9,696 research outputs found
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
Electromagnetic dipole moments of charged baryons with bent crystals at the LHC
We propose a unique program of measurements of electric and magnetic dipole
moments of charm, beauty and strange charged baryons at the LHC, based on the
phenomenon of spin precession of channeled particles in bent crystals. Studies
of crystal channeling and spin precession of positively- and negatively-charged
particles are presented, along with feasibility studies and expected
sensitivities for the proposed experiment using a layout based on the LHCb
detector.Comment: 19 pages, 13 figure
Novel method for the direct measurement of the tau lepton dipole moments
A novel method for the direct measurement of the elusive magnetic and
electric dipole moments of the tau lepton is presented. The experimental
approach relies on the production of tau+ leptons from Ds+ -> tau+ nu_tau
decays, originated in fixed-target collisions at the LHC. A sample of polarized
tau+ leptons is kinematically selected and subsequently channeled in a bent
crystal. The magnetic and electric dipole moments of the tau+ lepton are
measured by determining the rotation of the spin-polarization vector induced by
the intense electromagnetic field between crystal atomic planes. The
experimental technique is discussed along with the expected sensitivities.Comment: 4 pages, 4 figures, 2 pages supplemental material. Accepted by
Phys.Rev.Let
Search for new physics via baryon EDM at LHC
Permanent electric dipole moments (EDMs) of fundamental particles provide
powerful probes for physics beyond the Standard Model. We propose to search for
the EDM of strange and charm baryons at LHC, extending the ongoing experimental
program on the neutron, muon, atoms, molecules and light nuclei. The EDM of
strange baryons, selected from weak decays of charm baryons produced
in pp collisions at LHC, can be determined by studying the spin precession in
the magnetic field of the detector tracking system. A test of CPT symmetry can
be performed by measuring the magnetic dipole moment of and
baryons. For short-lived and
baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam
and channeled in a bent crystal, the spin precession is induced by the intense
electromagnetic field between crystal atomic planes. The experimental layout
based on the LHCb detector and the expected sensitivities in the coming years
are discussed.Comment: Proceeding of Lepton Photon Interactions at High Energies (2017
Association of patients' geographic origins with viral hepatitis co-infection patterns, Spain
To determine if hepatitis C virus seropositivity and active hepatitis B virus infection in HIV-positive patients vary with patients' geographic origins, we studied co-infections in HIV-seropositive adults. Active hepatitis B infection was more prevalent in persons from Africa, and hepatitis C seropositivity was more common in persons from eastern Europe.Ministerio de Sanidad. Instituto de Salud Carlos II
Validity of a self-reported diagnosis of depression among participants in a cohort study using the Structured Clinical Interview for DSM-IV (SCID-I).
Abstract
Background: Depression assessment in population studies is usually based on depressive
symptoms scales. However, the use of scales could lead to the choice of an arbitrary cut-off
point depending on the sample characteristics and on the patient diagnosis. Thus, the use of a
medical diagnosis of depression could be a more appropriate approach.
Objective: To validate a self-reported physician diagnosis of depression using the Structured
Clinical Interview for DSM-IV (SCID-I) as Gold Standard and to assess the factors associated to
a valid self-reported diagnosis.
Methods: The SUN Project is a cohort study based on university graduates followed-up through
postal questionnaires. The response to the question included in the questionnaire: Have you
ever been diagnosed of depression by a physician? was compared to that obtained through the
SCID-I applied by a psychiatrist or a clinical psychologist. The percentages of confirmed
depression and non-depression were assessed for the overall sample and according to several
characteristics. Logistic regression models were fitted to ascertain the association between
different factors and a correct classification regarding depression status.
Results: The percentage of confirmed depression was 74.2%; 95% confidence interval (95%
CI) =63.3-85.1. Out of 42 participants who did not report a depression diagnosis in the
questionnaire, 34 were free of the disease (%confirmed non-depression=81.1%; 95% CI=69.1-
92.9). The probability of being a true positive was higher among ex- smokers and non-smokers
and among those overweight or obese but the differences were not statistically significant.
Conclusion: The validity of a self-reported diagnosis of depression in the SUN cohort is
adequate. Thus, this question about depression diagnosis could be used in further
investigations regarding this disease in this graduate cohort study
On the search for the electric dipole moment of strange and charm baryons at LHC
Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange \u39b baryons, selected from weak decays of charm baryons produced in pp collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of \u39b and \u39b\uaf baryons. For short-lived \u39bc+ and \u39ec+ baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed
Norepinephrine-evoked pain in fibromyalgia. A randomized pilot study [ISRCTN70707830]
BACKGROUND: Fibromyalgia syndrome displays sympathetically maintained pain features such as frequent post-traumatic onset and stimuli-independent pain accompanied by allodynia and paresthesias. Heart rate variability studies showed that fibromyalgia patients have changes consistent with ongoing sympathetic hyperactivity. Norepinephrine-evoked pain test is used to assess sympathetically maintained pain syndromes. Our objective was to define if fibromyalgia patients have norepinephrine-evoked pain. METHODS: Prospective double blind controlled study. Participants: Twenty FM patients, and two age/sex matched control groups; 20 rheumatoid arthritis patients and 20 healthy controls. Ten micrograms of norepinephrine diluted in 0.1 ml of saline solution were injected in a forearm. The contrasting substance, 0.1 ml of saline solution alone, was injected in the opposite forearm. Maximum local pain elicited during the 5 minutes post-injection was graded on a visual analog scale (VAS). Norepinephrine-evoked pain was diagnosed when norepinephrine injection induced greater pain than placebo injection. Intensity of norepinephrine-evoked pain was calculated as the difference between norepinephrine minus placebo-induced VAS scores. RESULTS: Norepinephrine-evoked pain was seen in 80 % of FM patients (95% confidence intervals 56.3 – 94.3%), in 30 % of rheumatoid arthritis patients and in 30 % of healthy controls (95% confidence intervals 11.9 – 54.3) (p < 0.05). Intensity of norepinephrine-evoked pain was greater in FM patients (mean ± SD 2.5 ± 2.5) when compared to rheumatoid arthritis patients (0.3 ± 0.7), and healthy controls (0.3 ± 0.8) p < 0.0001. CONCLUSIONS: Fibromyalgia patients have norepinephrine-evoked pain. This finding supports the hypothesis that fibromyalgia may be a sympathetically maintained pain syndrome
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