119936495
Hadronic Physics with Antiprotons at FAIR
The physics program of the future FAIR facility covers a wide range of topics that address central issues of strong interactions and QCD. The antiproton beam of unprecedented quality in the momentum range from 1 GeV/c to 15 GeV/c will allow to make high precision, high statistics measurements, from charmonium spectroscopy to the search for exotic hadrons and the study of nucleon structure, from the study of in-medium modifications of hadron masses to the physics of hypernuclei. These topics form the scientific program of the PANDA experiment. In addition to that the possibility to polarize antiprotons will provide the possibility to perform new, unique measurements of single- and double-spin observables, which are part of the experimental program of PAX.
119456485
Measurement of the branching ratios psi-prime ---> e+ e-, psi-prime ---> J/psi pi pi and psi-prime ---> J/psi eta
The authors have measured several branching ratios for {psi}' decay using the data collected by FNAL E835 experiment during year 2000, obtaining {beta}({psi}' {yields} e{sup +}e{sup -}) = 0.0068 {+-} 0.0001 {+-} 0.0004, {beta}({psi}' {yields} J/{psi}{pi}{sup +}{pi}{sup -}) = 0.292 {+-} 0.005 {+-} 0.018, {beta}({psi}' {yields} J/{psi}{pi}{sup 0}{pi}{sup 0}) = 0.167 {+-} 0.005 {+-} 0.014 and {beta}({psi}' {yields} J/{psi}{eta}) = 0.028 {+-} 0.002 {+-} 0.002. They also present a measurement of the dipion mass distribution in the decays {psi}' {yields} J/{psi}{pi}{pi}.
125782352
Experimental Study of the Strong Interaction at FAIR
The physics program of the future FAIR facility covers a wide range of topics that address central issues of strong interactions and QCD. The antiproton beam of unprecedented quality in the momentum range from 1 GeV/c to 15 GeV/c will allow to make high precision, high statistics measurements, from charmonium spectroscopy to the search for exotic hadrons and the study of nucleon structure, from the study of in-medium modification s of hadron masses to the physics of hypernuclei. In addition to that the possibility to polarize antiprotons will provide access to a wealth of singleand double-spin observables, opening up the possibility to perform new, unique measurements, like the transversity distribution of the valence quarks in the proton, new measurements of singlespin asymmetries and the first determination of the relative phase of the electric and magnetic form factors of the proton in the time-like region. In this paper we will discuss the experimental program of the PANDA and PAX experiments, which will address these fundamental issues at FAIR.
123064237
The charged trigger of the experiment E835 at Fermilab
Abstract Fermilab experiment E835 studies the charmonium states primarily through their electromagnetic decays. A kinematical charged trigger has been designed to select the electromagnetic final states e + e − and e + e − X and the hadronic decay c c → φφ →4 K ± . A detailed description of the charged trigger is presented here. The design, its implementation and the performances are given.
120547065
Charmonium states at the Fermilab Antiproton Accumulator. New results from E835
Abstract Experiment E835 has collected a large sample of charmonium states using a hydrogen jet and the virtually monoenergetic stochastically cooled antiproton beam. We present an improved measurement of the ξ c 0 mass and width, preliminary results of analysis of the ξ c 0 decay to μ 0 μ 0 and γγ and the final value of our measurements of the η c parameters.
39950378
Measurement of the gamma gamma partial width of the chi 2 charmonium resonance.
The E760 Collaboration has studied the reaction [ital [bar p]p][r arrow][chi][sub 2][r arrow][gamma][gamma] using a hydrogen gas jet target in the Fermilab antiproton acumulator ring. The following values are obtained for the branching ratio and partial width to two photons; [ital B]([chi][sub 2][r arrow][gamma][gamma])=(1.60[plus minus]0.45)[times]10[sup [minus]4] and [Gamma]([chi][sub 2][r arrow][gamma][gamma])=321[plus minus]95 eV.
18925167
The WINGS survey: a progress report
A two-band (B and V ) wide–field imaging survey of a complete, all–sky X–ray selected sample of 78 clusters in the redshift range z = 0.04 − 0.07 is presented. The aim of this survey is to provide the astronomical community with a complete set of homogeneous, CCD–based surface photometry and morphological data of nearby cluster galaxies located within 1.5 Mpc from the cluster center. The data collection has been completed in seven observing runs at the INT and ESO 2.2-m telescopes. For each cluster, photometric data of about 2500 galaxies (down to V ∼ 23) and detailed morphological information of about 600 galaxies (down to V ∼ 21) are obtained by using specially designed automatic tools. As a natural follow up of the photometric survey, we also illustrate a long term spectroscopic program we are carrying out with the WHT-WYFFOS and AAT-2dF multifiber spectrographs. Star formation rates and histories, as well as metallicity estimates will be derived for about 350 galaxies per cluster from the line indices and equivalent widths measurements, allowing us to explore the link between the spectral properties and the morphological evolution in highto low-density environments, and across a wide range in cluster X-ray luminosities and optical properties.
14276856
The fundamental plane of early-type galaxies in nearby clusters from the WINGS database
By exploting the data of three large surveys (WINGS, NFPS, and SDSS), we analyze the fundamental plane (FP) of early-type galaxies (ETGs) in 59 nearby clusters ( -->0.04 < z < 0.07). We show that the variances of the FP coefficients for our clusters are just marginally consistent with the hypothesis of universality of the FP. We found they are influenced by the distribution of photometric/kinematic properties of galaxies in the particular sample under analysis, suggesting that the FP is actually a bent surface. We also find a strong correlation between the local density and the FP coefficients, while they appear to be poorly correlated with the global properties of clusters. The relation between luminosity and mass of our galaxies, computed by assuming Sersic luminosity profiles, indicates that, for a given mass, the greater the light concentration, the higher the luminosity, while, for a given luminosity, the lower the light concentration, the greater the mass. Moreover, the M/L versus mass relation (again with Sersic profile fitting) turns out to be steeper and broader than that obtained for the Coma Cluster sample with de Vaucouleurs profile fitting. This broadness, together with the FP bending, might reconcile the FP phenomenology with the expectations from the ΛCDM cosmology. We conclude that the claimed universality of the FP of ETGs is still far from being proved and that systematic biases might affect the studies of luminosity evolution of ETGs, since data sets at different redshifts and with different distributions of the photometric/kinematic galaxy properties are compared each other.
14499782
A spectrophotometric model applied to cluster galaxies: the wings dataset
Context. The WIde-field Nearby Galaxy-cluster Survey (wings) is a project aiming at the study of the galaxy populations in clusters in the local universe (0.04 < z < 0.07) and the influence of environment on the physical properties of galaxies. This survey provides a high quality set of spectroscopic data for ∼6000 galaxies in 48 clusters. The study of such a large amount of objects requires automatic tools capable of extracting as much information as possible from the data. Aims. In this paper we describe a stellar population synthesis technique that reproduces the observed optical spectra of galaxies performing an analysis based on spectral fitting of the stellar content, extinction and, when possible, metallicity. Methods. A salient feature of this model is the possibility of treating dust extinction as a function of age, allowing younger stars to be more obscured than older ones. Our technique, for the first time, takes into account this feature in a spectral fitting code. A set of template spectra spanning a wide range of star formation histories is built, with features closely resembling those of typical spectra in our sample in terms of spectral resolution, noise and wavelength coverage. Our method of analyzing these spectra allows us to test the reliability and the uncertainties related to each physical parameter we are inferring. The well-known degeneracy problem, i.e. the non-uniqueness of the best fit solution (mass and extinction in different age bins), can be addressed by assigning adequate error bars to the recovered parameters. The values found in this way, together with their error bars, identify the region of parameter space which contains all the possible solutions for a given spectrum. A comparison test was also performed on a wings subsample, containing objects in common with the Sloan Digital Sky Survey, yielding excellent agreement. Results. We find that the stellar content as a function of age is reliably recovered in four main age bins and that the uncertainties only mildly depend on the S/N ratio. The metallicity of the dominant stellar population is not always recoverable unambiguosly, depending on the Star Formation History pattern.
119251924
A multiwavelength study of the IRAS Deep Survey galaxy sample - III. Spectral classification and dynamical properties
The infrared deep sample (IDS), in the north ecliptical polar region (NEPR), is the first complete, far--IR selected sample, on which numerous studies of galaxy evolution are based. Here we present and analyze the spectral classification of several galaxies in the IDS sample together with rotation curves which allow estimating the lower mass limits of a subsample of objects. We measured fluxes and intensity ratios of the emission lines in the visible region of the spectrum (lambda 4000-9000 A) for 75 galaxy members. Moreover, for some of them (55%), the spectra obtained with the Keck II telescope have sufficient wavelength and spatial resolution to derive their rotation curve. These galaxies turn out to be disk like systems, with a high fraction (~50%) of interacting systems. The spectroscopic classification of 42 galaxies, using the emission-line ratio diagnostic diagrams, shows that the NEPR sample is predominantly composed of starburst galaxies (71%), while the fraction of AGNs (7%) and LINERs (21%) is small. The dynamical analysis allows us to estimate the lower mass limits of 39 galaxies. The rest-frame FIR luminosity distribution of these galaxies spans the same range as that of the FIR selected complete sample, i.e. three orders of magnitude, with the same mean value, log(L_FIR)=10.2. This emphasizes that such galaxies represent FIR properties of the whole sample well. Moreover, their optical properties are typical of the sample itself since 62% of these belong to the 60mu selected complete sample.
14196899
Study of ISM tracers in galaxies
We collected data for two samples of normal and interacting galaxies for a total of 2953 galaxies having fluxes in one or more of the following wavebands: FIR, 21 cm line, CO(1-0) lines and soft X-ray. The large set of data obtained allowed us to revisit some of the already known relations between the different tracers of the interstellar medium (ISM), such as the link between the FIR flux and the CO line emission, the relation between X-ray emission and the blue or FIR luminosity. The relation lacking from observations for early-type galaxies has been discussed and explained in detail in the frame of a suitable theoretical model, obtained by coupling chemo-dynamical N-body simulations with a dusty spectrophotometric code of population synthesis.