Research archive
arXiv papers from October 2001
The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.
Ath. Kehagias, M. Konstantinidou
The starting point of this paper is the introduction of a new measure of inclusion of fuzzy set A in fuzzy set B. Previously used inclusion measures take values in the interval [0,1]; the inclusion measure proposed here takes values in a Boolean lattice. In other words, inclusion is viewed as an L-fuzzy valued relation between fuzzy sets. This relation is re
Jens Erler
I review and compare various techniques to obtain the value of the QED coupling, alpha, at the Z pole. GigaZ precisions would require a much more accurate determination than available today. A combination of the virtues of current methods may help to achieve this goal.
- Application of bent crystals at IHEP 70-GeV accelerator to enhance the efficiency of its usagehep-ex
V. I. Kotov, A. G. Afonin, V. M. Biryukov, Y. A. Chesnokov
Bent crystal was extracting 70-GeV protons with average intensity 4*10^11 (as measured in external beamline) per spill of 1.6 s duration, in parallel to the simultaneous work of two internal targets in the accelerator ring. An additional crystal, placed in the external beamline, was deflecting a small part of the extracted beam with intensity 10^7 protons to
Christian Fleischhack, Jerzy Lewandowski
It is shown that the definition of physical integration measures via ``exponential of minus the action times kinematical integration measure'' typically contradicts properties of physical models. In particular, theories with uncountably many non-vanishing Wilson-loop expectation values cannot be gained this way. The results are rigorous within the Ashtekar a
Jonathan L. Feng, Konstantin T. Matchev
The 2.6 sigma deviation in the muon's anomalous magnetic moment has strong implications for supersymmetry. In the most model-independent analysis to date, we consider gaugino masses with arbitrary magnitude and phase, and sleptons with arbitrary masses and left-right mixings. For tan(beta)=50, we find that 1 sigma agreement requires at least one charged supe
N. Wang, R. N. Manchester, J. Zhang, X. J. Wu
A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing dedispersion of the pulsar signals is provided by a 2X128X2.5 MHz filterbank/digitiser system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period de
Adam S. Sikora
A natural topology on the space of left orderings of an arbitrary semi-group is introduced. It is proved that this space is compact and that for free abelian groups it is homeomorphic to the Cantor set. An application of this result is a new proof of the existence of universal Grobner bases.
Brandon Murakami, Kazuhiro Tobe, James D. Wells
Attention is called to potentially dangerous lepton-flavor violation (LFV) induced by the D-terms of additional U(1) flavor-dependent gauge symmetries in supersymmetric models. In such models, LFV persists despite an arbitrarily high scale for the U(1) breaking and despite arbitrarily small gauge couplings. In light of recent experimental observations of neu
B. Huisgen-Zimmermann, S. O. Smalo
We show that string algebras are `homologically tame' in the following sense: First, the syzygies of arbitrary representations of a finite dimensional string algebra $\Lambda$ are direct sums of cyclic representations, and the left finitistic dimensions, both little and big, of $\Lambda$ can be computed from a finite set of cyclic left ideals contained in th
Atish Dabholkar
String propagation on a cone with deficit angle $2\pi(1-{1\over N})$ is considered for the purpose of computing the entropy of a large mass black hole. The entropy computed using the recent results on condensation of twisted-sector tachyons in this theory is found to be in precise agreement with the Bekenstein-Hawking entropy.
Jianwei Qiu, George Sterman
We review the extension of the factorization formalism of perturbative QCD to soft rescattering associated with hard processes in nuclei.
- Electromagnetism, metric deformations, ellipticity and gauge operators on conformal 4-manifoldshep-th
Thomas Branson, A. Rod Gover
On Riemannian signature conformal 4-manifolds we give a conformally invariant extension of the Maxwell operator on 1-forms. We show the extension is in an appropriate sense injectively elliptic, and recovers the invariant gauge operator of Eastwood and Singer. The extension has a natural compatibility with the de Rham complex and we prove that, given a certa
O. J. P. Eboli, S. M. lietti, Prakash Mathews
We analyze the potential of the CERN Large Hadron Collider (LHC) to search for excited spin-1/2 electrons and neutrinos. Assuming a SU(2)_L X U(1)_Y invariant model, we study in detail the single production of excited electrons and neutrinos and respective backgrounds through the reactions p p -> e+ e- V and e+- \nu V with V=photon, W, or Z. We show that the
Saurya Das, Parthasarathi Majumdar, Rajat K. Bhaduri
We compute leading order corrections to the entropy of any thermodynamic system due to small statistical fluctuations around equilibrium. When applied to black holes, these corrections are shown to be of the form $-k\ln(Area)$. For BTZ black holes, $k=3/2$, as found earlier. We extend the result to anti-de Sitter Schwarzschild and Reissner-Nordstrom black ho
Jessica L. Rosenberg, Stephen E. Schneider
We use the HI-selected galaxy sample from the Arecibo Dual-Beam Survey (Rosenberg & Schneider 2000) to determine the shape of the HI mass function of galaxies in the local universe using both the step-wise maximum likelihood and the 1/V_tot methods. Our survey region spanned all 24 hours of right ascension at selected declinations between 8 and 29 degrees co
K. U. Kasemir, M. Pieck, L. R. Dalesio
Being easy to learn and well suited for a self-contained desktop laboratory setup, many casual programmers prefer to use the National Instruments LabVIEW environment to develop their logic. An ActiveX interface is presented that allows integration into a plant-wide distributed environment based on the Experimental Physics and Industrial Control System (EPICS
L. K. Townsley, P. S. Broos, G. Chartas, E. Moskalenko
We have implemented a Monte Carlo algorithm to model and predict the response of various kinds of CCDs to X-ray photons and minimally-ionizing particles and have applied this model to the CCDs in the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer. This algorithm draws on empirical results and predicts the response of all basic types of X-ray C
Craig Warner, Fred Hamann, Joseph C. Shields, Anca Constantin
We estimate the metallicity in the broad emission-line region of the redshift z=4.16 quasar, BR2248-1242, by comparing line ratios involving nitrogen to theoretical predictions. BR2248-1242 has unusually narrow emission lines with large equivalent widths, thus providing a rare opportunity to measure several line-ratio abundance diagnostics. The combined diag
Alexander Dvorsky, Siddhartha Sahi
We consider the groups G which arise from real semisimple Jordan algebras via the Tits-Koecher-Kantor construction. Such a G is characterized by the fact that it admits a parabolic subgroup P=LN which is conjugate to its opposite, and for which the nilradical N is abelian. In this situation, the Levi component L has a finite number of orbits on N; and each o
R. Roiban, J. Walcher
We study conformal field theories for strings propagating on compact, seven-dimensional manifolds with G_2 holonomy. In particular, we describe the construction of rational examples of such models. We argue that analogues of Gepner models are to be constructed based not on N=1 minimal models, but on Z_2 orbifolds of N=2 models. In Z_2 orbifolds of Gepner mod
- Marked variability in modern-time gravitational data indicates a large secular increase in the mass of ponderable bodiesphysics.gen-ph
V. Raicu
In spite of two hundred years of considerable efforts directed towards improvement in the experimental techniques, gravitational measurements have provided unsettled results for Newton's gravitational constant G. Analysis of the published (over ~75 years) small-scale gravitational measurements, presented in this report, unveils a large secular increase in th
E. S. Swanson
Modern experiment requires a reliable theoretical framework for low energy QCD. Some of the requirements for constructing a new model of QCD are presented here. Progress toward these requirements are highlighted.
Fedor S. Kilin
The optimal planning trajectory is analyzed on the basis of the growth model with effectiveness. The saving per capital value has to be rather high initially with smooth decrement in the future years.
Claude LeBrun
The Yamabe invariant Y(M) of a smooth compact manifold is roughly the supremum of the scalar curvatures of unit-volume constant-scalar-curvature Riemannian metrics g on M. (To be precise, one only considers those constant-scalar-curvature metrics which are Yamabe minimizers, but this technicality does not, e.g. affect the sign of the answer.) In this article
K. U. Kasemir, L. R. Dalesio
The Channel Archiver has been operational for more than two years at Los Alamos National Laboratory and other sites. This paper introduces the available components (data sampling engine, viewers, scripting interface, HTTP/CGI integration and data management), presents updated performance measurements and reviews operational experience with the Channel Archiv
Federico M. Spedalieri
The properties of deterministic LOCC transformations of three qubit pure states are studied. We show that the set of states in the GHZ class breaks into an infinite number of disjoint classes under this type of transformation. These classes are characterized by the value of a quantity that is invariant under these transformations, and is defined in terms of
D. Lehavi, R. Livné
Let F be a smooth plane curve of degree 3. Let \gb be an element in Pic(F)[2]-{0}. Let us define F':={\ol{p(p+\gb)}|p in F}\subset(P^2)^*. In this note we show that F' is a smooth embedding of F/\gb. Moreover, let \gb' be the generator of Pic(F)/\gb, and let p in F be a flex, then \ol{p(p+\gb)}+\gb' is a flex on F'. We present two proofs.
Richard L. Hall, Nasser Saad, Attila B. von Keviczky
Infinite series sum_{n=1}^infty {(alpha/2)_n / (n n!)}_1F_1(-n, gamma, x^2), where_1F_1(-n, gamma, x^2)={n!_(gamma)_n}L_n^(gamma-1)(x^2), appear in the first-order perturbation correction for the wavefunction of the generalized spiked harmonic oscillator Hamiltonian H = -d^2/dx^2 + B x^2 + A/x^2 + lambda/x^alpha 0 <= x < infty, alpha, lambda > 0, A >= 0. It
Korkut Bardakci, Charles B. Thorn
The N_c to infinity limit of a matrix quantum field theory is equivalent to summing only planar Feynman diagrams. The possibility of interpreting this sum as some kind world-sheet theory has been in the air ever since 't Hooft's original paper. We establish here just such a world sheet description for a scalar quantum field with interaction term g\Tr\phi^3,
Jonathan Earl Holland, George Sparling
This paper applies the notion of relative CR embeddings to study two related questions. First, it answers negatively the question posed by Penrose whether every shear-free null rotating congruence is analytic. Second, it proves that given any shear-free null rotating congruence, there exists a null electromagnetic field which is null with respect to the give
C. I. Lazaroiu, R. Roiban
We discuss gauge-fixing, propagators and effective potentials for topological A-brane composites in Calabi-Yau compactifications. This allows for the construction of a holomorphic potential describing the low-energy dynamics of such systems, which generalizes the superpotentials known from the ungraded case. Upon using results of homotopy algebra, we show th
Jamal Jalilian-Marian, Sangyong Jeon
Using the recently proposed $gg --> eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in $pA$ collisions. We show that measuring $\eta'$ production cross-section at moderate $x_{\eta'}$ yields direct information on the small $x$ gluon distribution function of the nucleus. At RHIC, the smallest accessible $x$ turns out to be $
Amnon Besser, Rob de Jeu
We define complexes analogous to Goncharov's complexes for the K-theory of discrete valuation rings of characteristic zero. Under suitable assumptions in K-theory, there is a map from the cohomology of those complexes to the K-theory of the ring. In case the ring is the localization of the ring of integers in a number field, there are no assumptions necessar
Beth Parks, Joseph Loomis, Evan Rumberger, David N. Hendrickson
We use time-domain terahertz spectroscopy to measure the position and linewidth of single photon transitions in Mn$_{12}$-acetate. This linewidth is compared to the linewidth measured in tunneling experiments. We conclude that local magnetic fields (due to dipole or hyperfine interactions) cannot be responsible for the observed linewidth, and suggest that th
Constantin M. Petridi, P. B. Krikelis
We propound the thesis that there is a limitation to the number of possible structures which are axiomatically endowed with identities involving operations. In the case of algebras with a binary operation satisfying a formally reducible (to be explained) identity between two n-iterates of the operation, it is established that the frequency of such algebras g
S. P. Barrow, representing the CLAS collaboration
The large acceptance and high multiplicity capabilities of the CLAS detector make it possible to study a wide range of previously unmeasured strange baryon production processes. Studies of the decay angular distributions of electroproduced strange baryons have yielded several interesting new results. The $\Lambda$(1520) electroproduction decay angular distri
G. S. Sharov
For the linear string baryon model $q$-$q$-$q$ the small disturbances of its rotational motion (quasirotational states) are investigated. The spectrum of these states is obtained in the form of Fourier series and the complex eigenfrequencies are found in this spectrum. So the classic rotational motions of the linear string baryon model are unstable (unlike t
L. Jenkovszky, V. K. Magas, E. Predazzi
By introducing Q^2-dependence in resonance-reggeon "soft" dual models with nonlinear trajectories, they are extended to "hard" processes, sharing the property of parton-hadron duality. The resulting object is a two-component complex function of three variables - s,t and Q^2, reducing to classical dual models on the mass shell and to deep inelastic structure
K. Splittorff
The response of the QCD vacuum to quark chemical potentials on the order of the pion mass is studied within the context of chiral perturbation theory. For two colour QCD diquark condensation sets in when the baryon chemical potential becomes larger than the pion mass. This leading order result is confirmed at next to leading order. Next a set of massive spin
- Comment on "Fun and frustration with quarkonium in a 1+1 dimension," by R. S. Bhalerao and B. Ram [Am. J. Phys. 69 (7), 817-818 (2001)]quant-ph
Antonio S. de Castro
The Dirac equation in a 1+1 dimension with the Lorentz scalar potential g|x| is approached. It is claimed that the eigenfunctions are proportional to the parabolic cylinder functions instead Hermite polynomials. Numerical evaluation of the quantization condition does not result in frustration.
J. Bourgain, S. Jitomirskaya
We study regularity properties of the Lyapunov exponent L of quasiperiodic operators with analytic potential, under no assumptions on the Diophantine class of the frequency. We prove that L is jointly continuous, in frequency and energy, at every irrational frequency.
S. A. Stanford, B. P. Holden, P. Rosati, P. R. Eisenhardt
We report the discovery of an X-ray luminous galaxy cluster at z =1.11. RDCS J0910+5422 was selected as an X-ray cluster candidate in the ROSAT Deep Cluster Survey on the basis of its spatial extent in a Rosat PSPC image. Deep optical and near-IR imaging reveal a red galaxy overdensity around the peak of the X-ray emission, with a significant excess of objec
A. Andreone, G. Ausanio, E. Di Gennaro, G. Lamura
We present a study of the electrodynamic response of MgB2 pellets and thin film samples exhibiting critical temperatures ranging between 26 and 38 K. We have performed accurate measurements of the surface impedance ZS =RS+iXS as a function of the temperature and of the magnitude of the electromagnetic field. The temperature variation and the field dependence
Tae-Sun Park, Kuniharu Kubodera, Dong-Pil Min, Mannque Rho
By combining effective field theory with the standard nuclear physics approach (SNPA) we obtain a high-precision estimate of the $S$ factor for the solar $hep$ process. The accurate wave functions available in SNPA are used to evaluate the nuclear matrix elements for the transition operators that result from chiral perturbation theory (ChPT). All the contrib
K. U. Kasemir, L. R. Dalesio
The Allen-Bradley ControlLogix line of pro-grammable logic controllers (PLCs) offers several in-terfaces: Ethernet, ControlNet, DeviceNet, RS-232 and others. The ControlLogix Ethernet interface module 1756-ENET uses EtherNet/IP, the ControlNet protocol, encapsulated in Ethernet packages, with specific service codes. A driver for the Experimental Physics and
Ali Mohammad-Djafari
Traditionally, the MaxEnt workshops start by a tutorial day. This paper summarizes my talk during 2001'th workshop at John Hopkins University. The main idea in this talk is to show how the Bayesian inference can naturally give us all the necessary tools we need to solve real inverse problems: starting by simple inversion where we assume to know exactly the f
Marcello Ortaggio
A new class of exact solutions is presented which describes impulsive waves propagating in the Nariai universe. It is constructed using a six-dimensional embedding formalism adapted to the background. Due to the topology of the latter, the wave front consists of two non-expanding spheres. Special sub-classes representing pure gravitational waves (generated b
A. Capella, D. Sousa
Charged multiplicities in nucleus--nucleus collisions are calculated in the Dual Parton Model taking into account shadowing corrections. Its dependence on the number of collisions and participants is analyzed and found in agreement with experiment at SPS and RHIC energies. Using these results, we compute the $J/\psi$ suppression at SPS as a function of the t
P. Moskal, H. H. Adam, A. Budzanowski, R. Czyzykiewicz
A measurement of the pp --> p p eta reaction at the excess energy of Q = 15.5 +- 0.4 MeV has been carried out at the internal beam facility COSY-11 with an integrated luminosity of 811 nb^-1 The number of ~24000 identified events permits a precise determination of total (2.32 +- 0.05 +- 0.35 \mu b) and differential cross sections. Preliminary investigations
Rocio Gonzalez-Diaz, Pedro Real
We propose a method for calculating cohomology operations for finite simplicial complexes. Of course, there exist well--known methods for computing (co)homology groups, for example, the reduction algorithm consisting in reducing the matrices corresponding to the differential in each dimension to the Smith normal form, from which one can read off (co)homology
Bernard Metsch, Ulrich Loering
On the basis of the three-particle Bethe-Salpeter equation we formulated a relativistic quark model for baryons. Assuming the propagators to be given by their free form with constituent quark masses and the interaction kernel by an instantaneous potential, which contains a string-like parameterization of confinement and a flavor dependent interaction motivat
B. Czerny, V. T. Doroshenko, M. Nikolajuk, A. Schwarzenberg-Czerny
We analyze observations of the Seyfert galaxy NGC 4151 covering 90 years in the optical band and 27 years in the 2-10 keV X-ray band. We compute the Normalized Power Spectrum Density (NPSD), the Structure Function (SF) and the Autocorrelation Function (ACF) for these data. The results show that the optical and X-ray variability properties are significantly d
Lian-You Shan, Bing-Lin Young, Xinmin Zhang
We propose a statistical formulation to estimate possible errors in long baseline neutrino oscillation experiments caused by uncertainties in the Earth matter density. A quantitative investigation of the effect is made on the CP asymmetry in future neutrino factory experiments.
Ulrich Loering, Bernard Metsch
The Nucleon- and the Lambda-excitation spectrum exhibit parity doublets, i.e. states of the same spin but with opposite parity being almost degenerate in mass. It is shown that in a relativistic quark model with instantaneous interaction kernels, where confinement is implemented by a linearly rising potential and the major mass splittings are generated from
- Electrodynamics of Magnetars: Implications for the Persistent X-ray Emission and Spindown of the Soft Gamma Repeaters and Anomalous X-ray Pulsarsastro-ph
C. Thompson, M. Lyutikov, S. R. Kulkarni
(ABBREVIATED) We consider the structure of neutron star magnetospheres threaded by large-scale electrical currents, and the effect of resonant Compton scattering by the charge carriers (both electrons and ions) on the emergent X-ray spectra and pulse profiles. In the magnetar model for the SGRs and AXPs, these currents are maintained by magnetic stresses act
Victor Alvarez, Jose Andres Armario, Maria Dolores Frau, Rocio Gonzalez-Diaz
We use homological perturbation machinery specific for the algebra category [P. Real. Homological Perturbation Theory and Associativity. Homology, Homotopy and Applications vol. 2, n. 5 (2000) 51-88] to give an algorithm for computing the differential structure of a small 1--homological model for commutative differential graded algebras (briefly, CDGAs). The
David Charlton
The current status of experimental tests of the electroweak sector of the Standard Model is reviewed.
M. E. Sainio
A brief review of the pion-nucleon sigma-term is given. Aspects of both chiral perturbation theory and phenomenology are discussed.
Larisa Jonke, Stjepan Meljanac
We analyze the algebra of observables and the physical Fock space of the finite Chern-Simons matrix model. We observe that the minimal algebra of observables acting on that Fock space is identical to that of the Calogero model. Our main result is the identification of the states in the l-th tower of the Chern-Simons matrix model Fock space and the states of
A. Bode, H. Panagopoulos, Y. Proestos
We calculate the 3-loop bare $\beta$-function of QCD, formulated on the lattice with the clover fermionic action. The dependence of our result on the number of colors $N$, the number of fermionic flavors $N_f$, and the clover parameter $c_{SW}$, is shown explicitly. A direct outcome of our calculation is the two-loop relation between the bare coupling consta
J. F. Vazquez-Poritz
We consider a brane world scenario which arises as the near-horizon region of a non-extremal D5-brane. There is a quasi-localized massive graviton mode, as well as harmonic modes of higher mass which are bound to the brane to a lesser degree. Lorentz invariance is slightly broken, which may have observable effects due to the leakage of the metastable gravito
C. Isola, M. Ladisa, G. Nardulli, T. N. Pham
We present estimates of the charming penguin contribution to B => K pi, pi pi,K eta, K eta' decays due to intermediate charmed meson states. We find that this contribution is indeed significant for B => K pi decays, and its inclusion, together with the tree and penguin terms, produces large branching ratios in agreement with data, though the analysis is affe
M. R. S. Hawkins
The variability of active galactic nuclei (AGN) has long held the promise of shedding light on their detailed structure, and possibly other astrophysical phenonema. Different emission mechanisms lead to different patterns of variability in flux which are in principle easily distinguishable. Recent predictions for the expected spectrum of variations for vario
T. Inoue, J. C. Nacher, M. J. Vicente Vacas, E. Oset
We study the S-wave interaction of mesons with baryons in the strangeness S=0 sector in a coupled channel unitary approach. The basic dynamics is drawn from the lowest order meson baryon chiral Lagrangians. Small modifications inspired by models with explicit vector meson exchange in the t-channel are also considered. In addition the pi pi N channel is inclu
S. Calchi Novati, G. Iovane, A. A. Marino, M. Auriere
We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31), aimed to the detection of gravitational microlensing effects as a probe of the presence of dark matter in our and in M31 halo. The analysis is performed using the pixel lensing te
Peter Rowlands, J. P. Cullerne, Brian D. Koberlein
Based on a fundamental symmetry between space, time, mass and charge, a series of group structures of physical interest is generated, ranging from C2 to E8. The most significant result of this analysis is a version of the Dirac equation combining quaternions and multivariate vectors, which is already second quantized and intrinsically supersymmetric, and whi
Panagiota Kanti, Kyriakos Tamvakis
We investigate the possibility of obtaining localized black hole solutions in brane worlds by introducing a dependence of the four-dimensional line--element on the extra dimension. An analysis, performed for the cases of an empty bulk and of a bulk containing either a scalar or a gauge field, reveals that no conventional type of matter can support such a dep
Asa Ben-Hur, Joshua Feinberg, Shmuel Fishman, Hava T. Siegelmann
The phase space flow of a dynamical system leading to the solution of Linear Programming (LP) problems is explored as an example of complexity analysis in an analog computation framework. An ensemble of LP problems with $n$ variables and $m$ constraints ($n>m$), where all elements of the vectors and matrices are normally distributed is studied. The convergen
Bernd Gehrmann, Stefan Kurth, Juri Rolf, Ulli Wolff
We study the Schr\"odinger functional coupling for lattice Yang-Mills theory coupled to an improved bosonic spinor field, which corresponds to QCD with minus two light flavors. This theory serves as a less costly testcase than QCD for the scaling of the coupling.
- The nonlinear-electrodynamic bending of the x-ray and gamma-ray in the magnetic field of pulsars and magnetarsastro-ph
Victor I. Denisov, Irene P. Denisova, Sergey I. Svertilov
It was shown that according to the non-linear electrodynamics of vacuum electromagnetic rays should bend in the field of magnetic dipole. The angles of ray bending in the gravitational and magnetic fields of pulsars and magnetars were obtained. In the case of pulsars with $b\sim R\sim $ 100 km, $B_0\sim 10^{13} G$ the value of the angle of non-linear electro
Naichung Conan Leung
We develop the foundation of the complex symplectic geometry of Lagrangian subvarieties in a hyperkahler manifold. We establish a characterization, a Chern number inequality, topological and geometrical properties of Lagrangian submanifolds. We discuss a category of Lagrangian subvarieties and its relationship with the theory of Lagrangian intersection. We a
Duilia F. de Mello, Tommy Wiklind, Marcio A. G. Maia
In order to study whether there is any correlation between nuclear activities, gas content, and the environment where galaxies reside, we have obtained optical and millimetric spectra for a well-defined sample of intermediate Hubble type spirals in dense environments and in the field. We found that these spirals in dense environments have on average: less mo
- Cometary molecular clouds around RNO6. On-going star formation near the double cluster h and chi Perseiastro-ph
R. Bachiller, A. Fuente, M. S. N. Kumar
We present molecular line observations of the star-forming cloud around RNO6 along with a newly discovered nearby molecular cloud that we name RNO6NW. Both clouds display striking similarities in their cometary structures and overall kinematics. By using 13CO line observations, we estimate that these clouds have similar sizes (~4.5 pc) and masses (~200 solar
N. Timneanu, J. Kwiecinski, L. Motyka
We formulate and analyse a saturation model for the total gamma gamma and gamma* gamma* cross-sections and for the real photon structure function F_2^gamma(x,Q^2). The model is based on a picture in which the gamma* gamma* total cross-section for arbitrary photon virtualities is driven by the interaction of colour dipoles, into which the virtual photons fluc
Nelson R. F. Braga, Cresus F. L. Godinho
We show how to translate boundary conditions into constraints in the symplectic quantization method by an appropriate choice of generalized variables. This way the symplectic quantization of an open string attached to a brane in the presence of an antisymmetric background field reproduces the non commutativity of the brane coordinates.
Peter Gillan
The Standard Model plus gravitation is derived from general relativity with three dimensions of time. I claim that when the Lagrangian for general relativity is calculated using three dimensions of time, the unified field theory results. I call it 3D time, which stands for three dimensions of time. This theory differs from other higher-dimensional theories b
A. Vereshagin
A method is described for dealing with effective theories of hadron scattering. It allows one to reduce the number of independent renormalization prescriptions in those theories and gives a possibility to make numerical predictions. As an illustration, we show the results of comparison with the known data on $\pi\pi$, $\pi K$ and $\pi N$ elastic scattering.
Marek Tasevsky
The differences between quark and gluon jets are studied using LEP results on jet widths, scale dependent multiplicities, ratios of multiplicities, slopes and curvatures and fragmentation functions. It is emphasized that the observed differences stem primarily from the different quark and gluon colour factors.
TARO Collaboration, S. Choe, Ph. de Forcrand, M. García Pérez
Responses to chemical potential of the pseudoscalar meson screening mass and the chiral condensate in lattice QCD are investigated. On a $16 \times 8^2 \times \4$ lattice with two flavors of staggered quarks the first and second responses below and above $T_c$ are evaluated. Different behavior in the low and the high temperature phases are observed, which ma
Sven Moch, Peter Uwer, Stefan Weinzierl
High precision analyses of experimental data for e+ e- annihillation, such as determination of jet rates or event shape observables, call for complete next-to-next-to-leading order (NNLO) perturbative QCD predictions. In this talk, we discuss the various ingredients entering the calculation of the NNLO corrections in e+ e- annihillation.
Wolfgang Lueck, Thomas Schick
:Let G be a group together with an descending nested sequence of normal subgroups G=G_0, G_1, G_2 G_3, ... of finite index [G:G_k] such the intersection of the G_k-s is the trivial group. Let (X,Y) be a compact 4n-dimensional Poincare' pair and p: (\bar{X},\bar{Y}) \to (X,Y) be a G-covering, i.e. normal covering with G as deck transformation group. We get as
- On a Manifestation of Dibaryon Resonances in the Structure of Proton-Proton Total Cross-Section at Low Energieshep-ph
A. A. Arkhipov
A manifestation of narrow diproton resonances in the early discovered global structure of proton-proton total cross section at low energies is discussed. It is also discussed the existence of new particle with the mass $1.833 MeV$ predicted early.
Stefano Bellucci, Alexei Deriglazov, Anton Galajinsky
We compare N=2 string and N=4 topological string within the framework of the sigma model approach. Being classically equivalent on a flat background, the theories are shown to lead to different geometries when put in a curved space. In contrast to the well studied Kaehler geometry characterising the former case, in the latter case a manifold has to admit a c
S. Digal, P. Petreczky, H. Satz
We use recent lattice data on the heavy quark potential in order to determine the dissociation temperatures of different quarkonium states in hot strongly interacting matter. Our analysis shows in particular that certain quarkonium states dissociate below the deconfinement point.
Duilia F. de Mello, Marcio A. G. Maia, Tommy Wiklind
We present optical and millimetric data for 47 intermediate Hubble type spiral galaxies located either in dense environments or in the field. We compare correlations between global parameters, such as far-infrared luminosity, blue luminosity, and total molecular gas content, with other samples of galaxies, including normal galaxies, clusters and ultraluminou
Monica Vazquez
The substructure of jets produced in an exclusive and a charm-induced dijet sample in photoproduction and in charged and neutral current interactions has been studied with the ZEUS detector at HERA. Jets were identified using the longitudinally invariant k_T cluster algorithm in the laboratory frame. The substructure of jets has been studied in terms of the
A. O. Parry, A. J. Wood, E. Carlon, A. Drzewiński
The phase boundaries for corner wetting (filling) in square and diagonal lattice Ising models are exactly determined and show a universal shift relative to wetting near the bulk criticality. More generally, scaling theory predicts that the filling phase boundary shift for wedges and cones is determined by a universal scaling function $R_d(\psi)$ depending on
Qi-Shu Yan, Dong-Sheng Du
In this letter we show that in the extra dimension model, contrary to the widely accepted conception, the simply truncated $\phi^4$ and non-Abelian SU(N) Kaluza-Klein theories are not renormalizable, i.e. the tree level relations of the effective theories can not sustain the quantum corrections. The breaking down of the tree level relations of the effective
- Teleportation implementation of non-deterministic quantum logic operations by using linear optical elementsquant-ph
XuBo Zou, K. Pahlke, W. Mathis
We present a feasible scheme to implement the non-deterministic quantum logic operation of Knill, Laflamme and Milburn (Nature, 409, 46-52(2001)) by using a teleportation protocol, which requires only single-photon sources, linear optical elements and photon detectors.
- A combined analysis technique for the search for fast magnetic monopoles with the MACRO detectorhep-ex
The MACRO Collaboration
We describe a search method for fast moving ($\beta > 5 \times 10^{-3}$) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confir
Daniel Schaerer
We present realistic models for massive Population III stars and stellar populations based on non-LTE model atmospheres, recent stellar evolution tracks and up-to-date evolutionary synthesis models, to study their spectral properties, including their dependence on age, star formation history, and IMF. (..) The main results regarding integrated stellar popula
Alexios Beveratos, Sergei Kuehn, Rosa Brouri, Thierry Gacoin
We report on the realization of a stable solid state room temperature source for single photons. It is based on the fluorescence of a single nitrogen-vacancy (NV) color center in a diamond nanocrystal. Antibunching has been observed in the fluorescence light under both continuous and pulsed excitation. Our source delivers 2*10^4 single-photon pulses per seco
R. Fiore, L. Jenkovszky, F. Paccanoni, A. Papa
We revise and update an earlier model for $J/\psi$ photoproduction based on a dipole Pomeron exchange. We show that the H1 and ZEUS experimental data reported recently can be well fitted by a soft Pomeron alone.
M. B. Gay Ducati, V. P. Goncalves, C. B. Mariotto
The diffractive photoproduction of vector mesons is usually described considering the two-gluon (Pomeron) exchange, non-diagonal parton distributions and the contribution of the real part to the cross section. In this letter we analyze the diffractive photoproduction of the $\Upsilon$ at HERA using an alternative model, the Color Evaporation Model (CEM), whe
S. Choi, K. Burnett
We study possible scenarios for quantum non-demolition measurements using Bose-Einstein condensates. We show that the interactions between condensate atoms makes it possible to measure the atom number with minimal back action on the system. This is an example of atomic nonlinear optics that has significant implications in the quantum state preparation of the
C. Adami, A. Mazure
We present an automated method to detect populations of groups in galaxy redshift catalogs. This method uses both analysis of the redshift distribution along lines of sight in fixed cells to detect elementary structures and a friend-of-friend algorithm to merge these elementary structures into physical structures. We apply this method to the SSRS2 galaxy red
Dorian Kcira
Measurements of the structure of the virtual photon in the transition region between quasi-real photons and those far from mass-shell have been made with the ZEUS detector at HERA, using an integrated luminosity of 38pb-1. Dijet final states are identified, and differential cross sections are presented in terms of xgo, an estimator of the fraction of the pho
J. J. M. in 't Zand, J. Swank, R. H. D. Corbet, C. B. Markwardt
A search for pulsations from the Be X-ray binary SAX J2239.3+6116, through observations with the Narrow Field Instruments on BeppoSAX and the Proportional Counter Array on RXTE, yielded the clear presence of a 1247 s coherent oscillation. Given the fairly high X-ray luminosity on previous occasions (up to a few times 10^36 erg/s in 2 to 28 keV), the oscillat
R. Bacher
In October 2000, the third PCaPAC (PCs and Particle Accelerator Controls) workshop took place at DESY. This paper presents a summary of the workshop. The workshop reviewed existing and new PC-based accelerator control systems, from small-scale to large-scale installations. It demonstrated convincingly the advantage of modern, commercial mass-market products
A. Denner, S. Dittmaier, M. Roth, D. Wackeroth
The relevance of radiative corrections to 4f production at LEP2 and future e+e- colliders is emphasized, and their treatment in the event generator RacoonWW is briefly discussed. In particular, the non-universal corrections are compared with the signature of anomalous triple gauge-boson couplings. For 4f+gamma production the influence of anomalous quartic ga