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Resumen: Objetivos: Los conductos pancreáticos y las papilas duodenales presentan localización y morfología variable. Esta variabilidad debe ser conocida al realizar procedimientos endoscópicos, quirúrgicos o radiológicos que los involucren; procedimientos necesarios en el diagnóstico y tratamiento de ciertas patologías biliodigestivas. El objetivo del presente trabajo es estudiar la anatomía de estas estructuras, registrar posibles variantes y llevar a cabo una revisión de la literatura. Material y método: Se realizó un estudio observacional descriptivo, en el que se disecaron 40 bloques duodeno-pancreáticos de cadáveres adultos de ambos sexos conservados en solución a base de formaldehído. Se registró la frecuencia de presentación, localización y morfología de ambas papilas duodenales, la prevalencia de los conductos pancreáticos principal y accesorio y el sitio de unión entre ambos conductos. Estos hallazgos se compararon con la literatura clásica y reciente. Resultados obtenidos: La frecuencia relativa porcentual de las papilas duodenales mayor y menor fue del 100% y 87.5% respectivamente. La primera se localizó predominantemente en la segunda porción del duodeno, en su tercio medio y en el sector posteromedial (82.5%); mientras que la papila menor se encontró fundamentalmente en el tercio superior de la segunda porción duodenal, sector anteromedial (80%). Los conductos pancreáticos principal y accesorio se encontraron en el 97.5% y el 87.5% de los casos, respectivamente. Se encontró unión entre los conductos pancreáticos en el 54.3%. Conclusiones: Existió predominancia en la anatomía clásica de las estructuras estudiadas.

Introducción: Los meniscos son dos fibrocartílagos destinados a mejorar la coaptación entre las superficies articulares de la articulación femorotibial de la rodilla. De manera inconstante, sus cuernos anteriores se encuentran unidos por el ligamento transverso. En resonancia magnética, la inserción del ligamento transverso puede dar lugar a una falsa imagen (pitfall) de rotura del cuerno anterior de los meniscos, al generar una línea de alta señal entre el ligamento y el cuerno anterior. El objetivo del presente trabajo es determinar la frecuencia del ligamento transverso en material cadavérico y en resonancia magnética. Material y método: Se disecaron 35 rodillas de cadáveres adultos formolados, de ambos sexos, 18 derechas y 17 izquierdas, sin patología osteoarticular ostensible. Concomitantemente se revisaron 195 resonancias magnéticas de rodillas de pacientes adultos, realizadas desde enero de 2019 hasta octubre de 2020, en el Hospital de Clínicas. En ambos casos se registró la frecuencia del ligamento transverso. Resultados: Estudio cadavérico: el ligamento transverso se encontró en 25 casos (71,4%). Estudio imagenológico: dos resonancias presentaron criterios de exclusión. El ligamento transverso se encontró en 105 casos (54,4%). Conclusiones: El ligamento transverso se encontró en más de la mitad de los individuos estudiados, independientemente del método de estudio. Esto es relevante dada la importancia clínica e imagenológica de dicho ligamento.

Introducción: la pared anterolateral del abdomen comprende 4 músculos: oblicuo externo, oblicuo interno, transverso abdominal y recto abdominal, que le permiten participar en funciones diversas. Las mismas pueden afectarse por una eventración. Cuando alcanzan grandes tamaños, su reparación puede representar un desafío para el cirujano general. La eventroplastia con malla irreabsorbible es el patrón oro para su tratamiento, pero este puede requerir de procedimientos adicionales. El objetivo del presente trabajo consistió en reproducir las técnicas de separación de componentes en material cadavérico, y realizar una revisión de la literatura. Material y Métodos: se utilizaron 2 cadáveres adultos, de ambos sexos, formolados. Se reprodujo la técnica de separación de componentes anterior mediante la liberación del músculo oblicuo externo. La separación de componentes posterior se realizó mediante labrado de un plano retro rectal y posterior progresión de la disección en sentido lateral. Resultados: Los colgajos generados permitieron un avance de la placa muscular medialmente. Conclusiones: el conocimiento anatómico de la pared anterolateral del abdomen es la base para la realización de las técnicas de separación de componentes. La reproducción en material cadavérico es un paso inicial en el entrenamiento quirúrgico de las mismas.

We are very grateful to the Fermilab Directorate and the Fermilab Theoretical Physics Department for their financial and logistical support of the first workshop of the Muon g -2 Theory Initiative (held near Fermilab in June 2017) [123], which was crucial for its success, and indeed for the successful start of the Initiative. Financial support for this workshop was also provided by the Fermilab Distinguished Scholars program, the Universities Research Association through a URA Visiting Scholar award, the Riken Brookhaven Research Center, and the Japan Society for the Promotion of Science under Grant No. KAKEHNHI-17H02906. We thank Shoji Hashimoto, Toru Iijima, Takashi Kaneko, and Shohei Nishida for hosting the HVP workshop at KEK [124] and the KEK Theory Center and the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics for providing logistical and financial support. The HLbL workshop at the University of Connecticut [125] was hosted by the University of Connecticut Physics Department. We also gratefully acknowledge support for the second plenary workshop in Mainz [126] from the Deutsche Forschungsgemeinschaft via the Cluster of Excellence "Precision Physics, Fundamental Interactions and Structure of Matter'' (PRISMA), the Collaborative Research Centre "The low-energy frontier of the Standard Model'' (SFB 1044), as well as the Helmholtz Institute Mainz. And finally, we thank the Institute for Nuclear Theory at the University of Washington for hosting the third plenary workshop [127] and for its kind hospitality and stimulating research environment. This workshop was supported in part by the U.S. Department of Energy, Office of Science, under Award Nos. DE-FG02-00ER41132, DE-SC0020106, and by the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics. This review benefited from discussions with O. Cata, N. Christ, L.Y. Dai, H. Davoudiasl, S. Fayer, S. Ganguly, A. Gasparian, S. Hashimoto, T. Iijima, K. Kampf, D. Kawall, I. Larin, Z. Pagel, M. Petschlies, A. Rebhan, K. Schilcher, K. Shimomura, E. Shintani, D. Steffen, S. Tracz, C. Tu, and T. Yamazaki. The work in this paper was supported by CNRS, by Conacyt (Ciencia Basica 2015) under Grant No. 250628, by CONACyT-Mexico under Grant No. CB2014-22117, by Coordinacion de la Investigacion Cientifica (CIC-UMSNH) under Grant No. 4.10, by Danmarks Frie Forskningsfond under Grant No. 8021-00122B, by Deutsche Forschungsgemeinschaft Collaborative Research Centers CRC 1044, CRC 1044 -204404729, CRC 110, and under Grant No. HI 2048/1-1, Prisma Cluster for Excellence PRISMA+ EXC2118/1, STO/876/6-1, by European Research Council under the European Union's Horizon 2020 research and innovation programme under Grant Agreement Nos. 668679, 757646, 771971-SIMDAMA, 813942, by the European Union H2020-MSCA-COFUND2016 under Grant No. 754510, by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 843134, by European Union EuroPLEx Grant H2020-MSCA-ITN-2018-813942, by European Union STRONG 2020 project under Grant Agreement No. 824093, by the Excellence Initiative of Aix-Marseille University -A*MIDEX, a French "Investissements d'Avenir" program, through the Chaire d'Excellence program and the OCEVU Laboratoire d'Excellence (ANR-11-LABX-0060), by the Fermilab Distinguished Scholars program, by Fondo SEP-Cinvestav under Grant No. 142, Fundacao para a Ciencia e a Tecnologia under Grant No. SFRH/BPD/109443/2015, by Generalitat de Catalunya under Grant No. 2017SGR1069, by the Helmholtz Association (German Federal Ministry of Education and Research), by the Helmholtz-Institut Mainz, by the Istituto Nazionale di Fisica Nucleare (INFN), by the Isaac Newton Trust, by the Japan Society for the Promotion of Science under Grant Nos. KAKENHI-15H05742, 16K05317, 16K05323, 16K05338, 17H01133, 17H02906, 18H05226, 19K21872, 20K03926, 20K03960, by Junta de Andalucia under Grant No. A-FQM-467-UGR18, by KEK, by Ministerio de Ciencia e Innovacion under Grant No. CICYTFEDER-FPA2017-86989-P, by Ministerio de Industria, Economia y Competitividad under Grant Nos. FPA2016-78220-C3-3-P, FPA2017-86989-P, PGC2018-094857-B-I00, SEV-2016-0588, SEV-2016-0597, by Laboratoires d'Excellence FIRST-TF grants, a French "Investissements d'Avenir'' program, by the Ministry of Science and Higher Education of the Russian Federation under Grant Agreement No. 14.W03.31.0026, by the National Research Foundation of South Africa, by the Natural Sciences and Engineering Research Council of Canada, by the Portuguese Science Foundation (FCT) Investigator Grant IF/00898/2015, by the Romanian Ministry of Education and Research under Grant No. PN19060101, by the Russian Science Foundation under Grant No. RSF 18-12-00128, by the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya under Grant No. 2017 SGR 1069, by the Swedish Research Council under Grant Nos. 2016-05996, 2019-03779, by the Swiss National Science Foundation under Grant Nos. PP00P2_176884, PCEFP2_181117, by The Leverhulme Trust under Grant No. ECF-2019-223, by the UK Science and Technology Facilities Council (STFC) under Grant Nos. ST/N504130/1, ST/P000290/1, ST/P00055X/1, ST/P000630/1, ST/P000711/1, ST/P000746/1, ST/S000879/1, ST/S000925/1, by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Nos. DE-SC0009919, DE-SC0009998, DE-SC0010005, DE-SC0010120, DE-SC0010339, DE-SC0012391, DE-SC0012704, DE-SC0013682, DE-SC0013895, DE-SC0015655, by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Award Nos. DE-AC02-05CH11231, DE-FG02-00ER41132, DE-FG02-97ER41020, by the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics, "Incubation Platform for Intensity Frontier", by the U.S. National Science Foundation under Grant Nos. NSF-PHY-1316222, PHY14-14614, PHY17-19626, and PHY19-23131, and by the U.S. National Institute of Standards and Technology (NIST) Precision Measurement Grant Program under Award No. 60NANB16D271. This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics., We review the present status of the Standard Model calculation of the anomalous magnetic moment of the muon. This is performed in a perturbative expansion in the fine-structure constant and is broken down into pure QED, electroweak, and hadronic contributions. The pure QED contribution is by far the largest and has been evaluated up to and including with negligible numerical uncertainty. The electroweak contribution is suppressed by and only shows up at the level of the seventh significant digit. It has been evaluated up to two loops and is known to better than one percent. Hadronic contributions are the most difficult to calculate and are responsible for almost all of the theoretical uncertainty. The leading hadronic contribution appears at and is due to hadronic vacuum polarization, whereas at the hadronic light-by-light scattering contribution appears. Given the low characteristic scale of this observable, these contributions have to be calculated with nonperturbative methods, in particular, dispersion relations and the lattice approach to QCD. The largest part of this review is dedicated to a detailed account of recent efforts to improve the calculation of these two contributions with either a data-driven, dispersive approach, or a first-principle, lattice-QCD approach. The final result reads and is smaller than the Brookhaven measurement by 3.7. The experimental uncertainty will soon be reduced by up to a factor four by the new experiment currently running at Fermilab, and also by the future J-PARC experiment. This and the prospects to further reduce the theoretical uncertainty in the near future – which are also discussed here – make this quantity one of the most promising places to look for evidence of new physics., Fermilab Directorate, Fermilab Theoretical Physics Department, Fermilab Distinguished Scholars program, Universities Research Association through a URA Visiting Scholar award, Riken Brookhaven Research Center, Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) Japan Society for the Promotion of Science KAKEHNHI-17H02906 KAKENHI-15H05742 16K05317 16K05323 16K05338 17H01133 17H02906 18H05226 19K21872 20K03926 20K03960, High Energy Accelerator Research Organization (KEK), U.S.-Japan Science and Technology Cooperation Program in High Energy Physics, Deutsche Forschungsgemeinschaft via the Cluster of Excellence "Precision Physics, Fundamental Interactions and Structure of Matter'' (PRISMA), Collaborative Research Centre "The low-energy frontier of the Standard Model'' SFB 1044, Helmholtz Institute Mainz, United States Department of Energy (DOE) DE-FG02-00ER41132 DE-SC0020106, Centre National de la Recherche Scientifique (CNRS), Conacyt (Ciencia Basica 2015) 250628, Consejo Nacional de Ciencia y Tecnologia (CONACyT) CB2014-22117, Coordinacion de la Investigacion Cientifica (CIC-UMSNH) 4.10, Danmarks Frie Forskningsfond 8021-00122B, German Research Foundation (DFG) CRC 1044 CRC 1044 -204404729 CRC 110 HI 2048/1-1, Prisma Cluster for Excellence PRISMA+ EXC2118/1 STO/876/6-1, European Research Council (ERC) 668679 757646 771971-SIMDAMA 813942, European Union (EU) 754510, European Union (EU) 843134, European Union EuroPLEx Grant H2020-MSCA-ITN-2018-813942, European Union STRONG 2020 project 824093, French National Research Agency (ANR), OCEVU Laboratoire d'Excellence ANR-11-LABX-0060, Fondo SEP-Cinvestav 142, Portuguese Foundation for Science and Technology SFRH/BPD/109443/2015, Generalitat de Catalunya 2017SGR1069, Helmholtz Association (German Federal Ministry of Education and Research), Istituto Nazionale di Fisica Nucleare (INFN), Isaac Newton Trust, Junta de Andalucia A-FQM-467-UGR18, Instituto de Salud Carlos III Spanish Government CICYTFEDER-FPA2017-86989-P, Ministerio de Industria, Economia y Competitividad FPA2016-78220-C3-3-P FPA2017-86989-P PGC2018-094857-B-I00 SEV-2016-0588 SEV-2016-0597, Laboratoires d'Excellence FIRST-TF grants, Ministry of Science and Higher Education of the Russian Federation 14.W03.31.0026, National Research Foundation - South Africa, Natural Sciences and Engineering Research Council of Canada (NSERC) CGIAR, Portuguese Science Foundation (FCT) Investigator Grant IF/00898/2015, Romanian Ministry of Education and Research PN19060101, Russian Science Foundation (RSF) RSF 18-12-00128, Generalitat de Catalunya 2017 SGR 1069, Swedish Research Council 2016-05996 2019-03779, Swiss National Science Foundation (SNSF) PP00P2_176884 PCEFP2_181117, Leverhulme Trust ECF-2019-223, UK Research & Innovation (UKRI) Science & Technology Facilities Council (STFC) ST/N504130/1 ST/P000290/1 ST/P00055X/1 ST/P000630/1 ST/P000711/1 ST/P000746/1 ST/S000879/1 ST/S000925/1, United States Department of Energy (DOE) DE-SC0009919 DE-SC0009998 DE-SC0010005 DE-SC0010120 DE-SC0010339 DE-SC0012391 DE-SC0012704 DE-SC0013682 DE-SC0013895 DE-SC0015655, United States Department of Energy (DOE) DE-FG02-00ER41132 DE-AC02-05CH11231 DE-FG02-97ER41020 DE-AC02-07CH11359, U.S.-Japan Science and Technology Cooperation Program in High Energy Physics, "Incubation Platform for Intensity Frontier", National Science Foundation (NSF) NSF-PHY-1316222 PHY14-14614 PHY17-19626 PHY19-23131, U.S. National Institute of Standards and Technology (NIST) Precision Measurement Grant 60NANB16D271

Introducción: la conformación del sistema venoso ácigos es variable, lo forman las venas ácigos, la hemiácigos y la hemiácigos accesoria. Dispuesto en paralelo respecto a las venas cavas, reviste importancia como vía alternativa, para el retorno venoso hacia el corazón. Materiales y método: 12 cadáveres adultos formolados y 12 tomografías computadas de pacientes adultos de ambos sexos. Se registró: tipo de sistema ácigos (según clasificación de Anson), calibre en origen y terminación de vena ácigos y hemiácigos, nivel vertebral de terminación de cada una. Resultados: 14(58%) casos femeninos, 10(42%) casos masculinos. El tipo II se halló en 14 (58%) casos, distribuido en 9 (38%) casos del subtipo 2A, 3 (12%) casos del subtipo 2B, 1 (4%) caso del subtipo 2D, 1 (4%) caso del subtipo 2C. El tipo III fue encontrado en 9 (38%) casos. Se encontró 1 (4%) caso tipo I. El calibre promedio del origen de vena ácigos fue 4,2mm (2mm-7,7mm), y de la vena hemiácigos fue de 3mm (2mm-6,9mm). El calibre de terminación de la vena ácigos fue 8,3mm (4,2mm-10,3mm), Para la vena hemiácigos fue de 4,9mm (3,3mm-7,2mm). El nivel vertebral de terminación medio de la vena ácigos fue T4 con 14 (58%) casos y de la vena hemiácigos T8 con 8 (28,5%) casos. Conclusión: el tipo de sistema ácigos es variable, y no se correlaciona con lo descrito por autores clásicos, pero si con autores contemporáneos. Hay gran correlación con distintos autores sobre los niveles vertebrales de terminación de vena ácigos, hemiácigos y hemiácigos accesoria.

Introducción: La reparación endovascular de los aneurismas aorto-ilíacos con dispositivos de rama ilíaca permiten excluir el aneurisma de forma eficaz, así como mantener la circulación de la pelvis. Sin embargo, no todas las anatomías son aptas para esta tecnología. Esto motivó el siguiente estudio, cuyo objetivo es evaluar la compatibilidad de la anatomía de los vasos ilíacos con respecto a los valores preestablecidos de estos dispositivos, en una población cadavérica. Materiales y métodos: Se disecaron 53 bifurcaciones ilíacas arteriales, de cadáveres adultos formolados. Se registró: sexo, lado (derecho o izquierdo), longitud de la arteria ilíaca común (L1), longitud de la arteria iliaca interna (L2), y calibres de la arteria ilíaca común (C1), de la bifurcación ilíaca (C2), de la arteria iliaca interna (C3) y externa (C4). Las variables cuantitativas fueron comparadas con los requerimientos de 3 casas comerciales que fabrican estos dispositivos. Resultados: Los valores promedio obtenidos fueron de: L1: 54,52 mm; L2: 40,59 mm; C1: 11,73 mm; C2: 15,34 mm; C3: 7,28 mm; C4: 8,36 mm. Del total de casos estudiados, 5 casos (9.43%) cumplieron con los requisitos de la primera casa comercial, los restantes 48 (90,57%) no lo hicieron. Ocho casos (15,09%) cumplieron con los de la segunda casa, 45 (84,91%) no lo hicieron. Finalmente, 18 casos (33,96%) cumplieron con los requisitos de la tercer casa comercial, mientras que los restantes 35 casos (66,04%) no lo hicieron. Conclusiones: El cirujano debe estar al tanto de esta y otras técnicas de sello distal de aneurismas aorto-ilíacos, ya que no todas las bifurcaciones iliacas cumplen los requisitos de las casas comerciales. Es fundamental determinar la morfometría de cada caso para ver su compatibilidad con los dispositivos.

The MEG experiment at the Paul Scherrer Institut (PSI) represents the state of the art in the search for the charged Lepton Flavor Violating μ+→e+γ decay, setting the most stringent upper limit on the BR(μ+→e+γ)≤4.2×10^-13 (90% C.L.). An upgrade of MEG, MEG II, was designed, commissioned and recently started the physics data taking. Its goal is to reach a sensitivity level of . In order to 6×10^-14 reconstruct the positron momentum vector a Cylindrical Drift CHamber (CDCH) with unprecedented peculiarities was built, featuring angular and momentum resolutions at the 6.5 mrad and 100 keV/c level. The CDCH is a 2-meter long, 60 cm in diameter, low-mass, single volume detector with high granularity: 9 layers of 192 drift cells, few mm wide, defined by wires in a stereo configuration for longitudinal hit localization. The filling gas mixture is Helium:Isobutane 90:10. The total radiation length is 1.5×10^-3 X0, thus minimizing the Multiple Coulomb Scattering and allowing for a single-hit resolution

The models loading layers of the multilayer road construction under the influence of the moving vertical load was reviewed, as well as forms of forced and natural vibrations. By numerical analysis are set to dynamic deflection, the speed and acceleration of vibration, dynamic compressive stress - strain, which is a measure of strength, also a benchmark for testing road construction materials on endurance

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminium nucleus ($\mu-e$ conversion, $\mu^- N \to e^- N$); a lepton flavor violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90 % upper limit of branching ratio of $7\times 10^{-15}$, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the \mue conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described., Comment: A minor correction applied in Eq. 3

The MEG experiment, designed to search for the μ+→e+γ decay, completed data-taking in 2013 reaching a sensitivity level of 5.3×10^−13 for the branching ratio. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6×10^−14, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance

In the article the analysis of methods of calculating non-rigid road pavements according to the criterion of elastic deflection. The possibility of using different solutions (Burmister, Korsunsky, Ivanov, etc.) to calculate the deflection of layers of monolithic and granular materials is evaluated. Based on this analysis, the formulas for calculating the equivalent modulus of elasticity of a two-layer system, the upper layer of which is made of monolithic or granular material, are recommended. The authors made the modification of formulas for calculating the deflection of asphalt concrete layers and the equivalent modulus of elasticity on their surface. The modification was made by introducing into the calculated dependences a scalar quantity, called damage. To calculate the damage, the principle of equivalence of deformations is recommended, in which the damage is determined using the relations of elastic modules of the damaged and solid body. To calculate the elastic modulus of the damaged body, a functional dependence on the number of loads was obtained.

The article assesses the possibility of using ash and slag mixture for the construction of a road bed. To this end, the traditional and modern methods of calculation of road surfaces are analyzed, which allow establishing the parameters of strength and deformability that require experimental determination. Experimental determination of strength and deformability parameters is performed by laboratory tests. For the implementation of tests the authors make samples of ash and slag mixture of different density. During the experiments, the metal stamp is pressed into the model and the experimental dependences of the sediment on the pressure are determined. This makes it possible to calculate the California Bearing Ratio, the deformation modulus, and to establish the pressures at which the mixture of ash and slag operates under compaction or shear conditions. Mathematical models are developed to calculate the parameters of strength and deformability from the value of pressure.

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

A search for the decay μ + → e + γ , performed at PSI and based on data from the initial three months of operation of the MEG experiment, yields an upper limit on the branching ratio of BR ( μ + → e + γ ) ⩽ 2.8 × 10 − 11 (90% C.L.). This corresponds to the measurement of positrons and photons from ∼ 10 14 stopped μ + -decays by means of a superconducting positron spectrometer and a 900 litre liquid xenon photon detector.

In 1992-2000, data on e + e − annihilation into hadrons were collected in the energy range 0.36 s 1.4 GeV with the CMD-2 and SND detectors at the VEPP-2M collider in Novosibirsk. The results of the R ( s ) measurements in these experiments are presented.

The MEG experiment at PSI searches for the decay μ→eγ at a level of ≈10^−13 on the branching ratio BR(μ→eγ/μ→tot), well beyond the present experimental limit (BR≤1.2×10^−11) and is sensitive to the predictions of SUSY-GUT theories. To reach this goal the experiment uses one of the most intense continuous surface muon beams available (≈10^8μ/s) and relies on advanced technology (LXe calorimetry, a gradient-field superconducting spectrometer as well as flexible and powerful trigger and acquisition systems). In order to maintain the highest possible energy, time and spatial resolutions for such detector, frequent calibration and monitoring, using a Cockcroft–Walton proton accelerator, are required. The proton beam is brought to the centre of MEG by a special bellows insertion system and travels in a direction opposite to the one of the normal μ-beam. Protons interact with a lithium tetraborate (Li2B4O7) nuclear target and produce one γ (17.6 MeV) from the reaction 3-7 Li(p, γ)8-4 or two coincident γs (11.67 and 4.4 MeV) from the reaction 11-5 B(p, γ)12-6 C*. The 17.6 MeV γ is used for calibrating and monitoring the LXe calorimeter (σEγ/Eγ=3.85±0.15% at 17.6 MeV) while the coincident 11.67 and 4.4 MeV γs are used to measure the relative timing of the calorimeter and the spectrometer timing counters (σ_delta_t=0.450±0.015ns).

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton-flavor-violating decay μ→eγ. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8×10^14 muon decays, gives a 90% C.L. upper limit of 2.4×10^-12 on the branching ratio of the μ→eγ decay, constituting the most stringent limit on the existence of this decay to date.

A search for the decay μ+→e+γ, performed at PSI and based on data from the initial three months of operation of the MEG experiment, yields an upper limit on the branching ratio of BR(μ+→e+γ)2.8×10^−11 (90% C.L.). This corresponds to the measurement of positrons and photons from ~10^14 stopped μ+ decays by means of a superconducting positron spectrometer and a 900 litre liquid xenon photon detector.

The final results of the search for the lepton flavour violating decay $$\mathrm {\mu }^+ \rightarrow \mathrm {e}^+ \mathrm {\gamma }$$ based on the full dataset collected by the MEG experiment at the Paul Scherrer Institut in the period 2009–2013 and totalling $$7.5\times 10^{14}$$ stopped muons on target are presented. No significant excess of events is observed in the dataset with respect to the expected background and a new upper limit on the branching ratio of this decay of $$ \mathcal{B} (\mu ^+ \rightarrow \mathrm{e}^+ \gamma ) < 4.2 \times 10^{-13}$$ (90 % confidence level) is established, which represents the most stringent limit on the existence of this decay to date.

Results are presented of a calculation of the flow around a sphere of a two-phase supersonic jet, discharging into a vacuum. Calculations were performed by the determination method with use of a difference grid constructed on the basis of characteristic ratios [1], The parameters of the unperturbed jet were determined with the two-velocity and two-temperature model of mutually penetrating flows of continuous media (gas and particles) [2, 3] by the network method [4]. In calculating the flow around the sphere, as in [5–7], it was assumed that the particles do not affect the gas flow in the shock layer. An analysis of the effect of particles on gasdynamic parameters in a shock layer was performed in [8].

The authors consider the conditions of extremal intensity of fluorescence on the axis of a cylindrical vessel filled with a solution and placed in an elliptical illuminator. They show that under radial pumping or pumping that is isotropic in a plane perpendicular to the vessel axis the fluorescence on the axis of a cylindrical vessel attains maximum intensity when the optical density (ɛCR) of the vessel is equal to 1.

In the production of bimetal apparatus by facing, it is necessary to provide a facing metal (cladding layer) the corrosion resistance of which is similar to the corrosion resistance of the electrode metal in the original condition. However, in all of the known methods of facing including manual, electric arc, mechanized wire, or 0.7-0.8 mm thick strip, the depth of fusion of the base metal is 2-6 mm, which leads to significan t participation of the base metal in the faced layer and, consequent!y, to a reduction in its corrosion resistance. To avoid this, facing is done with high-alloy electrodes in three and more layers.

We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon decays collected in the MEG experiment in the years 2009--2010 and measured the branching ratio B($\mu^+ \to e^+\nu\bar{\nu}\gamma$) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 for E_e > 45 MeV and E_{\gamma} > 40 MeV, consistent with the Standard Model prediction. The precise measurement of this decay mode provides a basic tool for the timing calibration, a normalization channel, and a strong quality check of the complete MEG experiment in the search for $\mu^+ \to e^+\gamma$ process., Comment: 8 pages, 7 figures. Added an introduction to NLO calculation which was recently calculated. Published version

Multiple scattering effects of 12 and 20 GeV electrons on 8 and 20 mm thickness carbon targets have been studied with high-resolution silicon microstrip detectors of the UA9 apparatus at the H8 line at CERN. Comparison of the scattering angle between data and GEANT4 simulation shows excellent agreement in the core of the distributions leaving some residual disagreement in the tails., 14 pages, 16 figures. Updated to match published version

The MEG (Mu to Electron Gamma) experiment has been running at the Paul Scherrer Institut (PSI), Switzerland since 2008 to search for the decay μ +→e+ γ by using one of the most intense continuous μ + beams in the world. This paper presents the MEG components: the positron spectrometer, including a thin target, a superconducting magnet, a set of drift chambers for measuring the muon decay vertex and the positron momentum, a timing counter for measuring the positron time, and a liquid xenon detector for measuring the photon energy, position and time. The trigger system, the read-out electronics and the data acquisition system are also presented in detail. The paper is completed with a description of the equipment and techniques developed for the calibration in time and energy and the simulation of the whole apparatus., The European Physical Journal C, 73 (4), ISSN:1434-6044, ISSN:1434-6052