113 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
A study of Wigner functions for discrete-time quantum walks
We perform a systematic study of the discrete time Quantum Walk on one
dimension using Wigner functions, which are generalized to include the
chirality (or coin) degree of freedom. In particular, we analyze the evolution
of the negative volume in phase space, as a function of time, for different
initial states. This negativity can be used to quantify the degree of departure
of the system from a classical state. We also relate this quantity to the
entanglement between the coin and walker subspaces.Comment: 16 pages, 8 figure
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
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
Genetic diversity and population structure of Leishmania infantum from Southeastern France : evaluation using Multi-Locus Microsatellite Typing
In the south of France, Leishmania infantum is responsible for numerous cases of canine leishmaniasis (CanL), sporadic cases of human visceral leishmaniasis (VL) and rare cases of cutaneous and muco-cutaneous leishmaniasis (CL and MCL, respectively). Several endemic areas have been clearly identified in the south of France including the Pyrenees-Orientales, Cevennes (CE), Provence (P), Alpes-Maritimes (AM) and Corsica (CO). Within these endemic areas, the two cities of Nice (AM) and Marseille (P), which are located 150 km apart, and their surroundings, concentrate the greatest number of French autochthonous leishmaniasis cases. In this study, 270 L. infantum isolates from an extended time period (1978-2011) from four endemic areas, AM, P, CE and CO, were assessed using Multi-Locus Microsatellite Typing (MLMT). MLMT revealed a total of 121 different genotypes with 91 unique genotypes and 30 repeated genotypes. Substantial genetic diversity was found with a strong genetic differentiation between the Leishmania populations from AM and P. However, exchanges were observed between these two endemic areas in which it seems that strains spread from AM to P. The genetic differentiations in these areas suggest strong epidemiological structuring. A model-based analysis using STRUCTURE revealed two main populations: population A (consisting of samples primarily from the P and AM endemic areas with MON-1 and non-MON-1 strains) and population B consisting of only MON-1 strains essentially from the AM endemic area. For four patients, we observed several isolates from different biological samples which provided insight into disease relapse and re-infection. These findings shed light on the transmission dynamics of parasites in humans. However, further data are required to confirm this hypothesis based on a limited sample set. This study represents the most extensive population analysis of L. infantum strains using MLMT conducted in France
Allelic and genotypic associations of DRD2 Taq I A polymorphism with heroin dependence in Spanish subjects: a case control study
Background: Conflicting associations with heroin dependence have been found involving the A1 allele of dopamine D2 receptor gene ( DRD2) TaqI A polymorphism. Methods: We compared two samples of unrelated Spanish individuals, all of European origin: 281 methadone-maintained heroin-dependent patients ( 207 males and 74 females) who frequently used non-opioid substances, and 145 control subjects ( 98 males and 47 females). Results: The A1-A1 genotype was detected in 7.1% of patients and 1.4% of controls ( P = 0.011, odds ratio = 5.48, 95% CI 1.26-23.78). Although the A1 allele was not associated with heroin dependence in the entire sample, the frequency of A1 allele was higher in male patients than in male controls ( 24.4% vs. 16.3%, P = 0.024, odds ratio = 1.65, 95% CI 1.07-2.57). A logistic regression analysis showed an interaction between DRD2 alleles and gender ( odds ratio = 1.77, 95% CI 1.15-2.70). Conclusion: Our results indicate that, in Spanish individuals, genotypes of the DRD2 TaqI A polymorphism contribute to variations in the risk of heroin dependence, while single alleles contribute only in males
Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators
Quantum phases of matter are characterized by the underlying correlations of
the many-body system. Although this is typically captured by a local order
parameter, it has been shown that a broad class of many-body systems possesses
a hidden non-local order. In the case of bosonic Mott insulators, the ground
state properties are governed by quantum fluctuations in the form of correlated
particle-hole pairs that lead to the emergence of a non-local string order in
one dimension. Using high-resolution imaging of low-dimensional quantum gases
in an optical lattice, we directly detect these pairs with single-site and
single-particle sensitivity and observe string order in the one-dimensional
case.Comment: 9 pages, 7 figure
Analysis of the vertexes , and radiative decays ,
In this article, we study the vertexes and with the light-cone QCD sum rules, then assume the vector meson
dominance of the intermediate , and , and
calculate the radiative decays and .Comment: 28 pages, 4 tables, revised versio
Visualisation of Leishmania donovani Fluorescent Hybrids during Early Stage Development in the Sand Fly Vector
hybrids were produced by co-infecting sand flies with two strains carrying different drug resistance markers. However, the location and timing of hybridisation events in sand flies has not been described. strains carrying hygromycin or neomycin resistance genes and red or green fluorescent markers. Fed females were dissected at different times post bloodmeal (PBM) and examined by fluorescent microscopy or fluorescent activated cell sorting (FACS) followed by confocal microscopy. In mixed infections strains LEM3804 and Gebre-1 reached the cardia and stomodeal valves more rapidly than strains LEM4265 and LV9. Hybrids unequivocally expressing both red and green fluorescence were seen in single flies of both vectors tested, co-infected with LEM4265 and Gebre-1. The hybrids were present as short (procyclic) promastigotes 2 days PBM in the semi-digested blood in the endoperitrophic space. Recovery of a clearly co-expressing hybrid was also achieved by FACS. However, hybrids could not sustain growth in vitro. has profound epidemiological significance, because it facilitates the emergence and spread of new phenotypic traits
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