Results for "W. Benbow"

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VERITAS Observations of BlazarsJan 05 2010The VERITAS array of four 12-m diameter imaging atmospheric-Cherenkov telescopes in southern Arizona is used to study very high energy (VHE; E>100 GeV) gamma-ray emission from astrophysical objects. VERITAS is currently the most sensitive VHE gamma-ray ... More
Upper Limits from HESS Observations of AGN in 2005-2007Sep 28 2007Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov telescopes. ... More
A search for Very High Energy gamma-ray emission from Passive Super-massive Black HolesSep 18 2007Jets of Active Galactic Nuclei (AGN) are established emitters of very high energy (VHE; >100 GeV) gamma-rays. VHE radiation is also expected to be emitted from the vicinity of super-massive black holes (SMBH), irrespective of their activity state. Accreting ... More
Multi-wavelength Observations of PG 1553+113 with HESSSep 28 2007Very high energy (VHE; >100 GeV) gamma-ray observations of PG 1553+113 were made with the High Energy Stereoscopic System (HESS) in 2005 and 2006. A strong signal, ~10 standard deviations, is detected by HESS during the 2 years of observations (24.8 hours ... More
Status of the Schwarzchild-Couder Medium-Sized Telescope for the Cherenkov Telescope ArrayOct 12 2016The Cherenkov Telescope Array (CTA) is planned to be the next-generation very-high-energy (VHE; E > 100 GeV) gamma-ray observatory. It is anticipated that CTA will improve upon the sensitivity of the current generation of VHE experiments, such as VERITAS, ... More
Discovery of Very High Energy gamma - ray emission from the extreme BL Lac object H2356-309 with H.E.S.SFeb 20 2006The understanding of acceleration mechanisms in active galactic nuclei (AGN) jets and the measurement of the extragalactic-background-light (EBL) density are closely linked and require the detection of a large sample of very-high-energy (VHE) emitting ... More
Status of the Milagro Gamma Ray ObservatoryJun 24 1999The Milagro Gamma Ray Observatory is the world's first large-area water Cherenkov detector capable of continuously monitoring the sky at TeV energies. Located in northern New Mexico, Milagro will perform an all sky survey of the Northern Hemisphere at ... More
First Results of a Study of TeV Emission from GRBs in MilagritoOct 29 1999Milagrito, a detector sensitive to gamma-rays at TeV energies, monitored the northern sky during the period February 1997 through May 1998. With a large field of view and high duty cycle, this instrument was used to perform a search for TeV counterparts ... More
Search for Short Duration Bursts of TeV Gamma Rays with the Milagrito TelescopeJun 24 1999The Milagrito water Cherenkov telescope operated for over a year. The most probable gamma-ray energy was ~1 TeV and the trigger rate was as high as 400 Hz. We have developed an efficient technique for searching the entire sky for short duration bursts ... More
A Survey of the Northern Sky for TeV Point SourcesMar 21 2001May 17 2001A search for steady TeV point sources anywhere in the northern sky has been made with data from the Milagrito air-shower-particle detector. Over 3 x 10**9 events collected from 1997 February to 1998 May have been used in this study. No statistically significant ... More
The high-energy gamma-ray fluence and energy spectrum of GRB 970417a from observations with MilagritoJul 06 2002Evidence of TeV emission from GRB970417a has been previously reported using data from the Milagrito detector. Constraints on the TeV fluence and the energy spectrum are now derived using additional data from a scaler system that recorded the rate of signals ... More
An All-Sky Search for Steady VHE Gamma-Ray SourcesJun 23 1999The Milagrito water Cherenkov detector in the Jemez Mountains near Los Alamos, New Mexico took data from February 1997 to April 1998. Milagrito served as a prototype for the larger Milagro detector, which has just begun operations. Milagrito was the first ... More
Calibration of the Milagro Cosmic Ray TelescopeJun 25 1999The Milagro detector is an air shower array which uses the water Cherenkov technique and is capable of continuously monitoring the sky at energies near 1 TeV. The detector consists of 20000 metric tons of pure water instrumented with 723 photo-multiplier ... More
Milagrito Detection of TeV Emission from Mrk 501Jun 24 1999The Milagro water Cherenkov detector near Los Alamos, New Mexico, has been operated as a sky monitor at energies of a few TeV between February 1997 and April 1998. Serving as a test run for the full Milagro detector, Milagrito has taken data during the ... More
Instrumented Water Tanks can Improve Air Shower Detector SensitivityJul 15 1999Previous works have shown that water Cherenkov detectors have superior sensitivity to those of scintillation counters as applied to detecting extensive air showers (EAS). This is in large part due to their much higher sensitivity to EAS photons which ... More
Detection of 6 November 1997 Ground Level Event by MilagritoJun 24 1999Solar Energetic Particles from the 6 November 1997 solar flare/CME(coronal mass ejection) with energies exceeding 10 GeV have been detected by Milagrito, a prototype of the Milagro Gamma Ray Observatory. While particle acceleration beyond 1 GeV at the ... More
Study of the Shadows of the Moon and the Sun with VHE Cosmic RaysJun 24 1999Milagrito, a prototype for the Milagro detector, operated for 15 months in 1997-8 and collected 8.9 billion events. It was the first extensive air shower (EAS) array sensitive to showers intiated by primaries with energy below 1 TeV. The shadows of the ... More
H.E.S.S. observations of galaxy clustersAug 10 2007Clusters of galaxies, the largest gravitationally bound objects in the universe, are expected to contain a significant population of hadronic and leptonic cosmic rays. Potential sources for these particles are merger and accretion shocks, starburst driven ... More
A Spectacular VHE Gamma-Ray Outburst from PKS 2155-304 in 2006Sep 28 2007Since 2002 the VHE (>100 GeV) gamma-ray flux of the high-frequency peaked BL Lac PKS 2155-304 has been monitored with the High Energy Stereoscopic System (HESS). An extreme gamma-ray outburst was detected in the early hours of July 28, 2006 (MJD 53944). ... More
Observation of the giant radio galaxy M87 at TeV energies with H.E.S.SApr 18 2005The giant radio galaxy M 87 was observed at TeV energies with the Cherenkov telescopes of the H.E.S.S. collaboration (High Energy Stereoscopic System). The observations have been performed in the year 2003 during the comissioning phase and in 2004 with ... More
Highlights from the VERITAS AGN Observation ProgramOct 12 2016The VERITAS array of four 12-m imaging atmospheric-Cherenkov telescopes began full-scale operations in 2007, and is one of the world's most sensitive detectors of astrophysical very high energy (VHE; E>100 GeV) gamma rays. Observations of active galactic ... More
Highlights of the VERITAS Blazar ProgramOct 12 2012The VERITAS array of 12-m atmospheric-Cherenkov telescopes in southern Arizona began full-scale operations in 2007, and is one of the world's most-sensitive detectors of astrophysical VHE (E>100 GeV) gamma rays. Approximately 50 blazars are known to emit ... More
The VERITAS Blazar Key Science ProjectAug 10 2009The VERITAS array of 12-m atmospheric-Cherenkov telescopes in southern Arizona is currently the world's most-sensitive detector of astrophysical very high energy (VHE; E>100 GeV) gamma rays. Approximately 25 blazars are known to emit VHE photons, and ... More
A Search for Pulsed Very High-Energy Gamma Rays from Thirteen Young Pulsars in Archival VERITAS DataApr 19 2019We conduct a search for periodic emission in the very high-energy gamma-ray band (VHE; E > 100 GeV) from a total of 13 pulsars in an archival VERITAS data set with a total exposure of over 450 hours. The set of pulsars includes many of the brightest young ... More
Gamma-ray Observations Under Bright Moonlight with VERITASMar 03 2017Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so ... More
Very-high-energy observations of the binaries V 404 Cyg and 4U 0115+634 during giant X-ray outburstsAug 23 2016Transient X-ray binaries produce major outbursts in which the X-ray flux can increase over the quiescent level by factors as large as $10^7$. The low-mass X-ray binary V 404 Cyg and the high-mass system 4U 0115+634 underwent such major outbursts in June ... More
Search for Magnetically Broadened Cascade Emission From Blazars with VERITASJan 02 2017We present a search for magnetically broadened gamma-ray emission around active galactic nuclei (AGN), using VERITAS observations of seven hard-spectrum blazars. A cascade process occurs when multi-TeV gamma rays from AGN interact with extragalactic background ... More
Highlights from the VERITAS AGN Observation ProgramAug 28 2015The VERITAS array of four 12-m imaging atmospheric-Cherenkov telescopes began full-scale operations in 2007, and is one of the world's most sensitive detectors of astrophysical VHE (E>100 GeV) $\gamma$-rays. Observations of active galactic nuclei (AGN) ... More
VHE Blazar Discoveries with VERITASSep 30 2011The VERITAS array of 12-m atmospheric-Cherenkov telescopes is used in an intensive observation program focused on the discovery of VHE (E > 100 GeV) gamma-ray-emitting blazars. Since VERITAS began full-scale operation in 2007, more than 1000 hours of ... More
Highlights of the VERITAS Blazar Observation ProgramSep 30 2011The VERITAS array of 12-m atmospheric-Cherenkov telescopes in southern Arizona began full-scale operations in 2007, and it is one of the world's most sensitive detectors of astrophysical VHE (E > 100 GeV) gamma rays. Forty-one blazars are known to emit ... More
Very High Energy outburst of Markarian 501 in May 2009Aug 04 2016The very high energy (VHE; E $>$ 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54938--54956), 2009, as part of an extensive multi-wavelength campaign from radio to VHE. Strong VHE $\gamma$-ray activity was detected on May ... More
Strongly Lensed Jets, Time Delays, and the Value of H0Aug 25 2014Nov 10 2014In principle, the most straightforward method of estimating the Hubble constant relies on time delays between mirage images of strongly-lensed sources. It is a puzzle, then, that the values of H0 obtained with this method span a range from 50 - 100 km/s/Mpc. ... More
VERITAS: Status and HighlightsNov 04 2011The VERITAS telescope array has been operating smoothly since 2007, and has detected gamma-ray emission above 100 GeV from 40 astrophysical sources. These include blazars, pulsar wind nebulae, supernova remnants, gamma-ray binary systems, a starburst ... More
A search for enhanced very high energy gamma-ray emission from the March 2013 Crab Nebula flareSep 23 2013Jan 08 2014In March 2013, a flaring episode from the Crab Nebula lasting ~2 weeks was detected by the Fermi-LAT (Large Area Telescope on board the Fermi Gamma-ray Space Telescope). VERITAS provides simultaneous observations throughout this period. During the flare, ... More
Multiwavelength Observations of The TeV Binary LS I +61 303 with VERITAS, Fermi-LAT and Swift-XRT During a TeV OutburstOct 29 2013We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift-XRT (2-10 keV). The data were taken from December 2011 through January ... More
Long term observations of B2 1215+30 with VERITASOct 24 2013We report on VERITAS observations of the BL Lac object B2 1215+30 between 2008 and 2012. During this period, the source was detected at very high energies (VHE; E > 100 GeV) by VERITAS with a significance of $8.9\sigma$ and showed clear variability on ... More
Multiwavelength observations and modeling of 1ES 1959+650 in a low flux stateJul 25 2013We report on the VERITAS observations of the high-frequency peaked BL Lac object 1ES 1959+650 in the period 2007-2011. This source is detected at TeV energies by VERITAS at 16.4 standard deviation (sigma) significance in 7.6 hours of observation in a ... More
A Medium Sized Schwarzschild-Couder Cherenkov Telescope Mechanical Design Proposed for the Cherenkov Telescope ArraySep 10 2015The Cherenkov Telescope Array (CTA) is an international next-generation ground-based gamma-ray observatory. CTA will be implemented as southern and northern hemisphere arrays of tens of small, medium and large-sized imaging Cherenkov telescopes with the ... More
Constraints on Very High Energy gamma-ray emission from Gamma-Ray BurstsMar 11 2005The Milagro gamma-ray observatory employs a water Cherenkov detector to observe extensive air showers produced by high energy particles interacting in the Earth's atmosphere. Milagro has a wide field of view and high duty cycle, monitoring the northern ... More
Active Galactic Nuclei under the scrutiny of CTAApr 10 2013Active Galactic Nuclei (hereafter AGN) produce powerful outflows which offer excellent conditions for efficient particle acceleration in internal and external shocks, turbulence, and magnetic reconnection events. The jets as well as particle accelerating ... More
Pairwise Comparisons Rating Scale ParadoxNov 24 2015Dec 01 2015This study demonstrates that incorrect data are entered into a pairwise comparisons matrix for processing into weights for the data collected by a rating scale. Unprocessed rating scale data lead to a paradox. A solution to it, based on normalization, ... More
Geometric relation between centrality and the impact parameter in relativistic heavy-ion collisionsOct 08 2001We show, under general assumptions which are well satisfied in relativistic heavy-ion collisions, that the geometric relation of centrality c to the impact parameter b, namely c ~ pi b^2/sigma_inel, holds to a very high accuracy for all but most peripheral ... More
In-Medium Modifications of Hadron Masses and Chemical Freeze-Out in Ultra-Relativistic Heavy-Ion CollisionsOct 06 1999We confront the hypothesis of chemical freeze-out in ultra-relativistic heavy-ion collisions with the hypothesis of large modifications of hadron masses in nuclear medium. We find that the thermal-model predictions for the ratios of particle multiplicities ... More
A Free Field Representation of the Osp(2|2) current algebra at level k=-2, and Dirac Fermions in a random SU(2) gauge potentialDec 11 2000The Osp(2|2) current algebra at level k=-2 is known to describe the IR fixed point of 2D Dirac fermions, subject to a random SU(2) gauge potential. We show that this theory has a simple free-field representation in terms of a compact, and a non-compact ... More
The Single-Electron-Box and the Helicity Modulus of an inverse square XY-ModelDec 19 1996We calculate the average number of electrons on a metallic single-electron-box as a function of the gate voltage for arbitrary values of the tunneling conductance. In the vicinity of the plateaus the problem is equivalent to calculating the helicity modulus ... More
Radiative capture of protons by deuteronsAug 17 1998Sep 03 1998The differential cross section for radiative capture of protons by deuterons is calculated using different realistic NN interactions. We compare our results with the available experimental data below $E_x = 20 MeV$. Excellent agreement is found when taking ... More
Triton photodisintegration with realistic potentialsDec 05 1997The photodisintegration of $^{3}$H is treated by means of coupled integral equations using separable versions of the Paris and the Bonn potentials in their kernel. The differential cross section for the inverse reaction is obtained via detailed balance. ... More
Topological phases: Classification of topological insulators and superconductors of non-interacting Fermions, and beyondDec 30 2015After briefly recalling the quantum entanglement-based view of topological phases of matter in order to outline the general context, we give an overview of different approaches to the classification problem of topological insulators and superconductors ... More
Large lepton flavour violating signals in supersymmetric particle decaysOct 24 2002We study lepton flavour violating signals at a future e+ e- linear collider within the general MSSM, allowing for the most general flavour structure. We demonstrate that there is a large region in parameter space with large signals, while being consistent ... More
Temperature-dependent quasiparticle band structure of the ferromagnetic semiconductor EuSJun 24 2002We present calculations for the temperature-dependent electronic structure of the ferromagnetic semiconductor EuS. A combination of a many-body evaluation of a multiband Kondo-lattice model and a first-principles T=0--bandstructure calculation (tight-binding ... More
Toponium as Nonabelian Positronium ?Jul 01 1993The expected large mass $m_t$ of the top quark provides for the first time a chance to discuss the bound-states of the corresponding quantum system as the nonabelian generalization of positronium, using the full power of relativistic quantum field theoretic ... More
Detecting Relic Gravitational Waves in the CMB: Comparison of Planck and Ground-based ExperimentsJul 09 2009We compare the detection abilities for the relic gravitational waves by two kinds of forthcoming cosmic microwave background radiation (CMB) experiments, space-based Planck satellite and the various ground-based experiments. Comparing with the ground-based ... More
Subtracted Dispersion Relations for In-Medium Meson Correlators in QCD Sum RulesJan 22 1999We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out the importance of scattering terms, as well as finite, well-defined subtraction constants. ... More
Low temperature thermodynamics of inverse square spin models in one dimensionApr 29 1998We present a field-theoretic renormalization group calculation in two loop order for classical O(N)-models with an inverse square interaction in the vicinity of their lower critical dimensionality one. The magnetic susceptibility at low temperatures is ... More
Photodisintegration of the triton with realistic potentialsDec 08 1997The process $\gamma + t \to n + d$ is treated by means of three-body integral equations employing in their kernel the W-Matrix representation of the subsystem amplitudes. As compared to the plane wave (Born) approximation the full solution of the integral ... More
Pac-Learning Recursive Logic Programs: Efficient AlgorithmsMay 01 1995We present algorithms that learn certain classes of function-free recursive logic programs in polynomial time from equivalence queries. In particular, we show that a single k-ary recursive constant-depth determinate clause is learnable. Two-clause programs ... More
Rigorous QCD-Potential for the $t\bar{t}$-System at ThresholdAug 02 1994Aug 04 1994Recent evidence for the top mass in the region of 160 $GeV$ for the first time provides an opportunity to use the full power of relativistic quantum field theoretical methods, available also for weakly bound systems. Because of the large decay width $\G$ ... More
Weak Coupling Limit and Genuine QCD Predictions for Heavy QuarkoniaAug 03 1994Although individual levels of toponium will be unobservable, the top--anti--top system near threshold fulfills all requirements of a rigorous perturbation theory in QCD for weakly bound systems. Corresponding techniques from positronium may thus be transferred ... More
A note on radial basis function computingJun 03 2001This note carries three purposes involving our latest advances on the radial basis function (RBF) approach. First, we will introduce a new scheme employing the boundary knot method (BKM) to nonlinear convection-diffusion problem. It is stressed that the ... More
Limits on Very High Energy Emission from Gamma-Ray Bursts with the Milagro ObservatoryNov 17 2003Feb 06 2004The Milagro telescope monitors the northern sky for 100 GeV to 100 TeV transient emission through continuous very high energy wide-field observations. The large effective area and ~100 GeV energy threshold of Milagro allow it to detect very high energy ... More
Resolving the High Energy Universe with Strong Gravitational Lensing: The Case of PKS 1830-211Apr 20 2015Jul 08 2015Gravitational lensing is a potentially powerful tool for elucidating the origin of gamma-ray emission from distant sources. Cosmic lenses magnify the emission from distance sources and produce time delays between mirage images. Gravitationally-induced ... More
Search for a TeV Component of GRBs using the Milagrito DetectorJun 24 1999Observing gamma ray bursts (GRBs) in the TeV energy range can be extremely valuable in providing insight to GRB radiation mechanisms and in constraining source distances. The Milagrito detector was an air shower array which used the water Cherenkov technique ... More
Evidence for TeV Emission from GRB 970417aJan 07 2000Milagrito, a detector sensitive to very high energy gamma rays, monitored the northern sky from February 1997 through May 1998. With a large field of view and a high duty cycle, this instrument was well suited to perform a search for TeV gamma-ray bursts ... More
Large lepton flavor violating signals in supersymmetric particle decays at future e+ e- collidersJan 30 2002We study lepton flavor violating signals at a future e+ e- linear collider within the general MSSM, allowing for the most general flavor structure. We demonstrate that there is a large region in parameter space with large signals, while being consistent ... More
Nucleon Structure Functions from Relativistic Constituent QuarksJun 30 1994We investigate deep inelastic lepton scattering from the nucleon within a constituent quark picture, in which the internal structure of constituent quarks is modeled by meson and diquark dressing. In a covariant framework this structure leads to a breakdown ... More
Pac-learning Recursive Logic Programs: Negative ResultsMay 01 1995In a companion paper it was shown that the class of constant-depth determinate k-ary recursive clauses is efficiently learnable. In this paper we present negative results showing that any natural generalization of this class is hard to learn in Valiant's ... More
On the variability of the GeV and multi-TeV gamma-ray emission from the Crab NebulaNov 18 2010Feb 15 2011Recently the AGILE $\gamma$-ray telescope has reported the enhanced $\gamma$-ray emission above 100 MeV from the direction of the Crab Nebula during a period of a few days. This intriguing observation has been confirmed by the Fermi-LAT telescope. This ... More
Strong gravitational lensing as a tool to investigate the structure of jets at high energiesMar 20 2014Jun 03 2014The components of blazar jets that emit radiation span a factor of $10^{10}$ in scale. The spatial structure of these emitting regions depends on the observed energy. Photons emitted at different sites cross the lens plane at different distances from ... More
Parton distribution functions in the pion from lattice QCDMar 21 2003Jun 30 2003We analyze the moments of parton distribution functions in the pion calculated in lattice QCD, paying particular attention to their chiral extrapolation. Using the lowest three non-trivial moments calculated on the lattice, we assess the accuracy with ... More
Moments of Isovector Quark Distributions in Lattice QCDOct 16 2002We investigate the connection of lattice calculations of moments of isovector parton distributions to the physical regime through extrapolations in the quark mass. We consider the one pion loop renormalisation of the nucleon matrix elements of the corresponding ... More
A Monte Carlo Study of Pairwise ComparisonsMay 07 2015Consistent approximations obtained by geometric means ($GM$) and the principal eigenvector ($EV$), turned out to be close enough for 1,000,000 not-so-inconsistent pairwise comparisons matrices. In this respect both methods are accurate enough for most ... More
First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument CampaignSep 16 2015Sep 24 2015We report on simultaneous broadband observations of the TeV-emitting blazar Markarian 501 between 1 April and 10 August 2013, including the first detailed characterization of the synchrotron peak with Swift and NuSTAR. During the campaign, the nearby ... More
Observation and Spectral Measurements of the Crab Nebula with MilagroOct 03 2011The Crab Nebula was detected with the Milagro experiment at a statistical significance of 17 standard deviations over the lifetime of the experiment. The experiment was sensitive to approximately 100 GeV - 100 TeV gamma ray air showers by observing the ... More
Extraction of parton distributions from lattice QCDOct 02 2003We review the calculation of moments of both the polarized and unpolarized parton distribution functions of the nucleon in lattice QCD, and in particular their extrapolation to the physical region. We also discuss the reconstruction of the x dependence ... More
Moments of Isovector Quark Distributions from Lattice QCDJun 03 2002Jul 19 2002We present a complete analysis of the chiral extrapolation of lattice moments of all twist-2 isovector quark distributions, including corrections from N pi and Delta pi loops. Even though the Delta resonance formally gives rise to higher order non-analytic ... More
Connecting structure functions on the lattice with phenomenologyJan 30 2002We examine the extraction of moments of parton distributions from lattice data, focusing in particular on the chiral extrapolation as a function of the quark mass. Inclusion of the correct chiral behavior of the spin-averaged isovector distribution resolves ... More
Parton distributions from lattice QCDAug 02 2001Sep 27 2001We extract the x dependence of the nonsinglet u-d distribution function in the nucleon from the lowest few moments calculated on the lattice, using an extrapolation formula which ensures the correct behavior in the chiral and heavy quark limits. We discuss ... More
Accretion disk wind in the AGN broad-line region: Spectroscopically resolved line profile variations in Mrk110Jun 19 2003Detailed line profile variability studies of the narrow line Seyfert 1 galaxy Mrk110 are presented. We obtained the spectra in a variability campaign carried out with the 9.2m Hobby-Eberly Telescope at McDonald Observatory. The integrated Balmer and Helium ... More
New differential equations in the six-vertex modelAug 19 2015Dec 14 2015This letter is concerned with the analysis of the six-vertex model with domain-wall boundaries in terms of partial differential equations (PDEs). The model's partition function is shown to obey a system of PDEs resembling the celebrated Knizhnik-Zamolodchikov ... More
Off-shell scalar products for the $XXZ$ spin chain with open boundariesDec 17 2014Jan 23 2015In this work we study scalar products of Bethe vectors associated with the $XXZ$ spin chain with open boundary conditions. The scalar products are obtained as solutions of a system of functional equations. The description of scalar products through functional ... More
On the elliptic $\mathfrak{gl}_2$ solid-on-solid model: functional relations and determinantsJun 20 2016In this work we study an elliptic solid-on-solid model with domain-wall boundaries having the elliptic quantum group $\mathcal{E}_{p, \gamma}[\widehat{\mathfrak{gl}_2}]$ as its underlying symmetry algebra. We elaborate on results previously presented ... More
Cancellations in Neutrinoless Double Beta Decay and the Neutrino Mass MatrixAug 04 2000Dec 19 2000In a degenerate scheme with mass m_0 a complete analysis of the allowed range of the effective electron neutrino Majorana mass <m> is performed. Special attention is paid to effects of cancellations caused either by intrinsic CP parities of the eigenstates ... More
Neutrino oscillation experiments and limits on lepton-number and lepton-flavor violating processesMar 15 2000Jun 19 2000Using a three neutrino framework we investigate bounds for the effective Majorana neutrino mass matrix. The mass measured in neutrinoless double beta decay is its (11) element. Lepton-number and -flavor violating processes sensitive to each element are ... More
The Mode-Coupling Theory of the Glass TransitionFeb 09 1997We give a brief introduction to the mode-coupling theory of the glass transition, a theory which was proposed a while ago to describe the dynamics of supercooled liquids. After presenting the basic equations of the theory, we review some of its predictions ... More
Low-energy sum rules and large-$N_c$ consistency conditionsFeb 02 1994The large-$N_c$ consistency conditions for axial vector and isovector magnetic couplings of pions to baryons are discussed from the point of view of low-energy current-algebra sum rules (Adler-Weisberger, Cabibbo-Radicati). In particular, we show how ... More
Nucleon structure at large x: nuclear effects in deuteriumJun 21 2010I review quark momentum distributions in the nucleon at large momentum fractions x. Particular attention is paid to the impact of nuclear effects in deuterium on the d/u quark distribution ratio as x -> 1. A new global study of parton distributions, using ... More
Flavor Asymmetries in the Proton and Semi-Inclusive ProcessesJun 24 1999Semi-inclusive electron scattering provides a powerful tool with which to study the spin and flavor distributions in the proton. Greater kinematic coverage at the proposed Electron-Polarized Ion Collider facility will enable the valence d/u ratio to be ... More
Quark Asymmetries in the ProtonJun 16 1998We review recent experimental and theoretical developments in the study of the sea quark structure of the proton. In the light quark sector, we analyse the recent pp and pD Drell-Yan data from the E866/NuSea experiment at Fermilab, and their implication ... More
Flavor Decomposition of the NucleonSep 21 1999Oct 04 1999I review some recent developments in the study of quark flavor distributions in the nucleon, including (i) valence quark distributions and the quark-hadron duality prediction for the x -> 1 d/u ratio (ii) sea quark asymmetries and electromagnetic form ... More
Models of Interacting Dark EnergyApr 26 2012Any non-gravitational coupling between dark matter and dark energy modifies the cosmological dynamics. Interactions in the dark sector are considered to be relevant to address the coincidence problem. Moreover, in various models the observed accelerated ... More
Planet influence on the shape of the hosting star - ellipsoidal variations of tau BootisDec 18 2008Dec 18 2008This paper presents estimations on the possibility of detection of ellipsoidal variations by means of measuring brightness of the star distorted by a close massive planet using Wilson-Devinney method. The problem was already discussed by Phafl et al. ... More
Polarization Observables in $γN\to K\bar{K}N$Dec 10 2004Dec 10 2004We explore some of the rich structure of the polarization observables recently developed for processes like $\gamma N\to\pi\pi N$ and $\gamma N\to K \bar{K} N$ in the framework of a specific model for the latter process. Emphasis is placed on observables ... More
HQET and Form Factor Effects in $B\to K^{(*)}\ell^+\ell^-$Dec 07 1995We examine the rates for the exclusive decays $B\to K^{(*)}\ell^+\ell^-$. We use the scaling predictions of the heavy quark effective theory to extract the necessary form factors from fits to various combinations of data. These data include the $D\to ... More
On the Heterotic/F-Theory Duality in Eight DimensionsOct 26 1999We review quantitative tests on the duality between the heterotic string on T^2 and F-theory on K3. On the heterotic side, certain threshold corrections to the effective action can be exactly computed at one-loop order, and the issue is to reproduce these ... More
Chiral Rings in Topological (W-)GravityFeb 28 1993Talk given at the 26th Workshop: ``From Superstrings to Supergravity", Erice - Sicily, 5-12 December 1992. We review the superconformal properties of 2d matter coupled to gravity, and extensions thereof. Focusing on topological strings, we recall how ... More
Measuring Chiral Parameters in the Strongly Interacting W system at a Linear ColliderSep 12 1996In the absence of a Higgs particle vector boson scattering amplitudes are generally described by an electroweak chiral Lagrangian below the resonance region. For a Linear Collider with CMS energy $\sqrt{s}=1.6 TeV$ and an integrated luminosity of $200 ... More
THE SOLAR NEUTRINO PROBLEMMar 24 1995The solar neutrino problem has persisted for almost three decades. Recent results from Kamiokande, SAGE, and GALLEX indicate a pattern of neutrino fluxes that is very difficult to reconcile with plausible variations in standard solar models. This situation ... More
Mott-Hubbard transition of cold atoms in optical latticesNov 15 2002May 05 2003We discuss the superfluid to Mott-insulator transition of cold atoms in optical lattices recently observed by Greiner (Nature 415, 39 (2002)). The fundamental properties of both phases and their experimental signatures are discussed carefully, ... More
Introduction to Landau DampingJan 20 2016The mechanism of Landau damping is observed in various systems from plasma oscillations to accelerators. Despite its widespread use, some confusion has been created, partly because of the different mechanisms producing the damping but also due to the ... More
Spacecone quantization of AdS superparticleMay 27 2010Jun 10 2010We first-quantize the superparticle describing free 10D IIB supergravity on AdS_5xS^5. We choose the worldline coordinate to be a combination of the bulk (spatial) coordinates of anti de Sitter space and the sphere. The Hamiltonian is independent of this ... More