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 Photons (5)
 Photoionization (4)
 Rescattering (4)
 Chemical Imaging (3)
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 Differential Cross Sections (3)
 Atoms (3)
 Argon (3)
 Electrons (3)
 Intense Laser Pulse (3)
 Critical Points (3)
 Electrodynamics (3)
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 Impact Ionization (2)
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 High Order Harmonic Generation (2)
 Harmonic Analysis (2)
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 Infrared Laser (2)
 Dinger Equation (2)
 CarrierEnvelope Phase (2)
 Atomic Physics (2)
 Aligned Molecules (2)
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 Fluctuations (2)
 Harmonic Generation (2)
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Articles 1  30 of 52
FullText Articles in Physical Sciences and Mathematics
(E,2e) Study Of TwoCenter Interference Effects In The Ionization Of N₂, Leigh R. Hargreaves, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Ola A. AlHagan, Don H. Madison, Chuangang Ning
(E,2e) Study Of TwoCenter Interference Effects In The Ionization Of N₂, Leigh R. Hargreaves, Christopher J. Colyer, Mark A. Stevenson, B. Lohmann, Ola A. AlHagan, Don H. Madison, Chuangang Ning
Physics Faculty Research & Creative Works
A number of previous studies have suggested the possibility of twocenter interference effects in the single ionization of diatomic molecules such as H_{2} and N_{2}. While interference effects have been successfully observed in the ionization of H_{2}, to date evidence for interference in N_{2} ionization has yet to be conclusively demonstrated. This study presents triply differential cross sections for electron impact ionization of N_{2}, measured using the (e,2e) technique. The data are probed for signatures of twocenter interference effects. Evidence for interference manifesting in the cross sections is observed.
Nonlinear Evolution Of Baryon Acoustic Oscillations From Improved Perturbation Theory In Real And Redshift Spaces, Atsushi Taruya, Takahiro Nishimichi, Shun Saito, Takashi Hiramatsu
Nonlinear Evolution Of Baryon Acoustic Oscillations From Improved Perturbation Theory In Real And Redshift Spaces, Atsushi Taruya, Takahiro Nishimichi, Shun Saito, Takashi Hiramatsu
Physics Faculty Research & Creative Works
We study the nonlinear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of renormalized PT, which provides a nonperturbative way to treat the gravitational clustering of largescale structure, we apply the closure approximation that truncates the infinite series of loop contributions at oneloop order, and obtain a closed set of integral equations for power spectrum and nonlinear propagator. The resultant integral expressions are basically equivalent to those previously derived in the form of evolution equations, and they keep important nonperturbative properties which can dramatically improve ...
Systematic Analysis Of DoubleIonization Dynamics Based On FourBody Dalitz Plots, Daniel Fischer, Michael Schulz, Katharina R. Schneider, Marcelo F. Ciappina, Tom Kirchner, Aditya H. Kelkar, S. Hagman, Manfred Grieser, Kai Uwe Kuhnel, Robert Moshammer, Joachim Hermann Ullrich
Systematic Analysis Of DoubleIonization Dynamics Based On FourBody Dalitz Plots, Daniel Fischer, Michael Schulz, Katharina R. Schneider, Marcelo F. Ciappina, Tom Kirchner, Aditya H. Kelkar, S. Hagman, Manfred Grieser, Kai Uwe Kuhnel, Robert Moshammer, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
We report on an experimental and theoretical systematic study of double ionization of helium by ion impact in terms of fourparticle Dalitz plots. Several collision systems covering abroad range of perturbation parameters η (projectile charge to speed ratio) were investigated. With increasing η we observe a systematic trend from features, characteristic to correlated doubleionization mechanisms, to signatures of higherorder processes not requiring electronelectron correlations [the mechanism called "twosteptwo projectileelectron interaction" (TS2)]. The data for the largest η can qualitatively be amazingly well described by a simple model only including the TS2 mechanism.
FourBody Model For Transfer Excitation, Allison L. Harris, Jerry Peacher, Don H. Madison, James Colgan
FourBody Model For Transfer Excitation, Allison L. Harris, Jerry Peacher, Don H. Madison, James Colgan
Physics Faculty Research & Creative Works
We present here a fourbody model for transferexcitation collisions, which we call the fourbody transferexcitation (4BTE) model. Each twobody interaction is explicitly included in the 4BTE model, allowing us to study the effects of individual twobody interactions. We apply our model to fully differential cross sections for proton+helium collisions, and study the effect of the incident projectileatom interaction, the scattered projectileion interaction, the projectilenuclear interaction, and electron correlation within the target atom.
Correlated TwoPhoton Emission By Transitions Of DiracVolkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura
Correlated TwoPhoton Emission By Transitions Of DiracVolkov States In Intense Laser Fields: Qed Predictions, Erik Lotstedt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
In an intense laser field, an electron may decay by emitting a pair of photons. The two photons emitted during the process, which can be interpreted as a laserdressed double Compton scattering, remain entangled in a quantifiable way: namely, the socalled concurrence of the photon polarizations gives a gaugeinvariant measure of the correlation of the hard gamma rays. We calculate the differential rate and concurrence for a backscattering setup of the electron and photon beam, employing Volkov states and propagators for the electron lines, thus accounting nonperturbatively for the electronlaser interaction. The nonperturbative results are shown to differ significantly compared ...
Nuclear Form Factor, Validity Of The Equivalent Photon Approximation And Coulomb Corrections To Muon Pair Production In PhotonNucleus And NucleusNucleus Collisions, Ulrich D. Jentschura, V. G. Serbo
Nuclear Form Factor, Validity Of The Equivalent Photon Approximation And Coulomb Corrections To Muon Pair Production In PhotonNucleus And NucleusNucleus Collisions, Ulrich D. Jentschura, V. G. Serbo
Physics Faculty Research & Creative Works
We study in detail the influence of the nuclear form factor both on the Born cross section and on the Coulomb corrections to the photoproduction of muon pairs off heavy nuclei (γ Z→μ + μ  Z) and in heavyion collisions (ZZ→ZZ μ + μ ). Our findings indicate a number of issues which have not been sufficiently described as yet in the literature: (i) the use of a realistic form factor, based on the Fermi charge distribution for the nucleus, is absolutely indispensable for reliable theoretical predictions; (ii) we checked quantitatively that the equivalent photon approximation has a very good accuracy ...
Analysis Of Angular Dependence Of StrongField Tunneling Ionization For Co₂, SongFeng Zhao, Cheng Jin, AnhThu Le, T. F. Jiang, C. D. Lin
Analysis Of Angular Dependence Of StrongField Tunneling Ionization For Co₂, SongFeng Zhao, Cheng Jin, AnhThu Le, T. F. Jiang, C. D. Lin
Physics Faculty Research & Creative Works
We analyzed the discrepancy of the angular dependence of strongfield ionization for CO₂ among the different theoretical calculations and experiments. Using a more accurate groundstate wave function of CO₂ in the asymptotic region, we showed that the accuracy in the earlier tunneling ionization theory of Tong et al. [Phys. Rev. A 66, 033402 (2002)] is much improved. We also concluded that the angular dependence deduced from the experiment of Pavicic [Phys. Rev. Lett. 98, 243001 (2007)] appears to be too narrowly distributed.
Search For GravitationalWave Bursts In The First Year Of The Fifth Ligo Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For GravitationalWave Bursts In The First Year Of The Fifth Ligo Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present the results obtained from an allsky search for gravitationalwave (GW) bursts in the 642000 Hz frequency range in data collected by the LIGO detectors during the first year (November 2005November 2006) of their fifth science run. The total analyzed live time was 268.6 days. Multiple hierarchical data analysis methods were invoked in this search. The overall sensitivity expressed in terms of the rootsumsquare (rss) strain amplitude h_{rss} for gravitationalwave bursts with various morphologies was in the range of 6 x 10^{22} Hz ^{1/2} to a few x 10^{21}Hz_{1/2}. No GW ...
Search For High Frequency GravitationalWave Bursts In The First Calendar Year Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For High Frequency GravitationalWave Bursts In The First Calendar Year Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present an allsky search for gravitational waves in the frequency range 1 to 6 kHz during the first calendar year of LIGO's fifth science run. This is the first untriggered LIGO burst analysis to be conducted above 3 kHz. We discuss the unique properties of interferometric data in this regime. 161.3 days of triplecoincident data were analyzed. No gravitational events above threshold were observed and a frequentist upper limit of 5.4 year^{1} on the rate of strong gravitationalwave bursts was placed at a 90% confidence level. Implications for specific theoretical models of gravitationalwave emission are ...
Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya
Nonlinear Power Spectrum In The Presence Of Massive Neutrinos: Perturbation Theory Approach, Galaxy Bias, And Parameter Forecasts, Shun Saito, Masahiro Takada, Atsushi Taruya
Physics Faculty Research & Creative Works
Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the highprecision measurements of galaxy power spectrum, when combined with CMB information. In this paper we develop a method to model galaxy power spectrum in the weakly nonlinear regime for a mixed dark matter [cold dark matter (CDM) plus finitemass neutrinos] model, based on perturbation theory (PT) whose validity is well tested by simulations for a CDM model. In doing this we carefully study various aspects of the nonlinear clustering (nonlinear neutrino perturbations and the higherorder growth functions), and then arrive at a useful approximation allowing ...
Nonperturbative Treatment Of Double Compton Backscattering In Intense Laser Fields, Erik Lotstedt, Ulrich D. Jentschura
Nonperturbative Treatment Of Double Compton Backscattering In Intense Laser Fields, Erik Lotstedt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
The emission of a pair of entangled photons by an electron in an intense laser field can be described by twophoton transitions of laserdressed, relativistic DiracVolkov states. In the limit of a small laser field intensity, the twophoton transition amplitude approaches the result predicted by double Compton scattering theory. Multiexchange processes with the laser field, including a large number of exchanged laser photons, cannot be described without the fully relativistic DiracVolkov propagator. The nonperturbative treatment significantly alters theoretical predictions for future experiments of this kind. We quantify the degree of polarization correlation of the photons in the final state by ...
Search For Gravitational Wave Ringdowns From Perturbed Black Holes In Ligo S4 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Wave Ringdowns From Perturbed Black Holes In Ligo S4 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
According to general relativity a perturbed black hole will settle to a stationary configuration by the emission of gravitational radiation. Such a perturbation will occur, for example, in the coalescence of a black hole binary, following their inspiral and subsequent merger. At late times the waveform is a superposition of quasinormal modes, which we refer to as the ringdown. The dominant mode is expected to be the fundamental mode, l = m = 2. Since this is a wellknown waveform, matched filtering can be implemented to search for this signal using LIGO data. We present a search for gravitational waves from black ...
First Ligo Search For Gravitational Wave Bursts From Cosmic (Super)Strings, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Ligo Search For Gravitational Wave Bursts From Cosmic (Super)Strings, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report on a matchedfilter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models. Many grand unified theoryscale models (with string tension ...
On The Transition Rate Of The Fe X Red Coronal Line, Gunter Brenner, Jose R. Crespo LopezUrrutia, Sven Bernitt, Daniel Fischer, Rainer Ginzel, Kai Uwe Kuhnel, Volkhard Mackel, Paul H. Mokler, Martin C. Simon, Joachim Hermann Ullrich
On The Transition Rate Of The Fe X Red Coronal Line, Gunter Brenner, Jose R. Crespo LopezUrrutia, Sven Bernitt, Daniel Fischer, Rainer Ginzel, Kai Uwe Kuhnel, Volkhard Mackel, Paul H. Mokler, Martin C. Simon, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
We present a lifetime measurement of the 3s ^{2}3p ^{5 2} P^{o} _{1/2} first excited finestructure level of the ground state configuration in chlorinelike Fe X, which relaxes to the ground state through a magnetic dipole (M1) transition (the socalled red coronal line) with a wavelength accurately determined to 637.454(1) nm. Moreover, the Zeeman splitting of line was observed. The lifetime of 14.2(2) ms is the most precise one measured in the red wavelength region and agrees well with advanced theoretical predictions and an empirically scaled interpolation based on experimental values from the ...
Einstein@Home Search For Periodic Gravitational Waves In Early S5 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Einstein@Home Search For Periodic Gravitational Waves In Early S5 Ligo Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
This paper reports on an allsky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data were searched for quasimonochromatic waves with frequencies f in the range from 50 to 1500 Hz, with a linear frequency drift ḟ (measured at the solar system barycenter) in the range f/τ < ḟ < 0.1f/τ, for a minimum spindown age τ of 1000 years for signals below 400 Hz and 8000 years above 400 Hz. The main computational work of ...
Relativistic (Zα)2 Corrections And Leading Quantum Electrodynamic Corrections To The TwoPhoton Decay Rate Of Ionic States, Benedikt J. Wundt, Ulrich D. Jentschura
Relativistic (Zα)2 Corrections And Leading Quantum Electrodynamic Corrections To The TwoPhoton Decay Rate Of Ionic States, Benedikt J. Wundt, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We calculate the relativistic corrections of relative order (Zα) 2 to the twophoton decay rate of higher excited S and D states in ionic atomic systems, and we also evaluate the leading radiative corrections of relative order α (Zα) 2 ln [(Zα) 2]. We thus complete the theory of the twophoton decay rates up to relative order α3 ln (α). An approach inspired by nonrelativistic quantum electrodynamics is used. We find that the corrections of relative order (Zα) 2 to the twophoton decay are given by the Zitterbewegung, by the spinorbit coupling and by relativistic corrections to the electron mass ...
Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Waves From Low Mass Compact Binary Coalescence In 186 Days Of Ligo's Fifth Science Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report on a search for gravitational waves from coalescing compact binaries, of total mass between 2 and 35M_{⊙}, using LIGO observations between November 14, 2006 and May 18, 2007. No gravitationalwave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass. The LIGO cumulative 90%confidence rate upper limits of the binary coalescence of neutron stars, black holes and black holeneutron star systems are 1.4x10^{2}, 7.3x10^{4} and 3.6x10yr^{1}L_{10}^{1}, respectively, where L_{10} is 10^{10} times the blue solar ...
ThreeBody Dynamics In Single Ionization Of Atomic Hydrogen By 75 Kev Proton Impact, Ahmad Hasan, Michael Schulz, Aaron C. Laforge, Jason S. Alexander, M. F. Ciappina, M. A. Khakoo, Kisra Nayomal Egodapitiya
ThreeBody Dynamics In Single Ionization Of Atomic Hydrogen By 75 Kev Proton Impact, Ahmad Hasan, Michael Schulz, Aaron C. Laforge, Jason S. Alexander, M. F. Ciappina, M. A. Khakoo, Kisra Nayomal Egodapitiya
Physics Faculty Research & Creative Works
Doubly differential cross sections for single ionization of atomic hydrogen by 75 keV proton impact have been measured and calculated as a function of the projectile scattering angle and energy loss. This pure threebody collision system represents a fundamental test case for the study of the reaction dynamics in fewbody systems. A comparison between theory and experiment reveals that threebody dynamics is important at all scattering angles and that an accurate description of the role of the projectiletargetnucleus interaction remains a major challenge to theory.
LightParticle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
LightParticle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
Physics Faculty Research & Creative Works
The ionization of the 3p orbital of argon by incident electrons and positrons is studied by means of the post version of the continuum distorted waveeikonal initialstate model. Results are presented at both 200 and 500 eV impact energies for conditions amenable to present experiments. Differences in the fully differential cross sections (FDCSs) are analyzed and the influence of the projectile charge sign on the emission dynamics is discussed. The FDCSs are found to display the classic binary plus recoil peak structure at 500 eV, but transition to a more complicated fourlobed structure at the lower impact energy.
Thermal Expansion And Grüneisen Parameter In Quantum Griffiths Phases, Thomas Vojta
Thermal Expansion And Grüneisen Parameter In Quantum Griffiths Phases, Thomas Vojta
Physics Faculty Research & Creative Works
We consider the behavior of the Grüneisen parameter, the ratio between thermal expansion and specific heat, at pressuretuned infiniterandomness quantumcritical points and in the associated quantum Griffiths phases. We find that the Grüneisen parameter diverges as ln (T_{0} /T) with vanishing temperature T in the quantum Griffiths phases. at the infiniterandomness critical point itself, the Grüneisen parameter behaves as [ln (T_{0} /T)]^{1+1/ (νψ)} where ν and ψ are the correlation length and tunneling exponents. Analogous results hold for the magnetocaloric effect at magneticfieldtuned transitions. We contrast clean and dirty systems, we discuss subtle differences between Ising ...
Accurate Retrieval Of Atomic Structures From HighOrder Harmonic Spectra, Toshihito Umegaki, Toru Morishita, Shinichiro Minemoto, Yuichiro Oguchi, AnhThu Le, Shinichi Watanabe, Hirofumi Sakai
Accurate Retrieval Of Atomic Structures From HighOrder Harmonic Spectra, Toshihito Umegaki, Toru Morishita, Shinichiro Minemoto, Yuichiro Oguchi, AnhThu Le, Shinichi Watanabe, Hirofumi Sakai
Physics Faculty Research & Creative Works
We extracted the photorecombination cross sections from the highorder harmonic spectra generated from rare gases by intense femtosecond pulses. By taking the ratio between the observed highorder harmonic spectra and recolliding electron wave packets, we successfully obtained the photorecombination cross sections.
Quantitative Rescattering Theory For HighOrder Harmonic Generation From Molecules, AnhThu Le, R. R. Lucchese, S. Tonzani, Toru Morishita, C. D. Lin
Quantitative Rescattering Theory For HighOrder Harmonic Generation From Molecules, AnhThu Le, R. R. Lucchese, S. Tonzani, Toru Morishita, C. D. Lin
Physics Faculty Research & Creative Works
The quantitative rescattering theory (QRS) for highorder harmonic generation (HHG) by intense laser pulses is presented. According to the QRS, HHG spectra can be expressed as a product of a returning electron wave packet and the photorecombination differential cross section of the laserfree continuum electron back to the initial bound state. We show that the shape of the returning electron wave packet is determined mostly by the laser. The returning electron wave packets can be obtained from the strongfield approximation or from the solution of the timedependent Schrödinger equation (TDSE) for a reference atom. The validity of the QRS is ...
Simulations Of Baryon Acoustic Oscillations. Ii. Covariance Matrix Of The Matter Power Spectrum, Ryuichi Takahashi, Naoki Yoshida, Masahiro Takada, Takahiko Matsubara, Naoshi Sugiyama, Issha Kayo, Atsushi J. Nishizawa, Takahiro Nishimichi, Shun Saito, Atsushi Taruya
Simulations Of Baryon Acoustic Oscillations. Ii. Covariance Matrix Of The Matter Power Spectrum, Ryuichi Takahashi, Naoki Yoshida, Masahiro Takada, Takahiko Matsubara, Naoshi Sugiyama, Issha Kayo, Atsushi J. Nishizawa, Takahiro Nishimichi, Shun Saito, Atsushi Taruya
Physics Faculty Research & Creative Works
We use 5000 cosmological Nbody simulations of 1 h^{3} Gpc^{3} box for the concordance ËCDM model in order to study the sampling variances of a nonlinear matter power spectrum. We show that the nonGaussian errors can be important even on large length scales relevant for baryon acoustic oscillations (BAOs). Our findings are the following: (1) the nonGaussian errors degrade the cumulative signaltonoise ratios (S/Ns) for the power spectrum amplitude by up to a factor of 2 and 4 for redshifts z = 1 and 0, respectively; (2) there is little information on the power spectrum amplitudes in the ...
Stacked Search For Gravitational Waves From The 2006 Sgr 1900+14 Storm, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Stacked Search For Gravitational Waves From The 2006 Sgr 1900+14 Storm, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present the results of a LIGO search for shortduration gravitational waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search method is used, "stacking" the GW data around the times of individual softgamma bursts in the storm to enhance sensitivity for models in which multiple bursts are accompanied by GW emission. We assume that variation in the time difference between burst electromagnetic emission and potential burst GW emission is small relative to the GW signal duration, and we timealign GW excess power timefrequency tilings containing individual burst triggers to their corresponding electromagnetic emissions. We ...
String Resonances At The Large Hadron Collider, Arunava Roy, Marco Cavaglia
String Resonances At The Large Hadron Collider, Arunava Roy, Marco Cavaglia
Physics Faculty Research & Creative Works
The Large Hadron Collider promises to discover new physics beyond the standard model. An exciting possibility is the formation of string resonances at the TeV scale. In this article, we show how string resonances may be detected at the LHC in the pp →γ + jet channel. Our study is based on eventshape variables, missing energy and momentum, maximum transverse momentum of photons and dijet invariant mass. These observables provide interesting signatures which enable us to discriminate string events from the standard model background.
Search For Gravitational Waves From Low Mass Binary Coalescences In The First Year Of Ligo's S5 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Waves From Low Mass Binary Coalescences In The First Year Of Ligo's S5 Data, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We have searched for gravitational waves from coalescing low mass compact binary systems with a total mass between 2M_{⊙} and 35M_{⊙} and a minimum component mass of 1M_{⊙} using data from the first year of the fifth science run of the three LIGO detectors, operating at design sensitivity. Depending on the mass, we are sensitive to coalescences as far as 150 Mpc from the Earth. No gravitationalwave signals were observed above the expected background. Assuming a population of compact binary objects with a Gaussian mass distribution representing binary neutron star systems, black holeneutron star binary systems, and ...
Retrieval Of Target Photorecombination Cross Sections From HighOrder Harmonics Generated In A Macroscopic Medium, Cheng Jin, AnhThu Le, C. D. Lin
Retrieval Of Target Photorecombination Cross Sections From HighOrder Harmonics Generated In A Macroscopic Medium, Cheng Jin, AnhThu Le, C. D. Lin
Physics Faculty Research & Creative Works
We investigate highorder harmonic generation (HHG) in a thin macroscopic medium by solving Maxwell's equation using microscopic singleatom induced dipole moment calculated from the recently developed quantitative rescattering (QRS) theory. We show that macroscopic HHG yields calculated from QRS compared well with those obtained from solving the singleatom timedependent Schrödinger equation but with great saving of computer time. We also show that macroscopic HHG can be expressed as a product of a "macroscopic wave packet" and the photorecombination cross section of the target gas. The latter enables us to extract target structure from the experimentally measured HHG spectra, thus ...
Treatment Of IonAtom Collisions Using A PartialWave Expansion Of The Projectile Wavefunction, T. G. Wong, M. Foster, J. Colgan, Don H. Madison
Treatment Of IonAtom Collisions Using A PartialWave Expansion Of The Projectile Wavefunction, T. G. Wong, M. Foster, J. Colgan, Don H. Madison
Physics Faculty Research & Creative Works
We present calculations of ionatom collisions using a partialwave expansion of the projectile wavefunction. Most calculations of ionatom collisions have typically used classical or planewave approximations for the projectile wavefunction, since partialwave expansions are expected to require prohibitively large numbers of terms to converge scattering quantities. Here we show that such calculations are possible using modern highperformance computing. We demonstrate the utility of our method by examining elastic scattering of protons by hydrogen and helium atoms, problems familiar to undergraduate students of atomic scattering. Application to ionization of helium using partialwave expansions of the projectile wavefunction, which has long been ...
Probing Molecular Frame Photoionization Via Laser Generated HighOrder Harmonics From Aligned Molecules, AnhThu Le, R. R. Lucchese, M. T. Lee, C. D. Lin
Probing Molecular Frame Photoionization Via Laser Generated HighOrder Harmonics From Aligned Molecules, AnhThu Le, R. R. Lucchese, M. T. Lee, C. D. Lin
Physics Faculty Research & Creative Works
Present experiments cannot measure molecular frame photoelectron angular distributions (MFPAD) for ionization from the outermost valence orbitals of molecules. We show that the details of MFPAD can be retrieved with highorder harmonics generated by infrared lasers from aligned molecules. Using accurately calculated photoionization transition dipole moments for fixedinspace molecules, we show that the dependence of the magnitude and phase of the highorder harmonics on the alignment angle of the molecules observed in recent experiments can be quantitatively reproduced. This result provides the needed theoretical basis for ultrafast dynamic chemical imaging using infrared laser pulses.
Feasibility Of Coherent Xuv Spectroscopy On The 1s2s Transition In Singly Ionized Helium, Maximilian Herrmann, Martin K. Haas, Ulrich D. Jentschura, Franz Kottmann, Dietrich Leibfried, Guido Saathoff, Christoph Gohle, Akira Ozawa, V. Batteiger, S. Knunz, Nikolai N. Kolachevsky, H. A. Schussler, Theodor Wolfgang Hansch, Th H. Udem
Feasibility Of Coherent Xuv Spectroscopy On The 1s2s Transition In Singly Ionized Helium, Maximilian Herrmann, Martin K. Haas, Ulrich D. Jentschura, Franz Kottmann, Dietrich Leibfried, Guido Saathoff, Christoph Gohle, Akira Ozawa, V. Batteiger, S. Knunz, Nikolai N. Kolachevsky, H. A. Schussler, Theodor Wolfgang Hansch, Th H. Udem
Physics Faculty Research & Creative Works
The 1S2S twophoton transition in singly ionized helium is a highly interesting candidate for precision tests of boundstate quantum electrodynamics (QED). With the recent advent of extreme ultraviolet frequency combs, highly coherent quasicontinuouswave light sources at 61 nm have become available, and precision spectroscopy of this transition now comes into reach for the first time. We discuss quantitatively the feasibility of such an experiment by analyzing excitation and ionization rates, propose an experimental scheme, and explore the potential for QED tests.