How many of the scaling trends in pppp collisions will be violated at sqrt{s_NN} = 14 TeV ? - Predictions from Monte Carlo quark-gluon string model

Multiplicity, rapidity and transverse momentum distributions of hadrons produced both in inelastic and nondiffractive $pp$ collisions at energies from $\sqrt{s} = 200$\,GeV to 14\,TeV are studied within the Monte Carlo quark-gluon string model (QGSM). Good agreement with the available experimental data up to $\sqrt{s} = 13$\,TeV is obtained, and predictions are made for the collisions at top LHC energy $\sqrt{s} = 14$\,TeV. The model indicates that Feynman scaling and extended longitudinal scaling remain valid in the fragmentation regions, whereas strong violation of Feynman scaling is observed at midrapidity. The Koba-Nielsen-Olesen (KNO) scaling in multiplicity distributions is violated at LHC also. The origin of both maintenance and violation of the scaling trends is traced to short range correlations of particles in the strings and interplay between the multistring processes at ultrarelativistic energies

Cross-sections for nuclide production in 56Fe target irradiated by 300, 500,750, 1000, 1500, and 2600 MeV protons compared with data on hydrogen target irradiation by 300, 500, 750, 1000, and 1500 MeV/nucleon 56Fe ions

Cross-sections for radioactive nuclide production in 56Fe(p,x) reactions at 300, 500, 750, 1000, 1500, and 2600 MeV were measured using the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of products of half-lives from 6.6 min to 312 days have been obtained via the direct-spectrometry method. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculations by 15 codes, namely: MCNPX (INCL, CEM2k, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01, .G1, .S1), LAQGSM03 (.01, .G1, >.S1), CASCADE-2004, LAHETO, and BRIEFF. Most of our data are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A<30 light nuclei, indicating that further improvements in nuclear reaction models are needed, and pointing out as well to a necessity of more complete measurements of such reactions.Comment: 53 pages, 9 figures, 6 tables, only pdf file, submitted to Phys. Rev.

Anisotropic flow of charged and identified hadrons in the quark-gluon string model for Au+Au collisions at sqrt(s) = 200 GeV

The pseudorapidity behaviour of the azimuthal anisotropy parameters v_1 and v_2 of inclusive charged hadrons and their dependence on the centrality has been studied in Au+Au collisions at full RHIC energy of sqrt(s) = 200 GeV within the microscopic quark-gluon string model. The QGSM simulation results for the directed flow v_1 show antiflow alignment within the pseudorapidity range |eta| < 2 in a fair agreement with the experimental v_1(eta) data, but cannot reproduce the further development of the antiflow up to |eta| around 3.5. The eta dependence of the elliptic flow v_2 extracted from the simulations agrees well with the experimental data in the whole pseudorapidity range for different centrality classes. The centrality dependence of the integrated elliptic flow of charged hadrons in the QGSM almost coincides with the PHOBOS experimental distribution. The transverse momentum dependence of the elliptic flow of identified and inclusive charged hadrons is studied also. The model reproduces quantitatively the low p_T part of the distributions rather good, but underestimates the measured elliptic flow for transverse momenta p_T > 1 GeV/c. Qualitatively, however, the model is able to reproduce the saturation of the v_2(p_T) spectra with rising p_T as well as the crossing of the elliptic flow for mesons and baryons.Comment: REVTeX, 10 pages, 10 figures, v2: extended discussion of the model results, accepted for publication in Phys. Rev.

Some indication for a missing chiral partner eta_4 around 2 GeV

The high-lying mesons in the light quark sector previously obtained from the partial wave analysis of the proton-antiproton annihilation in flight at 1.9 - 2.4 GeV region at CERN reveal a very high degree of degeneracy. This degeneracy can be explained as due to an effective restoration of both SU(2)_L * SU(2)_R and U(1)_A symmetries combined with a principal quantum number n + J. In this case there must be chiral partners for the highest spin states in the 2 and 2.3 GeV bands presently missing in the data. Here we reanalyze the Crystal Barrel data and show an indication for existence of the missing $4^{-+}$ state around 2 GeV. This result calls for further experimental search of the missing states both in the proton-antiproton annihilation and in the production reactions.Comment: 4 pp. A fit with the energy-dependent width has been added that agrees with the previous analysis. Accepted by PR

CEM03 and LAQGSM03 - new modeling tools for nuclear applications

An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions realized in the code CEM2k and the Los Alamos version of the Quark-Gluon String Model (LAQGSM) have been developed recently at LANL to describe reactions induced by particles and nuclei for a number of applications. Our CEM2k and LAQGSM merged with the GEM2 evaporation/fission code by Furihata have predictive powers comparable to other modern codes and describe many reactions better than other codes; therefore both our codes can be used as reliable event generators in transport codes for applications. During the last year, we have made a significant improvements to the intranuclear cascade parts of CEM2k and LAQGSM, and have extended LAQGSM to describe photonuclear reactions at energies to 10 GeV and higher. We have produced in this way improved versions of our codes, CEM03.01 and LAQGSM03.01. We present a brief description of our codes and show illustrative results obtained with CEM03.01 and LAQGSM03.01 for different reactions compared with predictions by other models, as well as examples of using our codes as modeling tools for nuclear applications.Comment: 12 pages, 10 figures, to be published in Journal of Physics: Conference Series: Proc. Europhysics Conf. on New Trends in Nuclear Physics Applications and Technologies (NPDC19), Pavia, Italy, September 5-9, 200

COMBINING QuEChERS PREPARATION AND MICELLAR ELECTROKINETIC CHROMATOGRAPHY FOR DETERMINATION OF NEONICOTINOID INSECTICIDES IN FRUITS AND VEGETABLES

The possibility of electrophoretic separation and simultaneous determination of 7 neonicotinoids (imidacloprid, acetamiprid, thiamethoxam, thiacloprid, nitenpyram, clothianidin and dinotefuran) by micellar electrokinetic chromatography is shown. We propose a method for extracting and concentrating of neonicotinoid insecticides from vegetables and fruits using the sample preparation QuEChERS. The optimum compositions of the salting-out mixtures for extraction and sorbents for purification of the resulting extracts from vegetables and fruits were selected. Extraction of pesticides from the fruits was performed by acetonitrile using a mixture of sodium citrates (Na3C6H5O7·2H2O, Na2HC6H5O7·1,5Н2О) with the following clean-up of 2 ml of the extract with sorbent PSA (100 mg) and anhydrous magnesium sulfate (300 mg). During the analysis of vegetables ethyl acetat was used as an extractant in the presence of anhydrous magnesium sulfate and sodium chloride with the following clean-up of 2 ml of the extract with sorbent PSA (100 mg) and graphitized carbon black (10 mg). In optimal conditions the recovery of the analytes ranged from 62 to 81 % for fruits and from 38 to 76 % for vegetables. The limits of quantification of neonicotinoids with a 10.0 g weight sample were from 0.25 to 0.65 mg·kg-1 and from 0.04 to 0.13 mg·kg-1 for fruits and vegetables respectively. The relative standard deviation of the test results does not exceed 0.1. Duration of analysis is 1-1.5 hr.Key words: neonicotinoids, micellar electrokinetic chromatography, QuEChERS, vegetables, fruits(Russian)DOI:http://dx.doi.org/10.15826/analitika.2015.19.1.003 D.S. Bol’shakov1, V.G. Amelin1,2, T.B. Nikeshina1 1Federal Centre for Animals Health (ARRIAH), Yur’evets, Vladimir, Russian Federation2Vladimir State University named after Alexander and Nikolay Stoletovs, Vladimir, Russian Federatio

Combining QuEChERS preparation and micellar electrokinetic chromatography for determination of neonicotinoid insecticides in fruits and vegetables

Показана возможность электрофоретического разделения и одновременного определения семи неоникотиноидов (имидаклоприда, ацетамиприда, тиаметоксама, тиаклоприда, нитенпирама, клотианидина и динотефурана) методом мицеллярной электрокинетической хроматографии. Предложен способ извлечения и концентрирования неоникотиноидных инсектицидов из овощей и фруктов с использованием дисперсионной твердофазной экстракции QuEChERS. Выбраны оптимальные составы высаливающих смесей для экстракции и сорбентов для очистки полученных экстрактов. Извлечение пестицидов из фруктов проводили ацетонитрилом с использованием смеси цитратов натрия и очисткой 2 мл полученного экстракта смесью 100 мг сорбента PSA и 300 мг безводного сульфата магния. Для анализа овощей в качестве экстрагента применяли этилацетат в присутствии безводного сульфата магния и хлорида натрия, с последующей очисткой 2 мл экстракта 100 мг сорбента PSA и 10 мг графитированной сажи. В оптимальных условиях степени извлечения пестицидов варьируются от 62 до 81 % для фруктов и от 38 до 76 % для овощей. Нижние границы определяемых содержаний пестицидов при массе пробы 10.0 г с учетом концентрирования составили от 0.25 до 0.65 мг/кг и от 0.04 до 0.13 мг/кг для фруктов и овощей соответственно. Относительное стандартное отклонение результатов анализа не превышает 0.1. Продолжительность анализа - 1-1.5 ч.The possibility of electrophoretic separation and simultaneous determination of 7 neonicotinoids (imidacloprid, acetamiprid, thiamethoxam, thiacloprid, nitenpyram, clothianidin and dinotefuran) by micellar electrokinetic chromatography is shown. We propose a method for extracting and concentrating of neonicotinoid insecticides from vegetables and fruits using the sample preparation QuEChERS. The optimum compositions of the salting-out mixtures for extraction and sorbents for purification of the resulting extracts from vegetables and fruits were selected. Extraction of pesticides from the fruits was performed by acetonitrile using a mixture of sodium citrates (Na₃C₆H₅O₇·2H₂O, Na₂HC₆H₅O₇·1,5Н₂О) with the following clean-up of 2 ml of the extract with sorbent PSA (100 mg) and anhydrous magnesium sulfate (300 mg). During the analysis of vegetables ethyl acetat was used as an extractant in the presence of anhydrous magnesium sulfate and sodium chloride with the following clean-up of 2 ml of the extract with sorbent PSA (100 mg) and graphitized carbon black (10 mg). In optimal conditions the recovery of the analytes ranged from 62 to 81 % for fruits and from 38 to 76 % for vegetables. The limits of quantification of neonicotinoids with a 10.0 g weight sample were from 0.25 to 0.65 mg·kg⁻¹ and from 0.04 to 0.13 mg·kg⁻¹ for fruits and vegetables respectively. The relative standard deviation of the test results does not exceed 0.1. Duration of analysis is 1-1.5 hr

Hbt Analysis of Anisotropic Transverse Flow

The effects of anisotropic transverse collective flow on the HBT correlation function is studied. There exist three different physics contributions related to flow which affect the correlation function: anisotropic source shape, anisotropic space-momentum correlations in pion emission, and the effects related to the HBT measurement of the size of a moving source in different reference frames. Resolution of these contributions experimentally can lead to a detailed understanding of both collective flow in nucleus-nucleus collisions and the HBT technique itself. A method is presented which permits the derivation of model independent relations between the radius of a source measured in a frame in which it is moving and in its rest frame.Comment: latex, 16 pages, 1 figur

Transverse momentum dependence of directed particle flow at 160 AGeV

The transverse momentum ($p_t$) dependence of hadron flow at SPS energies is studied. In particular, the nucleon and pion flow in S+S and Pb+Pb collisions at 160 AGeV is investigated. For simulations the microscopic quark-gluon string model (QGSM) is applied. It is found that the directed flow of pions $v_1(y, \Delta p_t)$ changes sign from a negative slope in the low-$p_t$ region to a positive slope at $p_t \geq 0.6$ GeV/c as recently also observed experimentally. The change of the flow behaviour can be explained by early emission times for high-$p_t$ pions. We further found that a substantial amount of high-$p_t$ pions are produced in the very first primary NN collisions at the surface region of the touching nuclei. Thus, at SPS energies high-$p_t$ nucleons seem to be a better probe for the hot and dense early phase of nuclear collisions than high-$p_t$ pions. Both, in the light and in the heavy system the pion directed flow $v_1(p_t, \Delta y)$ exhibits large negative values when the transverse momentum approaches zero, as also seen experimentally in Pb+Pb collisions. It is found that this effect is caused by nuclear shadowing. The proton flow, in contrary, shows the typical linear increase with rising $p_t$.Comment: REVTEX, 20 pages incl. 6 figures, revised and extended versio