We consider two-body and quasi-two-body decays of the type
f
1
→
f
2
B
, where
f
1
and
f
2
are spin-1/2 fermions and
B
a spin-0 or spin-1 boson. After recalling the non-covariant formalism for decay ...amplitudes, we derive the expression of the differential decay width and of the polarizations of the final spinning particles, both on- and off-shell. We find an intriguing geometrical interpretation of the results about the polarization. We also illustrate some methods for measuring the polarizations of the resonances and for optimizing data analysis. Then we propose applications to semi-leptonic weak decays, with a major attention to the
T
-odd component of the polarization; this may help to find, simultaneously, possible time-reversal violations and hints to physics beyond the standard model. We suggest also a
CPT
test. Last, we discuss some
T
-odd observables for the production process of
f
1
and for the study of the strong final state interactions of non-leptonic decays.
We consider two-body and quasi-two-body decays of the type $f_1 \rightarrow f_2 B$, where $f_1$ and $f_2$ are spin-1/2 fermions and B a spin-0 or spin-1 boson. After recalling the non-covariant ...formalism for decay amplitudes, we derive the expression of the differential decay width and of the polarizations of the final spinning particles, both on- and off-shell. We find an intriguing geometrical interpretation of the results about the polarization. We also illustrate some methods for measuring the polarizations of the resonances and for optimizing data analysis. Then we propose applications to semi-leptonic weak decays, with a major attention to the T-odd component of the polarization, this may help to find, simultaneously, possible time-reversal violations and hints to physics beyond the standard model. We suggest also a CPT test. Last, we discuss some T-odd observables for the production process of $f_1$ and for the study of the strong final state interactions of non-leptonic decays.
Erratum to: Polarization in Ajaltouni, Z. J; Di Salvo, E
The European physical journal. C, Particles and fields,
06/2021, Volume:
81, Issue:
6
Journal Article
Λb decays into Λ-vector Ajaltouni, Z.J.; Conte, E.; Leitner, O.
Physics letters. B,
05/2005, Volume:
614, Issue:
3-4
Journal Article
Peer reviewed
Open access
A complete study of the angular distributions of the processes, Λb→ΛV(1−), with Λ→pπ− and V(J/Ψ)→ℓ+ℓ− or V(ρ0)→π+π−, is performed. Emphasis is put on the initial Λb polarization produced in the ...proton–proton collisions. The polarization density-matrices as well as angular distributions are derived and help to construct T-odd observables which allow us to perform tests of both time-reversal and CP violation.
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