相关论文: The Lifetime Asymmetry of Polarized Muons in Fligh…
The fermion lifetime was usually calculated in terms of spin states. However, after comparing spin states with helicity states and chirality states, it is pointed out that a spin state is helicity degenerate, and so it can not be used for…
Based on the parity violation in Standard model, we study the dependence of lifetime on the helicity of an initial-state fermion in weak interactions. It is pointed out that if the initial fermions in the decays are longitudinally…
We present an analytical study of the spin projection operator of the spin state and the helicity state. It is pointed out emphatically that the former is Lorentz covariant, while the latter is a nonrelativistic two-component operator. In…
Measurements of lifetimes can be done in two ways. For very short lived particles, the width can be measured. For long lived ones, the lifetime can be directly measured, for example, using a displaced vertex. Practically, the lifetime…
The left-right polarization-dependent asymmetry of the weak interaction mass is investigated. Based on the Standard Model, the calculation shows that the weak interaction mass of left-handed polarized fermions is always greater than that of…
Polarization of a vortex state fermion has rich structure due to the nontrivial momentum distribution of wave function. This larger freedom provides an unique opportunity to prepare fermions in exotic polarized states, which do not exist…
The MuLan collaboration has measured the lifetime of the positve muon to a precision of 1.0 parts per million. The Fermi constant is determined to a precision of 0.6 parts per million.
A hybrid ferromagnet/semiconductor device is used to determine a lower bound on the spin lifetime for conduction electrons in silicon. We use spin precession to self-consistently measure the drift velocity vs. drift field of spin-polarized…
Recent STAR measurements suggest a difference in the global spin polarization between hyperons and anti-hyperons, especially at relatively low collision beam energy. One possible cause of this difference is the potential presence of…
While biologists have not yet reached a consensus on the definition of life, homochirality - the specific molecular handedness of biomolecules - is a phenomenon only produced by life. The unraveling of its origin requires interdisciplinary…
The experimental test problem of the left-right polarization-dependent lifetime asymmetry is discussed. It shows that the existing experiments cannot demonstrate the lifetime asymmetry to be right or wrong after analyzing the measurements…
In this work, our purpose is to show how the symmetry of identical particles can influence the time evolution of free particles in the nonrelativistic and relativistic domains. For this goal, we consider a system of either two…
The muLan experiment at the Paul Scherrer Institute will measure the lifetime of the positive muon with a precision of 1 ppm, giving a value for the Fermi coupling constant G_F at the level of 0.5 ppm. Meanwhile, by measuring the observed…
The ground state of an impurity immersed in a Fermi sea changes from a polaron to a molecule as the interaction strength is increased. We show here that the coupling between these two states is strongly suppressed due to a combination of…
We search for a dependence of the lifetime of $^{20}\text{Na}$ nuclei on the nuclear spin direction. Such a directional dependence would be evidence for Lorentz-invariance violation in weak interactions. A difference in lifetime between…
We calculate the helicity and chirality effects experienced by a spin-1/2 particle subjected to classical electromagnetic and gravitational fields. The helicity evolution is then determined in the non-relativistic, relativistic, and…
We discuss special type of polarization asymmetry (``handedness") in the process $e^+e^-\to 4\pi$, when one of initial particles is longitudinally polarized. The asymmetry is proportional to the degree of polarization and to the width to…
The Fermi Constant, G_F, describes the strength of the weak force and is determined most precisely from the mean life of the positive muon, tau_mu. Advances in theory have reduced the theoretical uncertainty on G_F as calculated from tau_mu…
Living organisms exhibit consistent homochirality. It is argued that the specific, binary choice made is not an accident but is a consequence of parity violation in the weak interaction expressed by cosmic irradiation. The secondary muons…
We analyze Planck scale induced modifications of the relativistic time dilation using data from the Muon Storage Ring experiment at CERN. By examining the lifetimes of muons, we establish, for the first time, a constraint on such quantum…