Isospin breaking in pion-deuteron scattering and the pion-nucleon scattering lengths

In recent years, high-accuracy data for pionic hydrogen and deuterium have become the primary source of information on the pion-nucleon scattering lengths. Matching the experimental precision requires, in particular, the study of isospin-breaking corrections both in pion-nucleon and pion-deuteron scattering. We review the mechanisms that lead to the cancellation of potentially enhanced virtual-photon corrections in the pion-deuteron system, and discuss the subtleties regarding the definition of the pion-nucleon scattering lengths in the presence of electromagnetic interactions by comparing to nucleon-nucleon scattering. Based on the pi^{+/-} p channels we find for the virtual-photon-subtracted scattering lengths in the isospin basis a^{1/2}=(170.5 +/- 2.0) x 10^{-3} mpi^{-1} and a^{3/2}=(-86.5 +/- 1.8) x 10^{-3} mpi^{-1}.Comment: 6 pages, 1 figure, Proceedings for the 7th International Workshop on Chiral Dynamics, Newport News, Virginia, USA, August 6-10, 201

Potensi Keanekaragaman Jenis dan Sebaran Spons di Perairan Pulau Saponda Laut Kabupaten Konawe

Penelitian potensi keanekaragaman jenis dan sebaran spons di Perairan Pulau Saponda Laut Kabupaten Konawe dilaksanakan pada bulan Juni 2015. Tujuan dari penelitian ini adalah untuk mengetahui biodiversitas, kepadatan, frekuensi kemunculan, dan sebaran jenis spons berdasarkan kedalaman. Penelitian ini menggunakan metode transek sabuk (belt transek) dengan ukuran 500m­­2. Pengamatan dilakukan di tiga titik stasiun penelitian yang diambil berdasarkan keberadaan spons. Kepadatan berturut-turut didapatkan sebesar 0,5 ind/10m2 (Utara), 0,3 ind/10m2 (Selatan), dan 0,2 ind/10m2 (Timur). Frekuensi kemunculan tertinggi didapat pada spons jenis Stylotella sp. yang tersebar di kedalaman 2, 4 dan 9 m di semua titik stasiun penelitian. Jumlah species spons yang ditemukan di Perairan Pulau Saponda Laut sebanyak 12 species yang masuk dalam 10 family 9 ordo. Secara umum index keanekaragaman spons di lokasi penelitian masuk dalam kategori sedang

Arus Jenuh Dan Panjang Antrian Pada Simpang Bersinyal Angkatan 66 Kota Palembang

The high saturation flow, long queues, and long delays at the signalized intersection are the factors causing traffic congestion at the intersection. This study discussed saturation flow analysis and long queues at the Angkatan 66 signalized intersection in Palembang City. The intersection legs at this intersection, namely Jln. Sukamto toward Jln. Basuki Rakhmat, Jln. Amphibi toward Jln. Angkatan 66, have high saturation flows and long queues, so that the intersection needs to be improved. There are 3 improvement alternatives, including the change in cycle time period, the change in intersection geometric, and the construction of flyover. Of the three alternatives, only the construction of fly over construction can reduce significantly the queue lengths

Interplay of quark and meson degrees of freedom in a near-threshold resonance

We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S-matrix. In particular, the scattering t-matrix may possess zeros in this case. We also discuss possible implications for production reactions as well as studies within lattice QCD.Comment: LaTeX2e, 11 pages, minor typo corrections, to appear in Eur.Phys.J.

Towards a high precision calculation for the pion-nucleus scattering lengths

We calculate the leading isospin conserving few-nucleon contributions to pion scattering on $^2$H, $^3$He, and $^4$He. We demonstrate that the strong contributions to the pion-nucleus scattering lengths can be controlled theoretically to an accuracy of a few percent for isoscalar nuclei and of 10% for isovector nuclei. In particular, we find the $\pi$-$^3$He scattering length to be $(62 \pm 4\pm 7)\times 10^{-3} m_{\pi}^{-1}$ where the uncertainties are due to ambiguities in the $\pi$-N scattering lengths and few-nucleon effects, respectively. To establish this accuracy we need to identify a suitable power counting for pion-nucleus scattering. For this purpose we study the dependence of the two-nucleon contributions to the scattering length on the binding energy of $^2$H. Furthermore, we investigate the relative size of the leading two-, three-, and four-nucleon contributions. For the numerical evaluation of the pertinent integrals, aMonte Carlo method suitable for momentum space is devised. Our results show that in general the power counting suggested by Weinberg is capable to properly predict the relative importance of $N$-nucleon operators, however, it fails to capture the relative strength of $N$- and $(N+1)$-nucleon operators, where we find a suppression by a factor of 5 compared to the predicted factor of 50. The relevance for the extraction of the isoscalar $\pi$-N scattering length from pionic $^2$H and $^4$He is discussed. As a side result, we show that beyond the calculation of the $\pi$-$^2$H scattering length is already beyond the range of applicability of heavy pion effective field theory.Comment: 24 pages, 14 figures, 10 table

Chiral corrections to the isovector double scattering term for the pion-deuteron scattering length

The empirical value of the real part of the pion-deuteron scattering length can be well understood in terms of the dominant isovector $\pi N$-double scattering contribution. We calculate in chiral perturbation theory all one-pion loop corrections to this double scattering term which in the case of $\pi N$-scattering close the gap between the current-algebra prediction and the empirical value of the isovector threshold T-matrix $T_{\pi N}^-$. In addition to closing this gap there is in the $\pi d$-system a loop-induced off-shell correction for the exchanged virtual pion. Its coordinate space representation reveals that it is equivalent to $2\pi$-exchange in the deuteron. We evaluate the chirally corrected double scattering term and the off-shell contribution with various realistic deuteron wave functions. We find that the off-shell correction contributes at most -8% and that the isovector double scattering term explains at least 90% of the empirical value of the real part of the $\pi d$-scattering length.Comment: 4 pages, 2 figures, to be published in The Physical Review

Phenomenology of pp->pp eta reaction close to threshold

The recent high statistics measurement of the pp -> pp eta reaction at an excess energy Q=15.5 MeV has been analysed by means of partial wave decomposition of the cross section. Guided by the dominance of the final state 1S0 pp interaction (FSI), we keep only terms involving the FSI enhancement factor. The measured p-p and p-eta effective mass spectra can be well reproduced by lifting the standard on-shell approximation in the enhancement factor and by allowing for a linear energy dependence in the leading 3P0->1S0,s partial wave amplitude. Higher partial waves seem to play only a marginal role

Identification of a hypothetical membrane protein interactor of ribosomal phosphoprotein P0

The ribosomal phosphoprotein P0 of the human malarial parasite Plasmodium falciparum (PfP0) has been identified as a protective surface protein. In Drosophila, P0 protein functions in the nucleus. The ribosomal function of P0 is mediated at the stalk of the large ribosomal subunit at the GTPase centre, where the elongation factor eEF2 binds. The multiple roles of the P0 protein presumably occur through interactions with other proteins. To identify such interacting protein domains, a yeast two-hybrid screen was carried out. Out of a set of sixty clones isolated, twelve clones that interacted strongly with both PfP0 and the Saccharomyces cerevisiae P0 (ScP0) protein were analysed. These belonged to three broad classes: namely (i) ribosomal proteins; (ii) proteins involved in nucleotide binding; and (iii) hypothetical integral membrane proteins. One of the strongest interactors (clone 67B) mapped to the gene YFL034W which codes for a hypothetical integral membrane protein, and is conserved amongst several eukaryotic organisms. The insert of clone 67B was expressed as a recombinant protein, and immunoprecipitaion (IP) reaction with anti-P0 antibodies pulled down this protein along with PfP0 as well as ScP0 protein. Using deletion constructions, the domain of ScP0, which interacted with clone 67B, was mapped to 60-148 amino acids. It is envisaged that the surface localization of P0 protein may be mediated through interactions with putative YFL034W-like proteins in P. falciparum

The Sausapor Declaration: Challenges in promoting good governance to protect customary communities and natural resources in Tambrauw district, West Papua

The Sausapor Declaration has served as a stepping stone towards convening and balancing the dynamics of governmental politics, conservation efforts, the protection of customary communities’ rights, and the sustainable management of natural resources in Tambrauw District. The Declaration supported the establishment of Tambrauw as a Conservation District, while also acknowledging the rights of customary communities in shaping political priorities of the local government, which include: a) stewardship of extensive remaining tropical forests (91.9% forest cover); b) management of protected areas, which represent 77-80% of the total area of the District; c) acknowledging the cultural traditions of five major indigenous groups; and, d) securing the active support of formal institutions for these goals. Two stages have shaped the effort to establish the Conservation District.  The first stage involved the period prior to the formal declaration, while the second ecompasses development and implementation of related policies.  Establishing local regulations and protecting local communities required extensive lobbying with the provincial and national government, as well as advocacy in various seminars, including both national and international conferences that provided strategic opportunities for securing support for the Conservation District. These steps have been instrumental in gaining legitimacy and public support for relevant conservation policies and for protecting the rights of customary communities. As one example, the review of Tambrauw spatial planning documents  (RTRW) led to prioritizing eco-tourism as a leading sector for economic development, along with the creation of an overall agropolitan and renewable energy strategy

Melanosis and quality attributes of chill stored farm raised whiteleg shrimp (Litopenaeus vannamei)

Loss of market value of shrimp is mainly due to the formation of black spot called melanosis. A study was conducted for 14 days to determine the extent of melanosis and quality changes during that period of freshly har-vested whiteleg shrimp (Litopenaeus vannamei) under chilled storage (2?). Among quality parameters, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBAR-S), were varied from 13.17 mg % to 44.50 mg % and 0.04to 2.57 mg malondehaldehyde/kg of fat respectively whereas melanosis score and metric chroma (C) exhibited significant increases during chilled storage (P<0.05). There was a slight increase in moisture, crude fat and pH from 73.96 % to 74.57 %, 1.05 % to 1.14 % and 6.52 to 7.60 respectively at 14th day of storage. Loss of protein from 22.51 % to 21.28 % may be due to decrease in available amino acids during chilled storage and total plate count (TPC) showed gradual increase of bacterial load up to 1.73*107 log CFU/g at the end of chilled storage. The sensory analysis by panellists indicated, the acceptability of white leg shrimp was up to 6 days in chilled condition and formation of black spot is one of the major parameter for rejection by the panellists