National Geodetic Satellite Program /NGSP/ Station Solutions

Results derived from short arc, orbital solution of twelve stations, PAGEOS networ

Universal Unitarity Triangle and Physics Beyond the Standard Model

We make the simple observation that there exists a universal unitarity triangle for all models, like the SM, the Two Higgs Doublet Models I and II and the MSSM with minimal flavour violation, that do not have any new operators beyond those present in the SM and in which all flavour changing transitions are governed by the CKM matrix with no new phases beyond the CKM phase. This universal triangle can be determined in the near future from the ratio (Delta M)_d/(Delta M)_s and sin(2 beta) measured first through the CP asymmetry in B_d^0 to psi K_S and later in K to pi nu nubar decays. Also suitable ratios of the branching ratios for B to X_{d,s} nu nubar and B_{d,s} to mu^+ mu^- and the angle gamma measured by means of CP asymmetries in B decays can be used for this determination. Comparison of this universal triangle with the non-universal triangles extracted in each model using epsilon, (Delta M)_d and various branching ratios for rare decays will allow to find out in a transparent manner which of these models, if any, is singled out by experiment. A virtue of the universal triangle is that it allows to separate the determination of the CKM parameters from the determination of new parameters present in the extensions of the SM considered here.Comment: 12 pages, 1 figur

Renormalization of the Cabibbo-Kobayashi-Maskawa Quark Mixing Matrix

We have investigated the present renormalization prescriptions of Cabibbo-Kobayashi-Maskawa (CKM) matrix. When considering the prescription which is formulated with reference to the case of zero mixing we find it doesn't satisfy the unitary condition of the bare CKM matrix. After added a delicate patch this problem can be solved at one-loop level. In this paper We generalize this prescription to all loop levels and keep the unitarity of the bare CKM matrix, simultaneously make the amplitude of an arbitrary physical process involving quark mixing convergent and gauge independent. We also find that in order to keep the CKM counterterms gauge independent the unitarity of the bare CKM matrix must be preserved.Comment: has been revised, 8 pages, 1 figur

A re-analysis of the NuSTAR and XMM-Newton broad-band spectrum of Ser~X-1

Context: Ser X-1 is a well studied LMXB which clearly shows a broad iron line. Recently, Miller et al. (2103) have presented broad-band, high quality NuSTAR data of SerX-1.Using relativistically smeared self-consistent reflection models, they find a value of R_in close to 1.0 R_ISCO (corresponding to 6 R_g), and a low inclination angle, less than 10 deg. Aims: The aim of this paper is to probe to what extent the choice of reflection and continuum models (and uncertainties therein) can affect the conclusions about the disk parameters inferred from the reflection component. To this aim we re-analyze all the available public NuSTAR and XMM-Newton. Ser X-1 is a well studied source, its spectrum has been observed by several instruments, and is therefore one of the best sources for this study. Methods: We use slightly different continuum and reflection models with respect to those adopted in literature for this source. In particular we fit the iron line and other reflection features with self-consistent reflection models as reflionx (with a power-law illuminating continuum modified with a high energy cutoff to mimic the shape of the incident Comptonization spectrum) and rfxconv. With these models we fit NuSTAR and XMM-Newton spectra yielding consistent spectral results. Results: Our results are in line with those already found by Miller et al. (2013) but less extreme. In particular, we find the inner disk radius at about 13 R_g and an inclination angle with respect to the line of sight of about 27 deg. We conclude that, while the choice of the reflection model has little impact on the disk parameters, as soon as a self-consistent model is used, the choice of the continuum model can be important in the precise determination of the disk parameters from the reflection component. Hence broad-band X-ray spectra are highly preferable to constrain the continuum and disk parameters.Comment: 13 pages including 8 figures. Accepted for publication in A&

Recent developments in radiative B decays

We report on recent theoretical progress in radiative B decays. We focus on a calculation of logarithmically enhanced QED corrections to the branching ratio and forward-backward asymmetry in the inclusive rare decay anti-B --> X(s) l+ l-, and present the results of a detailed phenomenological analysis. We also report on the calculation of NNLO QCD corrections to the inclusive decay anti-B --> X(s) gamma. As far as exclusive modes are concerned we consider transversity amplitudes and the impact of right-handed currents in the exclusive anti-B --> K^* l+ l- decay. Finally, we state results for exclusive B --> V gamma decays, notably the time-dependent CP-asymmetry in the exclusive B --> K^* gamma decay and its potential to serve as a so-called ``null test'' of the Standard Model, and the extraction of CKM and unitarity triangle parameters from B --> (rho,omega) gamma and B --> K^* gamma decays.Comment: 5 pages, 2 figures. Accepted for publication in the proceedings of International Europhysics Conference on High Energy Physics (EPS-HEP2007), Manchester, England, 19-25 Jul 200

High precision locations of long-period events at La Fossa Crater (Vulcano Island, Italy)

Since the last eruption in 1888-90, the volcanic activity on Vulcano Island (Aeolian Archipelago, Italy) has been limited to fumarolic degassing. Fumaroles are mainly concentred at the active cone of La Fossa in the northern sector of the island and are periodically characterized by increases in the temperature as well as in the amount of both CO2 and He .Seismic background activity at Vulcano is dominated by micro-seismicity originating at shallow depth (<1-1.5 km) under La Fossa cone. This seismicity is related to geothermal system processes and comprises long period (LP) events. LPs are generally considered as the resonance of a fluid-filled volume in response to a trigger. We analyzed LP events recorded during an anomalous degassing period (August-October 2006) applying a high precision technique to define the shape of the trigger source. Absolute and high precision locations suggest that LP events recorded at Vulcano, during 2006, were produced by a shallow focal zone ca. 200 m long, 40 m wide and N30-40E oriented. Their occurrence is linked to magmatic fluid inputs that by modifying the hydrothermal system cause excitation of a fluid-filled cavity

Minimal prescription corrected spectra in heavy quark decays

The Minimal Prescription procedure is applied to tame the Landau pole singularities of resummed formulae for heavy quark decays. Effects of the final quark mass are taken into account. Explicit expressions are obtained for the t->b and b->c transitions for both the frozen coupling approximation and in the QCD running coupling case.Comment: Text revised, as accepted by Phys Rev D. Same content, formulas and conclusions. Title changed, one figure and appendix added. 24 pages, 10 figure

Updating the orbital ephemeris of the dipping source XB 1254-690 and the distance to the source

XB 1254-690 is a dipping low mass X-ray binary system hosting a neutron star and showing type I X-ray bursts. We aim at obtaining more accurate orbital ephemeris and at constraining the orbital period derivative of the system for the first time. In addition, we want to better constrain the distance to the source in order to locate the system in a well defined evolutive scenario. We apply for the first time an orbital timing technique to XB 1254-690, using the arrival times of the dips present in the light curves that have been collected during 26 years of X-ray pointed observations performed from different space missions. We estimate the dip arrival times using a statistical method that weights the count-rate inside the dip with respect to the level of the persistent emission outside the dip. We fit the obtained delays as a function of the orbital cycles both with a linear and a quadratic function. We infer the orbital ephemeris of XB 1254-690 improving the accuracy of the orbital period with respect to previous estimates. We infer a mass of M$_{2}=0.42\pm 0.04$ M$_{\odot}$ for the donor star, in agreement with the estimations already present in literature, assuming that the star is in thermal equilibrium while it transfers part of its mass via the inner Lagrangian point, and assuming a neutron star mass of 1.4 M$_{\odot}$. Using these assumptions, we also constrain the distance to the source, finding a value of 7.6$\pm 0.8$ kpc. Finally, we discuss the evolution of the system suggesting that it is compatible with a conservative mass transfer driven by magnetic braking.Comment: 13 pages, 5 figures, accepted for publication in Research in Astronomy and Astrophysics (RAA

Heavy Quark Parameters and Vcb from Spectral Moments in Semileptonic B Decays

We extract the heavy quark masses and non-perturbative parameters from the Delphi preliminary measurements of the first three moments of the charged lepton energy and hadronic mass distributions in semileptonic B decays, using a multi-parameter fit. We adopt two formalisms, one of which does not rely on a 1/mc expansion and makes use of running quark masses. The data are consistent and the level of accuracy of the experimental inputs largely determines the present sensitivity. The results allow to improve on the uncertainty in the extraction of Vcb.Comment: 13 pages, 2 figure

Evidence of a non-conservative mass transfer for XTE J0929-314

Context. In 1998 the first accreting millisecond pulsar, SAX J1808.4-3658, was discovered and to date 18 systems showing coherent, high frequency (> 100 Hz) pulsations in low mass X-ray binaries are known. Since their discovery, this class of sources has shown interesting and sometimes puzzling behaviours. In particular, apart from a few exceptions, they are all transient with very long X-ray quiescent periods implying a quite low averaged mass accretion rate onto the neutron star. Among these sources, XTE J0929-314 has been detected in outburst just once in about 15 years of continuous monitoring of the X-ray sky. Aims. We aim to demonstrate that a conservative mass transfer in this system will result in an X-ray luminosity that is higher than the observed, long-term averaged X-ray luminosity. Methods. Under the hypothesis of a conservative mass transfer driven by gravitational radiation, as expected for this system given the short orbital period of about 43.6 min and the low mass of the companion implied by the mass function derived from timing techniques, we calculate the expected mass transfer rate in this system and predict the long-term averaged X-ray luminosity. This is compared with the averaged, over 15 years, X-ray flux observed from the system, and a lower limit of the distance to the source is inferred. Results. This distance is shown to be > 7.4 kpc in the direction of the Galactic anticentre, implying a large height, > 1.8 kpc, of the source with respect to the Galactic plane, placing the source in an empty region of the Galaxy. We suggest that the inferred value of the distance is unlikely. (abridged)Comment: 6 pages, 2 figures, accepted for publication in Astronomy & Astrophysics (A&A