Correcting for Distortions due to Ionization in the STAR TPC

Physics goals of the STAR Experiment at RHIC in recent (and future) years drive the need to operate the STAR TPC at ever higher luminosities, leading to increased ionization levels in the TPC gas. The resulting ionic space charge introduces field distortions in the detector which impact tracking performance. Further complications arise from ionic charge leakage into the main TPC volume from the high gain anode region. STAR has implemented corrections for these distortions based on measures of luminosity, which we present here. Additionally, we highlight a novel approach to applying the corrections on an event-by-event basis applicable in conditions of rapidly varying ionization sources.Comment: 6 pages, 7 figures, proceedings of the Workshop on Tracking in High Multiplicity Environments (TIME 05) in Zurich, Switzerland, submitted to Nucl. Instr. and Meth.

Beam halo dynamics and control with hollow electron beams

Experimental measurements of beam halo diffusion dynamics with collimator scans are reviewed. The concept of halo control with a hollow electron beam collimator, its demonstration at the Tevatron, and its possible applications at the LHC are discussed.Comment: 5 pages, 4 figures, in Proceedings of the 52nd ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB2012), Beijing, China, 17-21 September 201

Experimental and Theoretical Investigation into the Effect of the Electron Velocity Distribution on Chaotic Oscillations in an Electron Beam under Virtual Cathode Formation Conditions

The effect of the electron transverse and longitudinal velocity spread at the entrance to the interaction space on wide-band chaotic oscillations in intense multiple-velocity beams is studied theoretically and numerically under the conditions of formation of a virtual cathode. It is found that an increase in the electron velocity spread causes chaotization of virtual cathode oscillations. An insight into physical processes taking place in a virtual cathode multiple velocity beam is gained by numerical simulation. The chaotization of the oscillations is shown to be associated with additional electron structures, which were separated out by constructing charged particle distribution functions.Comment: 9 pages, 8 figure

ПІСЛЯПОЛОГОВИЙ ПЕРІОД У ЖІНОК З ЛЕЙОМІОМОЮ МАТКИ

 These inspections are in-process resulted 100 women with the leiomyoma of uterus in 3,6-12 months after births. All patient is conduct the clinical, hormonal,, bacteriological and ultrasonic immunoassay of uterus and appendages in general lines. For women through 3,6 and 12 months afterbirths relative giperestrogeniya was marked and gipoprogesteronemiya, that can be instrumental in growth of miomatoznikh knots. Through 6 and 12 months there was a disbalance of protizapal’nikhand prozapal’nikh reactions of organism. In 12 months afterbirths for women (50), which got the recommended therapy the noted tendency to normalization of correlation of hormonal and immunological status. For women (50) which got symptomatic therapy or did not treat oneself prozapal’niy character of violations was in general kept, that showed up the increase of concentrations of FNP and decline of correlation of RR of 75/FPN. Such changes can stimulate growth of leyomiomatoznikh knots. В работе приведены данные обследования 100 женщин с лейомиомой матки через 3,6-12 месяцев после родов. Всем больным проведено в общих чертах клиническое, гормональное, иммунологическое, бактериологическое и ультразвуковое обследование матки и придатков. У женщин через 3,6 и 12 месяцев после родов отмечалась относительная гиперэстрогения и гипопрогестеронемия, что может способствовать росту миоматозныхузлов. Через 6 и 12 месяцев наблюдался дисбаланс противовоспалительных и и прозапальных реакций организма. Через 12 месяцев после родов у женщин (50), которые получали рекомендованную терапию отмеченная тенденция к нормализации соотношения гормонального и иммунологического статуса. У женщин (50), которые получали симптоматическую терапию или не лечились вообще хранился прозапальний характер нарушений, что проявлялось повышением концентраций ФНП и снижением соотношения РР75/ФПН. Такие изменения могут стимулировать рост лейомиоматознихузлов. У роботі наведені дані обстеження 100жінокз лейоміомою матки через 3,6-12 місяців після пологів. Усім хворим проведено загальнокпінічне, гормональне, імунологічне, бактеріологічне та ультразвукове обстеження матки і придатків. У жінок через 3,6 та 12 місяців після пологів відмічалась відносна гіперестрогенія та ппопрогестеронемія, що може сприяти росту міоматозних вузлі в. Через 6 та 12 місяців спостерігався дисбаланс протизапальних і прозапальних реакцій організму. Через 12 місяців після пологів у жінок (50), які отримували рекомендовану терапію відмічена тенденція до нормалізаці співвідношення гормонального та імунологічного статусу. Ужінок(50), які отримували симптоматичну терапію або не лікувались взагалі зберігався прозапальний характер порушень, що проявлялось підвищенням концентрацій ФНП та зниженням співвідношення РР 75/ФНП. Такі зміни можуть стимулювати ріст лейоміоматозних вузлів

Investigation of the Chaotic Dynamics of an Electron Beam with a Virtual Cathode in an External Magnetic Field

The effect of the strength of the focusing magnetic field on chaotic dynamic processes occurring inan electron beam with a virtual cathode, as well as on the processes whereby the structures form in the beamand interact with each other, is studied by means of two-dimensional numerical simulations based on solving a self-consistent set of Vlasov-Maxwell equations. It is shown that, as the focusing magnetic field is decreased,the dynamics of an electron beam with a virtual cathode becomes more complicated due to the formation andinteraction of spatio-temporal longitudinal and transverse structures in the interaction region of a vircator. The optimum efficiency of the interaction of an electron beam with the electromagnetic field of the vircator isachieved at a comparatively weak external magnetic field and is determined by the fundamentally two-dimensional nature of the motion of the beam electrons near the virtual cathode.Comment: 12 pages, 8 figure

Characterization of Multiblock (Segmented) Copolyurethane- Imides and Nanocomposites Based Thereof Using AFM, Nanotribology, and Nanoindentation Methods

This chapter reviews our results on the morphology, tribological, and local mechanical property investigations of new copoly(urethane-imide)s (coPUIs) and nanocomposites based thereof using atomic force microscopy (AFM) and nanoindentation (NI) methods. AFM in the contact mode of lateral forces revealed the presence of different contrast phases on the surface of synthesized films which depends on the chemical structure of monomers used. Single-walled carbon nanotubes (SWCNTs), carbon nanofibers, graphene, tungsten disulfide and tungsten diselenide were introduced into coPUI matrices. Dependencies of microhardness and modulus of elasticity on the depth of indentation have been obtained. It was found that for each synthesized coPUI, there is only one type of carbon nanomaterials that exerts the greatest influence on their characteristics. The improvement of mechanical properties is found to mainly depend on the nature of the polymer matrix and filler. Our results showed that effective methods for improving of tribological characteristics can be either modification by SWCNTs (up to 1 wt.%) or heating at 30°C. Synthesized coPUI films and nanocomposites are very promising materials and can be used as thermoplastic elastomers for tribological applications, and their physical-mechanical properties can be controlled both by temperature and by mechanical action

Asymptotic W-symmetries in three-dimensional higher-spin gauge theories

We discuss how to systematically compute the asymptotic symmetry algebras of generic three-dimensional bosonic higher-spin gauge theories in backgrounds that are asymptotically AdS. We apply these techniques to a one-parameter family of higher-spin gauge theories that can be considered as large N limits of SL(N) x SL(N) Chern-Simons theories, and we provide a closed formula for the structure constants of the resulting infinite-dimensional non-linear W-algebras. Along the way we provide a closed formula for the structure constants of all classical W_N algebras. In both examples the higher-spin generators of the W-algebras are Virasoro primaries. We eventually discuss how to relate our basis to a non-primary quadratic basis that was previously discussed in literature.Comment: 61 page

An action principle for Vasiliev's four-dimensional higher-spin gravity

We provide Vasiliev's fully nonlinear equations of motion for bosonic gauge fields in four spacetime dimensions with an action principle. We first extend Vasiliev's original system with differential forms in degrees higher than one. We then derive the resulting duality-extended equations of motion from a variational principle based on a generalized Hamiltonian sigma-model action. The generalized Hamiltonian contains two types of interaction freedoms: One set of functions that appears in the Q-structure of the generalized curvatures of the odd forms in the duality-extended system; and another set depending on the Lagrange multipliers, encoding a generalized Poisson structure, i.e. a set of polyvector fields of ranks two or higher in target space. We find that at least one of the two sets of interaction-freedom functions must be linear in order to ensure gauge invariance. We discuss consistent truncations to the minimal Type A and B models (with only even spins), spectral flows on-shell and provide boundary conditions on fields and gauge parameters that are compatible with the variational principle and that make the duality-extended system equivalent, on shell, to Vasiliev's original system.Comment: 37 pages. References added, corrected typo

Measurements of the transverse-momentum-dependent cross sections of J /ψ production at mid-rapidity in proton+proton collisions at s =510 and 500 GeV with the STAR detector

We present measurements of the differential cross sections of inclusive J/ψ meson production as a function of transverse momentum (pTJ/ψ) using the μ+μ- and e+e- decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the μ+μ- channel is for

The Higher Spin/Vector Model Duality

This paper is mainly a review of the dualities between Vasiliev's higher spin gauge theories in AdS4 and three dimensional large N vector models, with focus on the holographic calculation of correlation functions of higher spin currents. We also present some new results in the computation of parity odd structures in the three point functions in parity violating Vasiliev theories.Comment: 55 pages, 1 figure. Contribution to J. Phys. A special volume on "Higher Spin Theories and AdS/CFT" edited by M. R. Gaberdiel and M. Vasiliev. v2: references adde