146 research outputs found
The CP-Conserving Direction
A symmetry transformation is well defined in the case of an invariant theory,
being the corresponding operator undetermined otherwise. However, we show that,
even with CP violation, it is possible to determine the CP transformation by
separating the Lagrangian of the Standard Model in a CP-conserving and a
CP-violating part, in a unique way, making use of the empirically known quark
mixing hierarchy. To order \lambda^3 for the Bd-system, the CP-conserving
direction matches one of the sides of the (bd) unitarity triangle. We use this
determination to calculate the rephasing invariant parameter \epsilon, which
measures CP-mixing in the B0-B0bar system.Comment: 12 pages, no figure. Version to appear in JHE
T and CPT in B-Factories
For the Bd meson system, CP, T and CPT indirect violation can be described
using two physical parameters, epsilon and delta. The traditional observables
based on flavour tag and used in the kaon system, are not helpful in the Bd
case, and new asymmetries have to be introduced. Here such alternative
observables, based on CP tag, are presented, together with the first estimation
on the sensitivity that current asymmetric B-factories can achieve on their
measurement.Comment: 7 pages, Talk given at the International Europhysics conference on
HEP, HEP2001, July 2001, Budapest (Hungary
Direct test of time-reversal symmetry in the entangled neutral kaon system at a -factory
We present a novel method to perform a direct T (time reversal) symmetry test
in the neutral kaon system, independent of any CP and/or CPT symmetry tests.
This is based on the comparison of suitable transition probabilities, where the
required interchange of in out states for a given process is obtained
exploiting the Einstein-Podolsky-Rosen correlations of neutral kaon pairs
produced at a -factory. In the time distribution between the two decays,
we compare a reference transition like the one defined by the time ordered
decays with the T -conjugated one defined by . With the use of this and other T conjugated comparisons, the KLOE-2
experiment at DANE could make a significant test
Investigation of the 1+1 dimensional Thirring model using the method of matrix product states
We present preliminary results of a study on the non-thermal phase structure
of the (1+1) dimensional massive Thirring model, employing the method of matrix
product states. Through investigating the entanglement entropy, the fermion
correlators and the chiral condensate, it is found that this approach enables
us to observe numerical evidence of a Kosterlitz-Thouless phase transition in
the model.Comment: 7 pages, 4 figures; contribution to the proceedings of Lattice 2018
conferenc
Novel T-Violation observable open to any pair of decay channels at meson factories
Quantum entanglement between the two neutral mesons produced in meson factories has allowed the first indisputable direct observation of Time Reversal Violation in the time evolution of the neutral meson between the two decays. The exceptional meson transitions are directly connected to semileptonic and CP eigenstate decay channels. The possibility of extending the observable asymmetries to more decay channels confronts the problem of the ¿orthogonality condition¿, which can be stated with this tonguetwister: Given a decay channel f, which is the decay channel f' such that the meson state not decaying to f is orthogonal to the meson state not decaying to f? In this Letter we propose an alternative T-Violation asymmetry at meson factories which allows its opening to any pair of decay channels. Instead of searching which is the pair of decay channels associated to the T-reverse meson transition, we build an asymmetry which tags the initial states of both the Reference and the T-reverse meson transitions. This observable filters the appropriate final states by means of two measurable survival probabilities. We discuss the methodology to be followed in the analysis of the new observable and the results expected in specific examples
CPT violation in entangled B0-B0bar states and the demise of flavour tagging
We discuss the demise of flavour tagging due to the loss of the
particle-antiparticle identity of neutral B-mesons in the
Einstein-Podolsky-Rosen correlated states. Such a situation occurs in cases
where the CPT operator is ill-defined, as happens, for example, in quantum
gravity models with induced decoherence in the matter sector. The time
evolution of the perturbed B0-B0bar initial state, as produced in B-factories,
is sufficient to generate new two-body states. For flavour specific decays at
equal times, we discuss two definite tests of the two body entanglement: (i)
search for the would-be forbidden B0 B0 and B0bar B0bar states; (ii) deviations
from the indistinguishable probability between the permuted states B0bar B0 and
B0 B0bar.Comment: 12 pages LATEX, one eps figure incorporate
Intrinsic CPT violation and decoherence for entangled neutral mesons
We present a combined treatment of quantum-gravity-induced effects and
intrinsic CPT violation in entangled neutral-Kaon states. Our analysis takes
into consideration two types of effects: first, those associated with the loss
of particle-antiparticle identity, as a result of the ill-defined nature of the
CPT operator, and second, effects due to the non-unitary evolution of the Kaons
in the space-time foam. By studying a variety of phi-factory observables,
involving identical as well as general final states, we derive analytical
expressions, to leading order in the associated CPT violating parameters, for
double-decay rates and their time-integrated counterparts. Our analysis shows
that the various types of the aforementioned effects may be disentangled
through judicious combinations of appropriate observables in a phi factory.Comment: 31 pages revtex, nine eps figures incorporated, Journal version
(typos and latex errors corrected, discussion augmented, no changes in
conclussions
Comparison of Leishmania killicki (syn. L-tropica) and Leishmania tropica population structure in Maghreb by microsatellite typing
Leishmania (L.) killicki (syn. L. tropica), which causes cutaneous leishmaniasis in Maghreb, was recently described in this region and identified as a subpopulation of L. tropica. The present genetic analysis was conducted to explore the spatio-temporal distribution of L. killicki (syn. L. tropica) and its transmission dynamics. To better understand the evolution of this parasite, its population structure was then compared with that of L. tropica populations from Morocco. In total 198 samples including 85 L. killicki (syn. L. tropica) (from Tunisia, Algeria and Libya) and 113 L. tropica specimens (all from Morocco) were tested. Theses samples were composed of 168 Leishmania strains isolated from human skin lesions, 27 DNA samples from human skin lesion biopsies, two DNA samples from Ctenodactylus gundi bone marrow and one DNA sample from a Phlebotomus sergenti female. The sample was analyzed by using MultiLocus Enzyme Electrophoresis (MLEE) and MultiLocus Microsatellite Typing (MLMT) approaches. Analysis of the MLMT data support the hypothesis that L. killicki (syn. L. tropica) belongs to the L. tropica complex, despite its strong genetic differentiation, and that it emerged from this taxon by a founder effect. Moreover, it revealed a strong structuring in L. killicki (syn. L. tropica) between Tunisia and Algeria and within the different Tunisian regions, suggesting low dispersion of L. killicki (syn. L. tropica) in space and time. Comparison of the L. tropica (exclusively from Morocco) and L. killicki (syn. L. tropica) population structures revealed distinct genetic organizations, reflecting different epidemiological cycles
- …