $638.0 \pm 132.8$ electron-like events ($4.8 σ$) from a data sample corresponding to $18.75 \times 10^{20}$ protons-on-target in neutrino mode, which is a 46\% increase in the data sample with respect to previously published results, and $11.27 \times 10^{20}$ protons-on-target in antineutrino mode. The additional statistics allow several studies to address questions on the source of the excess. First, we provide two-dimensional plots in visible energy and cosine of the angle of the outgoing lepton, which can provide valuable input…
We present a dark sector model that reproduces the KOTO, MiniBooNE and muon anomalous magnetic moment anomalies. The dark sector is comprised of a light scalar singlet $S$ that has a large coupling to a slightly heavier sterile neutrino that mixes with the active neutrinos. The scalar couples to standard model fermions via Yukawa couplings, and to photons via a higher-dimensional coupling. The KOTO signal is a result of the flavor-changing penguin process $K_L \to π^0 S$ followed by the decay of $S$ to neutrinos. The sterile neutrino produced in neutrino-nucleus scattering at MiniBooNE decays …
Current results of the MiniBooNE experiment show excess events that indicate neutrino oscillations, but only if one goes beyond the standard 3 family scenario. Recently a different explanation of the events has been given, not in terms of oscillations but by the production and decay of a massive sterile neutrino with large transition magnetic moment. We study the effect of such a sterile neutrino in the rare decays $τ^- \rightarrow μ^- μ^+ π^- ν$ and $τ^{-}\rightarrow μ^{-} μ^{+} e^{-} νν$. We find that searches for these decays featuring displaced vertices between the $μ^-$ and the other char…
A search for sub-GeV dark matter produced from collisions of the Fermilab 8 GeV Booster protons with a steel beam dump was performed by the MiniBooNE-DM Collaboration using data from $1.86 \times 10^{20}$ protons on target in a dedicated run. The MiniBooNE detector, consisting of 818 tons of mineral oil and located 490 meters downstream of the beam dump, is sensitive to a variety of dark matter initiated scattering reactions. Three dark matter interactions are considered for this analysis: elastic scattering off nucleons, inelastic neutral pion production, and elastic scattering off electrons.…
The excess of electron-like events measured by MiniBooNE challenges our understanding of neutrinos and their interactions. We review the status of this open problem and ongoing efforts to resolve it. After introducing the experiment and its results, we consider the main experimental backgrounds and the related physics of neutrino interactions with matter such as quasielastic-like scattering and weak pion production on nucleons and nuclei. Special attention is paid to single photon emission in neutral current interactions and, in particular, its coherent channel. The difficulties to reconcile t…
