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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Amplitude Analysis of B0 to K^ pi^-pi^0 and Evidence of Direct CP Violation in B to K^* pi decays

We analyze the decay B{sup 0} {yields} K{sup +} {pi}{sup -} {pi}{sup 0} with a sample of 454 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays to construct isospin amplitudes from B{sup 0} {yields} K{sup *}{pi} and B{sup 0} {yields} {rho}K decays. We measure the phase of the isospin amplitude {Phi}{sub 3/2}, useful in constraining the CKM unitarity triangle angle {gamma} and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B{sup 0} {yields} K{sup *+}{pi}{sup -} decays at the level of 3 {sigma} when measurements from both B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays are combined.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Sterile neutrino decay explanation of LSND and MiniBooNE anomalies

We examine a recently proposed explanation of the liquid scintillator neutrino detector and MiniBooNE anomalies, given in terms of a sterile neutrino N of the mass 40MeV < or approx. m{sub N} < or approx. 80MeV mixed with {nu}{sub {mu}} at the strength 10{sup -3} < or approx. |U{sub {mu}N}|{sup 2} < or approx. 10{sup -2} and which dominantly decays into a light neutrino and photon: N{yields}{nu}{gamma}. We check compatibility of this scenario with the existing experimental data on radiative {tau}-lepton and K-meson decays. We find that neither of these data are able to totally rule out the above indicated region of m{sub N}-|U{sub {mu}N}|{sup 2}. However, we show that the current experimental data on K{yields}{mu}{nu}{gamma} decay exclude a significant part of this region. We propose experimental cuts on this decay allowing to improve its sensitivity to the region in question. We also show that measurements of K{yields}{mu}{nu}ee decay have good prospects for testing the decaying sterile neutrino scenario.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Theoretical support for the {pi}(1300) and the recently claimed f{sub 0}(1790) as molecular resonances

A study of three-pseudoscalar {pi}KK and {pi}{pi}{eta} coupled system is made by solving the Faddeev equations within an approach based on unitary chiral dynamics. A resonance with total isospin one and spin-parity J{sup {pi}=}0{sup -} is found with mass {approx}1400 MeV when the KK system gets reorganized as the f{sub 0}(980). This resonance is identified with the {pi}(1300) listed by the Particle Data Group. Further, the two-body amplitude which describes the interaction between a {pi} and the f{sub 0}(980) is extracted from the study of the {pi}KK and {pi}{pi}{eta} system and is then employed to study the f{sub 0}(980){pi}{pi} system. As a result, a scalar resonance is found near 1790 MeV which drives the two f{sub 0}(980){pi} systems to resonate as the {pi}(1300) while the invariant mass of the two pions falls in the mass region of the scalar {sigma}(600). These findings support the existence of a new f{sub 0} resonance near 1790 MeV, as found by the BES and Crystal Barrel collaborations. Our results show that this f{sub 0}(1790) is definitely distinct to f{sub 0}(1710), the latter of which seems to possess a glueball structure dominantly.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Observation of the Decay B s 0 → K 0 K ¯ 0

We measure the decay B$^{0}_{s}$ → K 0 K¯ 0 using data collected at the Υ(5S) resonance with the Belle detector at the KEKB e + e – collider. The data sample used corresponds to an integrated luminosity of 121.4 fb–1. We measure a branching fraction B(B$^{0}_{s}$ → K 0 K¯ 0 ) = [19.6$^{+5.8}_{–5.1}$(stat.) ± 1.0(sys.)±2.0(N B$^{0}_{s}$B¯$^{0}_{s}$ )]×10 –6 with a significance of 5.1 standard deviations. Here, this measurement constitutes the first observation of this decay.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Search for the 𝐾 𝐿 → 𝜋 0 ⁢$𝜈⁢\bar{𝜈}$ Decay at the J-PARC KOTO Experiment

We performed a search for the 𝐾 𝐿 → 𝜋 0 ⁢$𝜈⁢\bar{𝜈}$ decay using the data taken in 2021 at the J-PARC KOTO experiment. With newly installed counters and new analysis method, the expected background was suppressed to 0.252 ± 0.055 stat ⁢ $^{+0.052}_{{−0.067^{syst}}}$. With a single event sensitivity of (9.33 ± 0.0⁢6 stat ±0.8⁢4 syst ) × 10 −10 , no events were observed in the signal region. An upper limit on the branching fraction for the decay was set to be 2.2 ×10 −9 at the 90% confidence level (C.L.), which improved the previous upper limit from KOTO by a factor of 1.4. With the same data, a search for 𝐾 𝐿 → 𝜋 0 ⁢𝑋 0 was also performed, where 𝑋 0 is an invisible boson with a mass ranging from 1 to 260 MeV/𝑐 2 . For 𝑋 0 with a mass of 135 MeV/𝑐 2 , an upper limit on the branching fraction of 𝐾 𝐿 → 𝜋 0 ⁢𝑋 0 was set to be 1.6 ×10 −9 at the 90% C.L.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

New Method for the Generation of Secondary Particle Beams at Accelerators

The generation of beams of secondary particles (π and K mesons) at proton accelerators is a difficult scientific and engineering problem. To obtain narrow directional particle beams for experiments, intense extracted proton beams are used, secondary particles (π and K mesons) are generated at an external target, and they are focused and transferred through long magneto-optical channels. In this work, a surprisingly simple method based on a crystal focusing device has been proposed to obtain secondary beams. An experiment on the production of a secondary beam using a crystal has been performed at the U-70 accelerator. Schemes for the formation of beams with energies E ~ 1 TeV have been proposed for large colliders such as the Large Hadron Collider.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2011

K{sub l3{gamma}}{sup +} decays revisited: Branching ratios and T-ODD momenta correlations

We calculate the branching ratios of the K{sup +} {yields} {pi}{sup 0}l{sup +}{nu}{sub l{gamma}} (l = e, Micro-Sign ) decays, and the T-odd triple momenta correlations {xi} = q {center_dot} [p{sub l} Multiplication-Sign p{sub {pi}}]/M{sub K}{sup 3}, due to the electromagnetic final-state interaction, in these processes. The contributions on the order of {omega}{sup -1} and {omega}{sup 0} to the corresponding amplitudes are treated exactly. For the branching ratios, the corrections on the order of {omega} are estimated and demonstrated to be small. We compare the results with those of other authors. In some cases our results differ considerably from the previous ones.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Measuring dynamical K/{pi} and p/{pi} fluctuations in AuAu collisions from the STAR experiment

Results from new measurements of dynamical K/{pi} and p/{pi} ratio fluctuations are presented. Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. The STAR experiment has previously acquired data in AuAu collisions at the energies {radical}s{sub NN} = 200, 130, 62.4, and 19.6 GeV and CuCu collisions at {radical}s{sub NN} = 200, 62.4, and 22.4 GeV. The commencing of a QCD critical point search at RHIC has extended the reach of possible measurements of dynamical K/{pi} and p/{pi} ratio fluctuations from AuAu collisions to lower energies. New results are compared to previous measurements and to theoretical predictions from the UrQMD model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Fluctuations and correlations as a signal of deconfinement

Event-by-event fluctuations of the K/{pi}, K/p, and p/{pi} ratio in central AA collisions have been studied for SPS and RHIC energies. The Hadron-String-Dynamical transport approach (HSD) can qualitatively reproduce the measured excitation function for the K/{pi} ratio fluctuations. The di-jet azimuthal correlations also have been investigated within the HSD model. We found that the suppression of the away-side jet in the hadronic mediumis not enough to explain the experimental data from RHIC. The additional suppression should be attributed to a quark-gluon plasma produced in heavy-ion collisions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2013

Recent study for multibaryon states with strangeness in pC interaction at 10 GeV/c

Strange multibaryon states with {Lambda}-hyperon and K{sub s}{sup 0} -meson subsystems has been studied from 700 000 stereo photographs or 10{sup 6} inelastic interactions which was obtained from expose of 2-m propane bubble chamber (PBC) LHEP, JINR to proton beams at 10 GeV/c. The obtained results from PBC can be divided into three subjects: in-medium effects of hadronic particles; baryon spectroscopy; hyper-nucleus production. At present the experimental situation is confused; so is theory. New accelerator research complexes has unique possibility for high-statistic and 4{pi}-geometry study of exotic states.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2013

Probing nuclei by deeply penetrating and peripherally interacting Hadron: Bridging low and high-energy processes

The search for signals of new phenomenon is an important trend in the contemporary strong interaction physics. The nuclear J/{psi} suppressions are considered as like candidates for the signals of unusual events, e.g. quark-gluon plasma. They were explained in the framework of Glauber approximation. On the contrary, we show that new experimental data on the total cross section of K{sup +}-nucleus interaction at intermediate energies cannot be described by the novel well-elaborated Glauber model. This may indicate a unique event in ground state nuclei (in-medium effect)

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2013

Measurement of neutral-meson masses in meson-nucleus interactions at a momentum of 7 GeV/c at the Hyperon-M setup

The π{sup 0}, η, K{sup 0}, ω, and f{sub 2}(1270) masses were measured at the HYPERON-Msetup in meson-nucleus interactions at a momentum of 7 GeV/c by using six nuclear targets: Be, C, Al, Cu, Sn, and Pb. The experiment in question proved to be insensitive to the expected effects of a modification to the omega-meson mass in nuclear matter. As for the f{sub 2}(1270) meson, its mass and width values averaged over all experimental data, <##> } m } f 2 $ m{sub {f_2 }} $ m{sub f{sub 2}} </##> = 1275.8 ± 1.0(stat.) ± 0.4(syst.) MeV/c{sup 2} and <##> } }&#x0393;<!-- ?? --> } f 2 $ /Gamma {sub {f_2 }} $ Γ{sub f{sub 2}} </##> = 190.3 ± 1.9(stat.) ± 1.8(syst.) MeV/c{sup 2}, agree well with the world-average values. At the same time, our experimental data do not rule out the possible effect of an in-medium modification to the f{sub 2}(1270)-meson mass for heavy nuclei at a level better than 0.4%.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗