83 research outputs found
Search for Solar Axions Produced by Primakoff Conversion Using Resonant Absorption by Tm Nuclei
The search for resonant absorption of the Primakoff solar axions by
Tm nuclei have been performed. Such an absorption should lead to the
excitation of low-lying nuclear energy level: Tm Tm
Tm (8.41 keV). The Si(Li) detector and Tm target
placed inside the low-background setup were used for that purpose. As a result,
a new restriction on the axion-photon coupling and axion mass was obtained:
(90% c.l.). In model
of hadronic axion this restriction corresponds to the upper limit on axion mass
- 191 eV for 90% c.l.Comment: 6 pages, 5 figures, submitted to Physics Letters
Today and Future Neutrino Experiments at Krasnoyarsk Nuclear Reactor
The results of undergoing experiments and new experiment propositions at
Krasnoyarsk underground nuclear reactor are presentedComment: 4 page
Долгосрочная эффективность и безопасность препарата нетакимаб у пациентов со среднетяжелым и тяжелым вульгарным псориазом. Результаты открытого продленного клинического исследования II фазы BCD-085-2-ext
Netakimabis original monoclonal antibody against IL-17. This article outlines the key results of a phase II open-label extension trial of netakimab 80 mg and 120 mg in patients with moderate-to-severe psoriasis.The main aim of the trial is to estimate efficacy, safety and immunogenicity of long-term treatment with netakimab 80 mg and 120 mg in patients with moderate-to-severe psoriasis.Materials and methods. The BCD-085-2-ext study is a comparative, open-label phase 2 clinical study of the effi - cacy and safety of netakimab in patients with moderate-to-severe plaque psoriasis who had finished BCD-085-2 (NCT02762994) trial. Main efficacy endpoints includePASI75, PASI90, PASI100, sPGA = 0–1 on week 38 of the trial, long-term PASI75/90/100 retention, efficacy keeping after switch from once every 2 week regimen to once every 4 week regimen. Safety endpoints include adverse events, serious adverse events number and their profile.Results. 103 patients were included. PASI75 at week 38 was reached by 98.06 %, PASI90 — by 92.23 %, PASI100 — by 59.22 % of patients. There were no cases of serious adverse event, early with drawal due to adverse events and cases of grade 4 toxicity according to CTCAE 4.03. There were no cases of binding antibodies to netakimab during the 38 weeks of the study.Conclusion. The first Russian original IL-17 inhibitor netakimabis promising modern medicine for moderate-to-severe plaque psoriasis treatment. Netakimabshowed high efficacy, favorable safety profile and low immunogenicity during one year of the treatment.В статье приводятся результаты международного открытого клинического исследования эффективности и безопасности российского оригинального ингибитора интерлейкина 17 — препарата нетакимаб — в дозе 80 и 120 мг у пациентов со среднетяжелым и тяжелым бляшечным псориазом.Цель исследования — оценить эффективность, безопасность и иммуногенность препарата нетакимаб при длительной терапии пациентов с бляшечным псориазом.Материалы и методы. BCD-085-2-ext (NCT03390101) — международное открытое многоцентровое сравнительное клиническое исследование эффективности и безопасности препарата нетакимаб в дозе 80 и 120 мг у больных среднетяжелым и тяжелым бляшечным псориазом, завершивших участие в исследовании BCD-085-2(NCT02762994). Основные показатели эффективности, оцениваемые в исследовании: достижение ответа PASI75, PASI90, PASI100, sPGA = 0–1 к 38 неделе исследования, длительное удержание ответа PASI75/90/100, сохранение эффективности по индексу PASI100 при переходе на более редкий режим введения препарата. Ключевые показатели безопасности включали число зарегистрированных нежелательных и серьезных нежелательных явлений, их профиль.Результаты. Всего были включены 103 пациента. Доля пациентов, достигших PASI75 к концу исследования, составила 98,06 % пациентов, PASI 90 — 92,23 %, PASI100 — 59,22 % пациентов. Не было зарегистрировано ни одного связанного с препаратом случая серьезных нежелательных явлений, досрочного выбывания по при- чине нежелательного явления, нежелательных явлений 4 степени по CTCAE 4.03, а также не было выявлено связывающих антител к препарату на протяжении всего периода терапии.Заключение. Первый отечественный оригинальный ингибитор IL-17 нетакимаб представляет собой перспективное современное средство для лечения среднетяжелого и тяжелого бляшечного псориаза. Препарат демонстрирует высокий терапевтический ответ по индексам PASI75, PASI90, PASI100 и sPGA в течение 1 года непрерывного применения, характеризуется благоприятным профилем безопасности и отсутствием иммуногенности
Kalb-Ramond excitations in a thick-brane scenario with dilaton
We compute the full spectrum and eigenstates of the Kalb-Ramond field in a
warped non-compact Randall-Sundrum -type five-dimensional spacetime in which
the ordinary four-dimensional braneworld is represented by a sine-Gordon
soliton. This 3-brane solution is fully consistent with both the warped
gravitational field and bulk dilaton configurations. In such a background we
embed a bulk antisymmetric tensor field and obtain, after reduction, an
infinite tower of normalizable Kaluza-Klein massive components along with a
zero-mode. The low lying mass eigenstates of the Kalb-Ramond field may be
related to the axion pseudoscalar. This yields phenomenological implications on
the space of parameters, particularly on the dilaton coupling constant. Both
analytical and numerical results are given.Comment: 10 pages, 13 figures, and 2 tables. Final version to appear in The
European Physical Journal
Second-order corrections to neutrino two-flavor oscillation parameters in the wave packet approach
We report about an analytic study involving the {\em intermediate} wave
packet formalism for quantifying the physically relevant information which
appear in the neutrino two-flavor conversion formula and help us to obtain more
precise limits and ranges for neutrino flavor oscillation. By following the
sequence of analytic approximations where we assume a strictly peaked momentum
distribution and consider the second-order corrections in a power series
expansion of the energy, we point out a {\em residual} time-dependent phase
which, coupled with the {\em spreading/slippage} effects, can subtly modify the
neutrino oscillation parameters and limits. Such second-order effects are
usually ignored in the relativistic wave packet treatment, but they present an
evident dependence on the propagation regime so that some small modifications
to the oscillation pattern, even in the ultra-relativistic limit, can be
quantified. These modifications are implemented in the confront with the
neutrino oscillation parameter range (mass-squared difference \Delta m^{\2}
and the mixing-angle ) where we assume the same wave packet parameters
previously noticed in the literature in a kind of {\em toy model} for some
reactor experiments. Generically speaking, our analysis parallels the recent
experimental purposes which concern with higher precision parameter
measurements. To summarize, we show that the effectiveness of a more accurate
determination of \Delta m^{\2} and depends on the wave packet width
and on the averaged propagating energy flux which still
correspond to open variables for some classes of experiments. \Comment: 25 pages, 5 figure
The IAXO Helioscope
The IAXO (International Axion Experiment) is a fourth generation helioscope with a sensitivity, in terms of detectable signal counts, at least 104 better than CAST phase-I, resulting in sensitivity on ga¿ one order of magnitude better. To achieve this performance IAXO will count on a 8-coil toroidal magnet with 60 cm diameter bores and equipped with X-ray focusing optics into 0.20 cm2 spots coupled to ultra-low background Micromegas X-ray detectors. The magnet will be on a platform that will allow solar tracking for 12 hours per day. The next short term objectives are to prepare a Technical Design Report and to construct the first prototypes of the hardware main ingredients: demonstration coil, X-ray optics and low background detector while refining the physics case and studying the feasibility studies for Dark Matter axions
The Next Generation of Axion Helioscopes: The International Axion Observatory (IAXO)
The International Axion Observatory (IAXO) is a proposed 4th-generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 \u2013 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion-photon coupling ga\u3b3 down to a few
710 1212 GeV 121 for a wide range of axion masses up to 3c 0.25 eV. This is an improvement over the currently best (3rd generation) axion helioscope, the CERN Axion Solar Telescope (CAST), of about 5 orders of magnitude in signal strength, corresponding to a factor 3c 20 in the axion photon coupling. IAXO's sensitivity relies on the construction of a large superconducting 8-coil toroidal magnet of 20 m length optimized for axion research. Each of the eight 60 cm diameter magnet bores is equipped with x-ray optics focusing the signal photons into 3c 0.2 cm2 spots that are imaged by very low background x-ray detectors. The magnet will be built into a structure with elevation and azimuth drives that will allow solar tracking for 12 hours each day. This contribution is a summary of our papers [1], [2] and [3] and we refer to these for further details
Study of cosmogenic activation above ground for the DarkSide-20k experiment
The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in 39Ar. Despite the outstanding capability of discriminating
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background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of 39Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as 37Ar and 3H are shown not to be relevant due to short half-life and assumed purification methods
Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel
Dark matter lighter than 10 GeV/c2 encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino fog for GeV-scale masses and significant sensitivity down to 10 MeV/c2 considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector’s sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies
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