arXiv subjects

Thomas Junk

Publications and source records attributed to Thomas Junk.

6 recordsLinked to original sources

arXiv2024

Invariant amplitudes, unpolarized cross sections, and polarization asymmetries in (anti)neutrino-nucleon elastic scattering

At leading order in weak and electromagnetic couplings, cross sections for (anti)neutrino-nucleon elastic scattering are determined by four nucleon form factors that depend on the momentum transfer $Q^2$. Including radiative corrections in the Standard Model and potential new physics contributions beyond the Standard Model, eight invariant amplitudes are possible, depending on both $Q^2$ and the (anti)neutrino energy $E_\nu$. We review the definition of these amplitudes and use them to compute both unpolarized and polarized observables including radiative corrections. We show that unpolarized accelerator neutrino cross-section measurements can probe new physics parameter space within the constraints inferred from precision beta decay measurements.

hep-ph↗

arXiv2024

Constraints on new physics with (anti)neutrino-nucleon scattering data

New physics contributions to the (anti)neutrino-nucleon elastic scattering process can be constrained by precision measurements, with controlled Standard Model uncertainties. In a large class of new physics models, interactions involving charged leptons of different flavor can be related, and the large muon flavor component of accelerator neutrino beams can mitigate the lepton mass suppression that occurs in other low-energy measurements. We employ the recent high-statistics measurement of the cross section for $\bar{\nu}_\mu p \to \mu^+ n$ scattering on the hydrogen atom by MINERvA to place new confidence intervals on tensor and scalar neutrino-nucleon interactions: $\mathfrak{Re} C_T = -1^{+14}_{-13} \times 10^{-4}$, $|\mathfrak{Im} C_T| \le 1.3 \times 10^{-3}$, and $|\mathfrak{Im} C_S| = 45^{+13}_{-19} \times 10^{-3}$. These results represent a reduction in uncertainty by a factor of $2.1$, $3.1$, and $1.2$, respectively, compared to existing constraints from precision beta decay.

hep-ph↗

arXiv2022

Neutrino Scattering Measurements on Hydrogen and Deuterium: A Snowmass White Paper

Neutrino interaction uncertainties are a limiting factor in current and next-generation experiments probing the fundamental physics of neutrinos, a unique window on physics beyond the Standard Model. Neutrino-nucleon scattering amplitudes are an important part of the neutrino interaction program. However, since all modern neutrino detectors are composed primarily of heavy nuclei, knowledge of elementary neutrino-nucleon amplitudes relies heavily on experiments performed in the 1970s and 1980s, whose statistical and systematic precision are insufficient for current needs. In this white paper, we outline the motivation for attempting measurements on hydrogen and deuterium that would improve this knowledge, and we discuss options for making these measurements either with the DUNE near detector or with a dedicated facility.

hep-ex↗

arXiv2022

Bubble Chamber Detectors with Light Nuclear Targets: A Snowmass 2021 White Paper

Neutrino cross sections are a critical ingredient in experiments that depend on neutrino scattering to reconstruct event kinematics and infer neutrino characteristics, like NOvA and T2K. An opportunity exists to reduce the 5-10% broad uncertainty on neutrino cross sections by producing more measurements of neutrino scattering from light nuclear targets at the relevant energies. Bubble chambers with light nuclear targets would be ideal for these measurements but the most recent device designed for use with an accelerator neutrino source is at least fifty years old. A new bubble chamber with light nuclear targets could be designed by observing how the technology has progressed for use in dark matter experiments and producing smaller modular devices that use more efficient cooling systems. A smaller modular device could also be designed for deployment to all functioning neutrino beams, but an investigation of the proper operating characteristics is necessary to adapt newer detectors to the structure of contemporary neutrino beams.

physics.ins-det↗

arXiv2014

Review of Physics Results from the Tevatron

We present a comprehensive review of the physics results obtained by the CDF and D0 collaborations up to summer 2014, with emphasis on those achieved in the Run II of the Tevatron collider which delivered a total integrated luminosity of ~10 fb-1 at sqrt{s}=1.96 TeV. The results are presented in six main physics topics: QCD, Heavy Flavor, Electroweak, Top quark, Higgs boson and searches for New Particles and Interactions. The characteristics of the accelerator, detectors, and the techniques used to achieve these results are also briefly summarized.

hep-ex↗

arXiv1999

Confidence Level Computation for Combining Searches with Small Statistics

This article describes an efficient procedure for computing approximate confidence levels for searches for new particles where the expected signal and background levels are small enough to require the use of Poisson statistics. The results of many independent searches for the same particle may be combined easily, regardless of the discriminating variables which may be measured for the candidate events. The effects of systematic uncertainty in the signal and background models are incorporated in the confidence levels. The procedure described allows efficient computation of expected confidence levels.

hep-ex↗