5,481 research outputs found
Discrete Symmetries CP, T, CPT
The role of Symmetry Breaking mechanisms to search for New Physics is of
highest importance. We discuss the status and prospects of the Discrete
Symmetries CP, T, CPT looking for their separate Violation in LHC experiments
and meson factories.Comment: 9 pages, 5 figures; Jagiellonian Symposium on Fundamental and Applied
Subatomic Physic
Photometric study of the double cluster h and chi Persei
We present uvbybeta CCD photometry of the central region of the double
cluster h and chi Persei. We identify 350 stars, of which 214 were not included
in Oosterhof catalogue. Our magnitude limit V=16.5 allows us to reach early F
spectral type and obtain very accurate fits to the ZAMS. We derive reddening
values of E(b-y)=0.44+-0.02 for h Persei and E(b-y)=0.39+-0.05 for chi Persei.
From the ZAMS fitting, we derive distance moduli V0-Mv=11.66+-0.20 and
V0-Mv=11.56+-0.20 for h and chi Persei respectively. These values are perfectly
compatible with both clusters being placed at the same distance and having
identical reddenings. The shift in the main-sequence turnoff and isochrone
fitting, however, show that there is a significant age difference between both
clusters, with the bulk of stars in h Persei being older than chi Persei. There
is, however, a significant population of stars in h Persei which are younger
than chi Persei. All this argues for at least three different epochs of star
formation, corresponding approximately to log t=7.0, 7.15 and 7.3.Comment: 47 pages, 15 figures and 29 tables. Uses aa.cls. Accepted for
publication in the Astronomy and Astrophysic
Absolute neutrino mass and the Dirac/Majorana distinction from the weak interaction of aggregate matter
The 2-mediated force has a range of microns, well beyond the atomic
scale. The effective potential is built from the t-channel absorptive part of
the scattering amplitude and depends on neutrino properties on-shell. We
demonstrate that neutral aggregate matter has a weak charge and calculate the
matrix of six coherent charges for its interaction with definite-mass
neutrinos. Near the range of the potential the neutrino pair is
non-relativistic, leading to observable absolute mass and Dirac/Majorana
distinction via different r-dependence and violation of the weak equivalence
principle.Comment: 6 pages, 3 figures, 1 tabl
Stimulated transitions in resonant atom Majorana mixing
Massive neutrinos demand to ask whether they are Dirac or Majorana particles.
Majorana neutrinos are an irrefutable proof of physics beyond the Standard
Model. Neutrinoless double electron capture is not a process but a virtual
mixing between a parent atom and a daughter
excited atom with two electron holes. As a mixing between two neutral atoms and
the observable signal in terms of emitted two-hole X-rays, the strategy,
experimental signature and background are different from neutrinoless double
beta decay. The mixing is resonantly enhanced for almost degeneracy and, under
these conditions, there is no irreducible background from the standard
two-neutrino channel. We reconstruct the natural time history of a nominally
stable parent atom since its production either by nature or in the laboratory.
After the time periods of atom oscillations and the decay of the short-lived
daughter atom, at observable times the relevant "stationary" states are the
mixed metastable long-lived state and the non-orthogonal short-lived excited
state, as well as the ground state of the daughter atom. We find that they have
a natural population inversion which is most appropriate for exploiting the
bosonic nature of the observed atomic transitions radiation. Among different
observables of the atom Majorana mixing, we include the enhanced rate of
stimulated X-ray emission from the long-lived metastable state by a
high-intensity X-ray beam: a gain factor of 100 can be envisaged at current
XFEL facilities. On the other hand, the historical population of the daughter
atom ground state can be probed by exciting it with a current pulsed optical
laser, showing the characteristic absorption lines: the whole population can be
excited in a shorter time than typical pulse duration.Comment: 17 pages, 4 figure
- …