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Papers by Asher Klatchko
Journal of Clinical Neurophysiology, 1997
![Research paper thumbnail of Limits on WWZ and WWγ Couplings from pp [over¯]→ eνjjX Events at s}= 1.8 TeV](https://attachments.academia-assets.com/67962307/thumbnails/1.jpg)
](Physical review letters, 1997
We present limits on anomalous WWZ and WWγ couplings from a search for WW and WZ production in pp... more We present limits on anomalous WWZ and WWγ couplings from a search for WW and WZ production in pp̅ collisions at sqrt[s] = 1.8 TeV. We use pp̅ →eνjjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 19921995 run. The data sample ...
Physical Review Letters, 1995
The W W γ gauge boson couplings were measured using pp → ℓνγ + X (ℓ = e, µ) events at √ s = 1.8 T... more The W W γ gauge boson couplings were measured using pp → ℓνγ + X (ℓ = e, µ) events at √ s = 1.8 TeV observed with the DØ detector at the Fermilab Tevatron Collider. The signal, obtained from the data corresponding to an integrated luminosity of 13.8 pb −1 , agrees well with the Standard Model prediction. A fit to the photon transverse energy spectrum yields limits at the 95% confidence level on the CP-conserving anomalous coupling parameters of −1.6 < ∆κ < 1.8 (λ = 0) and −0.6 < λ < 0.6 (∆κ = 0).
We show that a conformal mapping of the type, W = z π/α, describes how a shape of a 45° rotated c... more We show that a conformal mapping of the type, W = z π/α, describes how a shape of a 45° rotated cross transforms into a contact hole. We discuss its relevance to corner rounding seen on raster beam pattern generators.
It is shown that imaging with a quasi Gaussian beam (electron or laser microlithography) in thin ... more It is shown that imaging with a quasi Gaussian beam (electron or laser microlithography) in thin resist layers is equivalent to a diffusion process. Therefore when the spot size is of the order of the dimension of the sought feature, the image rendered by the convolution of the beam with the said feature obeys the steady state Laplace equation. Hence, we investigate the use of harmonic functions in an attempt to increase the acuity of the image. Working through the mathematical analysis and simulations we show that a certain mapping reminiscent of a 'conformal mapping' improves the acuity of the image in the corners. Experimental results support our conjecture.
Quantum Chromodyanamics (QCD), the theory of quarks and gluons, has been remarkably successful in... more Quantum Chromodyanamics (QCD), the theory of quarks and gluons, has been remarkably successful in the quantitative description of a large variety of seemingly diverse phenomena in particle physics. QCD describes strong interactions, which are characterized by a single free parameter, the strong coupling constant α{sub s}. The coupling constant is a measure of the strength of the strong force at the interaction vertex. It depends on q², the square of the four momentum transfer to the gluon, and is the QCD counter part to the fine structure constant α. It is generally accepted that e{sup +}eâ» annihilation experiments provide an ideal testing ground for QCD theory. An investigation of e{sup +}â» â hadronic events observed in the CLEO detector operating at the Cornell Electron Storage Ring (CESR) at an average center of mass energy of 10.5 GeV will be presented. By studying the hadronic jet structure, the value of α{sub s} is determined to be a α{sub s} = .138 {plus minus} .010 {plus minus} .009 at the CESR energy. This value is combined with other estimates of α from different experiments at various energies in order to determine the best value of Î, the QCD re-normalization scale parameter. A may be intuitively described as the energy below which perturbation calculations for QCD are no longer reliable. The value of Î determines the threshold energy suitable for experimental verification of QCD perturbation techniques. When the results from this study are combined with other values of α{sub s}, Î is determined to Î = .174 {plus minus} .010 {plus minus} .075 GeV.
24th Annual BACUS Symposium on Photomask Technology, 2004
We show that a conformal mapping of the type, W = z pi/alpha, describes how a shape of a 45° rota... more We show that a conformal mapping of the type, W = z pi/alpha, describes how a shape of a 45° rotated cross transforms into a contact hole. We discuss its relevance to corner rounding seen on raster beam pattern generators.
The ALTA 4300 system has been used to successfully write many advanced design layers previously o... more The ALTA 4300 system has been used to successfully write many advanced design layers previously only feasible with 50kV vector shaped beam tools. In order to further enlarge the application space of this high productivity an aerial image enhancement technique has been developed to deliver mask patterns that more closely match pattern data for corners and jogs. This image enhancement is done in real time in the ALTA system"s rasterizer by modifying the gray level mapping of pixels near the corner vertexes. SEM measurements of corner rounding with standard rasterization and the enhanced rasterization show an improvement of corner rounding radius from ~205 to ~132 nm. A direct comparison of SEM micrographs show no qualitative difference between vector scan mask features and those written with aerial image enhancement. This convincingly demonstrates that the ALTA 4300 system with the new image enhancement can write many layers requiring vector scan corner acuity.
The ALTA 4300 system has been used to successfully write many advanced designs previously only po... more The ALTA 4300 system has been used to successfully write many advanced designs previously only possible with 50kV VSB systems. In order to further enlarge the application space of this high productivity system, an aerial image enhancement technique has been developed to deliver mask patterns that more closely match the pattern data for corners and jogs. This image enhancement is done in real time in the ALTA system's rasterizer by modifying the gray level mapping of pixels near the corner vertexes. SEM measurements of corner rounding with standard rasterization and the enhanced rasterization show a 35% improvement of corner rounding radius from ~205 to ~132 nm. A direct comparison of SEM micrographs show little qualitative difference between vector scan mask features and those written with aerial image enhancement. This convincingly demonstrates that the ALTA 4300 system with the new image enhancement can write many layers requiring vector scan corner acuity.
23rd Annual BACUS Symposium on Photomask Technology, 2003
Photomask and Next-Generation Lithography Mask Technology XI, 2004
The ALTA 4300 system has been used to successfully write many advanced designs previously only po... more The ALTA 4300 system has been used to successfully write many advanced designs previously only possible with 50kV VSB systems. In order to further enlarge the application space of this high productivity system, an aerial image enhancement technique has been ...
Journal of Applied Physics, 2005
It is shown that patterning with a Gaussian beam on thin films is congruent to a diffusion proces... more It is shown that patterning with a Gaussian beam on thin films is congruent to a diffusion process. In particular, the acuity of the image patterned is tied to a steady state (Laplace equation). For a small spot size, pattern acuity improves locally when the Laplacian approaches zero at the said region. However, when the spot size (blur) of the
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1993
We describe the results of beam tests of three uranium-liquid argon calorimeter modules construct... more We describe the results of beam tests of three uranium-liquid argon calorimeter modules constructed for the Do detector at the Fermilab Tevatron collider. As part of the calibration procedure, these modules were exposed to beams of electrons, pions and muons between 10 and 150 GeV/c before their installation in the end calorimeter of the completed DO detector. We obtain an electromagnetic sampling resolution of 15 .7%/F and constant term of 0 .3% . The hadronic sampling resolution is 45%/F (degraded to 50%o/FE by the effects of upstream material) and the constant term is 4% . The calorimeter is linear to 0 .5%, and the electromagnetic to hadronic response ratio is between 1 .02 and 1 .09 over this range of momenta . For an electron efficiency of 95% we obtain a rejection factor against pions of -900-3000 for particles in the momentum range between 50 and 150 GeV/c . We also compare our results with the predictions of a detailed Monte Carlo simulation .
Journal of Clinical Neurophysiology, 1997
Physical review letters, 1997
We present limits on anomalous WWZ and WWγ couplings from a search for WW and WZ production in pp... more We present limits on anomalous WWZ and WWγ couplings from a search for WW and WZ production in pp̅ collisions at sqrt[s] = 1.8 TeV. We use pp̅ →eνjjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 19921995 run. The data sample ...
Physical Review Letters, 1995
The W W γ gauge boson couplings were measured using pp → ℓνγ + X (ℓ = e, µ) events at √ s = 1.8 T... more The W W γ gauge boson couplings were measured using pp → ℓνγ + X (ℓ = e, µ) events at √ s = 1.8 TeV observed with the DØ detector at the Fermilab Tevatron Collider. The signal, obtained from the data corresponding to an integrated luminosity of 13.8 pb −1 , agrees well with the Standard Model prediction. A fit to the photon transverse energy spectrum yields limits at the 95% confidence level on the CP-conserving anomalous coupling parameters of −1.6 < ∆κ < 1.8 (λ = 0) and −0.6 < λ < 0.6 (∆κ = 0).
We show that a conformal mapping of the type, W = z π/α, describes how a shape of a 45° rotated c... more We show that a conformal mapping of the type, W = z π/α, describes how a shape of a 45° rotated cross transforms into a contact hole. We discuss its relevance to corner rounding seen on raster beam pattern generators.
It is shown that imaging with a quasi Gaussian beam (electron or laser microlithography) in thin ... more It is shown that imaging with a quasi Gaussian beam (electron or laser microlithography) in thin resist layers is equivalent to a diffusion process. Therefore when the spot size is of the order of the dimension of the sought feature, the image rendered by the convolution of the beam with the said feature obeys the steady state Laplace equation. Hence, we investigate the use of harmonic functions in an attempt to increase the acuity of the image. Working through the mathematical analysis and simulations we show that a certain mapping reminiscent of a 'conformal mapping' improves the acuity of the image in the corners. Experimental results support our conjecture.
Quantum Chromodyanamics (QCD), the theory of quarks and gluons, has been remarkably successful in... more Quantum Chromodyanamics (QCD), the theory of quarks and gluons, has been remarkably successful in the quantitative description of a large variety of seemingly diverse phenomena in particle physics. QCD describes strong interactions, which are characterized by a single free parameter, the strong coupling constant α{sub s}. The coupling constant is a measure of the strength of the strong force at the interaction vertex. It depends on q², the square of the four momentum transfer to the gluon, and is the QCD counter part to the fine structure constant α. It is generally accepted that e{sup +}eâ» annihilation experiments provide an ideal testing ground for QCD theory. An investigation of e{sup +}â» â hadronic events observed in the CLEO detector operating at the Cornell Electron Storage Ring (CESR) at an average center of mass energy of 10.5 GeV will be presented. By studying the hadronic jet structure, the value of α{sub s} is determined to be a α{sub s} = .138 {plus minus} .010 {plus minus} .009 at the CESR energy. This value is combined with other estimates of α from different experiments at various energies in order to determine the best value of Î, the QCD re-normalization scale parameter. A may be intuitively described as the energy below which perturbation calculations for QCD are no longer reliable. The value of Î determines the threshold energy suitable for experimental verification of QCD perturbation techniques. When the results from this study are combined with other values of α{sub s}, Î is determined to Î = .174 {plus minus} .010 {plus minus} .075 GeV.
24th Annual BACUS Symposium on Photomask Technology, 2004
We show that a conformal mapping of the type, W = z pi/alpha, describes how a shape of a 45° rota... more We show that a conformal mapping of the type, W = z pi/alpha, describes how a shape of a 45° rotated cross transforms into a contact hole. We discuss its relevance to corner rounding seen on raster beam pattern generators.
The ALTA 4300 system has been used to successfully write many advanced design layers previously o... more The ALTA 4300 system has been used to successfully write many advanced design layers previously only feasible with 50kV vector shaped beam tools. In order to further enlarge the application space of this high productivity an aerial image enhancement technique has been developed to deliver mask patterns that more closely match pattern data for corners and jogs. This image enhancement is done in real time in the ALTA system"s rasterizer by modifying the gray level mapping of pixels near the corner vertexes. SEM measurements of corner rounding with standard rasterization and the enhanced rasterization show an improvement of corner rounding radius from ~205 to ~132 nm. A direct comparison of SEM micrographs show no qualitative difference between vector scan mask features and those written with aerial image enhancement. This convincingly demonstrates that the ALTA 4300 system with the new image enhancement can write many layers requiring vector scan corner acuity.
The ALTA 4300 system has been used to successfully write many advanced designs previously only po... more The ALTA 4300 system has been used to successfully write many advanced designs previously only possible with 50kV VSB systems. In order to further enlarge the application space of this high productivity system, an aerial image enhancement technique has been developed to deliver mask patterns that more closely match the pattern data for corners and jogs. This image enhancement is done in real time in the ALTA system's rasterizer by modifying the gray level mapping of pixels near the corner vertexes. SEM measurements of corner rounding with standard rasterization and the enhanced rasterization show a 35% improvement of corner rounding radius from ~205 to ~132 nm. A direct comparison of SEM micrographs show little qualitative difference between vector scan mask features and those written with aerial image enhancement. This convincingly demonstrates that the ALTA 4300 system with the new image enhancement can write many layers requiring vector scan corner acuity.
23rd Annual BACUS Symposium on Photomask Technology, 2003
Photomask and Next-Generation Lithography Mask Technology XI, 2004
The ALTA 4300 system has been used to successfully write many advanced designs previously only po... more The ALTA 4300 system has been used to successfully write many advanced designs previously only possible with 50kV VSB systems. In order to further enlarge the application space of this high productivity system, an aerial image enhancement technique has been ...
Journal of Applied Physics, 2005
It is shown that patterning with a Gaussian beam on thin films is congruent to a diffusion proces... more It is shown that patterning with a Gaussian beam on thin films is congruent to a diffusion process. In particular, the acuity of the image patterned is tied to a steady state (Laplace equation). For a small spot size, pattern acuity improves locally when the Laplacian approaches zero at the said region. However, when the spot size (blur) of the
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1993
We describe the results of beam tests of three uranium-liquid argon calorimeter modules construct... more We describe the results of beam tests of three uranium-liquid argon calorimeter modules constructed for the Do detector at the Fermilab Tevatron collider. As part of the calibration procedure, these modules were exposed to beams of electrons, pions and muons between 10 and 150 GeV/c before their installation in the end calorimeter of the completed DO detector. We obtain an electromagnetic sampling resolution of 15 .7%/F and constant term of 0 .3% . The hadronic sampling resolution is 45%/F (degraded to 50%o/FE by the effects of upstream material) and the constant term is 4% . The calorimeter is linear to 0 .5%, and the electromagnetic to hadronic response ratio is between 1 .02 and 1 .09 over this range of momenta . For an electron efficiency of 95% we obtain a rejection factor against pions of -900-3000 for particles in the momentum range between 50 and 150 GeV/c . We also compare our results with the predictions of a detailed Monte Carlo simulation .
It is common to recast the EPR paradox [1] along Bohm's formulation as the entanglement of the di... more It is common to recast the EPR paradox [1] along Bohm's formulation as the entanglement of the discrete values of spin (or helicity). In fact, the Bell and in particular, CHSH inequalities are concerned with the helicities of a pair of photons in coincidence experiments. Furthermore, it is customary to analyze the phenomenon of entanglement, in phase space with the Wigner function, as an interference effect which arises in the initial state and doesn't temper off [2]. However, the Wigner function 1 assumes free particles, which is not the case with a photon in a gravitational field. Also, since according to Einstein's Equivalence Principle (EEP) 2 , gravity is neither affected by spin, nor does it affect the spin of a particle, extending the EPR system to a non-flat spacetime brings about interesting questions regarding quantum entanglement. One of which is, could a system of two photons be entangled in its helicities and yet disentangled in their momenta?
Following Boltzmann's principle and in contrast to the Bekenstein–Hawking entropy, S = A/4 , we ... more Following Boltzmann's principle and in contrast to the Bekenstein–Hawking entropy, S = A/4 , we ascribe to the black hole (BH) entropy, a logarithmic dependence on the area, S = log (A). As the BH area is proportional to the mass squared, 𝑙𝑜𝑔 𝐴 ∝
2𝑙𝑜𝑔 𝑀 , we have, 𝛿𝑆 ∝ 𝛿M/M. This gives rise to a straightforward relation between the process of assembling the BH mass from infinitesimal elements, and its increasing entropy: 𝑀 = 𝑀 + 𝛿𝑀 → 𝑆 = 𝑆 + 𝛿𝑆. Surface gravity of a BH, defined as, 𝜅 = 1/4M, implies, 𝛿𝑆 ∝ 𝜅 𝛿𝑀, or an inverse temperature of the horizon, 1/T= 𝜅. We interpret this result as an indication of the " firewall " behind the BH event horizon. Because an observer falling into the horizon is believed to measure a rather low Unruh temperature, 𝑇 = ħ 𝜅/2π, the inevitable conclusion is that the equivalence principle must be violated at the event horizon, or else the BH undergoes a phase transition which lowers its temperature. Generalizing the notion of the horizon to any configuration in spacetime, we follow Verlinde and treat it as an elastomer membrane. As a result, the gravitational force emerges as surface tension of the membrane. As information is lost to heat via, δQ = T dS, we link the loss process to spacetime fluctuations. Using the Unruh effect we estimate the order of magnitude of these fluctuations for a weak field. We do this by analyzing the famous gravitational redshift experiment of Pound and Rebka. The implication therefore seems to be that quantum entanglement at a BH horizon may break down due to metric fluctuations.