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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 325 records · Page 18
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DOE OSTI2010

Meson Photoproduction off the Deuteron and off {sup 3}He

Photoproduction of mesons off the deuteron and He nuclei has been studied at the tagged photon facilities of the Bonn ELSA accelerator and the Mainz MAMI accelerator with the Crystal/ setup (Mainz). Meson photoproduction off the neutron has been investigated for different final states ({pi}{sup o}, {pi}{sup o} {pi}{sup o}, {pi}{sup o} {pi}{sup -}, {eta}, {eta}{sup '}, {eta}{pi}{sup o}). A surprising finding was a narrow structure in the {gamma}n{yields}n{eta} excitation function, which is not seen in the proton case. Photoproduction off {sup 3}He has provided further evidence for the formation of an h-mesic state.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Baryon spectroscopy: Recent results from the Crystal Barrel/TAPS experiment at ELSA

To understand the spectrum and the properties of baryon resonances, the CBELSA/TAPS experiment at ELSA investigates the photoproduction of single- and multi-meson final states off the nucleon. In the latter final states baryon cascades via Dp and Dh and also via higher mass baryon resonances are clearly observed. A partial wave analysis based on single and double meson photoproduction data as well as data from other reactions allows a first determination of resonance properties including partial decay widths of various N* and {Delta}* states. Those include also the decays into the different p{pi}{sup 0{pi}0} and p{pi}{sup 0{eta}} decay channels resulting partly in unexpected results. Recently not only single but also double polarisation experiments have been performed, which are absolutelly necessary to resolve ambiguities in the partial wave analyses (PWA) used to extract the resonances from the data; without the measurement of polarisation observables a model-independent PWA will not be possible. Polarisation observables have been investigated using linearly, circularly polarized or unpolarized photons impinging on an longitudinally polarized or unpolarized target. Given the angular coverage of the Crystal-Barrel/TAPS experiment this data cover almost the full angular range and phase space. This data will provide key information for the partial wave analyses and brings us one step closer towards the needed complete experiment.

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DOE OSTI2010

Latest results on the XYZ states from Belle and BaBar

Recent experimental studies of new charmonium-like states at B-factories are reviewed. This review covers updates on the exotic candidates, the X(3872) and Z(4430), searches and measurements of other new or known states in the mass region 3.9-4.7 GeV, and measurements of exclusive processes including a charmonium or a D(*)-meson pair in their final states, which are produced by initial-state-radiation processes related to the Y(4260) and other states.

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DOE OSTI2010

Early Hadron Physics at the LHC

The Large Hadron Collider (LHC) is presently undergoing beam commissioning in preparation for physics running in 2010 at a center of mass energy of 7 TeV. I will briefly describe the hadron physics capabilities of the ATLAS, CMS, and LHCb detectors, their performance with cosmic ray and early collision data, as well as their plans for physics with the first data.

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DOE OSTI2010

Recent Results from Experiments at COSY

In hadron physics, experiments using hadronic probes may shed light on open questions on the structure of hadrons, their interactions that are subject to the strong force and on the symmetries of nature. Therefore a major focus of the physics program studied at the COoler SYnchrotron COSY of the Forschungszentrum Juelich is the production of mesons and hyperons in hadron- hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. The COoler SYnchrotron COSY at Juelich accelerates protons and deuterons with momenta up to 3.7 GeV/c covering hadron physics in the light quark sector. The availability of the beam cooling systems allow precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets. Due to the excellent experimental conditions at COSY single- and double-polarization measurements can be performed with high reaction rates. With the operation of the recently installed WASA-at-COSY apparatus, high-statistics studies aiming at rare decays of {eta} and {eta}{sup '} are effectively turning COSY into a meson factory. This contribution summarizes the ongoing physics program at the COSY facility, using the detector systems ANKE, WASA and COSY-TOF highlighting a few selective recent results and outlining future developments. The research at COSY also provides a step towards the realization of FAIR with studies on spin manipulation and polarization build-up of protons in polarized targets.

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DOE OSTI2010

Light Meson Spectroscopy with KLOE

The KLOE experiment has collected an integrated luminosity of about 2.5 fb{sup -1} at the {phi} factory DA{phi}NE. {phi} radiative decays have been used to investigate the properties of the light scalar mesons f{sub 0}(980)/a{sub 0}(980), whose structure is still controversial.A direct search of {sigma}(600){yields}{pi}{sup 0{pi}0} decay has been performed with data taken at 1 GeV, where {phi} decays are suppressed.The whole KLOE data set includes also 100 million {eta}'s produced through the radiative decay {phi}{yields}{eta}{gamma} and tagged by means of the monochromatic recoil photon. From this sample we have investigated {eta} decays relevant to test ChPT predictions. We present published and preliminary results achieved from full statistics.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Study of the D{sup 0{yields}{pi}+{pi}-{pi}0} decay at BABAR

The Dalitz-plot of the decay D{sup 0{yields}{pi}+{pi}-{pi}0} measured by the BABAR collaboration shows the structure of a final state having quantum numbers I{sup G}J{sup PC} = 0{sup -}0{sup --}. An isospin analysis of this Dalitz-plot finds that the fraction of the I = 0 contribution is about 96%. This high I = 0 contribution is unexpected because the weak interaction violates the isospin.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Confirmation of pp-bar Mass Threshold Enhancement and X(1835) at BESIII

pp-bar mass threshold enhancement is studied using the data samples of J/{psi} and {psi}' collected with BESIII detector in 2009. The enhancement is evident in J/{psi} radiative decay, which is consistent with BESII result. No significant narrow enhancement is observed in {psi}' radiative decay. The study of J/{psi}{yields}{gamma}{pi}{sup +{pi}-{eta}}' is also presented, it is also consistent with BESII result, which shows that the X(1835) is confirmed at BESIII.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Diffractive pion production at COMPASS - First results on 3{pi} final states - neutral mode

The COMPASS experiment at CERN is designed for light hadron spectroscopy with emphasis on the detection of new states, in particular the search for exotic states and glue-balls. After a short pilot run in 2004 (190 GeV/c negative pion beam, lead target) showing significant production strength for an exotic J{sup PC} = 1{sup -+} state at 1.66 GeV/c{sup 2}, we have collected data with a 190 GeV/c negative charged hadron beam on a proton (liquid hydrogen) and nuclear targets in 2008 and 2009. The spectrometer features good coverage by electromagnetic calorimetry, and our data provide excellent opportunity for simultaneous observation of new states in two different decay modes in the same experiment. The diffractively produced (3{pi}){sup -} system for example can be studied in both modes {pi}{sup -}p{yields}{pi}{sup -{pi}+{pi}-}p and {pi}{sup -}p{yields}{pi}{sup -{pi}0{pi}0}p. Charged and neutral mode rely on completely different parts of the spectrometer. Observing a new state in both modes provides important crosscheck. First results of a preliminary PWA performed on the 2008 data are presented.

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DOE OSTI2010

Diffractive Pion Dissociation into {pi}{sup -{pi}+{pi}-{pi}+{pi}-} at COMPASS

At the COMPASS experiment a sample of {approx}380000 exclusive events of diffractive pion dissociation on a lead target into a {pi}{sup -{pi}+{pi}-{pi}+{pi}-} final state has been recorded in 2004. The 5{pi} invariant mass spectrum shows a momentum transfer dependent structure peaking around 1.8 GeV/c{sup 2}. In the (4{pi}){sup 0} subsystem there is a clear signal for the f{sub 1}(1285) resonance decaying into 4 pions. In this note we describe the data sample and explore the physics potential of this final state.

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DOE OSTI2010

Dalitz Plot Analysis of B{sup -{yields}}D{sup +{pi}-{pi}-}

We present a Dalitz plot analysis of B{sup -{yields}}D{sup +{pi}-{pi}-} decays, based on a sample of about 383 million {Upsilon}(4S){yields}BB-bar decays collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The analysis has been published previously in [1]. We measure the inclusive branching fraction of the three-body decay to be B(B{sup -{yields}}D{sup +{pi}+{pi}-}) = (1.08{+-}0.03(stat){+-}0.05(syst))x10{sup -3}. We observe the established D{sub 2}*{sup 0} and confirm the existence of D{sub 0}*{sup 0} in their decays to D{sup +{pi}-}, where the D{sub 2}*{sup 0} and D{sub 0}*{sup 0} are the 2{sup +} and 0{sup +} cu-bar P-wave states, respectively. We measure the masses and widths of D{sub 2}*{sup 0} and {Gamma}D{sub 0}*{sup 0} to be: mD{sub 2}* = (2460.4{+-}1.2{+-}1.2{+-}1.9) MeV/c{sup 2}, {Gamma}D{sub 2}* = (41.8{+-}2.5{+-}2.1{+-}2.0) MeV, mD{sub 0}* = (2297{+-}8{+-}5{+-}19) MeV/c{sup 2}, {Gamma}D{sub 0}* = (273{+-}12{+-}17{+-}45) MeV. The stated errors reflect the statistical and systematic uncertainties, and the uncertainty related to the assumed composition of signal events and the theoretical model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

The D{sub s1} and its D*K decays

Recently the Belle Collaboration has measured a new decay channel for the charmed strange meson D{sub s1}(2536){sup +{yields}}D{sup +{pi}-}K{sup +} together with an angular analysis of the D{sub s1}(2536){sup +{yields}}D*{sup +}K{sub S}{sup 0} decay. We study this reaction in a constituent quark model which has been able to reproduce the hadronic phenomenology and the baryon-baryon interaction. The reported branching fraction can be explained through a virtual D*{sup 0} and the properties of the D{sub s1}(2536){sup +} state are nicely reproduced. The influence of other intermediate states in the reaction D{sub s1}(2536){sup +{yields}}D{sup +{pi}-}K{sup +} has been analyzed giving negligible contributions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Study of {chi}{sub cj} Decays at BES III

In spring 2009 BES III has taken its first large data sample on the {psi}(2S) resonance. More than 1{center_dot}10{sup 8} {psi}(2S) decays have been recorded. First results on the analyses {chi}{sub cJ{yields}{pi}}{sup 0{pi}0}, {chi}{sub cj{yields}{eta}{eta}} and {chi}{sub cj{yields}{phi}{phi}} are presented. The decay mode {chi}{sub c1{yields}{phi}{phi}} has been observed for the first time. The results presented in this document are preliminary.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Studies of Bottomonium at B{sub A}B{sub AR}

We present studies of the bottomonium spectrum using 122 million {Upsilon}(3S) decays and 90 million {Upsilon}(2S) decays collected with the BABAR detector operating at the PEP II asymmetric-energy storage rings at SLAC. These studies include the first observation of the {eta}{sub b} meson and its confirmation, an energy scan between {radical}(s) = 10.54 and 11.20 GeV, and a measurement of the momentum distributions of open charm produced in {Upsilon}(1S) decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Studies of exotic charmonium-like hadrons at BaBar

Many new states have been recently discovered at the B-factories above the DD-bar threshold in the charmonium energy region. While some of them appear to be consistent with conventional cc-bar states others do not fit with any charmonium model expectation. A review of some of these new state is presented.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Study of kaonic final states in {pi}{sup -} p at 190 GeV

We discuss the status of analyses of data recorded in the 2008 and 2009 runs of the COMPASS experiment at CERN with sepcific focus on final states with K{sub S}{sup 0}K{sub S}{sup 0{pi}}- and K{sup +}K{sup -{pi}-} produced in {pi}{sup -}(190 GeV)p scattering. The interest in such final states is motivated by a summary of some of the relevant literature. We also show first results from the analysis of diffractively produced KK-bar{pi} states. Two prominent three-body structures, one around 1.8 GeV, the other at 2.2 GeV decaying via known KK-bar and K{pi} states are seen.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Search for scalar glueballs from heavy meson decays

We investigate the transition form factors of B meson decays into a scalar glueball in the light-cone formalism. Compared with form factors of B to ordinary scalar mesons, the B-to-glueball form factors have the same power in the expansion of 1/m{sub B}. Taking into account the leading twist light-cone distribution amplitude, we find that they are numerically smaller than those form factors of B to ordinary scalar mesons. In the presence of mixing between glueballs and ordinary scalar mesons, the possibility to extract the mixing parameters from semileptonic B decays and nonleptonic B decays are explored. We also point out a clean way to identify a glueball through B{sub c} decays.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Study of central production of charged pionic modes at COMPASS

The COmmon Muon and Proton Apparatus for Structure and Spectroscopy is a fixed target experiment at the CERN SPS accelerator. In the years 2008 and 2009 the collaboration focused on hadron spectroscopy: data with hadronic beams at a momentum of 190 GeV/c impinging on hydrogen, lead, nickel and tungsten targets were taken. In the preparation for this run-time, the apparatus was adapted to measure the formation of resonances by both diffractive scattering and central production. In the latter case, the study of charged pionic channels is well-suited to search for members of the f{sub 0} particle family, including some of the glueball candidates. The analysis of the newly taken data has started, these proceedings are meant to give a status and overview of the current activities.

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