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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 145 records · Page 8
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DOE OSTI2010

The Facility for Antiproton and Ion Research and the Compressed Baryonic Matter Experiment

The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific activities at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD phase diagram in the region of high baryon densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state of nuclear matter at high densities, and the search for the deconfinement and chiral phase transitions. The CBM detector is designed to measure both bulk observables with large acceptance and rare diagnostic probes such as charmed particles and vector mesons decaying into lepton pairs. The layout and the physics performance of the proposed CBM experimental facility will be discussed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2010

Hadron Physics at J-PARC

The Japan Proton Accelerator Research Complex, J-PARC, has just finished its phase-1 construction, and the proton beams have been delivered to the experimental facilities. The hadron experimental hall (Hadron Hall) is one of the experimental facilities at J-PARC, where secondary beams such as pions and kaons, as well as the primary proton beams, will be used for fixed target experiments. The first proton beam to the Hadron Hall was delivered in January and February, 2009, and the beam was resumed from October. The first experiments at the Hadron Hall are just being started, at a low-momentum beam lines for chaged partticle beams (K1.8BR and K1.8) and at a neutral kaon beam line. Other beam lines, such as K1.1 and high momentum beam lines, are planned. In this talk, physics topics to be conduced at the Hadron Hall will be introduced as well as the status and plan of the facility.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Unitarized Chiral Perturbation Theory and the meson spectrum

In this talk we briefly review how the unitarization of Chiral Perturbation Theory with dispersion relations can successfully describe the meson-meson scattering data and generate light resonances, whose mass, width and nature can be related to QCD parameters like quark masses and the number of colors.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
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.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
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.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Vector meson-vector meson interaction and dynamically generated resonances

Using the local hidden gauge formalism for the vector meson-vector meson interaction within a unitary approach we find that 11 states get dynamically generated. Five of them are associated to the f{sub 0}(1370), f{sub 0}(1710), f{sub 2}(1270), f{sub 2}'(1525), and K{sub 2}*(1430) resonances, by comparing the mass, width, and decay pattern of these states with those of their experimental counterparts. At the same time we predict six other states with the quantum numbers of h{sub 1}, a{sub 0}, b{sub 1}, a{sub 2}, K{sub 0}*, and K{sub 1} which could be tested by future experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

No indication of f{sub 0}(1370) in {pi}{pi} phase shift analyses

The scalar meson f{sub 0}(1370) - indicated in particular in the low energy pp-bar{yields}3 body reactions - is a crucial element in certain schemes of the scalar meson spectroscopy including glueballs. The most definitive results can be obtained from elastic and inelastic {pi}{pi} phase shift analyses using the constraints from unitarity where the discrete ambiguities can be identified and resolved. We reconsider the phase shift analyses for {pi}{sup +{pi}-{yields}{pi}+{pi}-}, {pi}{sup 0{pi}0}, KK-bar, {eta}{eta}. While a clear resonance signal for f{sub 0}(1500) in the resp. Argand diagrams is seen in all channels above a large 'background' from f{sub 0}(600) there is no clear signal of a second resonance 'f{sub 0}(1370)' in this mass range in any reaction, at the level of {approx}10% branching ratio into {pi}{pi}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

On how once subtracted dispersion relations lead to a precise determination of {pi}{pi} scattering and the f{sub 0}(600) parameters

We present and compare once and twice subtracted dispersion relations including crossing symmetry constraints in order to test the S- and P-wave {pi}{pi} amplitudes below 1100 MeV. We show that twice subtracted dispersion relations provide stringent constraints on the {pi}{pi} amplitudes below about 400 MeV than those with one subtraction. Above this energy GKPY eqs. become, however, a more demanding test of {pi}{pi} amplitudes, thus providing a new tool for the precise determination of {pi}{pi} scattering. We also show that due to strong constraints imposed by the GKPY eqs. they are useful for the determination of the f{sub (600)} pole position with high accuracy.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Study of a Narrow {pi}{sup +{pi}-} Peak at about 755 MeV/c{sup 2} in p-barn{yields}2{pi}{sup +}3{pi}{sup -} Annihilation at Rest

A narrow peak in the {pi}{sup +{pi}-} mass distribution was seen by the Rome-Syracuse Collaboration in p-barn{yields}2{pi}{sup +}3{pi}{sup -} annihilation at rest in 1970. It was ignored for 40 years. The reanalysis of this peak finds that it has the mass 757.4{+-}2.8{sub stat{+-}}1.2{sub sys} MeV/c{sup 2} and a width consistent with the experimental resolution. The evidence of the peak is 5.2 standard deviations. The peak is generated in (1.03{+-}0.21{sub stat{+-}}0.21{sub sys})% of the p-barn annihilations at rest. No spin analysis is possible with the statistics of the experiment but there are arguments suggesting that it has J{sup p} = 0{sup +}.

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.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Diffractive Dissociation into {pi}{sup -{pi}-{pi}+} Final States at COMPASS

QCD predicts gluonic excitations like hybrids to contribute to the meson spectrum in addition to qq-bar pair configurations. The most promising way to identify such states is the search for J{sup PC} quantum number combinations which are forbidden in the constituent quark model. The fixed target COMPASS experiment at CERN offers the opportunity to search for such states in the light quark sector with an unprecedented statistics.Diffractive reactions of 190 GeV/c pions on a lead target were studied by COMPASS during a pilot run in 2004. A Partial Wave Analysis (PWA) of the {pi}{sup -{pi}-{pi}+} final state with 42 waves including acceptance corrections through a phase-space Monte Carlo simulation of the spectrometer was performed. The exotic {pi}{sub 1}(1600) meson with quantum numbers J{sup PC} = 1{sup -+} has been clearly established in the rho-pi decay channel with a mass of 1660{+-}10(stat) MeV/c{sup 2} and a width of 269{+-}21(stat) MeV/c{sup 2}. The improved detector performance in 2008 allows us to study this channel with significantly higher statistics. First results of the ongoing analysis of the 2008 data taking period, using a 190 GeV/c pion beam on a liquid hydrogen target are presented in this paper.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

The covalent bond in Particle Spectroscopy

Meson resonances are linear combinations of qq-bar and meson-meson (MM) baryon resonances are combinations of qqq and meson-baryon. Mixing between these combinations arises via decays of confined states to meson-meson or meson-baryon. There is a useful analogy with the covalent bond in molecular physics. One eigenstate is lowered by the mixing. Cusps arise at thresholds. At sharp thresholds due to S-wave 2-particle decays, these cusps play a conspicuous role in many sets of data.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Charmonium molecules?

In this talk we present some recent studies of multiquark components in the charmonium sector. We study the possible existence of compact four quark-states and meson-meson molecules in the charmonium spectroscopy.

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

Baryon Spectroscopy and the Origin of Mass

The proton mass arises from spontaneous breaking of chiral symmetry and the formation of constituent quarks. Their dynamics cannot be tested by proton tomography but only by studying excited baryons. However, the number of excited baryons is much smaller than expected within quark models; even worse, the existence of many known states has been challenged in a recent analysis which includes - compared to older analyses - high-precision data from meson factories. Hence {pi}N elastic scattering data do not provide a well-founded starting point of any phenomenological analysis of the baryon excitation spectrum. Photoproduction experiments now start to fill in this hole. Often, they confirm the old findings and even suggest a few new states. These results encourage attempts to compare the pattern of observed baryon resonances with predictions from quark models, from models generating baryons dynamically from meson-nucleon scattering amplitudes, from models based on gravitational theories, and with the conjecture that chiral symmetry may be restored at high excitation energies. Best agreement is found with a simple mass formula derived within AdS/QCD. Consequences for our understanding of QCD are discussed as well as experiments which may help to decide on the validity of models.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2010

Meson-Meson molecules and compact four-quark states

The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of meson spectroscopy, beyond the simple quark-antiquark configurations. In this talk we review some recent studies of multiquark components in the charm sector and discuss in particular exotic and non-exotic four-quark systems.

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↗