相关论文: Old and new physics interpretations of the NuTeV a…
We study the impact of light gauge bosons on neutrino physics. We show that they can explain the NuTeV anomaly and also escape the constraints from neutrino experiments if they are very weakly coupled and have a mass of a few GeV. Lighter…
We report the correction from the asymmetric strange-antistrange sea of the nucleon by using both the light-cone baryon-meson fluctuation model and the chiral quark model, and show that a significant part of the NuTeV anomaly can be…
The NuTeV collaboration recently reported a value of sin2thetaW measured in neutrino-nucleon scattering that is 3 standard deviations above the standard model prediction. This result is derived assuming that (1) the strange sea is…
The strange sea of the proton is generally assumed to have quark - antiquark symmetry. However it has been known for some time that non-perturbative processes involving the meson cloud of the proton may break this symmetry. Recently this…
The NuTeV Collaboration reported a value of $\sin^{2}\theta_{w}$ measured in neutrino-nucleon deep inelastic scattering, and found that the value is three standard deviations from the world average value of other electroweak measurements.…
We summarize theoretical explanations of the three $\sigma$ discrepancy between $\sin^2 \theta_W$ measured by NuTeV and predicted by the Standard Model global fit. Possible new physics explanations ({\it e.g.} an unmized $Z'$) are not…
The NuTeV anomaly of a non-universal value of the fundamental parameter sin^2\theta_W in the electroweak theory has been interpreted as an indication for new physics beyond the Standard Model. However, the observed quantity depends on a…
Predictions of isospin asymmetries of valence and sea distributions are presented which are generated by QED leading ${\cal{O}}(\alpha)$ photon bremsstrahlung effects. Together with isospin violations arising from nonperturbative hadronic…
We consider the contributions of individual new particles to the anomalous magnetic moment of the muon, utilizing the generic framework of simplified models. We also present analytic results for all possible one-loop contributions, allowing…
Our recent theoretical analysis based on the flavor SU(3) chiral quark soliton model predicts fairly large particle-antiparticle asymmetry of the strange sea in the nucleon. We point out that the predicted magnitude of asymmetry is large…
A recent experimental study of excited $^{8}\!Be$ decay to its ground state reveals an anomaly in the final states angle distribution. This exceptional result is attributed to a new vector gauge boson X(16.7). We study the significance of…
A neutron or proton excess in nuclei leads to an isovector-vector mean-field which, through its coupling to the quarks in a bound nucleon, implies a shift in the quark distributions with respect to the Bjorken scaling variable. We show that…
Charge and isospin symmetry violations to valence and sea distribution functions in the nucleon are evaluated (at low resolution scale) by means of a meson cloud model and light-cone quark wave functions. Their perturbative evolution are…
The origin of cosmic ray events with $E \gsim 10^{11}$ GeV remains mysterious. In this talk I briefly summarize several proposed particle physics explanations: a breakdown of Lorentz invariance, the ``$Z-$burst'' scenario, new hadrons with…
We calculate the strange quark and antiquark distributions of the nucleon by using the effective chiral quark model, and find that the strange-antistrange asymmetry can bring a contribution of about 60--100% to the NuTeV deviation of…
Results from the next to leading order (NLO) dimuon analysis from the NuTeV experiment at FNAL are presented. Charged current interactions in neutrino-nucleon scattering with two oppositely charged muons in the final state allow direct…
The $s$-$\bar{s}$ asymmetry in nucleon sea is an important observable for understanding nucleon structure and strong interaction. There have been many theoretical attempts on this subject and recently on its relation to the "NuTeV anomaly".…
Additional Z' gauge bosons are predicted by a wide variety of extensions of the standard model (SM). Possibilities include TeV-scale bosons with electroweak coupling, very light bosons which nearly decouple from the standard model…
Based on quantum fluctuations in momentum and of the proton into meson-baryon pairs, we develop a physical model for the non-perturbative x-shape of parton density functions in the proton. The model describes the proton structure function…
A $Z'$ boson associated with a broken $U(1)_{L_{\mu} - L_{\tau}}$ gauge symmetry offers an economical solution to the long-standing $g_\mu-2$ anomaly, confirmed and strengthened by recent measurements at Fermilab. Here, we revisit the…