3,112 research outputs found

    Anomaly induced QCD potential and Quark Decoupling

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    We explore the anomaly induced effective QCD meson potential in the framework of the effective Lagrangian approach. We suggest a decoupling procedure, when a flavored quark becomes massive, which mimics the one employed by Seiberg for supersymmetric gauge theories. It is seen that, after decoupling, the QCD potential naturally converts to the one with one less flavor. We study the NcN_c and NfN_f dependence of the η\eta^{\prime} mass.Comment: 11 pages, RevTe

    Analysis of error growth and stability for the numerical integration of the equations of chemical kinetics

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    Error growth and stability analyzed for numerical integration of differential equations in chemical kinetic

    Investigating the Light Scalar Mesons

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    We first briefly review a treatment of the scalars in meson meson scattering based on a non-linear chiral Lagrangian, with unitarity implemented by a "local" modification of the scalar propagators. It is shown that the main results are confirmed by a treatment in the SU(3) linear sigma model in which unitarity is implemented "globally". Some remarks are made on the speculative subject of the scalars' quark structure.Comment: 9 pages,3 figures,talk at hadron2001, Protvin

    HE 0047-1756: A new gravitationally lensed double QSO

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    The quasar HE 0047-1756, at z=1.67, is found to be split into two images 1.44" apart by an intervening galaxy acting as a gravitational lens. The flux ratio for the two components is roughly 3.5:1, depending slightly upon wavelength. The lensing galaxy is seen on images obtained at 800 nm and 2.1 \mu; there is also a nearby faint object which may be responsible for some shear. The spectra of the two quasar images are nearly identical, but the emission line ratio between the two components scale differently from the continuum. Moreover, the fainter component has a bluer continuum slope than the brighter one. We argue that these small differences are probably due to microlensing. There are hints of an Einstein ring emanating from the brighter image toward the fainter one.Comment: 4 pages, submitted to A&A Letter

    Complementary Ansatz for the neutrino mass matrix

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    We propose a simple Ansatz for the three generation neutrino mass matrix MνM_\nu which is motivated from an SO(10) grand unified theory. The Ansatz can be combined with information from neutrino oscillation experiments and bounds on neutrinoless double beta decay to determine the neutrino masses themselves and to reconstruct, with some assumptions, the matrix Mν M_\nu .Comment: 15 pages, RevteX, submitted to Phys. Rev.

    Exact relativistic beta decay endpoint spectrum

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    The exact relativistic form for the beta decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN collaboration. We also discuss the three neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future beta decay endpoint experiments.Comment: 12 pages, 3 figure

    Magnetization of small lead particles

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    The magnetization of an ensemble of isolated lead grains of sizes ranging from below 6 nm to 1000 nm is measured. A sharp disappearance of Meissner effect with lowering of the grain size is observed for the smaller grains. This is a direct observation by magnetization measurement of the occurrence of a critical particle size for superconductivity, which is consistent with Anderson's criterion.Comment: 7 pages, 5 figures, Submitted to PR

    The Gravitational Lens Candidate FBQ 1633+3134

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    We present our ground-based optical imaging, spectral analysis, and high resolution radio mapping of the gravitational lens candidate FBQ 1633+3134. This z=1.52, B=17.7 quasar appears double on CCD images with an image separation of 0.66 arcseconds and a flux ratio of ~3:1 across BVRI filters. A single 0.27 mJy radio source is detected at 8.46 GHz, coincident to within an arcsecond of both optical components, but no companion at radio wavelengths is detected down to a flux level of 0.1 mJy (3 sigma). Spectral observations reveal a rich metal-line absorption system consisting of a strong Mg II doublet and associated Fe I and Fe II absorption features, all at an intervening redshift of z=0.684, suggestive of a lensing galaxy. Point spread function subtraction however shows no obvious signs of a third object between the two quasar images, and places a detection limit of I > 23.0 if such an object exists. Although the possibility that FBQ 1633+3134 is a binary quasar cannot be ruled out, the evidence is consistent with it being a single quasar lensed by a faint, metal-rich galaxy.Comment: 24 pages, 5 figures. Accepted by AJ. A calibration error affecting B and V band apparent magnitudes has been corrected. The conclusions of the paper are not change

    Toy model for two chiral nonets

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    Motivated by the possibility that nonets of scalar mesons might be described as mixtures of "two quark" and "four quark" components, we further study a toy model in which corresponding chiral nonets (containing also the pseudoscalar partners) interact with each other. Although the "two quark" and "four quark" chiral fields transform identically under SU(3)L×_L \times SU(3)R_R transformations they transform differently under the U(1)A_A transformation which essentially counts total (quark + antiquark) content of the mesons. To implement this we formulate an effective Lagrangian which mocks up the U(1)A_A behavior of the underlying QCD. We derive generating equations which yield Ward identity type relations based only on the assumed symmetry structure. This is applied to the mass spectrum of the low lying pseudoscalars and scalars. as well as their "excitations". Assuming isotopic spin invariance, it is possible to disentangle the amount of"two quark" vs."four quark" content in the pseudoscalar π,K,η\pi, K ,\eta type states and in the scalar κ\kappa type states. It is found that a small "four quark" content in the lightest pseudoscalars is consistent with a large "four quark" content in the lightest of the scalar κ\kappa mesons. The present toy model also allows one to easily estimate the strength of a "four quark" vacuum condensate. There seems to be a rich and interesting structure.Comment: Numerical results updated, typos corrected, references update

    Chandra X-ray Observations of the Quadruply Lensed Quasar RX J0911.4+0551

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    We present results from X-ray observations of the quadruply lensed quasar RX J0911.4+0551 using data obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. The 29 ks observation detects a total of ~404 X-ray photons (0.3 to 7.0 keV) from the four images of the lensed quasar. Deconvolution of the aspect corrected data resolves all four lensed images, with relative positions in good agreement with optical measurements. When compared to contemporaneous optical data, one of the lensed images (component A3) is dimmer by a factor of ~6 in X-rays with respect to the 2 brighter images (components A1 and A2). Spectral fitting for the combined images shows significant intrinsic absorption in the soft (0.2 to 2.4 keV) energy band, consistent with the mini-BAL nature of this quasar, while a comparison with ROSAT PSPC observations from 1990 shows a drop of ~6.5 in the total soft bandpass flux. The observations also detect ~157 X-ray photons arising from extended emission of the nearby cluster (peaked ~42" SW of RXJ0911.4+0551) responsible for the large external shear present in the system. The Chandra observation reveals the cluster emission to be complex and non-spherical, and yields a cluster temperature of kT = 2.3^{+1.8}_{-0.8} keV and a 2.0 to 10 keV cluster luminosity within a 1 Mpc radius of L_X = 7.6_{-0.2}^{+0.6} x 10^{43} ergs/s (error bars denote 90% confidence limits). Our mass estimate of the cluster within its virial radius is 2.3^{+1.8}_{-0.7} x 10^{14} solar, and is a factor of 2 smaller than, although consistent with, previous mass estimates based on the observed cluster velocity dispersion.Comment: 16 pages, 3 figures (figure 1 is color ps). Accepted by Ap
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