Measurement of electron neutrino and antineutrino cross sections at low momentum transfer

Accelerator based neutrino oscillation experiments seek to measure the relative number of electron and muon (anti)neutrinos at different $L/E$ values. However high statistics studies of neutrino interactions are almost exclusively measured using muon (anti)neutrinos since the dominant flavor of neutrinos produced by accelerator based beams are of the muon type. This work reports new measurements of electron (anti)neutrinos interactions in hydrocarbon, obtained by strongly suppressing backgrounds initiated by muon flavor (anti)neutrinos. Double differential cross sections as a function of visible energy transfer, $E_{\text{avail}}$, and transverse momentum transfer, $p_T$, or three momentum transfer, $q_3$ are presented.

Figure 1

Flux predictions for FHC mode (Left) and RHC mode (Right). The contributions from all neutrino types are shown for each beam mode.

Figure 2

RHC mean $dE/dX$ distribution.

Figure 3

Graphic description of upstream inline energy. Upstream inline energy is defined as the energy deposited inside a backward oriented 7.5° cone with its apex emanating from the interaction vertex.

Figure 4

Representation of signal and sideband regions with respective cuts. The “excess” sideband has been subdivided into low and high upstream inline energy.

Figure 5

Prebackground tuned FHC (top) and RHC (bottom) $p_T$ distribution for the incoherent ${\pi }^0$ sideband ($dE/dx>2.4\mathrm{MeV}$/cm, $\psi *E_e>0.5\mathrm{GeV}$).

Figure 6

Postbackground tuned $p_T$ FHC (top) and RHC (bottom) distribution for the incoherent ${\pi }^0$ sideband ($dE/dx>2.4\mathrm{MeV}$/cm, $\psi *E_e>0.5\mathrm{GeV}$).

Figure 7

Prebackground tuned $p_T$ FHC (top) and RHC (bottom) $p_T$ distribution for the coherent ${\pi }^0$ (low UIE) sideband ($dE/dx>2.4\mathrm{MeV}/\mathrm{cm}$, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}<10\mathrm{MeV}$).

Figure 8

Postbackground tuned $p_T$ FHC (top) and RHC (bottom) $p_T$ distribution for the coherent ${\pi }^0$ (low UIE) sideband ($dE/dx>2.4\mathrm{MeV}/\mathrm{cm}$, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}<10\mathrm{MeV}$).

Figure 9

Prebackground tuned FHC (top) and RHC (bottom) $p_T$ distribution for the diffractive ${\pi }^0$ (high UIE) sideband ($dE/dx>2.4\mathrm{MeV}$/cm, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}>10\mathrm{MeV}$).

Figure 10

Postbackground tuned FHC (top) and RHC (bottom) $p_T$ distribution for the diffractive ${\pi }^0$ (high UIE) sideband ($dE/dx>2.4\mathrm{MeV}$/cm, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}>10\mathrm{MeV}$). The disagreement in FHC, as a result of tension between this region and the incoherent ${\pi }^0$ sideband, is discussed in the text.

Figure 11

The high UIE sideband in FHC: demonstration of the tension in the tuning, and the alternate scenarios considered for (top) the coherent ${\pi }^0$ (low UIE) sideband, (middle) the diffractive ${\pi }^0$ (high UIE) sideband, and (bottom) the incoherent ${\pi }^0$ sideband.

Figure 12

RHC energy outside of electron candidate cone and vertex region in the diffractive ${\pi }^0$ (high UIE) sideband region of $dE/dx$ $>2.4\mathrm{MeV}/\mathrm{cm}$, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}>10\mathrm{MeV}$.

Figure 13

RHC upstream inline energy in the diffractive ${\pi }^0$ (high UIE) sideband region of $dE/dx$ $>2.4\mathrm{MeV}/\mathrm{cm}$, $\psi *E_e<0.5\mathrm{GeV}$, $E_{uie}>10\mathrm{MeV}$.

Figure 14

Postbackground tuned FHC (top) and RHC (bottom) $p_T$ distribution for the signal region of $dE/dx<2.4\mathrm{MeV}/\mathrm{cm}$.

Figure 15

Ratio of RHC/FHC ${\nu }_e$ in true neutrino energy.

Figure 16

Neutrino energy estimator vs true neutrino energy in RHC.

Figure 17

The top (bottom) plots show the scaled RHC (FHC) prediction for the electron antineutrino background to the FHC sample (electron neutrino background to the RHC sample) compared to the prediction for $p_T<1.6\mathrm{GeV}/\mathrm{c}$.

Figure 18

${\overline{\nu }}_e$ efficiency for $E_{\text{avail}}$ vs $q_3$ distribution.

Figure 19

${\overline{\nu }}_e$ efficiency for $E_{\text{avail}}$ vs $p_T$ distribution.

Figure 20

${\nu }_e$ efficiency for $E_{\text{avail}}$ vs $q_3$ distribution.

Figure 21

${\nu }_e$ efficiency for $E_{\text{avail}}$ vs $p_T$ distribution.

Figure 22

A decomposition of the ${\overline{\nu }}_e$ cross section result into contributing interaction types in $E_{\text{avail}}$ vs $q_3$ on a $y$ log scale. The $y$ axis is on a log scale truncated at ${10}^{-2}$ to enable a better view of the tail end of the cross section.

Figure 23

A decomposition of the ${\overline{\nu }}_e$ cross section result into contributing interaction types in $E_{\text{avail}}$ vs $p_T$ on a $y$ log scale. The $y$ axis is on a log scale truncated at ${10}^{-2}$ to enable a better view of the tail end of the cross section.

Figure 24

A decomposition of the ${\nu }_e$ cross section result into contributing interaction types in $E_{\text{avail}}$ vs $q_3$.

Figure 25

A decomposition of the ${\nu }_e$ cross section result into contributing interaction types in $E_{\text{avail}}$ vs $p_T$.

Figure 26

${\overline{\nu }}_e$: Total cross section error summary broken down into four major subgroups for $E_{\text{avail}}$ vs $q_3$.

Figure 27

${\overline{\nu }}_e$: Total cross section error summary broken down into four major subgroups for $E_{\text{avail}}$ vs $p_T$.

Figure 28

${\nu }_e$: Total cross section error summary broken down into four major subgroups for $E_{\text{avail}}$ vs $q_3$.

Figure 29

${\nu }_e$: Total cross section error summary broken down into four major subgroups for $E_{\text{avail}}$ vs $p_T$.

Figure 30

$d^2\sigma /d{E}_{\text{avail}}d{q}_3$ cross section per nucleon compared to the model with RPA and tune 2p2h components. Figure from Ref. [46].

Figure 31

The ${\overline{\nu }}_e$ cross section result truncated at 0.8 GeV on logy scale in $q_3$ for comparison to the LE result.

Figure 32

Comparison of published MINERvA ${\nu }_{\mu }$ ME measurements with the present ME ${\nu }_e$ results.