相关论文: Improved Limits on Long-Range Parity-Odd Interacti…
Various theories beyond the Standard Model predict new particles with masses in the sub-eV range with very weak couplings to ordinary matter. A parity-odd interaction between polarized nucleons and unpolarized matter proportional to…
We have constrained possible new interactions which produce nonrelativistic potentials between polarized neutrons and unpolarized matter proportional to $\alpha\vec{\sigma}\cdot\vec{v}$ where $\vec{\sigma}$ is the neutron spin and $\vec{v}$…
New particles with masses in the sub-eV range have been predicted by various theories beyond the Standard Model. Some can induce new spin-spin interactions between fermions. Existing constraints on such interactions between nucleons with…
Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity…
Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons.…
We report on the search for a CPT and Lorentz invariance violating coupling of the 3He and 129Xe nuclear spins (each largely determined by a valence neutron) to background tensor fields which permeate the universe. Our experimental approach…
Measurements of parity-violating longitudinal analyzing powers Az (normalized asymmetries) in polarized proton-proton scattering and in polarized neutron capture on the proton (n+p -> d+gamma) provide a unique window on the interplay…
In this paper, we discuss a possibility to improve constraints on spin-dependent short-range interactions in the range of 1 - 200 micrometer significantly. For such interactions, our constraints are without competition at the moment. They…
TRIUMF experiment 497 has measured the parity violating longitudinal analyzing power, A_z, in pp elastic scattering at 221.3 MeV incident proton energy. This paper includes details of the corrections, some of magnitude comparable to A_z…
The proton-proton parity-violating longitudinal asymmetry is calculated in the lab-energy range 0--350 MeV, using a number of different, latest-generation strong-interaction potentials--Argonne V18, Bonn-2000, and Nijmegen-I--in combination…
We have studied the relaxation of a spin-polarized gas in a magnetic field, in the presence of short-range spin-dependent interactions. As a main result we have established a link between the specific properties of the interaction and the…
We report a search for exotic spin-spin interactions between neutrons and electrons which could signal new physics beyond the Standard Model using slow neutron polarimetric imaging through a dense medium of polarized electrons. Our dense…
We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of…
We report the first experimental upper bound to our knowledge on possible in-matter torsion interactions of the neutron from a recent search for parity violation in neutron spin rotation in liquid He-4. Our experiment constrains a…
We report new measurements of the parity-violating asymmetry A_PV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta_lab>~6.0 degrees. The 4He result is A_PV = (+6.40 +/- 0.23 (stat) +/- 0.12 (syst)) x10^-6.…
A magnetometer using spin-polarized K and $^3$He atoms occupying the same volume is used to search for anomalous nuclear spin-dependent forces generated by a separate $^3$He spin source. We measure changes in the $^3$He spin precession…
Measurement of the parity-violating electron scattering asymmetry from ${}^{208}$Pb has demonstrated a new opportunity at Jefferson Lab to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a relatively…
Very light particles with CP-violating couplings to ordinary matter, such as axions or axion-like particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces…
We propose an original test of Lorentz invariance in the interaction between a particle spin and an electromagnetic field and report on a first measurement using ultracold neutrons. We used a high sensitivity neutron electric dipole moment…
Time-Reversal-Invariance non-conservation has now been unequivocally demonstrated in a direct measurement at CPLEAR. What about tests of time-reversal-invariance in systems other than the kaon system? Tests of time-reversal-invariance…