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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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715 records · Page 40
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DOE OSTI2011

Delta and Omega masses in a three-quark covariant Faddeev approach

We present the solution of the Poincare-covariant Faddeev equation for the {Delta}(1232) and {Omega}(1672) baryons. The covariant structure of the corresponding baryon amplitudes and their decomposition in terms of internal spin and orbital angular momentum is explicitly derived. The interaction kernel is truncated to a rainbow-ladder dressed-gluon exchange such that chiral symmetry and its dynamical breaking are correctly implemented. The resulting physical masses agree reasonably with experiment and their evolution with the pion mass compares favorably with lattice calculations. Evidence for the nonsphericity of the {Delta} resonance is discussed as well.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Lepton number violation in top quark and neutral B meson decays

Lepton number violation can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |{Delta}L|=2 decays in a scenario where a single heavy neutrino can enhance the amplitude via the resonant mechanism. Using current bounds on heavy neutrino mixings, the most optimistic branching ratios turn out to be at the level of 10{sup -6} for B{sup 0}{yields}D{sup +}e{sup -}e{sup -}{pi}{sup +} and t{yields}bl{sup +}l{sup +}W{sup -} decays. Searches for these lepton number violation decays at future facilities can provide complementary constraints on masses and mixings of Majorana neutrinos.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Residue theorem and summing over Kaluza-Klein excitations

Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluza-Klein modes in extension of the standard model with a warped extra dimension and the custodial symmetry SU(3){sub c}xSU(2){sub L}xSU(2){sub R}xU(1){sub X}xP{sub LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluza-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluza-Klein excitations in a universal extra dimension. Furthermore, we analyze the possible connection between the propagators in five-dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluza-Klein modes in four-dimensional effective theory, and recover some relations presented in the literature for warped and universal extra dimensions, respectively. As an example, we present the correction from new physics to the branching ratio of B{yields}X{sub s{gamma}} to the order O({mu}{sub EW}{sup 2}/{Lambda}{sub KK}{sup 2}) in extension of the standard model with a warped extra dimension and the custodial symmetry, where {Lambda}{sub KK} denotes the energy scale of low-lying Kaluza-Klein excitations and {mu}{sub EW} denotes the electroweak energy scale.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Unified description of BaBar and Belle data on the bottomonia decays Υ(mS) → Υ(nS) π + π -

We present a unified analysis of the decays of bottomonia Υ(mS)→Υ(nS)ππ (m>n, m=2,3,4,5, n=1,2,3), charmonia J/ψ→Φ(ππ,KK¯), ψ(2S)→J/ψππ, and the isoscalar S-wave processes ππ→ππ, KK¯, ηη. In this analysis we extend our recent study of low-lying (m=2,3) radial excitations of bottomonia to modes involving higher (m=4,5) excited states. Similarly as for the data on lower radial excitations, we confirm that the data for higher radially excited states from the BABAR and Belle collaborations can be described under conditions that the final bottomonium is a spectator and the multichannel ππ scattering is considered in a model-independent approach based on analyticity, unitarity and the uniformization procedure. Indeed we show that the dipion mass distributions in the two-pion transitions of both charmonia and bottomonia states are explained by a unified mechanism based on the contribution of the ππ and KK¯ coupled channels including their interference (final-state interactions). Furthermore, our main result is that the lower and higher radially excited states of charmonia and bottomonia have no specific features in mutual comparison and can be understood in a unified picture, e.g. proposed by our approach.

coupled-channel formalism↗
DOE OSTI2011

Observation of the {Xi}{sub b}{sup 0} Baryon

The observation of the bottom, strange baryon {Xi}{sub b}{sup 0} through the decay chain {Xi}{sub b}{sup 0}{yields}{Xi}{sub c}{sup +}{pi}{sup -}, where {Xi}{sub c}{sup +}{yields}{Xi}{sup -}{pi}{sup +}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}, is reported by using data corresponding to an integrated luminosity of 4.2 fb{sup -1} from pp collisions at {radical}(s)=1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sub -5.4}{sup +5.6} candidates is observed whose probability of arising from a background fluctuation is 3.6x10{sup -12}, corresponding to 6.8 Gaussian standard deviations. The {Xi}{sub b}{sup 0} mass is measured to be 5787.8{+-}5.0(stat){+-}1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sub b}{sup -} baryon is observed through the process {Xi}{sub b}{sup -}{yields}{Xi}{sub c}{sup 0}{pi}{sup -}, where {Xi}{sub c}{sup 0}{yields}{Xi}{sup -}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Search for CP Violation in {tau}{sup {+-}}{yields}K{sub S}{sup 0}{pi}{sup {+-}}{nu}{sub {tau}} Decays at Belle

We report on a search for CP violation in {tau}{sup {+-}}{yields}K{sub S}{sup 0}{pi}{sup {+-}}{nu}{sub {tau}} decays using a data sample of 699 fb{sup -1} collected by the Belle experiment at the KEKB electron-positron asymmetric-energy collider. The CP asymmetry is measured in four bins of the invariant mass of the K{sub S}{sup 0}{pi}{sup {+-}} system and found to be compatible with zero with a precision of O(10{sup -3}) in each mass bin. Limits for the CP violation parameter Im({eta}{sub S}) are given at the 90% confidence level. These limits are |Im({eta}{sub S})|<0.026 or better, depending on the parametrization used to describe the hadronic form factors, and improve upon previous limits by 1 order of magnitude.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Constraints and Tests of the OPERA Superluminal Neutrinos

The superluminal neutrinos detected by OPERA indicate Lorentz invariance violation (LIV) of the neutrino sector at the order of 10{sup -5}. We study the implications of the result in this work. We find that such a large LIV implied by OPERA data will make the neutrino production process {pi}{yields}{mu}+{nu}{sub {mu}} kinematically forbidden for a neutrino energy greater than about 5 GeV. The OPERA detection of neutrinos at 40 GeV can constrain the LIV parameter to be smaller than 3x10{sup -7}. Furthermore, the neutrino decay in the LIV framework will modify the neutrino spectrum greatly. The atmospheric neutrino spectrum measured by the IceCube Collaboration can constrain the LIV parameter to the level of 10{sup -12}. The future detection of astrophysical neutrinos of galactic sources is expected to be able to give an even stronger constraint on the LIV parameter of neutrinos.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Superluminal Neutrinos at OPERA Confront Pion Decay Kinematics

Violation of Lorentz invariance (VLI) has been suggested as an explanation of the superluminal velocities of muon neutrinos reported by OPERA. In this Letter, we show that the amount of VLI required to explain this result poses severe difficulties with the kinematics of the pion decay, extending its lifetime and reducing the momentum carried away by the neutrinos. We show that the OPERA experiment limits {alpha}=(v{sub {nu}}-c)/c<4x10{sup -6}. We then take recourse to cosmic-ray data on the spectrum of muons and neutrinos generated in Earth's atmosphere to provide a stronger bound on VLI: (v-c)/c<10{sup -12}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Measurement of Polarization and Search for CP Violation in B{sub s}{sup 0}{yields}{phi}{phi} Decays

We present the first measurement of polarization and CP-violating asymmetries in a B{sub s}{sup 0} decay into two light vector mesons, B{sub s}{sup 0}{yields}{phi}{phi}, and an improved determination of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb{sup -1} of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be f{sub L}=0.348{+-}0.041(stat){+-}0.021(syst), and the branching ratio B(B{sub s}{sup 0}{yields}{phi}{phi})=[2.32{+-}0.18(stat){+-}0.82(syst)]x10{sup -5}. Asymmetries of decay angle distributions sensitive to CP violation are measured to be A{sub u}=-0.007{+-}0.064(stat){+-}0.018(syst) and A{sub v}=-0.120{+-}0.064(stat){+-}0.016(syst).

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Isovector Q balls

Finite-energy solutions rotating at a constant angular velocity in isovector space are considered within theories that possess global SO(3) symmetry (isovector theories). It is shown that, for a nonlinear O(3) model (n field), such solutions exist only in the one-dimensional case. For the isovector theory proposed by S. Weinberg in order to describe low-energy properties of the {pi} mesons, such solutions exist at some values of parameters that appear in this theory. Some properties of these solutions are studied.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Measurements of spin observables in pseudo-scalar meson photo-production using polarized neutrons in solid HD

A measurement of psuedo-scalar meson photo production from longitudinally polarized solid HD has been carried out with the CLAS at Thomas Jefferson National Accelerator Facility (Jlab) with circularly and linearly polarized photon beams. Its aim is to measure a complete set of spin observables for the neutron simultaneously from the same experiment. As a polarized neutron, deutron in HD was used. Preliminary asymmetries are shown for the π{sup −} channel.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

GammeV: laser experiments at Fermilab for WISPs and other effects

The GammeV and GammeV-CHASE experiments have searched for Weakly Interacting Slim Particles (WISPs) and have published exclusion plots for axion-like particles and chameleons that couple to photons. R&D continues in long baseline optical cavities that might be required for a axion photon resonant regeneration experiment or a search for holographic noise.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗