Looking for a theory of faster-than-light particles

Several principal aspects of a theoretical approach to the theory of faster-than-light particles (tachyons) are considered in this note. They concern the resolution of such problems of tachyon theory as the causality violation by tachyons, the stability of the tachyon vacuum, and the stability of ordinary particles against the spontaneous emission of tachyons, i.e. the problems which are generally used as arguments against the possibility of such particles. It is demonstrated that all these arguments contain nontrivial loopholes which undermine their validity. A demand for a consistent tachyon theory is formulated, and several ideas for its construction are suggested.Comment: 41 pages, 5 figure

First observation of strong OZI rule violation in πN\pi N interactions

The data of the CERN WA56 experiment that triggered the fast proton produced in the $\pi^{+}p$ and $\pi^{-}p$ interactions at beam momenta 20 GeV/c and 12 GeV/c, respectively, are used to analyse the final states $p_{f} \phi (\omega)\pi^{\pm}$. A large excess (up to two orders of magnitude) of the $\phi/\omega$ cross sections ratio over the OZI prediction is observed

Клинико-морфологические особенности дыхательных расстройств у недоношенных новорождённых

Objective: to determine the causes of preterm labor and the factors contributing to the development of acute respiratory distress syndrome (ARDS) in the newborn. Subjects and methods. The paper presents the results of analyzing case histories and autopsy protocols of preterm neonates who died from ARDS. The study group comprised 20 (36.6%) very low-weight neonatal infants. Twelve (21.8%) neonates out of all the infants received the exogenous surfactants Curosurf and Surfactant BL. Lungs and placentas were histologically studied. Results. The study has demonstrated that various placen-tal abnormalities are one of the risk factors of preterm labor and ARDS. Intranatal amniotic fluid aspiration is a poor predictor. Conclusion. The efficiency of therapy with the exogenous surfactants depends on the quality of care delivered to a baby at birth, the time of switching the patient to artificial ventilation and the time of administration of a surfactant. Exogenous surfactants should be administered only in obstetric facilities that have all conveniences at their disposal to render a specialized aid to preterm infants. Key words: preterm neonate infants, acute respiratory distress syndrome, exogenous surfactants, primary atelectases, hyaline membranes.Цель — определить причину преждевременных родов и факторов, способствующих развитию ОРДС новорожденных. Материал и методы. В статье представлены результаты анализа историй болезни и протоколов патологоанатомиче-ских вскрытий 55 недоношенных новорождённых, погибших от ОРДС. В группу исследования вошли 20 (36,6%) новорождённых с экстремально низкой массой тела. Из общего числа детей, 12 (21,8%) новорождённых получили в комплексной терапии заболевания экзогенные сурфактанты: «Куросурф» и «Сурфактант БЛ». Проводили гистологическое исследование легких и плаценты. Результаты проведённого исследования показали, что одним из факторов, способствующих преждевременным родам и развитию ОРДС, является разнообразная патология плаценты. Неблагоприятным фактором является интранатальная аспирация околоплодных вод. Заключение. Эффективность терапии экзогенными сурфактантами зависит от качества оказываемой помощи ребёнку при рождении, времени перевода больного на ИВЛ и срока введения сурфактанта. Экзогенные сурфактанты должны вводиться только в родовспомогательных учреждениях, где есть все условия для оказания специализированной помощи недоношенным детям. Ключевые слова: недоношенные новорождённые, острый респираторный дистресс-синдром, экзогенные сурфактанты, первичные ателектазы, гиалиновые мембраны

Hardware-Controlled Method of Desalting Antigen Components of Cholera Chemical Vaccine

Experimentally substantiated is the possibility to apply tangential ultrafiltration for desalting antigen components of the tableted bivalent chemical cholera vaccine. Specified are the technological parameters of the process. It is demonstrated that the properties of choleragen-anatoxin (produced by Vibrio cholerae strain 569B Inaba) and O-antigens (produced from V. cholerae 569B Inaba and M-41 Ogawa strains) obtained using the designed methodology are as efficient as the ones manufactured using certified procedure and satisfy regulatory requirements. Experimentally substantiated technology for the desalting of antigen components of chemical cholera vaccine provides for the reduction of the time elapsed up to 5-6 hours from the original 3 to 4 days. It also allows for the manufacturing under controlled conditions. This hard-ware controlled method of desalting has been implemented into the vaccine production practice

Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP

An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light= \ell \equiv u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data are found to be better described when using the running mass. The measurement yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12 (theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of Quantum Chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.

Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance

This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.

A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events

Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.