Showing papers by "Chary Rangacharyulu published in 2009"
Osaka University1, Pusan National University2, Konan University3, Academia Sinica4, Tohoku University5, Nagoya University6, Japan Atomic Energy Agency7, Ohio University8, Kyoto University9, Yamagata University10, Chiba University11, Seoul National University12, Wakayama Medical University13, University of Miyazaki14, National Defense Academy of Japan15, Tokyo Institute of Technology16, University of Saskatchewan17, University of Minnesota18, Illinois Institute of Technology19, Michigan State University20
TL;DR: In this paper, the Fermi-motion-corrected nK{sup +} invariant mass distribution shows a narrow peak at 1.524{+-}0.2 nb/sr in the photon energy range from 2.0 to 2.4 GeV in the LEPS angular range.
Abstract: The {gamma}d{yields}K{sup +}K{sup -}pn reaction has been studied to search for the evidence of the {theta}{sup +} by detecting K{sup +}K{sup -} pairs at forward angles. The Fermi-motion-corrected nK{sup +} invariant mass distribution shows a narrow peak at 1.524{+-}0.002+0.003 GeV/c{sup 2}. The statistical significance of the peak calculated from a shape analysis is 5.1 {sigma}, and the differential cross section for the {gamma}n{yields}K{sup -}{theta}{sup +} reaction is estimated to be 12{+-}2 nb/sr in the photon energy range from 2.0 to 2.4 GeV in the LEPS angular range by assuming the isotropic production of the {theta}{sup +} in the {gamma}n center-of-mass system. The obtained results support the existence of the {theta}{sup +}.
100 citations
Osaka University1, Pusan National University2, Konan University3, Academia Sinica4, Tohoku University5, Nagoya University6, Japan Atomic Energy Agency7, Ohio University8, Kyoto University9, Yamagata University10, Chiba University11, Hokkaido University12, University of Miyazaki13, National Defense Academy of Japan14, University of Saskatchewan15, University of Minnesota16, Illinois Institute of Technology17, Michigan State University18
TL;DR: Differential cross sections for {eta} photoproduction from protons have been measured at E{sub {gamma}}=1.6-2.4 GeV in the backward direction.
Abstract: Differential cross sections for {eta} photoproduction from protons have been measured at E{sub {gamma}}=1.6-2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in {eta}{sup '},{omega}, and {pi}{sup 0} photoproductions. It is inferred that this unique structure in {eta} photoproduction is due to a baryon resonance with a large ss component that is strongly coupled to the {eta}N channel.
32 citations
Ohio University1, Osaka University2, Pusan National University3, Konan University4, Japan Atomic Energy Agency5, Academia Sinica6, Nagoya University7, Seoul National University8, Kyoto University9, Tohoku University10, Yamagata University11, Chiba University12, Wakayama Medical University13, University of Miyazaki14, Tokyo Institute of Technology15, Texas A&M University16, University of Saskatchewan17, University of Minnesota18, Michigan State University19
TL;DR: In this paper, the authors reported the first measurement of cross sections and beam asymmetries for photoproduction of the ε-Sigma(1385) resonance from a deuteron target.
Abstract: The $\ensuremath{\Sigma}(1385)$ resonance, or ${\ensuremath{\Sigma}}^{*}$, is well known as part of the standard baryon decuplet with spin $J=\frac{3}{2}$. Measurements of the reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\Sigma}}^{*0}$ are difficult to extract due to overlap with the nearby $\ensuremath{\Lambda}(1405)$ resonance. However, the reaction $\ensuremath{\gamma}n\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\Sigma}}^{*\ensuremath{-}}$ has no overlap with the $\ensuremath{\Lambda}(1405)$ due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the ${\ensuremath{\Sigma}}^{*\ensuremath{-}}$ from a deuteron target. The cross sections at forward angles range from 0.4 to $1.2\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$, with a broad maximum near ${E}_{\ensuremath{\gamma}}\ensuremath{\simeq}1.8\text{ }\text{ }\mathrm{GeV}$. The beam asymmetries are negative, in contrast with positive values for the $\ensuremath{\gamma}n\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\Sigma}}^{\ensuremath{-}}$ reaction.
27 citations
Academia Sinica1, National Sun Yat-sen University2, Osaka University3, Pusan National University4, Konan University5, Japan Atomic Energy Agency6, Tohoku University7, Kyoto University8, Nagoya University9, Ohio University10, Yamagata University11, Chiba University12, Wakayama Medical University13, University of Miyazaki14, National Defense Academy of Japan15, Tokyo Institute of Technology16, University of Saskatchewan17, University of Minnesota18, Michigan State University19
TL;DR: Photoproduction of Lambda with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment, and a large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles, suggesting the importance of the contact term.
Abstract: Photoproduction of LAMBDA(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K{sup +/0} angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K{sup +} angles.
27 citations
TL;DR: Extension of extended abstracts from the participants of the panel discussion: Is indivisible single photon really essential for quantum communications, computing and encryption?
Abstract: Compilation of extended abstracts from the participants of the panel discussion: Is indivisible single photon really essential for quantum communications, computing and encryption?
7 citations
TL;DR: In this paper, the definition of what constitutes an experimental "discovery" of an elementary particle is being reclassified as physical entities, where interactions and interactants become entangled and description of either one independent of the other is unattainable.
Abstract: The basic concepts of space and time have undergone radical changes in the course of history, which render the
Newtonian notions of elementary particles obsolete. This was inherent in the formulations of quantum mechanics, as
the zitterbewegung of quantum-mechanical free particles are not the same as that of classical ones. The quantum field
theories do not fare any better as particles and the corresponding fields are inseparable concepts. As physical concepts
are becoming fuzzy, the definition of what constitutes an experimental "discovery" of an elementary particle is being
revised. In these attempts, the quasi-particles, which are simple mathematical conveniences, tend to be reclassified as
physical entities. The current model depictions of physical vacuum as superconducting medium do not accommodate a
picture of elementary particles as individual entities. It is a situation where interactions and interactants become
entangled and description of either one independent of the other is unattainable.
1 citations