46 research outputs found

    Measurements of Ξ{\Xi }{^-} and Ξ+\overline{\Xi }{^+} production in proton–proton interactions at sNN\sqrt{s_{NN}}=17.3 GeV = 17.3 GeV in the NA61/SHINE experiment

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    International audienceThe production of Ξ(1321)\Xi (1321)^{-} and Ξ(1321)+\overline{\Xi }(1321)^{+} hyperons in inelastic p+p interactions is studied in a fixed target experiment at a beam momentum of 158 GeV ⁣/ ⁣c\hbox {Ge}\hbox {V}\!/\!c. Double differential distributions in rapidity y{y} and transverse momentum pTp_{T} are obtained from a sample of 33M inelastic events. They allow to extrapolate the spectra to full phase space and to determine the mean multiplicity of both Ξ{\Xi }{^-} and Ξ+\overline{\Xi }{^+} . The rapidity and transverse momentum spectra are compared to transport model predictions. The Ξ{\Xi }{^-} mean multiplicity in inelastic p+p interactions at 158 GeV ⁣/ ⁣c\hbox {Ge}\hbox {V}\!/\!c is used to quantify the strangeness enhancement in A+A collisions at the same centre-of-mass energy per nucleon pair

    Measurements of π±\pi^\pm, K±K^\pm, pp and pˉ\bar{p} spectra in 40^{40}Ar+45^{45}Sc collisions at 13AA to 150AA GeV/cc

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    The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of π±\pi^\pm, K±K^\pm, pp and pˉ\bar{p} produced in 40^{40}Ar+45^{45}Sc collisions at beam momenta of 13AA, 19AA, 30AA, 40AA, 75AA and 150AA GeV/cc. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the K±K^\pm/π±\pi^\pm ratios as well as of inverse slope parameters of the K±K^\pm transverse mass distributions are placed in between those found in inelastic pp+pp and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical (SMES, HRG) or dynamical (EPOS, UrQMD, PHSD, SMASH) models

    KS0K_S^0 meson production in inelastic p+p interactions at 31, 40 and 80 GeV/c beam momentum measured by NA61/SHINE at the CERN SPS

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    Measurements of KS0K_S^0 meson production via its π+π\pi^{+} \pi^{-} decay mode in inelastic p+p\textit{p+p} interactions at incident projectile momenta of 31, 40 and 80 GeV/cc (sNN=7.7,8.8\sqrt{s_{NN}}=7.7, 8.8 and 12.312.3 GeV, respectively) are presented. The data were recorded by the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicities of KS0K_S^0 mesons were determined to be (5.95±0.19(stat)±0.22(sys))×102(5.95 \pm 0.19 (stat) \pm 0.22 (sys)) \times 10^{-2} at 31 GeV/cc, (7.61±0.13(stat)±0.31(sys))×102(7.61 \pm 0.13 (stat) \pm 0.31 (sys)) \times 10^{-2} at 40 GeV/cc and (11.58±0.12(stat)±0.37(sys))×102(11.58 \pm 0.12 (stat) \pm 0.37 (sys)) \times 10^{-2} at 80 GeV/cc. The results on KS0K^{0}_{S} production are compared with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments.Comment: arXiv admin note: substantial text overlap with arXiv:2106.0753

    Measurements of K0^{0}S_{S}, Λ , and Λˉ\bar{Λ} production in 120 GeV / c p + C interactions

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    This paper presents multiplicity measurements of K0S, Λ, and ¯Λ produced in 120  GeV/c proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different periods. Decays of these neutral hadrons impact the measured π+, π−, p and ¯p multiplicities in the 120  GeV/c proton-carbon reaction, which are crucial inputs for long-baseline neutrino experiment predictions of neutrino beam flux. The double-differential multiplicities presented here will be used to more precisely measure charged-hadron multiplicities in this reaction, and to reweight neutral hadron production in neutrino beam Monte Carlo simulations

    Measurement of Hadron Production in π\pi^--C Interactions at 158 and 350 GeV/c with NA61/SHINE at the CERN SPS

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    We present a measurement of the momentum spectra of π±\pi^\pm, K±^\pm, p±^\pm, Λ\Lambda, Λˉ\bar{\Lambda} and KS0^{0}_{S} produced in interactions of negatively charged pions with carbon nuclei at beam momenta of 158 and 350 GeV/c. The total production cross sections are measured as well. The data were collected with the large-acceptance spectrometer of the fixed target experiment NA61/SHINE at the CERN SPS. The obtained double-differential pp-pTp_T spectra provide a unique reference data set with unprecedented precision and large phase-space coverage to tune models used for the simulation of particle production in extensive air showers in which pions are the most numerous projectiles

    Measurements of π+\pi^+, π\pi^-, pp, pˉ\bar{p}, K+K^+ and KK^- production in 120 GeV/cc p + C interactions

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    This paper presents multiplicity measurements of charged hadrons produced in 120 GeV/cc proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different data-taking periods, with increased phase space coverage in the second configuration due to the addition of new subdetectors. Particle identification via dE/dxdE/dx was employed to obtain double-differential production multiplicities of π+\pi^+, π\pi^-, pp, pˉ\bar{p}, K+K^+ and KK^-. These measurements are presented as a function of laboratory momentum in intervals of laboratory polar angle covering the range from 0 to 450 mrad. They provide crucial inputs for current and future long-baseline neutrino experiments, where they are used to estimate the initial neutrino flux

    Search for the critical point of strongly-interacting matter in 40^{40}Ar + 45^{45}Sc collisions at 150A Ge V /c using scaled factorial moments of protons

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    The critical point of dense, strongly interacting matter is searched for at the CERN SPS in 40^{40}Ar + 45^{45}Sc collisions at 150A Ge V /c. The dependence of second-order scaled factorial moments of proton multiplicity distribution on the number of subdivisions of transverse momentum space is measured. The intermittency analysis is performed using both transverse momentum and cumulative transverse momentum. For the first time, statistically independent data sets are used for each subdivision number. The obtained results do not indicate any statistically significant intermittency pattern. An upper limit on the fraction of correlated proton pairs and the power of the correlation function is obtained based on a comparison with the Power-law Model developed for this purpose

    Measurement of hadron production in π^{–}−C interactions at 158 and 350 GeV / c with NA61/SHINE at the CERN SPS

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    We present a measurement of the momentum spectra of π ±^{±}, K±^{±}, p±^{±}, Λ, Λ\overline{Λ}, and K0^{0}S_{S} produced in interactions of negatively charged pions with carbon nuclei at beam momenta of 158 and 350 GeV/c. The total production cross sections are measured as well. The data were collected with the large-acceptance spectrometer of the fixed target experiment NA61/SHINE at the CERN SPS. The obtained double-differential p−pT spectra provide a unique reference dataset with unprecedented precision and large phase-space coverage to tune models used for the simulation of particle production in extensive air showers in which pions are the most numerous projectiles

    Measurements of Ξ(1530)0{\Xi \left( 1530\right) ^{0}} and Ξ(1530)0{\overline{\Xi }\left( 1530\right) ^{0}} production in proton–proton interactions at sNN\sqrt{s_{NN}} = 17.3  = 17.3  GeV \text{ GeV } in the NA61/SHINE experiment

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    Double-differential yields of Ξ(1530)0\Xi\left(1530\right)^{0} and Ξ(1530)0\overline{\Xi}\left(1530\right)^{0} resonances produced in \pp interactions were measured at a laboratory beam momentum of 158~\GeVc. This measurement is the first of its kind in \pp interactions below LHC energies. It was performed at the CERN SPS by the \NASixtyOne collaboration. Double-differential distributions in rapidity and transverse momentum were obtained from a sample of 26\cdot106^6 inelastic events. The spectra are extrapolated to full phase space resulting in mean multiplicity of Ξ(1530)0\Xi\left(1530\right)^{0} (6.73 ±\pm 0.25 ±\pm 0.67)×104\times10^{-4} and Ξ(1530)0\overline{\Xi}\left(1530\right)^{0} (2.71 ±\pm 0.18 ±\pm 0.18)×104\times10^{-4}. The rapidity and transverse momentum spectra and mean multiplicities were compared to predictions of string-hadronic and statistical model calculations

    Functional analysis of the Kluyveromyces lactis PDR1 gene

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    In Saccharomyces cerevisiae, the simultaneous resistance to various cytotoxic compounds known as multidrug resistance (MDR) is caused by overexpression of membrane efflux pumps under the control of two main transcriptional activators Pdr1p and Pdr3p. In this work we describe the results of functional analysis of a single Kluyveromyces lactis homolog of the PDR1 gene, which encodes a zinc finger Zn(2) Cys(6)-containing transcription factor. The KlPDR1 deletion generated a strain hypersusceptible to oligomycin, antimycin A and azole antifungals. Overexpression of KlPDR1 from a multicopy plasmid in the Klpdr1 Delta mutant strain increased the tolerance of transformants to all the drugs tested (oligomycin, antimycin A and azole antifungals). The plasmid-borne KlPDR1 gene was able to complement drug hypersensitivity of the S. cerevisiae pdr1 Delta pdr3 Delta mutant strain. The KlPDR1 was found to be necessary for upregulation of the ATP-binding cassette transporter encoded by the KlPDR5 gene and rhodamine 6G efflux out of the cells. The KlPDR5 and some other K. lactis pleiotropic drug resistance (PDR) orthologues were found to contain putative PDR-responsive elements in their promoters. These results demonstrate that KlPdr1p is involved in K. lactis MDR and is required for cell's tolerance to various cytotoxic compounds
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