Vernstrom, T.
Scott, Douglas
Wall, J. V.
Condon, J. J.
Cotton, W. D.
Fomalont, E. B.
Kellermann, K. I.
Miller, N.
Perley, R. A.
Radio source counts constrain galaxy populations and evolution, as well as the global star formation history. However, there is considerable disagreement among the published 1.4-GHz source counts below 100 mu Jy. Here, we present a statistical method for estimating the mu Jy and even sub-mu Jy source count using new deep wide-band 3-GHz data in the Lockman Hole from the Karl G. Jansky Very Large Array. We analysed the confusion amplitude distribution P(D), which provides a fresh approach in the form of a more robust model, with a comprehensive error analysis. We tested this method on a large-scale simulation, incorporating clustering and finite source sizes. We discuss in detail our statistical methods for fitting using Markov chain Monte Carlo, handling correlations, and systematic errors from the use of wide-band radio interferometric data. We demonstrated that the source count can be constrained down to 50 nJy, a factor of 20 below the rms confusion. We found the differential source count near 10 mu Jy to have a slope of -1.7, decreasing to about -1.4 at fainter flux densities. At 3 GHz, the rms confusion in an 8-arcsec full width at half-maximum beam is similar to 1.2 mu Jy beam(-1), and a radio background temperature similar to 14 mK. Our counts are broadly consistent with published evolutionary models. With these results, we were also able to constrain the peak of the Euclidean normalized differential source count of any possible new radio populations that would contribute to the cosmic radio background down to 50 nJy.
Murillo-Morales, S.
Barron-Palos, L.
Chavez, E.
Araujo-Escalona, V.
A plan to study the total cross section for the C-13(d, p)C-14 nuclear reaction has been developed for energies in the center-of-mass frame between 133 and 400 keV. The proposed experiment will use a deuterium beam (1-3 MeV of energy) from the Instituto de Fisica-UNAM 5.5 MV Van de Graaff accelerator and the produced C-14 will be afterwards measured by AMS technique in the LEMA-UNAM (HVEE 1 MV Tandetron). One of the main goals is to study the performance of the LEMA-UNAM facility in the cross section measurement in comparison with other data reported in the literature, measured by other techniques. In this work we present the current status of these studies. The relevance of the C-13(d, p)C-14 reaction in the study of compound nucleus formation as well as in some astrophysics scenarios, and the importance of the development of the AMS technique to measure cross sections of nuclear reactions of astrophysical interest in Mixico are also discussed.
Pakou, A.
Keeley, N.
Cappuzzello, F.
Acosta, L.
Agodi, C.
Aslanoglou, X.
Calabrese, S.
Carbone, D.
Cavallaro, M.
Foti, A.
Marquinez-Duran, G.
Martel, I.
Mazzocco, M.
Parascandolo, C.
Pierroutsakou, D.
Rusek, K.
Sgouros, O.
Soukeras, V.
Strano, E.
Zagatto, V. A. B.
New data are presented for the Li-7(d, p)Li-8 stripping reaction which, together with previously reported elastic scattering data taken in the same experiment, provide a coherent set. These data, plus existing measurements of the elastic scattering and stripping at 6MeV/u were analysed within the same coupled reaction channels scheme. Good descriptions of the stripping data to the 0.0MeV 2(+) and 0.98MeV 1(+) states of Li-8 were obtained using a set of < Li-8 vertical bar Li-7 + n > overlaps taken from the literature, provided that the elastic scattering was also well described. Multi-step reaction paths made significant contributions to the description of the larger angle data. The asymptotic normalisation coefficients are compared with previous determinations.
Pakou, A.
Keeley, N.
Cappuzzello, F.
Acosta, L.
Agodi, C.
Aslanoglou, X.
Calabrese, S.
Carbone, D.
Cavallaro, M.
Foti, A.
Marquínez-Durán, G.
Martel, I.
Mazzocco, M.
Parascandolo, C.
Pierroutsakou, D.
Rusek, K.
Sgouros, O.
Soukeras, V.
Strano, E.
Zagatto, V. A. B.
Ong, H. J.
Tanihata, I.
Tamii, A.
Myo, T.
Ogata, K.
Fukuda, M.
Hirota, K.
Ikeda, K.
Ishikawa, D.
Kawabata, T.
Matsubara, H.
Matsuta, K.
Mihara, M.
Naito, T.
Nishimura, D.
Ogawa, Y.
Ozawa, A.
Pang, D. Y.
Sakaguchi, H.
Sekiguchi, K.
Suzuki, T.
Taniguchi, M.
Takashina, M.
Toki, H.
Yasuda, Y.
Yosoi, M.
Zenihiro, J.
The differential cross sections of the O-16(p,d) reaction populating the ground state and several low-lying excited states in O-15 were measured using 198-, 295- and 392-MeV proton beams at the Research Center for Nuclear Physics (RCNP), Osaka University, to study the effect of the tensor interactions in O-16 Dividing the cross sections for each excited state by the one for the ground state and comparing the ratios over a wide range of momentum transfer, we found a marked enhancement of the ratio for the positive-parity state(s). The observation is consistent with large components of high-momentum neutrons in the ground-state configurations of O-16 due possibly to the tensor interactions.
Let V denote a Volterra integration operator, acting in the space [image omitted] of analytic functions [image omitted] for which [image omitted] by [image omitted] Using the Duhamel product method, it is shown that for any positive integer k the sequence {(kn)!Vknf}n epsilon 0 is a basic sequence in [image omitted] equivalent to the basis [image omitted] if and only if f(0)0.
Serogroup B meningococcus antigens can successfully be combined with diphtheria, tetanus and pertussis toxoids (“DTP”) to provide effective combination vaccines for protecting against multiple pathogens. These combinations are effective with a range of different adjuvants, and with both pediatric-type and booster-type DTP ratios. The adjuvant can improve the immune response which the composition elicits; alternatively, by including an adjuvant it is possible for the compositions to have a relatively lower amount of antigen while nevertheless having immunogenicity which is comparable to unadjuvanted combination vaccines.
We investigate the nature of the recently observed narrow resonance Z(c)(3900), which is assumed to be a D*(D) overbar molecular state with quantum numbers I(G)J(P) = 1(+)1(+). Using QCD sum rules, we consider contributions up to dimension 8 in the operator product expansion and work at the leading order in alpha(s). The mass we arrived at is (3.88 +/- 0.17) GeV, which coincides with the mass of Z(c)(3900).
We examine the problem of determining the solutions to the Diophantine equation n(n + d) . . . (n + (k - 1)d) = by(2), where d is fixed and the largest prime divisor of b is no more than Ck. Here, C is fixed but arbitrary. Under some rather minor conditions, it is shown that there are finitely many solutions that can be effectively computed. Some new, largely combinatorial, ideas are introduced into the general theory to handle the case of arbitrary C as considered here.