Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userA Measurement of the Weak Mixing Angle in Neutrino-Nucleon Scattering at NuTeV
106
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The NuTeV experiment at Fermilab presents a determination of the electroweak mixing angle. High purity, large statistics samples of muon-neutrino and muon-antineutrino events allow the use of the Paschos-Wolfenstein relation. This considerably reduces systematic errors associated with charm production and other sources. With Standard Model assumptions, this measurement of sin2thw indirectly determines the W boson mass to a precision comparable to direct measurements from high energy e+e- and p-pbar colliders. NuTeV measures sin^2theta_W (on-shell) = 0.2253 +/- 0.0019(stat) +/- 0.0010(syst) which implies M_W = 80.26 +/- 0.11 GeV.
rate research
Read More
We report the measurement of sin2thetaW in neutrino-nucleon deep inelastic scattering from the NuTeV experiment. Using separate neutrino and anti-neutrino beams, NuTeV is able to determine sin2thetaW with low systematic errors by measuring the Paschos-Wolfenstein variable R-minus, a ratio of differences of neutrino and anti-neutrino neutral-current and charged-current cross-sections. NuTeV measures sin2thetaW(on-shell)= 0.2253+/-0.0019(stat)+/-0.0010(syst), which implies a W mass of 80.26+/-0.11 GeV.
The E158 experiment at SLAC has made the first measurement of parity violation in electron-electron (Moller) scattering. We report a preliminary result using 50% of the accumulated data sample for the right-left parity-violating cross-section asymmetry (APV) in the elastic scattering of 45 and 48 GeV polarized electron beams with unpolarized electrons in a liquid hydrogen target. We find APV = (-160 +- 21 (stat.) +- 17 (syst.)) parts per billion, with a significance of 6.3sigma for observing parity violation. In the context of the Standard Model, this yields a measurement of the weak mixing angle, sin^2(thetaW-MSBAR)(Q^2 = 0.026 GeV^2) = 0.2379 +- 0.0016 (stat.) +- 0.0013 (syst.). We also present preliminary results for the first observation of a single-spin transverse asymmetry in Moller scattering.
After the first measurement of the coherent elastic neutrino nucleus scattering (CENNS) by the COHERENT Collaboration, it is expected that new experiments will confirm the observation. Such measurements will allow to put stronger constraints or discover new physics as well as to probe the Standard Model by measuring its parameters. This is the case of the weak mixing angle at low energies, which could be measured with an increased precision in future results of CENNS experiments using, for example, reactor antineutrinos. In this work we analyze the physics potential of different proposals for the improvement of our current knowledge of this observable and show that they are very promising.
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05times10^{20}$ protons-on-target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($theta_{23} = pi/4$). Assuming the normal mass hierarchy, we find $Delta m^2 = (2.67 pm 0.11)times 10^{-3}$ eV$^2$ and $sin^2 theta_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6 $sigma$ significance.
We investigate the parton distribution function (PDF) uncertainty in the measurement of the effective weak mixing angle $sin^2theta_{text{eff}}^{ell}$ at the CERN Large Hadron Collider (LHC). The PDF-induced uncertainty is large in the proton-proton collisions at the LHC due to the dilution effect. The measurement of the Drell-Yan forward-backward asymmetry ($A_{FB}$) at the LHC can be used to reduce the PDF uncertainty in the $sin^2theta_{text{eff}}^{ell}$ measurement. However, when including the full mass range of lepton pairs in the $A_{FB}$ data analysis, the correlation between the PDF updating procedure and the $sin^2theta_{text{eff}}^{ell}$ extraction leads to a sizable bias in the obtained $sin^2theta_{text{eff}}^{ell}$ value. From our studies, we find that the bias can be significantly reduced by removing Drell-Yan events with invariant mass around the $Z$ pole region, while most of the sensitivity in reducing the PDF uncertainty remains. Furthermore, the lepton charge asymmetry in the $W$ boson events as a function of the rapidity of the charged leptons, $A_pm(eta_ell)$, is known to be another observable which can be used to reduce the PDF uncertainty in the $sin^2theta_{text{eff}}^{ell}$ measurement. The constraint from $A_pm(eta_ell)$ is complementary to that from the $A_{FB}$, thus no bias affects the $sin^2theta_{text{eff}}^{ell}$ extraction. The studies are performed using the Error PDF Updating Method Package ({sc ePump}), which is based on the Hessian updating methods. In this article, the CT14HERA2 PDF set is used as an example.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
