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September 12, 2011
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Date:26MondayNovember 2012Lecture
Measurement of Transparency Ratios for Protons from Short-Range Correlated Pairs
More information Time 14:45 - 15:45Location Edna and K.B. Weissman Building of Physical SciencesLecturer Or Hen
Tel Aviv UniversityOrganizer Department of Particle Physics and AstrophysicsContact Abstract Show full text abstract about Nuclear transparency, Tp(A), is a measure of the average pro...» Nuclear transparency, Tp(A), is a measure of the average probability for a struck proton to escape the nucleus without further interaction. It is usually defined as the ratio of the measured quasi-elastic A(e,e'p) cross section to a calculation that assumes no final state interactions (FSI). Nuclear transparencies were extracted for mean field protons, below the Fermi sea level, where the spectral functions are well known.
In this talk I will present a novel observable, the transparency ratios, Tp(A)/Tp(12C), for knockout of high-missing-momentum protons from the breakup of Short Range Correlated pairs (2N-SRC) in 27Al, 56Fe and 208Pb nuclei relative to 12C. The ratios were measured at large Q2 and xB>1.2 where the reaction is dominated by scattering off 2N-SRC. The transparency ratios of the knocked-out (leading) protons coming from 2N-SRC breakup are 20-30% lower than those of mean field protons and are in better agreement with Glauber calculations. The new transparencies scale as A-1/3, which is consistent with scattering from nucleons at the nuclear surface. Conditioned transparency ratios for recoiling protons from A(e,e'pp) scattering are consistent with unity, evidence of the low FSI of the recoil nucleon with the A-2 system. This analysis is part of a data mining initiative that will be described in the talk.
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Date:26MondayNovember 2012Lecture
New Approach to the Investigation of Nuclei
More information Time 16:15 - 17:15Location Edna and K.B. Weissman Building of Physical SciencesLecturer E. G. Drukarev
Petersburg Nuclear Physics Institute, Gatchina,St. Petersburg, RussiaOrganizer Department of Particle Physics and AstrophysicsContact Abstract Show full text abstract about Our approach is based on extension of the QCD (Quantum Chrom...» Our approach is based on extension of the QCD (Quantum Chromodynamics) sum rules (SR) method to systems with finite density of the baryon quantum number. It is based on the dispersion relations for the function, describing the system which carries the quantum numbers of the hadron. Exchange by the strongly correlated quark systems (mesons) is expressed in terms of exchange by the system of weakly interacting quarks with the same quantum numbers. The nucleon self-energies are obtained without employing a controversial conception of interaction between point-like nucleons. The calculation does not involve phenomenological parameters.
Application of the approach enables to express such characteristics of nucleon in nuclear matter as the Dirac effective mass m* and the vector self energy Sigma in terms of the density dependent QCD condensates. The condensates of the lowest dimension d=3 are the most important ones. These are the vector and the scalar quark condensate. The vector condensate is exactly proportional to the density due to conservation of the vector current. The linear part of the scalar condensate is presented in terms of the pion-nucleon sigma term, which can be expressed through the amplitude of the pion-nucleon elastic scattering. The most important next-to-leading condensates of dimension d=4 are expressed through the moments of the proton deep inelastic structure functions. Thus the most important density-dependent condensates are either calculated or related to observables. As a result, we find m* ~ -600 MeV, Sigma ~ 300 MeV at the phenomenological saturation value of density, in agreement with the results of the standard nuclear physics. We obtain also the density dependence of these characteristics.
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Date:26MondayNovember 2012Lecture
New Approach to the Investigation of Nuclei
More information Time 16:15 - 17:15Location Edna and K.B. Weissman Building of Physical SciencesLecturer E. G. Drukarev
Petersburg Nuclear Physics Institute, Gatchina,St. Petersburg, RussiaOrganizer Department of Particle Physics and AstrophysicsContact Abstract Show full text abstract about Our approach is based on extension of the QCD (Quantum Chrom...» Our approach is based on extension of the QCD (Quantum Chromodynamics) sum rules (SR) method to systems with finite density of the baryon quantum number. It is based on the dispersion relations for the function, describing the system which carries the quantum numbers of the hadron. Exchange by the strongly correlated quark systems (mesons) is expressed in terms of exchange by the system of weakly interacting quarks with the same quantum numbers. The nucleon self-energies are obtained without employing a controversial conception of interaction between point-like nucleons. The calculation does not involve phenomenological parameters.
Application of the approach enables to express such characteristics of nucleon in nuclear matter as the Dirac effective mass m* and the vector self energy Sigma in terms of the density dependent QCD condensates. The condensates of the lowest dimension d=3 are the most important ones. These are the vector and the scalar quark condensate. The vector condensate is exactly proportional to the density due to conservation of the vector current. The linear part of the scalar condensate is presented in terms of the pion-nucleon sigma term, which can be expressed through the amplitude of the pion-nucleon elastic scattering. The most important next-to-leading condensates of dimension d=4 are expressed through the moments of the proton deep inelastic structure functions. Thus the most important density-dependent condensates are either calculated or related to observables. As a result, we find m* ~ -600 MeV, Sigma ~ 300 MeV at the phenomenological saturation value of density, in agreement with the results of the standard nuclear physics. We obtain also the density dependence of these characteristics.
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Date:26MondayNovember 2012Lecture
מפגשים בחזית המדע
More information Time 19:15 - 21:00Location Davidson Institute of Science EducationOrganizer Science for All UnitHomepage Contact -
Date:27TuesdayNovember 2012Lecture
"Circadian Clocks & Polyamines: A Novel Metabolic Feedback Loop."
More information Time 10:00 - 10:30Location Wolfson Building for Biological ResearchLecturer Ziv Zwighaft, WIS-Department of Biological Chemistry Organizer Department of Biomolecular SciencesContact -
Date:27TuesdayNovember 2012Lecture
"The molecular basis of phosphate discrimination in arsenate rich environments”
More information Time 10:30 - 11:00Location Wolfson Building for Biological ResearchLecturer Mikael Elias
WIS-Department of Biological ChemistryOrganizer Department of Biomolecular SciencesContact -
Date:27TuesdayNovember 2012Lecture
Adaptive Control of a Nonlinear Output, with an Application to Wind-Turbine Control
More information Time 11:00 - 11:00Location Jacob Ziskind BuildingLecturer Yoav Sharon
MITOrganizer Faculty of Mathematics and Computer ScienceContact -
Date:27TuesdayNovember 2012Lecture
"Organic-based Magnets: New Chemistry and New Materials for this Millennium"
More information Time 11:00 - 11:00Title Department Of Organic Chemistry - Departmental SeminarLocation Helen and Milton A. Kimmelman BuildingLecturer Prof. Joel S. Miller
Department of Chemistry, University of Utah, Salt Lake CityOrganizer Department of Molecular Chemistry and Materials ScienceContact Abstract Show full text abstract about Organic-based materials exhibiting the technologically impor...» Organic-based materials exhibiting the technologically important property of bulk magnetism have been prepared and studied in collaboration with many research groups worldwide frequently exhibit supramolecular extended 3-D structures. These magnets are prepared via conventional organic synthetic chemistry methodologies, but unlike classical inorganic-based magnets do not require high-temperature metallurgical processing. Furthermore, these magnets are frequently soluble in conventional solvents (e. g., toluene, dichloromethane, acetonitrile, THF) and have saturation magnetizations more than twice that of iron metal on a mole basis, as well as in some cases coercive fields exceeding that of all commercial magnets (e.g., Co5Sm). Also several magnets with critical temperatures (Tc) exceeding room temperature have been prepared. In addition to an overview of magnetic behavior, numerous examples of structurally characterized magnets made from molecules will be presented. Our groups has discovered 8 families of molecule-based magnets, mostly organic-based, and have significantly contributed to an eight family based upon the Prussian blue structure. Four examples magnetically order above room temperature and as high at 127 oC. These will include [MIII(C5Me5)2][A], [MnIII(porphyrin)][A] (A = cyanocarbon etc. electron acceptors) as well as M[TCNE]x, which for M = V is a room temperature magnet that can be fabricated as a thin film magnet via Chemical Vapor Deposition (CVD) techniques. A newer class of magnets of [Ru2(O2CR)4]3[M(CN)6] (M = Cr, Fe; R = Me, t-Bu) composition will also discussed. For R = Me an interpenetrating, cubic (3-D) lattice forms and the magnet exhibits anomalous hysteresis, saturation magnetization, out-of-phase, "(T), AC susceptibility, and zero field cooled-field cooled temperature-dependent magnetization data. This is in contrast to R = t-Bu, which forms a layered (2-D) lattice. Additionally, new magnets possessing the nominal Prussian blue composition, M'[M(CN)6]x and (Cation)yM'[M(CN)6], but not their structure, will be described. The organic chemistry crucial to designing and preparing organic-based magnets will be discussed.
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Date:27TuesdayNovember 2012Lecture
"Mechanisms, rates and specificities in grass genome instability"
More information Time 11:15 - 11:15Location Arthur and Rochelle Belfer Building for Biomedical ResearchLecturer Prof. Jeffrey (Jeff) Bennetzen
Davison Life Sciences Complex, Department of Genetics, University of Georgia, Athens – GA, USAOrganizer Department of Plant and Environmental SciencesContact -
Date:27TuesdayNovember 2012Lecture
What can parasitoid wasps teach us about decision making in the brain of insects?
More information Time 12:30 - 12:30Location Gerhard M.J. Schmidt Lecture HallLecturer Prof. Frederic Libersat
Life Sciences Dept, Ben Gurion University of the Negev, Beer ShevaOrganizer Department of Brain SciencesContact Abstract Show full text abstract about Much like humans, animals may choose to initiate behavior ba...» Much like humans, animals may choose to initiate behavior based on their "internal state" rather than as a response to external stimuli alone. The neuronal underpinnings responsible for generating this ‘internal state’, however, remain elusive. The parasitoid jewel wasp hunts cockroaches to serve as a live food supply for its offspring. The wasp stings the cockroach in the head and delivers a neurotoxic venom cocktail directly inside the prey’s cerebral ganglia to apparently ‘hijack its free will’. Although not paralyzed, the stung cockroach becomes a living yet docile ‘zombie’ incapable of self-initiating walking or escape running.
We demonstrate that the venom selectively depresses the cockroach’s motivation or ‘drive’ to initiate and maintain walking-related behaviors, rather than inducing an overall decrease in arousal or a ‘sleep-like’ state. Such a decrease in the drive for walking can be attributed to a decrease in neuronal activity in a small region of the cockroach cerebral nervous system, the sub-esophageal ganglion (SEG). Specifically, we have used behavioral, neuro-pharmacological and electrophysiological methods to show that artificial focal injection of crude milked venom or procaine into the SEG of non-stung cockroaches decreases spontaneous and evoked walking, as seen with naturally-stung cockroaches. Moreover, spontaneous and evoked neuronal spiking activity in the SEG, recorded with an extracellular bipolar microelectrode, is markedly decreased in stung cockroaches as compared with non-stung controls. By injecting a venom cocktail directly into the SEG, the parasitoid Jewel Wasp selectively manipulates the cockroach’s motivation to initiate walking without interfering with other non-related behaviors.
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Date:27TuesdayNovember 2012Lecture
"The tails of p63 or 2 inactive 4 destruction"
More information Time 14:00 - 15:00Location Gerhard M.J. Schmidt Lecture HallLecturer Prof. Volker Doetsch
Institute of Biophysical Chemistry, Goethe University Frankfurt/GermanyOrganizer Department of Chemical and Structural BiologyContact -
Date:27TuesdayNovember 2012Cultural Events
"From East to West"- Concert
More information Time 20:30 - 20:30Title With Tilda RejwanLocation Michael Sela AuditoriumContact -
Date:28WednesdayNovember 2012Lecture
On representations of affine Lie superalgebras
More information Time 11:00 - 11:00Location Jacob Ziskind BuildingLecturer Prof. Maria Gorelik
Organizer Faculty of Mathematics and Computer ScienceContact -
Date:28WednesdayNovember 2012Lecture
Spotlight on Science
More information Time 12:00 - 13:30Title Harnessing DNA Repair for Lung Cancer Prevention and Early DetectionLocation Gerhard M.J. Schmidt Lecture HallLecturer Dr. Tamar Paz-Elizur
Department of Biological ChemistryContact -
Date:28WednesdayNovember 2012Cultural Events
The Yuval Trio- Concert
More information Time 12:30 - 13:30Title Music at NoonLocation Michael Sela AuditoriumContact -
Date:29ThursdayNovember 201202SaturdayFebruary 2013Cultural Events
A PEGION AND A BOY
More information Time All dayTitle Based on a novel by Meir ShalevLocation Michael Sela AuditoriumContact -
Date:29ThursdayNovember 2012Lecture
Biomedical super-resolved sensing
More information Time 12:00 - 12:00Location Jacob Ziskind BuildingLecturer Zeev Zalevsky
Bar-Ilan UniversityOrganizer Faculty of Mathematics and Computer ScienceContact -
Date:29ThursdayNovember 2012Lecture
Life Science Lecture
More information Time 15:00 - 16:00Title From letters to function: Cracking the code of gene regulationLocation Dolfi and Lola Ebner AuditoriumLecturer Prof. Eran Segal
Department of Computer Science and Applied MathematicsContact -
Date:30FridayNovember 2012Cultural Events
"A Jewish Wedding"- Lecture
More information Time 11:00 - 13:00Title With Dr. Ruhama AlbagLocation Dolfi and Lola Ebner AuditoriumContact -
Date:02SundayDecember 201206ThursdayDecember 2012Conference
FUNTRAP12- ISF Conference on Fundamental Interactions with Atom and Ion Traps
More information Time All dayLocation Edna and K.B. Weissman Building of Physical SciencesChairperson Michael HassHomepage Contact
