Qingzhen and Yamato-691: A tentative alphabet for the EH chondrites

Petrological investigations of unequilibrated EH chondrites revealed the presence of three subgroups. They are identified based on the presence of different concentrations of MnS in niningerite. These differences were produced by partitioning of Mn between niningerite and enstatite as a result of different f_S2 and f_O2 during their formation. In order of increasing MnS-contents and hence increasing f_S2 and decreasing f_O2 these groups are : (A) Yamato (Y)-691 and Abee, (B) Indarch, and (C) Yamato-74370,South Oman, Qingzhen, Kota Kota, Kaidun III, and St. Marks. In the third subgroup the meteorites follow an equilibration and evolution sequence; Y-74370 the most primitive and St. Marks the most equilibrated. Y-691 is the most primitive in its subgroup. Differences in the chemical compositions of minerals in Y-691 and Qingzhen reveal a dichotomy in the compositions of niningerite, djerfisherite, kamacite, and perryite. Niningerites in Y-691 contain the least MnS (3.6-6.7 mole%) and counterparts in Qingzhen the most (12-14 mole%). K/Na ratios in djerfisherite are lower in Qingzhen than in Y-691. The Si concentration in kamacite in Qingzhen is higher than in Y-691. Ni in perryite in Qingzhen is higher than in Y-691. Na and K are highly fractionated between two sulfide lithologies. Na resides mainly in chondrules in caswellsilverite, in a Cl-bearing glass in the chondrules, and in Cr-rich sulfides in the matrix. In contrast, K is confined to djerfisherite, which occurs only in sulfide-rich objects in the matrix, and is highly depleted in chondrules. Two new layer structure minerals were discovered in Y-691 : (a) Na-Cu-Cr-sulfide with the general formula (NaCu) CrS_2,and (b) a Na-Cu-Zn-Cr-sulfide. An evolution scheme was constructed for the EH chondrites in the solar nebula and in their parent bodies. Niningerite and oldhamite condensed first and probably acted as nucleation sites for condensing sulfides, metals and silicates. Both minerals are abundant in chondrules, indicating that chondrule formation preceded all other sulfide- and metal-rich objects. For the first time, planetary metamorphic events were recognized. The Qingzhen Reaction, a breakdown of djerfisherite to troilite, covellite, idaite, bornite, and other unidentified phases, was discovered in Qingzhen and Y-691. Thermal episodes took place in the parent bodies at 1.4 Ba (Qingzhen), and 800 Ma (Y-691). Reverse zoning in niningerite indicates that Fe diffused from troilite to niningerite during the thermal event. In Y-691 sphalerite also formed during the metamorphic episode due to mobilization of Zn (and other volatiles). EH chondrites condensed in a chemically inhomogeneous region of the solar nebula where considerable variations in sulfur and oxygen fugacities existed

Early copper metallurgy in Northern Chile

The Central Andean region of South America has a long tradition of mining and metallurgy. Such activities were fundamental to the economic, socio-political and ideological dynamics of the pre-Columbian cultures that inhabited this area. In spite of their importance, few archaeological investigations of metallurgy have been carried out in the Central Andes in general, and in current Chilean territory in particular. The present project investigates archaeometallurgical sites in northern Chile using scientific analysis, as a first step towards a large-scale map of prehistoric copper production and exchange across South America. This research involves documentation and sampling of already excavated archaeological materials from a number of copper-producing sites located in the Atacama District. Preliminary results of XRF analysis of artefacts from the collection of the R. P. Gustavo Le Paige Archaeological Museum, San Pedro de Atacama, have been obtained and enabled us to characterise the different elements present in the metal objects. These results might provide information on the nature of the raw materials used

Calibration of dosemeters used in mammography with different X ray qualities: Euromet Project No. 526

The effect of different X ray radiation qualities on the calibration of mammographic dosemeters was investigated within the framework of a EUROMET (European Collaboration in Measurement Standards) project. The calibration coefficients for two ionization chambers and two semiconductor detectors were established in 13 dosimetry calibration laboratories for radiation qualities used in mammography. They were compared with coefficients for other radiation qualities, including those defined in ISO 4037-1, with first half value layers in the mammographic range. The results indicate that the choice of the radiation quality is not crucial for instruments with a small energy dependence of the response. However, the radiation quality has to be chosen carefully if instruments with a marked dependence of their response to the radiation energy are calibrate

Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at [Formula: see text].

A search for physics beyond the standard model is performed with events having one or more hadronically decaying τ leptons, highly energetic jets, and large transverse momentum imbalance. The data sample corresponds to an integrated luminosity of 4.98 fb-1 of proton-proton collisions at [Formula: see text] collected with the CMS detector at the LHC in 2011. The number of observed events is consistent with predictions for standard model processes. Lower limits on the mass of the gluino in supersymmetric models are determined

Metallurgical knowledge and networks of supply in the 5th millennium BC Balkans: Belovode and Pločnik in their regional context

The recent set of excavations (campaigns 2012 and 2013) at the sites of Belovode and Pločnik (see Chapters 11 and 26) have shown the use of copper minerals and metallurgical activities to be highly consistent with results from previous analytical research (Radivojević 2007, 2012, 2013, 2015; Radivojević et al. 2010a; Radivojević and Rehren 2016). Specific aspects to emerge so far include: persistent selection of black and green manganese-rich copper ores for metal extraction; similar engineering parameters involved in the early copper smelting technology; field evidence from Belovode supporting the presence of pottery- lined hole-in-the-ground installations; consistent metal making and working technology remains at both sites; and direct absolute dating evidence that leaves no doubt for c. 5000 BC as the beginning of copper metallurgy in the Balkans. In this chapter we will synthesise the evidence for this c. 7,000 years old copper production technology within the Vinča culture, in its local and regional perspective, including data and debates on the provenance of copper ores

Measurement of K^0_e3 form factors

The semileptonic decay of the neutral K meson, KL -> pi e nu (Ke3), was used to study the strangeness-changing weak interaction of hadrons. A sample of 5.6 million reconstructed events recorded by the NA48 experiment was used to measure the Dalitz plot density. Admitting all possible Lorentz-covariant couplings, the form factors for vector (f_+(q^2)), scalar (f_S) and tensor (f_T) interactions were measured. The linear slope of the vector form factor lambda_+ = 0.0284+-0.0007+-0.0013 and values for the ratios |f_S/f_+(0)| = 0.015^{+0.007}_{-0.010}+-0.012 and |f_T/f_+(0)| = 0.05^{+0.03}_{-0.04}+-0.03 were obtained. The values for f_S and f_T are consistent with zero. Assuming only Vector-Axial vector couplings, lambda_+ = 0.0288+-0.0004+-0.0011 and a good fit consistent with pure V-A couplings were obtained. Alternatively, a fit to a dipole form factor yields a pole mass of M = 859+-18 MeV, consistent with the K^*(892) mass.Comment: 16 pages, 7 figures. submitted to Phys. Lett.

Latest Results from the Heidelberg-Moscow Double Beta Decay Experiment

New results for the double beta decay of 76Ge are presented. They are extracted from Data obtained with the HEIDELBERG-MOSCOW, which operates five enriched 76Ge detectors in an extreme low-level environment in the GRAN SASSO. The two neutrino accompanied double beta decay is evaluated for the first time for all five detectors with a statistical significance of 47.7 kg y resulting in a half life of (T_(1/2))^(2nu) = [1.55 +- 0.01 (stat) (+0.19) (-0.15) (syst)] x 10^(21) years. The lower limit on the half-life of the 0nu beta-beta decay obtained with pulse shape analysis is (T_(1/2))^(0_nu) > 1.9 x 10^(25) [3.1 x 10^(25)] years with 90% C.L. (68% C.L.) (with 35.5 kg y). This results in an upper limit of the effective Majorana neutrino mass of 0.35 eV (0.27 eV). No evidence for a Majoron emitting decay mode or for the neutrinoless mode is observed.Comment: 14 pages, revtex, 6 figures, Talk was presented at third International Conference ' Dark Matter in Astro and Particle Physics' - DARK2000, to be publ. in Proc. of DARK2000, Springer (2000). Please look into our HEIDELBERG Non-Accelerator Particle Physics group home page: http://www.mpi-hd.mpg.de/non_acc

Belle II Technical Design Report

The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO