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1. First Simultaneous Measurement of Differential Muon-Neutrino Charged-Current Cross Sections on Argon for Final States with and without Protons Using MicroBooNE Data

   https://doi.org/10.1103/PhysRevLett.133.041801  

   Abratenko, P ; Alterkait, O ; Andrade_Aldana, D ; Arellano, L ; Asaadi, J ; Ashkenazi, A ; Balasubramanian, S ; Baller, B ; Barr, G ; Barrow, D ; et al ( July 2024 , Physical Review Letters)

   We report the first double-differential neutrino-argon cross section measurement made simultaneously for final states with and without protons for the inclusive muon neutrino charged-current interaction channel. The proton kinematics of this channel are further explored with a differential cross section measurement as a function of the leading proton’s kinetic energy that extends across the detection threshold. These measurements use data collected with the MicroBooNE detector from$6.4\times {10}^{20}$protons on target from the Fermilab booster neutrino beam with a mean neutrino energy of$\sim 0.8\mathrm{GeV}$. Extensive data-driven model validation utilizing the conditional constraint formalism is employed. This motivates enlarging the uncertainties with an empirical reweighting approach to minimize the possibility of extracting biased cross section results. The extracted nominal flux-averaged cross sections are compared to widely used event generator predictions revealing severe mismodeling of final states without protons for muon neutrino charged-current interactions, possibly from insufficient treatment of final state interactions. These measurements provide a wealth of new information useful for improving event generators which will enhance the sensitivity of precision measurements in neutrino experiments.

   Published by the American Physical Society2024 

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2. Inclusive cross section measurements in final states with and without protons for charged-current νμ -Ar scattering in MicroBooNE

   https://doi.org/10.1103/PhysRevD.110.013006  

   Abratenko, P ; Alterkait, O ; Andrade_Aldana, D ; Arellano, L ; Asaadi, J ; Ashkenazi, A ; Balasubramanian, S ; Baller, B ; Barr, G ; Barrow, D ; et al ( July 2024 , Physical Review D)

   A detailed understanding of inclusive muon neutrino charged-current interactions on argon is crucial to the study of neutrino oscillations in current and future experiments using liquid argon time projection chambers. To that end, we report a comprehensive set of differential cross section measurements for this channel that simultaneously probe the leptonic and hadronic systems by dividing the channel into final states with and without protons. Measurements of the proton kinematics and proton multiplicity of the final state are also presented. For these measurements, we utilize data collected with the MicroBooNE detector from$6.4\times {10}^{20}$protons on target from the Fermilab booster neutrino beam at a mean neutrino energy of approximately 0.8 GeV. We present in detail the cross section extraction procedure, including the unfolding, and model validation that uses data to model comparisons and the conditional constraint formalism to detect mismodeling that may introduce biases to extracted cross sections that are larger than their uncertainties. The validation exposes insufficiencies in the overall model, motivating the inclusion of an additional data-driven reweighting systematic to ensure the accuracy of the unfolding. The extracted results are compared to a number of event generators and their performance is discussed with a focus on the regions of phase space that indicate the greatest need for modeling improvements.

   Published by the American Physical Society2024 

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3. First Search for Dark-Trident Processes Using the MicroBooNE Detector

   https://doi.org/10.1103/PhysRevLett.132.241801  

   Abratenko, P ; Alterkait, O ; Andrade_Aldana, D ; Arellano, L ; Asaadi, J ; Ashkenazi, A ; Balasubramanian, S ; Baller, B ; Barr, G ; Barrow, D ; et al ( June 2024 , Physical Review Letters)

   We present a first search for dark-trident scattering in a neutrino beam using a dataset corresponding to$7.2\times {10}^{20}$protons on target taken with the MicroBooNE detector at Fermilab. Proton interactions in the neutrino target at the main injector produce${\pi }^0$and$\eta$mesons, which could decay into dark-matter (DM) particles mediated via a dark photon$A^{\prime }$. A convolutional neural network is trained to identify interactions of the DM particles in the liquid-argon time projection chamber (LArTPC) exploiting its imagelike reconstruction capability. In the absence of a DM signal, we provide limits at the 90% confidence level on the squared kinematic mixing parameter${ϵ}^2$as a function of the dark-photon mass in the range$10\le M_{A^{\prime }}\le 400\mathrm{MeV}$. The limits cover previously unconstrained parameter space for the production of fermion or scalar DM particles$\chi$for two benchmark models with mass ratios$M_{\chi }/M_{A^{\prime }}=0.6$and 2 and for dark fine-structure constants$0.1\le {\alpha }_D\le 1$.

   Published by the American Physical Society2024 

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

   https://doi.org/10.1103/PhysRevD.109.092008  

   Henry, S ; Su, H ; Akhter, S ; Ahmad_Dar, Z ; Ansari, V ; Ascencio, M V ; Sajjad_Athar, M ; Bashyal, A ; Betancourt, M ; Bonilla, J L ; et al ( May 2024 , Physical Review D)

   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.

   Published by the American Physical Society2024 

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5. Trace anomaly form factors from lattice QCD

   https://doi.org/10.1103/PhysRevD.109.094504  

   Wang, Bigeng ; He, Fangcheng ; Wang, Gen ; Draper, Terrence ; Liang, Jian ; Liu, Keh-Fei ; Yang, Yi-Bo ( May 2024 , Physical Review D)

   The hadron mass can be obtained through the calculation of the trace of the energy-momentum tensor in the hadron which includes the trace anomaly and sigma terms. The anomaly due to conformal symmetry breaking is believed to be an important ingredient for hadron mass generation and confinement. In this work, we will present the calculation of the glue part of the trace anomaly form factors of the pion up to$Q^2\sim 4.3{\mathrm{GeV}}^2$and the nucleon up to$Q^2\sim 1{\mathrm{GeV}}^2$. The calculations are performed on a domain wall fermion ensemble with overlap valence quarks at seven valence pion masses varying from$\sim 250$to$\sim 540\mathrm{MeV}$, including the unitary point$\sim 340\mathrm{MeV}$. We calculate the radius of the glue trace anomaly for the pion and the nucleon from the$z$expansion. By performing a two-dimensional Fourier transform on the glue trace anomaly form factors in the infinite momentum frame with no energy transfer, we also obtain their spatial distributions for several valence quark masses. The results are qualitatively extrapolated to the physical valence pion mass with systematic errors from the unphysical sea quark mass, discretization effects in the renormalization sum rule, and finite-volume effects to be addressed in the future. We find the pion’s form factor changes sign, as does its spatial distribution, for light quark masses. This explains how the trace anomaly contribution to the pion mass approaches zero toward the chiral limit.