Topological phase in two flavor neutrino oscillations

We show that the phase appearing in neutrino flavor oscillation formulae has a geometric and topological contribution. We identify a topological phase appearing in the two flavor neutrino oscillation formula using Pancharatnam's prescription of quantum collapses between non-orthogonal states. Such quantum collapses appear naturally in the expression for appearance and survival probabilities of neutrinos. Our analysis applies to neutrinos propagating in vacuum or through matter. For the minimal case of two flavors with CP conservation, our study shows for the first time that there is a geometric interpretation of the neutrino oscillation formulae for the detection probability of neutrino species.Comment: 11 pages, 3 figures, accepted in Phys. Rev.

Measurement of air and nitrogen fluorescence light yields induced by electron beam for UHECR experiments

Most of the Ultra High Energy Cosmic Ray (UHECR) experiments and projects (HiRes, AUGER, TA, EUSO, TUS,...) use air fluorescence to detect and measure extensive air showers (EAS). The precise knowledge of the Fluorescence Light Yield (FLY) is of paramount importance for the reconstruction of UHECR. The MACFLY - Measurement of Air Cherenkov and Fluorescence Light Yield - experiment has been designed to perform such FLY measurements. In this paper we will present the results of FLY in the 290-440 nm wavelength range for dry air and pure nitrogen, both excited by electrons with energy of 1.5 MeV, 20 GeV and 50 GeV. The experiment uses a 90Sr radioactive source for low energy measurement and a CERN SPS electron beam for high energy. We find that the FLY is proportional to the deposited energy (E_d) in the gas and we show that the air fluorescence properties remain constant independently of the electron energy. At the reference point: atmospheric dry air at 1013 hPa and 23C, the ratio FLY/E_d=17.6 photon/MeV with a systematic error of 13.2%.Comment: 19 pages, 8 figures. Accepted for publication in Astroparticle Physic

Fluxes of atmospheric muons underwater depending on the small-x gluon density

The prompt muon contribution to the deep-sea atmospheric muon flux can serve as a tool for probing into the small-x feature of the gluon density inside of a nucleon, if the muon energy threshold could be lifted to 100 TeV. The prompt muon flux underwater is calculated taking into consideration predictions of recent charm production models in which the small-x behaviour of the gluon distribution is probed. We discuss the possibility of distinguishing the PQCD models of the charm production differing in the small-x exponent of the gluon distribution, in measurements of the muon flux at energies 10-100 TeV with neutrino telescopes.Comment: 9 pages, 4 eps figures, uses iopart.st

Large Non-perturbative Effects of Small \Delta m^2_{21}/\Delta m^2_{31} and \sin \theta_{13} on Neutrino Oscillation and CP Violation in Matter

In the framework of three generations, we consider the CP violation in neutrino oscillation with matter effects. At first, we show that the non-perturbative effects of two small parameters, \Delta m_{21}^2/\Delta m_{31}^2 and \sin \theta_{13}, become more than 50% in certain ranges of energy and baseline length. This means that the non-perturbative effects should be considered in detailed analysis in the long baseline experiments. Next, we propose a method to include these effects in approximate formulas for oscillation probabilities. Assuming the two natural conditions, \theta_{23}=45^\circ and the fact that the matter density is symmetric, a set of approximate formulas, which involve the non-perturbative effects, has been derived in all channels.Comment: 25 pages, 4 figures, version to appear in JHE

Исследование электрохимических свойств полипропиленовых трековых мембран с осажденным слоем полимера, полученным в процессе плазмохимической полимеризации гексаметилдисилозана

We report high-pressure Raman, synchrotron x-ray diffraction, and electrical transport studies on Weyl semimetals NbP and TaP along with first-principles density functional theoretical (DFT) analysis. The frequencies of first-order Raman modes of NbP harden with increasing pressure and exhibit a slope change at P-c similar to 9GPa. The pressure-dependent resistivity exhibits a minimum at P-c. The temperature coefficient of resistivity below Pc is positive as expected for semimetals but changes significantly in the high-pressure phase. Using DFT calculations, we show that these anomalies are associated with a pressure-induced Lifshitz transition, which involves the appearance of electron and hole pockets in its electronic structure. In contrast, the results of Raman and synchrotron x-ray diffraction experiments on TaP and DFT calculations show that TaP is quite robust under pressure and does not undergo any phase transition

A Foundational View on Integration Problems

The integration of reasoning and computation services across system and language boundaries is a challenging problem of computer science. In this paper, we use integration for the scenario where we have two systems that we integrate by moving problems and solutions between them. While this scenario is often approached from an engineering perspective, we take a foundational view. Based on the generic declarative language MMT, we develop a theoretical framework for system integration using theories and partial theory morphisms. Because MMT permits representations of the meta-logical foundations themselves, this includes integration across logics. We discuss safe and unsafe integration schemes and devise a general form of safe integration

Rephasing Invariants of CP and T Violation in the Four-Neutrino Mixing Models

We calculate the rephasing invariants of CP and T violation in a favorable parametrization of the 4x4 lepton flavor mixing matrix. Their relations with the CP- and T-violating asymmetries in neutrino oscillations are derived, and the matter effects are briefly discussed.Comment: RevTex 9 pages. Slight changes. Phys. Rev. D (in press

2-aryl-6-Polyfluoroalkyl-4-Pyrones as Promising Rf-Building-Blocks: Synthesis and Application for Construction of Fluorinated Azaheterocycles

A convenient and general method for the direct synthesis of 2-aryl-6-(trifluoromethyl)-4-pyrones and 2-aryl-5-bromo-6-(trifluoromethyl)-4-pyrones has been developed on the basis of one-pot oxidative cyclization of (E)-6-aryl-1,1,1-trifluorohex-5-ene-2,4-diones via a bromination/dehy-drobromination approach. This strategy was also applied for the preparation of 2-phenyl-6-polyfluoroalkyl-4-pyrones and their 5-bromo derivatives. Conditions of chemoselective enediones bromination were found and the key intermediates of the cyclization of bromo-derivatives to 4-pyrones were characterized. Synthetic application of the prepared 4-pyrones has been demonstrated for the construction of biologically important CF3-bearing azaheterocycles, such as pyra-zoles, pyridones, and triazoles. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Russian Science Foundation, grant number 18-13-00186

Constant regulation for stable CD8 T-cell functional avidity and its possible implications for cancer immunotherapy.

The functional avidity (FA) of cytotoxic CD8 T cells impacts strongly on their functional capabilities and correlates with protection from infection and cancer. FA depends on TCR affinity, downstream signaling strength, and TCR affinity-independent parameters of the immune synapse, such as costimulatory and inhibitory receptors. The functional impact of coreceptors on FA remains to be fully elucidated. Despite its importance, FA is infrequently assessed and incompletely understood. There is currently no consensus as to whether FA can be enhanced by optimized vaccine dose or boosting schedule. Recent findings suggest that FA is remarkably stable in vivo, possibly due to continued signaling modulation of critical receptors in the immune synapse. In this review, we provide an overview of the current knowledge and hypothesize that in vivo, codominant T cells constantly "equalize" their FA for similar function. We present a new model of constant FA regulation, and discuss practical implications for T-cell-based cancer immunotherapy