NuMI Target Research Articles

Muon Neutrino on Electron Elastic Scattering in the NOvA Near Detector and its Applications Beyond the Standard Model

Using the NuMI beam at Fermilab and the NOvA near detector, we study the process by which a muon neutrino elastically scatters off an electron in the detector to produce a very forward going electromagnetic shower. By comparing dE/dx for various particle hypotheses for both longitudinal and transverse directions in a multilayer perceptron neural network, we trained a Particle ID algorithm to identify the scattered electron in an inclusive dataset. Muon-neutrino-on-e elastic scattering provides a clean, purely leptonic process free from nuclear effects for understanding neutral current scattering and constraining the NuMI beam flux. Also, this technique can be applied in two broad areas of beyond the standard model physics: a large neutrino transition magnetic moment and light dark matter particles produced in the NuMI target, both of which would create an energy dependent enhancement in the elastic scattering cross section.

Measurement of charged pion production yields off the NuMI target

The fixed-target MIPP experiment, Fermilab E907, was designed to measure the production of hadrons from the collisions of hadrons of momenta ranging from 5 to 120 GeV/c on a variety of nuclei. These data will generally improve the simulation of particle detectors and predictions of particle beam fluxes at accelerators. The spectrometer momentum resolution is between 3 and 4%, and particle identification is performed for particles ranging between 0.3 and 80 GeV/c using $dE/dx$, time-of-flight and Cherenkov radiation measurements. MIPP collected $1.42 \times10^6$ events of 120 GeV Main Injector protons striking a target used in the NuMI facility at Fermilab. The data have been analyzed and we present here charged pion yields per proton-on-target determined in bins of longitudinal and transverse momentum between 0.5 and 80 GeV/c, with combined statistical and systematic relative uncertainties between 5 and 10%.

New light weakly-coupled particle searches in a neutrino detector

Neutrino detectors at the accelerator machines of the Intensity Frontier in particle physics are becoming commonplace. As their capabilities are being understood, they seem to have the potential for studies beyond the neutrino oscillations measurements. Besides these primary neutrino physics goals, a number of exotic searches can be done with such detectors in general, and the NOvA detectors that we present here, as a particular example. Specifically, we focus on simulating signatures in NOvA experiment's Near-Detector (300 ton, 900 m from the NuMI target of Fermilab) that correspond to beam-generated new physics states from hidden sectors, dark sectors, axion-like particles, heavy or sterile neutrinos, and heavy photons. As there are no physics generators that can inherently include such states, along with the mainstream production branches, we present here the initial stages of an effort to incorporate these signatures manually in the overall simulation framework of the NOvA experiment. For this, we discuss examples and examine the potential and challenges for detecting such signatures.

The NOvA Timing System: A system for synchronizing a long baseline neutrino experiment

The NOvA experiment is designed to measure key parameters in neutrino physics related to the neutrino mass hierarchy and the asymmetry between matter and anti-matter. To make these measurements the NOvA experiment must correlate the extraction of beam to the NuMI target with individual hits in both a near detector and a far detector located 810 km from Fermilab. Precisely correlating hits across these detectors and reconstructing particle trajectories require that all of the readout electronics be precisely synchronized to an absolute wall time with a channel to channel variation less than 15.6 ns. The NOvA Timing Distribution System accomplishes this through an integration of commercial GPS receiver technology and custom electronics. This paper describes the timing system, its component hardware and the synchronization method that is employed by it.

Status and latest results from MIPP

We briefly review the need for high quality hadron production data. The Main Injector Particle Production experiment (MIPP) at Fermilab collected data in 2005/2006 and published final results on forward neutron production and the charged kaon mass. Preliminary results on other topice, including particle production on the NuMI target, have also been presented. We provide a summary of past results and an outlook.

Improved Search for Muon-Neutrino to Electron-Neutrino Oscillations in MINOS

We report the results of a search for ν(e) appearance in a ν(μ) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (θ(23))sin(2)(2θ(13))<0.12(0.20) at 90% confidence level for δ = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (θ(23))sin(2)(2θ(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The θ(13) = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.

Fixed target hadron production measurements

The knowledge of light hadron production cross-sections in proton-nucleus interactions is an important prerequisite to the analysis of a wide variety of experiments. One of the important limiting factors for the precision of accelerator based and atmospheric neutrino oscillation experiments is the uncertainty in the composition and spectrum of the neutrino flux. Cosmic-ray experiments detecting extensive air-showers can greatly improve their ability to interpret the data when precise hadron production spectra are available over a large range of energies. Dedicated hadron production experiments have been taking data recently and are now publishing their results. Other experiments have just started their data-taking and plan to supply measurements which can significantly extend the kinematic range in which data will be available. Early measurements at the LHC can extend this range to much higher energies than available up to now. Recent results will be shown and compared with hadronic production models. An outlook of forthcoming results is given and the possibilities at the LHC are explored. The E910 experiment at BNL has recently published their p–Be data. The HARP experiment has presented results on the measurements of the double-differential production cross-section of charged pions in proton interactions with beryllium, carbon, aluminium, copper, tin, tantalum and lead targets. NA49 has measured pion production spectra in p–C interactions and a new experiment, NA61, has taken data using an upgraded version of this detector. NA61 plans to measure production spectra for the T2K experiment and for the calculation of extended air showers. MIPP has taken data with a copy of the NuMI target and is progressing in the analysis of these data. An upgrade of the readout of this experiment can greatly increase its potential.

NuMI target hadron production measurement in MIPP

Measurements of neutrino cross-section and oscillations depend heavily on neutrino flux predictions. Such predictions rely on hadron-nucleus interaction cross-section data, and yet the data are scarce. The E907 Main Injector Particle Production (MIPP) experiment at Fermilab is a full acceptance spectrometer with excellent particle identification capabilities. MIPP has collected ∼15 x 106 events of p's, π's and K's at various momenta (from 5 to 120 GeV) on several targets spanning the periodic table, from hydrogen to uranium including beryllium and carbon. In particular, MIPP has collected hadron production data on a spare NuMI target using 120 GeV/c protons from the Main Injector. We review the experiment, performance of the spectrometer and show preliminary results of particle production for thin and thick carbon targets.

Neutrino oscillation results from MINOS

We report an updated measurement of muon neutrino disappearance in the NuMI neutrino beam performed using the MINOS detectors. This preliminary result is based on an increased data set corresponding to 2.50 × 1020 protons on the NuMI target, and incorporates a number of improvements to our analysis. We observe 563 candidate vμ CC interactions in the far detector data, compared with an expectation of 738 ± 30 in the absence of oscillations. A maximum likelihood fit to the observed far detector energy spectrum assuming two-flavour vμ → vτ oscillations yields best fit oscillation parameters of Δm223 = 2.38+0.20−0.16 × 10−3eV2 and sin22θ23 = 1.00−0.08 with errors quoted at the 68% confidence level.

First MINOS Results with the NuMI Beam

The results from the initial exposure of the MINOS detectors to neutrinos produced by the Fermilab NuMI beam are reported here. The exposure consisted of 1.27 × 10 20 120 GeV protons incident on the NuMI target. The data show the observation of 215 neutrinos with energies below 30 GeV while 336 ± 14.4 events were expected. The data are consistent with ν μ disappearance via neutrino oscillations with | Δ m 23 2 | = 2.74 −0.26 +0.44 × 10 −3 eV 2 / c 4 and sin 2 2 θ 23 > 0.87 (68% C.L.).

Observation of Muon Neutrino Disappearance with the MINOS Detectors in the NuMI Neutrino Beam

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).