WorldWideScience

Sample records for negative pion induced

  1. Negative Pion Induced Fission with Heavy Target Nuclei

    Institute of Scientific and Technical Information of China (English)

    G. Sher; Mukhtar A. Rana; S. Manzoor; M. I. Shahzad

    2011-01-01

    We investigate fission induced by negative pions in copper and bismuth targets using CR-39 dielectric track detectors. The target-detector assemblies in Air-geometric configuration were exposed at the AGS facility of Brookhaven National Laboratory, USA. The exposed detectors were chemically etched under appropriate etching conditions and scanned to collect data in the form of fission fragments tracks produced as a result of interaction of pions with the target nuclei. Using the track counts, the experimental fission cross sections for copper and bismuth have been measured at energies of 500, 672, 1068 and 1665 MeV and compared with the calculation using the Cascade-Exciton Model code (CEM95). The values of fission probability based on experimental fission cross-sections have been compared with the theoretically calculated values of fission probabilities obtained using the CEM95 code. Good agreement is observed between the measured and computed results.

  2. Pion Induced Pion Production on Deuterium.

    Science.gov (United States)

    Sossi, Vesna

    This thesis describes measurements of the pion induced pion production reaction pi^+ d to pi^{+} pi^{-}p p performed with a 280 MeV incident pi^{+} beam at TRIUMF. The data are compared with an improved version of the Oset and Vicente-Vacas theoretical model (12). The goal of the experiment and of the analysis was to provide a larger body of data for the free reaction and to test the validity of theoretical models. In the process, the ability to determine the values of the coupling constants C, f_Delta, g _{N*Delta_tau} within such a model framework would be explored. The knowledge of the precise value of these coupling constants would constrain N^* decay branching ratios and other pion induced reaction mechanisms like Double Charge Exchange. A previous experiment (23) had indicated that the pion induced pion production on deuterium is essentially a quasifree process with the reaction occurring on the neutron leaving the proton merely a spectator. The main difference with respect to the free reaction is the effect of Fermi motion of the neutron. Although we were interested in studying the free reaction (pi^ {-}p to pi^ {+}pi^{-}n), we chose a deuterium target so that the experiment could be run with a pi^+beam, since the pi^- beam flux is about 6 times lower than the flux of the positive pion beam at 280 MeV, the energy at which our experiment was performed. Such a flux would have required a much longer running time for the experiment in order to achieve the same statistical accuracy. The quasifree nature of the process was also confirmed in our experiment. This experiment involved a coincidence measurement of the quasifree process and as such provided four-fold differential cross section spectra of the reaction thus allowing for a microscopic comparison between data and theoretical models. In the theoretical description we incorporated additional amplitudes for the N^* to N(pipi)_{p-wave} diagrams required to describe the reaction cross section at T_pi = 280 Me

  3. Neutrino induced 1-pion production

    CERN Document Server

    González-Jiménez, R; Van Dessel, N; Pandey, V; Jachowicz, N

    2016-01-01

    Neutrino-induced pion production constitutes an important contribution to neutrino-nucleus scattering cross sections at intermediate energies. A deep understanding of this process is mandatory for a correct interpretation of neutrino-oscillation experiments. We aim at contributing to the ongoing effort to understand the various experimental results obtained by different collaborations in a wide range of energies. In particular, in this work we analyze recent MiniBooNE and MINERvA charged-current neutrino 1-pion production data. We use a relativistic theoretical approach which accounts for resonant and non-resonant 1-pion production contributions.

  4. Fission of Weakly Prolate 119Sn and Weakly Oblate 209Bi Nuclei Induced by 500 and 672 MeV Negative Pions

    Institute of Scientific and Technical Information of China (English)

    Mukhtar Ahmed Rana; Gul Sher,Shahid Manzoor; M.I.Shahzad

    2011-01-01

    @@ Fission cross-sections of 119Sn and 209Bi induced by negative pions of two energies 500 and 672 MeV were measured using a CR-39 nuclear track detector.Target-detector stacks were exposed to pion beams at the Brookhaven National Laboratory(USA).Measurement results are compared with the corresponding calculations using the computer code CEM95.Agreement between measurements and calculations is fairly good for the 209Bi target nuclei whereas it is poor for 119Sn at both investigated energies of 500 and 672 MeV Fission cross-section results of 119Sn and 209Bi are explained using the equilibrium properties of these nuclides including nuclear electric quadrupole moments which determine the shapes of nuclei.A logarithmic dependence of fission cross-section on Z2/A is observed for the above-mentioned reactions and a critical limit of Z2/A is identified with the value of 30 which divides the curve of of versus Z2/A into two regimes,one with weak dependence and the other with strong dependence.%Fission cross-sections of 119Sn and 20gBi induced by negative pions of two energies 500 and 672 MeV were measured using a CR-39 nuclear track detector. Target-detector stacks were exposed to pion beams at the Brookhaven National Laboratory (USA). Measurement results are compared with the corresponding calculations using the computer code CEM95. Agreement between measurements and calculations is fairly good for the 209Bi target nuclei whereas it is poor for 119Sn at both investigated energies of 500 and 672 MeV. Fission cross-section results of 119Sn and 209Bi are explained using the equilibrium properties of these nuclides including nuclear electric quadrupole moments which determine the shapes of nuclei. A logarithmic dependence of fission cross-section on Z2/A is observed for the above-mentioned reactions and a critical limit of Z2/A is identified with the value of 30 which divides the curve of at versus Z2 /A into two regimes, one with weak dependence and the other with strong

  5. Neutrino-induced coherent pion production

    CERN Document Server

    Alvarez-Ruso, L; Hirenzaki, S; Vacas, M J Vicente; Leitner, T; Mosel, U

    2007-01-01

    We have investigated the neutrino induced coherent pion production reaction at the energies of interest for recent experiments like K2K and MiniBooNE. The model includes pion, nucleon and the Delta(1232) resonance. Medium effects in the production mechanism and the distortion of the pion wave function are taken into account. We find a strong reduction of the cross section due to these effects and also substantial modifications in the energy distributions of the final pion. The sensitivity of the results on the axial N-Delta coupling C5A(0) and the coherent fraction in neutral-current pi0 production are discussed.

  6. Pion-induced pion production on deuterium: a quasifree process

    Science.gov (United States)

    Sossi, V.; Iqbal, M. J.; Johnson, R. R.; Jones, G.; Pavan, M.; Rozon, F. M.; Sevior, M.; Vetterli, D.; Weber, P.; Sheffer, G.; Smith, G. R.; Camerini, P.; Grion, N.; Rui, R.; Stevenson, N. R.; Vicente-Vacas, M. J.

    1992-10-01

    A detailed experimental analysis of the π+d → π+π-pp in-plane coincidence data first presented by Rui et al. is compared to an expanded version of the Oset and Vicente-Vacas model for pion-induced pion production on a free nucleon. This extended model averages over Fermi motion to describe the assumed quasifree nature of the process occurring on the deuteron and includes nine additional diagrams to account for the N∗ → N(ππ) p-wave reaction channels. Experimental effects such as pion energy loss in the target and in the detectors, pion decay and muon detection are investigated and incorporated into the comparison of experimental data and theory. Inclusion of Fermi motion was found to be essential to provide good agreement between data and model confirming the quasifree nature of the reaction. When compared to the total-cross-section measurements of Manley et al., the free-reaction model yields a model-dependent estimate of the overall strength of the diagram containing the N∗ → N(ππ) s-wave vertex.

  7. Production of Two Pions Induced by Neutrinos

    CERN Document Server

    Valverde, M; Hernández, E; Singh, S K; Vacas, M J Vicente

    2008-01-01

    We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon pole, pion and contact terms is calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account.

  8. Neutrino induced coherent pion production

    CERN Document Server

    Hernández, E; Valverde, M; Vicente-Vacas, M J

    2009-01-01

    We discuss different parameterizations of the $C_5^A(q^2)$ $N\\Delta$ axial form factor, fitted to the old Argonne bubble chamber data for pion production by neutrinos, and we use coherent pion production to test their low $q^2$ behavior. We find moderate effects that will be difficult to observe with the accuracy of present experiments. We also discuss the use of the Rein-Sehgal model for low energy coherent pion production. By comparison to a microscopic calculation, we show the weaknesses of some of the approximations in that model that lead to very large cross sections as well as to the wrong shapes for differential ones. Finally we show that models based on the partial conservation of the axial current hypothesis are not fully reliable for differential cross sections that depend on the angle formed by the pion and the incident neutrino.

  9. Charged current neutrino induced coherent pion production

    CERN Document Server

    Alvarez-Ruso, L; Hirenzaki, S; Vacas, M J V

    2007-01-01

    We analyze the neutrino induced charged current coherent pion production at the energies of interest for recent experiments like K2K and MiniBooNE. Medium effects in the production mechanism and the distortion of the pion wave function, obtained solving the Klein Gordon equation with a microscopic optical potential, are included in the calculation. We find a strong reduction of the cross section due to these effects and also substantial modifications of the energy distributions of the final lepton and pion.

  10. The Centauro events as a result of induced pions emission

    CERN Document Server

    Karmanov, V A

    2002-01-01

    It is shown that only in the case of n pion production amplitude (at n > 10), which is symmetric enough relative to the momenta permutations, there is appreciable probability of events with nothing but charged or nothing but neutral pions. Significant enhancement of the probability of these events in comparison with that follows from Poisson distribution is caused by induced pions emission, in complete analogy with the phenomenon of the induced photon emission in QED.

  11. Energy dependence of negatively charged pion production in proton-proton interactions at the CERN SPS

    CERN Document Server

    AUTHOR|(SzGeCERN)663936; Dominik, Wojciech; Gaździck, Marek

    2016-01-01

    This thesis presents inclusive spectra of the negatively charged pions produced in inelastic proton-proton interactions measured at five beam momenta: 20, 31, 40, 80 and 158 GeV/c. The measurements were conducted in the NA61/SHINE experiment at CERN using a system of five Time Projection Chambers. The negatively charged pion spectra were calculated based on the negatively charged hadron spectra. Contribution of hadrons other than the primary pions was removed using EPOS simulations. The results were corrected for effects related to detection, acceptance, reconstruction efficiency and the analysis technique. Two-dimensional spectra were derived as a function of rapidity and transverse momentum or transverse mass. The spectra were parametrised by widths of the rapidity distributions, inverse slope parameters of the transverse mass distributions, mean transverse masses and the total pion multiplicities. The negatively charged pion spectra in proton-proton interactions belong to a broad NA61/SHINE programme of se...

  12. Exotic Theta^+ baryon production induced by photon and pion

    CERN Document Server

    Oh, Y; Lee, S H; Oh, Yongseok; Kim, Hungchong; Lee, Su Houng

    2004-01-01

    We investigate the photoproduction of the $\\Theta^+(1540)$ on a nucleon ($\\gamma n \\to K^- \\Theta^+$, $\\gamma p \\to \\bar{K}^0 \\Theta^+$) and the pion-induced $\\Theta^+$ production reaction on the proton ($\\pi^- p \\to K^- \\Theta^+$). The total cross sections near threshold are estimated by using hadronic models with effective interaction Lagrangians and form factors that preserve gauge-invariance of the electromagnetic current. The photoproduction cross sections are found to be a few hundred nb, with the cross section on the proton being larger than that on the neutron. The pion-induced production cross section is found to be around a few hundred $\\mu$b but sensitive to the $K^* N \\Theta$ coupling whose value is not yet known. We also study the production cross section assuming that the $\\Theta^+$ has negative parity. The cross sections are then found to be much suppressed compared to the case where $\\Theta^+$ has positive parity. Hence, the interpretation of the $\\Theta^+$ as an odd-parity pentaquark state se...

  13. Determination of the negatively charged pion-proton scattering length from pionic hydrogen

    CERN Document Server

    Ericson, Torleif Eric Oskar; Wycech, S

    2003-01-01

    We derive a closed, model independent, expression for the electromagnetic correction factor to the hadronic scattering length extracted from a hydrogenic atom with an extended charge and in the limit of a short ranged hadronic interaction to terms of order ((alpha)**2)(log(alpha)) in the limit of a non-relativistic approach. A hadronic negatively charged pion-proton scattering length of 0.0870(5), in units of inverse charged pion-mass, is deduced, leading to a pion-nucleon coupling constant from the GMO relation equals to 14.00(19).

  14. Mass dependence of pion-induced fission cross sections on the level density parameter

    Institute of Scientific and Technical Information of China (English)

    Zafar Yasin; Warda Iram; M.Ikram Shahzad

    2012-01-01

    Fission probabilities and fission cross sections strongly depend on the mass number of the target and energy of the projectile.In this research work,a cascade-exciton model (using CEM95 computer code) has been implemented to observe the dependence of pion-induced fission cross sections and fission probabilities on the target mass and ratio of the level density parameter in fission to neutron emission.The analysis has been performed for both the positive and negative pions as the projectile at 80,100 and 150 MeV energies.The computed cross sections satisfactorily reproduced the experimental findings when compared with the available experimental data in the literature.We observed a smooth dependence at 150 MeV,and a sharper dependence at 80 and 100 MeV pion energy,in the fissility region above 29.44.

  15. Pion Pion Correlations at Low Relative Momentum Produced in the Reactions Proton-Proton Going to Proton-Proton Pion, Negative Pion)(n) with N = 2,3,4,5,6

    Science.gov (United States)

    Uribe Duque, Jorge

    We have measured low relative momentum correlations between like sign pions produced in the reactions pp to pp(pi^+,pi^ {-})^{n} with n ranging from 2 to 6. The data sample consisted of 0.93 times10^6 fully reconstructed exclusive interactions, with incident proton momentum of 27.5 GeV/c, recorded by experiment E766 at the AGS in Brookhaven National Laboratory. By parametrizing the correlation with a function of Q^2 representing the dynamics of the reaction and the correlation itself, it was shown that the Q^2 scale does not depend on the final state multiplicity and has a value of 1.08 fermi. The "strength" of the correlation does depend on multiplicity. For negative pions the "strength" is 26% larger than for positive pions.

  16. Neutrino induced weak pion production off the nucleon and coherent pion production in nuclei at low energies

    CERN Document Server

    Amaro, J E; Nieves, J; Valverde, M; Vicente-Vacas, M J

    2009-01-01

    We present a microscopic model for neutrino induced one-pion production off the nucleon and its implementation for the purpose of calculating coherent pion production in nuclei. We further criticize the use of the Rein--Sehgal model for coherent pion production by low energy neutrinos. In particular, we show how the approximations in that model give rise to a much flatter differential cross section in the $\\eta=E_\\pi(1-\\cos\\theta_\\pi)$ variable. We discuss the limitations intrinsic to any approach based on the partial conservation of the axial current hypothesis and the inability of such models to properly determine the angular distribution of the outgoing pion with respect to the direction of the incoming neutrino. We show the effects of those limitation for the case of the $\\frac{d\\sigma}{d\\eta}$ differential cross section.

  17. Search for deeply bound pionic states in 208Pb via radiative atomic capture of negative pions

    Science.gov (United States)

    Raywood, K. J.; Lange, J. B.; Jones, G.; Pavan, M.; Sevior, M. E.; Hutcheon, D. A.; Olin, A.; Ottewell, D.; Yen, S.; Lee, S. J.; Sim, K. S.; Altman, A.; Friedman, E.; Trudel, A.

    1997-05-01

    A search for narrow, deeply bound pionic atom states via atomic radiative capture of negative pions in a target of 208Pb was carried out for pion kinetic energies of 20 and 25 MeV. Although no clear signature of any such gamma ray emission could be observed in the data, fits of the gamma ray spectra between the energies of 12 and 42 MeV involving a quadratic background together with a pair of peaks (1s, 2p) whose relative intensity was taken from theory yielded an overall strength for the peaks which are consistent (to a 67% confidence level) with radiative capture whose integrated cross section is 20.0 +/- 10.0 μb/sr at 90° for 20 MeV incident pions. A lower probability (40% confidence level) result was obtained when the fit was carried out without the peaks included, just the continuum background.

  18. Neutrino Induced Coherent Pion Production off Nuclei and PCAC

    CERN Document Server

    Hernández, E; Vicente-Vacas, M J

    2009-01-01

    We have critically reviewed the commonly used Rein--Sehgal model for neutrino induced coherent pion production. We have studied the validity of the main approximations implicit in that model, trying to compare with physical observables when that is possible and with microscopical calculations. Next, we have tried to elaborate a new improved model by removing the more problematic approximations, while keeping the model still reasonably simple. Last, we have discussed the limitations intrinsic to any approach based on the partial conservation of the axial current hypothesis. In particular, we have shown the inability of such models to determine the angular distribution of the outgoing pion with respect to the direction of the incoming neutrino, except for the $q^2= 0$ kinematical point.

  19. Nuclear fragmentation and charge-exchange reactions induced by pions in the $\\Delta$-resonance region

    CERN Document Server

    Feng, Zhao-Qing

    2016-01-01

    Dynamics of the nuclear fragmentations and the charge exchange reactions in pion-nucleus collisions near the $\\Delta$(1232) resonance energies has been investigated within the Lanzhou quantum molecular dynamics (LQMD) transport model. An isospin, momentum and density-dependent pion-nucleon potential is implemented in the model, which influences the pion dynamics, in particular the kinetic energy spectra, but weakly impacts the fragmentation mechanism. The absorption process in pion-nucleon collisions to form the $\\Delta$(1232) resonance dominates the heating mechanism of target nucleus. The excitation energy transferred to the target nucleus increases with the pion kinetic energy and is similar for both $\\pi^{-}$ and $\\pi^{+}$ induced reactions. The magnitude of fragmentation of target nucleus weakly depends on the pion energy. The isospin ratio in the pion double charge exchange is influenced by the isospin ingredient of target nucleus.

  20. Pion Polarizability at CERN COMPASS

    CERN Document Server

    Moinester, Murray

    2014-01-01

    The electric α π and magnetic β π charged p ion polariz abilities characterize the induced dipole moments of the pion during γπ scattering . The se fundamental characterisitcs of the pion provide stringent tests of various theoretical models , for example chiral perturbation theory ( Ch PT) . CERN COMPAS S investigated pion Compton scattering γπ → γ π , via radiative pion Primakoff scattering (Bremsstrahlung of 190 GeV/c negative pions) in the nuclear Coulomb field of the Ni nucleus: π + Ni → π + γ + Ni. The resulting data are equivalent to γπ Compton scatter ing for laboratory γ's having momenta of order 1 GeV/c incident on a target pion at rest. The data yield preliminary polarizability values α π = − β π = (1.9±0.7 stat ±0.8 syst ) ×10 − 4 fm 3 , in agreement with Ch PT .

  1. Atomic capture and transfer of negative pions stopped in binary mixtures of hydrogen with polyatomic gases

    Energy Technology Data Exchange (ETDEWEB)

    Vasilyev, V.A.; Levay, B.; Minkova, A.; Petrukhin, V.I.; Horvath, D.

    1985-12-01

    The atomic capture and transfer of stopped negative pions have been studied in binary gas mixtures of H/sub 2/+M, where M is CCl/sub 2/F/sub 2/, CClF/sub 3/, CBrF/sub 3/ or SF/sub 6/. The ..pi../sup 0/ yield, versus relative atomic concentration Csub(A) of M, goes through a maximum at Csub(A)proportional0.1 and levels off at zero at high concentrations. This phenomenon together with other observed characteristics of the atomic capture and transfer of pions in these systems is interpreted in the frame of a phenomenological model. The average transfer coefficients anti ..lambda..sub(Z) exhibit a weak concentration dependence. The estimated average atomic capture ratios anti A(Z/H) are lower than those found for noble gases, probably because of the mutual screening of the constituent atoms in the molecules. The probability of pion capture in an atomic orbit is not proportional to the stopping power of the components of the mixture. (orig.).

  2. Mass and energy dependence of pion-induced fission

    Science.gov (United States)

    Peterson, R. J.; Debarros, S.; Desouza, I. O.; Gaspar, M. B.; Khan, Hameed Ahmed; Manzoor, Shahid

    1995-06-01

    Data for fission induced by pi meson beams from 80 to 500 MeV are presented for nuclei from Fe through Pu as measured by solid state track detectors. The general trends for binary fission with π + are reproduced fairly well by a calculation in the ‘high excitation’ limit with standard level density and fission barrier parameters, but π - data are underpredicted. A universal dependence of the binary fission probabilities with the fissility ( Z±1)2/A is found to be valid for both pion beam charges for all beam energies below the delta resonance. Probabilities for observing three fragments with π + are not reproduced by a ternary fission application of the model found to work for binary fission.

  3. Systematic effects in the measurement of the negatively charged pion mass using laser spectroscopy of pionic helium atoms

    CERN Document Server

    Obreshkov, Boyan

    2016-01-01

    The collision-induced shift and broadening of selected dipole transition lines of pionic helium in gaseous helium at low temperatures up to $T=12$ K and pressure up to a few bar are calculated within variable phase function approach. We predict blue shift of the resonance frequencies of the $(n,l)=(16,15) \\rightarrow (16,14) $ and $(16,15) \\rightarrow (17,14)$ unfavored transitions and red shift for the favored transition $(17,16) \\rightarrow (16,15)$. The result may be helpful in reducing the systematic error in proposed future experiments for determination of the negatively charged pion mass from laser spectroscopy of metastable pionic helium atoms.

  4. Neutrino-induced pion production from nuclei at medium energies

    CERN Document Server

    Praet, C; Jachowicz, N; Ryckebusch, J

    2008-01-01

    We present a fully relativistic formalism for describing neutrino-induced $\\Delta$-mediated single-pion production from nuclei. We assess the ambiguities stemming from the $\\Delta$ interactions. Variations in the cross sections of over 10% are observed, depending on whether or not magnetic-dipole dominance is assumed to extract the vector form factors. These uncertainties have a direct impact on the accuracy with which the axial-vector form factors can be extracted. Different predictions for $C_5^A(Q^2)$ induce up to 40-50% effects on the $\\Delta$-production cross sections. To describe the nucleus, we turn to a relativistic plane-wave impulse approximation (RPWIA) using realistic bound-state wave functions derived in the Hartree approximation to the $\\sigma$-$\\omega$ Walecka model. For neutrino energies larger than 1 GeV, we show that a relativistic Fermi-gas model with appropriate binding-energy correction produces comparable results as the RPWIA which naturally includes Fermi motion, nuclear-binding effects...

  5. Caloric curve of 8 GeV/c negative pion and antiproton + Au reactions

    CERN Document Server

    Ruangma, A; Martin, E; Ramakrishnan, E; Rowland, D J; Veselsky, M; Winchester, E M; Yennello, S J; Beaulieu, L; Hsi, W C; Kwiatkowski, K K; Lefort, T; Viola, V E; Botvina, A; Korteling, R G; Pienkowski, L; Breuer, H; Gushue, S; Remsberg, L P

    2002-01-01

    The relationship between nuclear temperature and excitation energy of hot nuclei formed by 8 GeV/c negative pion and antiproton beams incident on 197Au has been investigated with the ISiS 4-pidetector array at the BNL AGS accelerator. The double-isotope-ratio technique was used to calculate the temperature of the hot system. The two thermometers used (p/d-3He/4He) and (d/t-3He/4He) are in agreement below E*/A ~ 7 MeV when corrected for secondary decay. Comparison of these caloric curves to those from other experiments shows some differences that may be attributable to instrumentation and analysis procedures. The caloric curves from this experiment are also compared with the predictions from the SMM multifragmentation model.

  6. CHARGE-EXCHANGE SCATTERING OF NEGATIVE PIONS BY HYDROGEN AT 230,260, 290, 317 AND 371 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Caris, John C

    1960-03-18

    The differential cross section for charge-exchange scattering of negative pions by hydrogen has been observed at 230, 260, 290, 317, and 371 Mev. The reaction was observed by detecting one gamma ray from the {pi}{sup 0} decay with a scintillation-counter telescope.

  7. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analysed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H) is found to be 0.128 +- 0.012.

  8. Studies on the atomic capture of stopped negative pions in binary mixtures of 3He with other gases

    Science.gov (United States)

    Bannikov, A. V.; Lévay, B.; Petrukhin, V. I.; Vasilyev, V. A.; Kochenda, L. M.; Markov, A. A.; Medvedev, V. I.; Sokolov, G. L.; Strakovsky, I. I.; Horváth, D.

    1983-07-01

    Systematic experimental study has been carried out on the atomic capture of negative pions by 3He in binary gas mixtures of 3He + Z, where Z is Ne, Ar, Kr, Xe, N 2, O 2, CO 2 and sf 6. The results are analysed in the framework of a phenomenological model. It is shown that there is no pion transfer from the 3Heπ - mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentrations, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A( Z/ 3He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a 3He + 4He mixture is A( 4He/ 3He) = 0.75 ± 0.13 , which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest (π - + 3He → π 0 + 3H) is found to be 0.128 ± 0.012.

  9. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analyzed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H is found to be 0.128 +- 0.012.

  10. Two-pion production in photon-induced reactions

    Indian Academy of Sciences (India)

    S Schadmand

    2006-05-01

    Differences in the photoproduction of mesons on the free proton and on nuclei are expected to reveal changes in the properties of hadrons. Inclusive studies of nuclear photoabsorption have provided evidence of medium modifications. However, the results have not been explained in a model independent way. A deeper understanding of the situation is anticipated from a detailed experimental study of meson photoproduction from nuclei in exclusive reactions. In the energy regime above the (1232) resonance, the dominant double pion production channels are of particular interest. Double pion photoproduction from nuclei is also used to investigate the in-medium modification of meson–meson interactions.

  11. Neutrino induced coherent single pion production at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Nahnhauer, R. (Institut fuer Hochenergiephysik, Zeuthen (Germany, F.R.))

    1991-04-01

    Available data about coherent single pion production in charged and neutral current reactions are reviewed and compared to the results of two corresponding models. A comparison of the axialvector-isovector coupling constant /{beta}/ derived in different experiments is given. Agreement is found between them and the prediction of the Standard Model. Possible new information from future analyses is mentioned. (orig.).

  12. Resonance production and decay in pion induced collisions with HADES

    Directory of Open Access Journals (Sweden)

    Scozzi Federico

    2017-01-01

    Full Text Available The main goal of the High Acceptance Di-Electron experiment (HADES at GSI is the study of hadronic matter in the 1-3.5 GeV/nucleon incident energy range. HADES results on e+ e− production in proton-nucleus reactions and in nucleus-nucleus collisions demonstrate a strong enhancement of the dilepton yield relative to a reference spectrum obtained from elementary nucleon-nucleon reactions. These observations point to a strong modification of the in-medium ρ spectral function driven by the coupling of the ρ to baryon-resonance hole states. However, to scrutinize this conjecture, a precise study of the role of the ρ meson in electromagnetic baryon-resonance transitions in the time-like region is mandatory. In order to perform this study, HADES has started a dedicated pion-nucleon programme. For the first time a combined measurement of hadronic and dielectron final states have been performed in π−-N reactions at four different pion beam momenta (0.656, 0.69, 0.748 and 0.8 GeV/c. First results on exclusive channels with one pion π−-p and two pions (nπ+π−, pπ−π0 in the final state, which are currently analysed within the partial wave analysis (PWA framework of the Bonn-Gatchina group, are discussed. Finally first results for the dielectron analysis will be shown.

  13. Measurement of Neutrino Induced, Charged Current, Charged Pion Production

    Energy Technology Data Exchange (ETDEWEB)

    Wilking, Michael Joseph [Univ. of Colorado, Boulder, CO (United States)

    2009-05-01

    Neutrinos are among the least understood particles in the standard model of particle physics. At neutrino energies in the 1 GeV range, neutrino properties are typically determined by observing the outgoing charged lepton produced in a charged current quasi-elastic interactions. The largest charged current background to these measurements comes from charged current pion production interactions, for which there is very little available data.

  14. Double Pion Production Reactions

    CERN Document Server

    Oset, E; Cano, F; Hernández, E; Kamalov, S S; Nacher, J C; Tejedor, J A G

    1999-01-01

    We report on reactions producing two pions induced by real and virtual photons or nucleons. The role of different resonances in these reactions is emphasized. Novel results on coherent two pion photoproduction in nuclei are also reported.

  15. Constraining the GENIE model of neutrino-induced single pion production using reanalyzed bubble chamber data

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Philip; McFarland, Kevin [University of Rochester, Department of Physics and Astronomy, Rochester, NY (United States); Wilkinson, Callum [University of Bern, Laboratory for High Energy Physics (LHEP), Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

    2016-08-15

    The longstanding discrepancy between bubble chamber measurements of ν{sub μ}-induced single pion production channels has led to large uncertainties in pion production cross section parameters for many years. We extend the reanalysis of pion production data in deuterium bubble chambers where this discrepancy is solved (Wilkinson et al., PRD 90, 112017 2014) to include the ν{sub μ}n → μ{sup -}pπ{sup 0} and ν{sub μ}n → μ{sup -}nπ{sup +} channels, and use the resulting data to fit the parameters of the GENIE pion production model. We find a set of parameters that can describe the bubble chamber data better than the GENIE default parameters, and provide updated central values and reduced uncertainties for use in neutrino oscillation and cross section analyses which use the GENIE model. We find that GENIE's non-resonant background prediction has to be significantly reduced to fit the data, which may help to explain the recent discrepancies between simulation and data observed by the MINERνA coherent pion and NOνA oscillation analyses. (orig.)

  16. neutrino induced threshold production of two pions and N^*(1440) electroweak form factors

    CERN Document Server

    Hernández, E; Singh, S K; Valverde, M; Vicente-Vacas, M J

    2007-01-01

    We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon, pion and contact terms are calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account. The numerical results for the cross sections are presented and compared with the available experimental data. It has been found that in the two pion channels with $\\pi^+\\pi^-$ and $\\pi^0\\pi^0$ in the final state, the contribution of the $N^*(1440)$ is quite important and could be used to determine the $N^*(1440)$ electroweak transition form factors if experimental data with better statistics become available in the future.

  17. Analyzing Powers and Differential Cross Sections for Polarized Proton Neutron Going to Negative Pion Proton Proton

    Science.gov (United States)

    Duncan, Fraser Andrew

    There is considerable interest in the pn to pi^-pp reaction which can proceed by a nonresonant channel from the isospin 0 pn initial state (an NDelta intermediate state cannot be formed). This thesis describes a measurement of analyzing powers and triple differential cross sections for a subset of this reaction, pn to pi^-pp(^1S_0) by isolating the quasifree process in pd to pi^-ppp_{s}. The experimental arrangement selects the relative S-wave component of the outgoing "diproton". The experiment was done on TRIUMF beam line 1B using a LD_2 target; the pion was detected in a magnetic spectrometer, the two outgoing protons in a scintillator bar array. The spectator proton was undetected. Data were taken in August 1989 at 353, 403 and 440 MeV beam energies. Of these the 403 and 440 MeV data are analysed in this thesis and analyzing powers and triple differential cross sections as a function of pion scattering angle extracted at centre of mass kinetic energies, T_{CM}, of 55 and 70 MeV (corresponding to the 403 and 440 MeV beam energies respectively). Partial wave analysis of the data shows that, while the isospin 0 channel dominates the reaction, contributing approximately 75% of the cross section at the energies studied here, there are significant contributions from the s and d-wave pion, isospin 1 channels. Of particular importance is the contribution from the s-wave pion, isospin 1, channel whose interference with the isospin 0 channels produces the characteristic shapes of the cross sections and analyzing powers observed in the data. The d-wave pion, isospin 1 channels, are also required to fully explain the observed analyzing power distributions, and are essential for the T_{CM} = 70MeV data. Comparisons of the pion production data measured in this experiment with pion absorption measurements on ^3He, where the absorption process is pi^-pp(^1S_0) to pn, show a shift in the shape of the differential cross section which can be interpreted as due to differences in

  18. Search for deeply bound pionic states in {sup 208}Pb via radiative atomic capture of negative pions

    Energy Technology Data Exchange (ETDEWEB)

    Raywood, K.J.; Lange, J.B.; Jones, G.; Pavan, M. [Department of Physics, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (CANADA); Sevior, M.E. [School of Physics, University of Melbourne, Parkville Victoria, 3052 (Australia); Hutcheon, D.A.; Olin, A.; Ottewell, D.; Yen, S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (CANADA); Lee, S.J.; Sim, K.S. [Department of Physics, Korea University, Seoul 136-701 (Korea); Altman, A. [Direx Medical Services, P.O. Box 4190, Petah-Tikva, 41920 (Israel); Friedman, E. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Trudel, A. [Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (CANADA)

    1997-05-01

    A search for narrow, deeply bound pionic atom states via atomic radiative capture of negative pions in a target of {sup 208}Pb was carried out for pion kinetic energies of 20 and 25 MeV. Although no clear signature of any such gamma ray emission could be observed in the data, fits of the gamma ray spectra between the energies of 12 and 42 MeV involving a quadratic background together with a pair of peaks (1s, 2p) whose relative intensity was taken from theory yielded an overall strength for the peaks which are consistent (to a 67{percent} confidence level) with radiative capture whose integrated cross section is 20.0 {plus_minus} 10.0 {mu}b/sr at 90{degree} for 20 MeV incident pions. A lower probability (40{percent} confidence level) result was obtained when the fit was carried out without the peaks included, just the continuum background. {copyright} {ital 1997} {ital The American Physical Society}

  19. Neutrino induced pion production at MiniBooNE and K2K energies

    CERN Document Server

    Leitner, T; Mosel, U; Alvarez-Ruso, L

    2009-01-01

    We investigate charged and neutral current neutrino-induced incoherent pion production off nuclei within the GiBUU model at energies relevant for the MiniBooNE and K2K experiments. Special attention is paid to the entanglement between measured CCQE and CC1pi+ cross sections. We further give predictions and compare to recent data measured at MiniBooNE.

  20. Neutrino induced pion production at MiniBooNE and K2K

    CERN Document Server

    Leitner, T; Mosel, U; Alvarez-Ruso, L

    2008-01-01

    We investigate charged and neutral current neutrino induced incoherent pion production off nuclei at MiniBooNE and K2K energies within the GiBUU model. We assume impulse approximation and treat the nucleus as a local Fermi gas of nucleons bound in a mean-field potential. In-medium spectral functions are also taken into account. The outcome of the initial neutrino nucleon reaction undergoes complex hadronic final state interactions. We present results for neutral current pi^0 and charged current pi^+ production and compare to MiniBooNE and K2K data.

  1. Nucleon-nucleon interaction with one-pion exchange and instanton-induced interactions

    Science.gov (United States)

    Vanamali, C. S.; Kumar, K. B. Vijaya

    2016-11-01

    Singlet (S10) and triplet (S31) nucleon-nucleon potentials are obtained in the framework of the SU(2) nonrelativistic quark model using the resonating-group method in the Born-Oppenheimer approximation. The full Hamiltonian used in the investigation includes the kinetic energy, two-body confinement potential, one-gluon-exchange potential (OGEP), one-pion exchange potential (OPEP), and instanton induced interaction (III), which includes the effect of quark exchange between the nucleons. The contribution of the OGEP, III, and OPEP to the nucleon-nucleon adiabatic potential is discussed.

  2. Measurement of Neutron Proton Going to Proton Proton Negative Pion at 443 Mev

    Science.gov (United States)

    Bachman, Mark Gregory

    Experiment E372 at TRIUMF measured the analyzing powers (A_{rm NO}, A_ {rm SO}, A_{rm LO}) and relative differential cross section for the reaction np to pppi ^- at 443 MeV. We directed a polarized neutron beam on to a liquid hydrogen target and measured the scattered events in a large solid angle detector capable of measuring the velocities and directions of all of the protons produced in the reaction as well as many of the pions. Kinematic analysis of the events allowed us to remove almost all background and resulted in a clean set of np to pppi^- events. These events were binned against appropriate kinematic variables to produce yields which correspond to relative differential cross sections, and asymmetries which correspond to A _{rm NO}, A_{rm SO}, and A_{rm LO }. These results are the first of their kind for this energy. Comparisons to a theoretical model of Kloet and Lomon and a preliminary study using partial waves are presented.

  3. Low Energy Positive-Negative Pion Interactions with S-D Shell Nuclei.

    Science.gov (United States)

    Tacik, Roman

    A magnetic spectrometer has been commissioned for use in performing low energy pion scattering experiments. It has been used to measure the differential cross sections for the elastic scattering of 50 MeV (pi)('(+OR-)) from ('12)C, ('18)O, and ('26)Mg targets, as well as the inelastic scattering to the 2(,1)('+) states of these nuclei. The analysis of the elastic scattering data has been performed with an optical potential model. It is found that the (pi)('(+OR-)) elastic cross sections for ('12)C and ('18)O are well described by calculations employ - ing a global parameter set('1), which has been previously shown to reproduce (pi)('(+OR-)) elastic scattering data for a range of nuclei. The (pi)('(+OR-)) elastic data for ('26)Mg require a variation of the p-wave potential parameters. A similar requirement is seen with (pi)('(+OR -)) - ('32)S elastic data('2). Distorted wave calculations, inputting separate neutron and pro- ton transition densities, have been performed for the analysis of the inelastic data. These calculations demonstrate a strong sensitivity of (pi)('(+OR-)) to protons, and (pi)('-) to neutrons, present in the nucleus. By varying the strengths of the neutron and proton transition densities, in order to reproduce the (pi)('(+OR -)) inelastic cross sections, it is possible to determine the ratio of neutron to proton matrix elements (M(,n)/M(,p)) for the given 2('+) states. It is shown that the value of M(,n)/M(,p) obtained in this way is independent of the optical potential param- eters used in the calculation. The extracted values of M(,n)/M(,p) are: 0.97 (+OR-) 0.08, 1.81 (+OR-) 0.15, and 0.90 (+OR-) 0.07 for ('12)C, ('18)O, and ('26)Mg. respectively. These values are in agreement with those obtained by other means. ('1)J. A. Carr et. al., Phys Rev C25 (82) 952. ('2)R. J. Sobie, PhD Thesis, University of Toronto, 1984.

  4. Pion-induced production of the $Z_c(3900)$ off nuclear target

    CERN Document Server

    Huang, Yin; Liu, Xiang; Zhang, Hong Fei; Xie, Ju Jun; Chen, Xu Rong

    2015-01-01

    We investigate the possibility to study the charmonium-like state $Z_c(3900)$ through the pion-induced production off nuclear target. By using high-energy pion beam, the $Z_c(3900)$ can be produced off proton or nucleus though the Primakoff effect. The production amplitude is calculated in an effective Lagrangian approach combined with the vector dominance model. The total cross sections of the $p(\\pi^-, Z^-_c(3900))$ and $p(\\pi^-, Z^-_c(3900)\\to J/\\psi\\pi^-)$ reactions are calculated, which order of magnitude is about 0.1 and 0.01nb, respectively, with an assumption of branch ratio 10\\% for the $Z_c(3900)$ decay in $J/\\psi\\pi$ channel. If proton target is replaced by nuclear target, the production of the $Z_c(3900)$ enhances obviously. The predicted total cross sections for the $A(\\pi^-, Z^-_c(3900))$ and $A(\\pi^-, Z^-_c(3900)\\to J/\\psi\\pi^-)$ reactions with $A=^{12}$C or $^{208}$Pb are on the order of magnitude of 100 and 10 nb, respectively, which is about one thousand times larger than the cross sections ...

  5. Neutrino induced pion production and nucleon knockout within the GiBUU transport model

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, T.; Mosel, U. [Inst. fuer Theoretische Physik, Univ. Giessen (Germany); Alvarez-Ruso, L. [Univ. de Valencia (Spain)

    2007-07-01

    There is an extensive experimental effort aiming at the precise determination of neutrino oscillation parameters. Its success depends critically on a good knowledge of neutrino-nucleus interactions in order to minimize the systematic uncertainties in neutrino fluxes, backgrounds and detector responses. We describe such charged and neutral current neutrino-nucleus interactions at intermediate neutrino energies within the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) coupled-channel transport model. We account for in-medium effects such as Fermi motion, Pauli blocking, nuclear binding, and final-state interactions which allows us to study exclusive channels as pion production and nucleon knockout. We find that final-state interactions modify considerably the distributions through rescattering, charge-exchange and absorption. Side-feeding induced by charge-exchange scattering is important in both cases. In the case of pions, there is a strong absorption associated with the in-medium pionless decay modes of the Delta, while nucleon knockout exhibits a considerable enhancement of low energy nucleons due to rescattering. At neutrino energies above 1 GeV, we also obtain that the contribution to nucleon knockout from Delta excitation is comparable to that from quasielastic scattering. (orig.)

  6. $K^0 \\Lambda$ and $D^- \\Lambda_c^+$ production induced by pion beams off the nucleon

    CERN Document Server

    Kim, Sang-Ho; Hosaka, Atsushi

    2016-01-01

    We present a comparative study of the pion induced production of $K^0 \\Lambda$ and $D^- \\Lambda_c^+$ off the nucleon. A hybrid framework is utilized by combining an effective Lagrangian method with a Regge approach. We consider the $t$-channel process in a plannar diagram by vector-meson Reggeon exchanges and the $u$-channel one in a non-planar diagram by baryon Reggeon exchanges. The present model reproduces the $K^0 \\Lambda$ production data well with a few parameters. Having fixed them, we predict the $D^- \\Lambda_c^+$ production, which turns out to be about $10^4-10^6$ times smaller than the strangeness one, depending on the kinematical regions.

  7. Comparison between high-energy proton and charged pion induced damage in Lead Tungstate calorimeter crystals

    CERN Document Server

    Lecomte, P; Nessi-Tedaldi, F; Pauss, F; Renker, D

    2007-01-01

    A Lead Tungstate crystal produced for the electromagnetic calorimeter of the CMS experiment at the LHC was cut into three equal-length sections. The central one was irradiated with 290 MeV/c positive pions up to a fluence of (5.67 +- 0.46)x10^13 /cm^2, while the other two were exposed to a 24 GeV/c proton fluence of (1.17 +- 0.11) x 10^13/ cm^2. The damage recovery in these crystals, stored in the dark at room temperature, has been followed over two years. The comparison of the radiation-induced changes in light transmission for these crystals shows that damage is proportional to the star densities produced by the irradiation.

  8. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Colin E. [Yale Univ., New Haven, CT (United States)

    2011-05-01

    Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for νμ → νe oscillation - a channel that may yield insight into the vanishingly small mixing parameter θ13, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single π0 (NC 1π0) production. Unfortunately, the available data concerning NC 1π0 production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1π0 production yield substantially differing predictions in the critical Eν ~ 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data (~ 106 neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1π0 production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1π0 cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the

  9. Studying ρ-N couplings with HADES in pion-induced reactions

    Science.gov (United States)

    Scozzi, Federico

    2016-11-01

    The High-Acceptance Di-Electron Spectrometer (HADES) operates at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt with pion, proton and heavyion beams provided by the synchrotron SIS18. In summer 2014, HADES took data using a pion beam on carbon and polyethylene targets. A large part of the data was taken at a pion beam momentum of 0.69 GeV/c in order to explore di-pion and di-electron production in the second resonance region and the sub-threshold coupling of the ρ to baryonic resonances. In this contribution lepton identification will be discussed as well the purity of reconstructed e+e-. Finally we will show the preliminary di-electon raw spectra.

  10. A Measurement of Neutrino-Induced Charged-Current Neutral Pion Production

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Robert H. [Univ. of Colorado, Boulder, CO (United States)

    2010-01-01

    This work presents the first comprehensive measurement of neutrino-induced charged-current neutral pion production (CCπ0) off a nuclear target. The Mini Booster Neutrino Experiment (MiniBooNE) and Booster Neutrino Beam (BNB) are discussed in detail. MiniBooNE is a high-statistics (~ 1, 000, 000 interactions) low-energy (Evϵ 2 0.5 - 2.0 GeV) neutrino experiment located at Fermilab. The method for selecting and reconstructing CCπ0 events is presented. The π0 and μ- are fully reconstructed in the final state allowing for the measurement of, among other things, the neutrino energy. The total observable CCπ0 cross-section is presented as a function of neutrino energy, along with five differential cross-sections in terms of the final state kinematics and Q2. The results are combined to yield a flux-averaged total cross-section of <σ>Φ = (9.2 ± 0.3stat. ± 1.5syst.) × 10-39 cm2/CH2 at energy 965 MeV. These measurements will aid future neutrino experiments with the prediction of their neutrino interaction rates.

  11. Pion induced double charge exchange reactions in the Delta resonance region

    CERN Document Server

    Buss, O; Larionov, A B; Mosel, U

    2006-01-01

    We have applied the Giessen BUU (GiBUU) transport model to the description of the double charge exchange (DCX) reaction of pions with different nuclear targets at incident kinetic energies of 120-180 MeV . The DCX process is highly sensitive to details of the interactions of pions with the nuclear medium and, therefore, represents a major benchmark for any model of pion scattering off nuclei at low and intermediate energies. The impact of surface effects, such as the neutron skins of heavy nuclei, is investigated. The dependence of the total cross section on the nuclear mass number is also discussed. We achieve a good quantitative agreement with the extensive data set obtained at LAMPF. Furthermore, we compare the solutions of the transport equations obtained in the test-particle ansatz using two different schemes - the full and the parallel ensemble method.

  12. INVESTIGATION OF PION ABSORPTION IN HEAVY-ION INDUCED SUBTHRESHOLD-PI-0 PRODUCTION

    NARCIS (Netherlands)

    MAYER, RS; HENNING, W; HOLZMANN, R; SIMON, RS; DELAGRANGE, H; LEFEVRE, F; MATULEWICZ, T; MERROUCH, R; MITTIG, W; OSTENDORF, RW; SCHUTZ, Y; BERG, FD; KUHN, W; METAG, [No Value; NOVOTNY, R; PFEIFFER, M; BOONSTRA, AL; Löhner, H.; VENEMA, LB; WILSCHUT, HW; ARDOUIN, D; DABROWSKI, H; ERAZMUS, B; LEBRUN, C; SEZAC, L; BALLESTER, F; CASAL, E; DIAZ, J; FERRERO, JL; MARQUES, M; MARTINEZ, G; NIFENECKER, H; FORNAL, B; FRIENDL, L; SUJKOWSKI, Z

    1993-01-01

    We present results from an experimental study of reabsorption effects in subthreshold pi0 production in the reaction Xe-129 + Au-197 at 44 MeV/nucleon. Within the picture of pion generation in nucleon-nucleon scattering we deduce, from our data and from a comparison with the systematics of productio

  13. Dynamical Model of Weak Pion Production Reactions

    CERN Document Server

    Sato, T; Lee, T S H

    2003-01-01

    The dynamical model of pion electroproduction has been extended to investigate the weak pion production reactions. The predicted cross sections of neutrino-induced pion production reactions are in good agreement with the existing data. We show that the renormalized(dressed) axial N-$\\Delta$ form factor contains large dynamical pion cloud effects and this renormalization effects are crucial in getting agreement with the data. We conclude that the N-$\\Delta$ transitions predicted by the constituent quark model are consistent with the existing neutrino induced pion production data in the $\\Delta$ region.

  14. Pion rescattering in two-pion decay of heavy quarkonia

    CERN Document Server

    Lähde, T A

    2002-01-01

    The role of pion rescattering in pi pi decay of radially excited heavy quarkonia modeled in terms of a Q pi pi coupling, is investigated within the framework of the covariant Blankenbecler-Sugar equation. The effects of pion rescattering (or pion exchange) are shown to be large, unless the coupling of the two-pion system to the heavy quarks is mediated by a fairly light scalar sigma meson, which couples to the gradients of the pion fields. The Hamiltonian model for the quarkonium states is formed of linear scalar confining, screened one-gluon exchange and instanton induced interaction terms. The widths and energy distributions of the basic decays psi'->J/psi pi pi and UPSILON'-> UPSILON pi pi are shown to be satisfactorily described by this model. The implications of this model for the decays of the UPSILON(3S) state are discussed.

  15. Exclusive measurements of pion nucleon going to pion pion nucleon

    Science.gov (United States)

    Kermani, Mohammad Arjomand

    The pion induced pion production reactions π±p/toπ±π+n were studied at projectile incident energies of 223, 243, 264, 284, and 305 MeV. The Canadian High Acceptance Orbit Spectrometer (CHAOS) was used to detected the charged particles, which originated from the interaction of the incident pion beam with a cryogenic liquid hydrogen target. The experimental results are presented in the form of single, double and triple differential cross sections. Total cross sections obtained by integrating the differential quantities are also reported. The experimental data, namely the π-p/toπ-π+n double differential cross sections, were used as input to the Chew-Low extrapolation procedure which was utilized to determine on-shell π+π- elastic scattering cross sections in the near threshold region. The Chew-Low results (the extrapolated πpi cross sections) were then used in a dispersion analysis (Roy equations) to obtain the πpi isospin zero S-wave scattering length. We find a00=0.209/pm 0.011μ-1. In addition, the invariant mass distributions from the (π+π-) channel were fitted to determine the model parameters for the extended model of Oset and Vicente-Vacas. We find that the model parameters obtained from fitting the (π+π-) data do not describe the invariant mass distributions in the (π+π+) channel.

  16. Neutrino induced pion production at MiniBooNE and K2K within the GiBUU model

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Tina; Buss, Oliver; Mosel, Ulrich [Institut fuer Theoretische Physik, Universitaet Giessen (Germany); Alvarez Ruso, Luis [Universidad de Murcia (Spain)

    2009-07-01

    The interest in neutrino nucleus reactions is driven by the discovery of neutrino oscillations where one now aims at a precise determination of neutrino oscillation parameters. This demands for an equally precise knowledge of the neutrino nucleus interaction process. Neutrino induced pion production is strongly influenced by nuclear effects. Their understanding is crucial since neutral current {pi}{sup 0} production is a major background in {nu}{sub e} appearance experiments, while charged current {pi}{sup +} production introduces a background to {nu}{sub {mu}} disappearance searches. We have investigated both, charged and neutral current neutrino induced pion production off nuclei, at MiniBooNE and K2K energies within the GiBUU transport model. Assuming impulse approximation, we treat the nucleus as a local Fermi gas of nucleons bound in a density and momentum potential. The outcome of the initial neutrino nucleon reaction undergoes complex hadronic final state interactions where in-medium spectral functions of the particles are taken into account. We present results for neutral current {pi}{sup 0} and charged current {pi}{sup +} production and compare to first MiniBooNE and K2K data.

  17. Triangular flow of negative pions emitted in PbAu collisions at $\\sqrt{s_{NN}} $= 17.3~GeV

    CERN Document Server

    Adamová, D.

    Differential triangular flow, $v_3(p_T)$, of negative pions is measured at $\\sqrt{s_{NN}}$= 17.3~GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30\\% with a mean centrality of 5.5\\%. This is the first measurement of the triangular flow at SPS energies. The $p_T$ range extends from about 0.05~GeV/c to more than 2~GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydro calculation combined with an UrQMD cascade model for the late stages.

  18. Neutral current coherent pion production

    CERN Document Server

    Alvarez-Ruso, L; Vacas, M J Vicente

    2007-01-01

    We investigate the neutrino induced coherent pion production reaction at low and intermediate energies. The model includes pion, nucleon and Delta(1232) resonance as the relevant hadronic degrees of freedom. Nuclear medium effects on the production mechanisms and pion distortion are taken into account. We obtain that the dominance of the Delta excitation holds due to large cancellations among the background contributions. We consider two sets of vector and axial-vector N-Delta transition form-factors, evidencing the strong sensitivity of the results to the axial coupling C5A(0). The differences between neutrino and antineutrino cross sections, emerging from interference terms, are also discussed.

  19. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    S K Singh; M Sajjad Athar; Shakeb Ahmad

    2006-04-01

    The charged current pion production induced by neutrinos in 12C, 16O and 56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of in the nuclear medium. The pion absorption effects have also been taken into account.

  20. Eta photoproduction in a combined analysis of pion- and photon-induced reactions

    CERN Document Server

    Rönchen, D; Haberzettl, H; Haidenbauer, J; Meißner, U -G; Nakayama, K

    2015-01-01

    The $\\eta N$ final state is isospin-selective and thus provides access to the spectrum of excited nucleons without being affected by excited $\\Delta$ states. To this end, the world database on eta photoproduction off the proton up to $E\\sim 2.3$~GeV is analyzed, including data on differential cross sections, and single and double polarization observables. The resonance spectrum and its properties are determined in a combined analysis of eta and pion photoproduction off the proton together with the reactions $\\pi N\\to \\pi N$, $\\eta N$, $K\\Lambda$ and $K\\Sigma$. For the analysis, the so-called J\\"ulich coupled-channel framework is used, incorporating unitarity, analyticity, and effective three-body channels. Parameters tied to photoproduction and hadronic interactions are varied simultaneously. The influence of recent MAMI $T$ and $F$ asymmetry data in eta photoproduction is discussed in detail.

  1. Measurement of negatively charged pion spectra in inelastic p+p interactions at p{sub lab} = 20, 31, 40, 80 and 158 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, N.; Blondel, A.; Bravar, A.; Debieux, S.; Haesler, A.; Korzenev, A.; Murphy, S.; Ravonel, M. [University of Geneva, Geneva (Switzerland); Aduszkiewicz, A.; Dominik, W.; Kielczewska, D.; Kirejczyk, M.; Matulewicz, T.; Posiadala, M.; Skrzypczak, E. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Ali, Y.; Brzychczyk, J.; Majka, Z.; Marcinek, A.; Planeta, R.; Staszel, P.; Wyszynski, O. [Jagiellonian University, Cracow (Poland); Anticic, T.; Kadija, K.; Susa, T. [Rudjer Boskovic Institute, Zagreb (Croatia); Antoniou, N.; Christakoglou, P.; Davis, N.; Diakonos, F.; Kapoyannis, A.; Panagiotou, A.D.; Vassiliou, M. [University of Athens, Athens (Greece); Baatar, B.; Bunyatov, S.A.; Kolesnikov, V.I.; Krasnoperov, A.; Lyubushkin, V.V.; Malakhov, A.I.; Melkumov, G.L.; Tereshchenko, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Bay, F.; Luise, S.Di; Rubbia, A.; Sgalaberna, D. [ETH, Zurich (Switzerland); Blumer, J.; Dembinski, H.; Engel, R.; Mathes, H.J.; Roth, M.; Szuba, M.; Ulrich, R.; Unger, M. [Karlsruhe Institute of Technology, Karlsruhe (Germany); Bogomilov, M.; Kolev, D.; Tsenov, R. [University of Sofia, Faculty of Physics, Sofia (Bulgaria); Busygina, O.; Golubeva, M.; Guber, F.; Ivashkin, A.; Kurepin, A.; Marin, V.; Petukhov, O.; Sadovsky, A. [Institute for Nuclear Research, Moscow (Russian Federation); Czopowicz, T.; Dynowski, K.; Grebieszkow, K.; Maksiak, B.; Peryt, W.; Pluta, J.; Slodkowski, M. [Warsaw University of Technology, Warsaw (Poland); Drozhzhova, T.; Feofilov, G.A.; Igolkin, S.; Kondratiev, V.P.; Vechernin, V.V.; Vinogradov, L. [St. Petersburg State University, St. Petersburg (Russian Federation); Dumarchez, J.; Robert, A.; Zambelli, L. [LPNHE, University of Paris VI and VII, Paris (France); Ereditato, A.; Hierholzer, M.; Nirkko, M.; Pistillo, C.; Redij, A. [University of Bern, Bern (Switzerland); Fodor, Z.; Fulop, A.; Kiss, T.; Laszlo, A.; Marton, K.; Palla, G.; Sipos, R.; Tolyhi, T.; Vesztergombi, G. [KFKI Research Institute for Particle and Nuclear Physics, Budapest (Hungary); Gazdzicki, M. [Jan Kochanowski University in Kielce, Kielce (Poland); University of Frankfurt, Frankfurt (Germany); Grzeszczuk, A.; Kaptur, E.; Kisiel, J.; Kowalski, S.; Larsen, D.; Pulawski, S.; Schmidt, K.; Wilczek, A.; Zipper, W. [University of Silesia, Katowice (Poland); Hasegawa, T.; Kobayashi, T.; Nakadaira, T.; Nishikawa, K.; Sakashita, K.; Sekiguchi, T.; Shibata, M.; Tada, M. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Idczak, R.; Kovesarki, P.; Turko, L. [University of Wroclaw, Wroclaw (Poland); Jokovic, D.; Manic, D.; Puzovic, J.; Savic, M. [University of Belgrade, Belgrade (Serbia); Kleinfelder, S. [University of California, Irvine (United States); Mackowiak-Pawlowska, M.; Renfordt, R.; Rustamov, A.; Stroebele, H. [University of Frankfurt, Frankfurt (Germany); Matveev, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Mrowczynski, S.; Rybczynski, M.; Seyboth, P.; Stefanek, G.; Wlodarczyk, Z.; Wojtaszek-Szwarc, A. [Jan Kochanowski University in Kielce, Kielce (Poland); Palczewski, T.; Rondio, E.; Stepaniak, J. [National Centre for Nuclear Research, Warsaw (Poland); Paul, T.; Veberic, D. [University Nova Gorica, Laboratory of Astroparticle Physics, Nova Gorica (Slovenia); Popov, B.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); LPNHE, University of Paris VI and VII, Paris (France); Rauch, W. [Fachhochschule Frankfurt, Frankfurt (Germany); Roehrich, D. [University of Bergen, Bergen (Norway); Collaboration: NA61/SHINE Collaboration

    2014-03-15

    We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c (√(s) = 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus-nucleus and proton-nucleus collisions. (orig.)

  2. Measurement of negatively charged pion spectra in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c

    Science.gov (United States)

    Abgrall, N.; Aduszkiewicz, A.; Ali, Y.; Anticic, T.; Antoniou, N.; Baatar, B.; Bay, F.; Blondel, A.; Blumer, J.; Bogomilov, M.; Bravar, A.; Brzychczyk, J.; Bunyatov, S. A.; Busygina, O.; Christakoglou, P.; Czopowicz, T.; Davis, N.; Debieux, S.; Dembinski, H.; Diakonos, F.; Luise, S. Di; Dominik, W.; Drozhzhova, T.; Dumarchez, J.; Dynowski, K.; Engel, R.; Ereditato, A.; Feofilov, G. A.; Fodor, Z.; Fulop, A.; Gaździcki, M.; Golubeva, M.; Grebieszkow, K.; Grzeszczuk, A.; Guber, F.; Haesler, A.; Hasegawa, T.; Hierholzer, M.; Idczak, R.; Igolkin, S.; Ivashkin, A.; Joković, D.; Kadija, K.; Kapoyannis, A.; Kaptur, E.; Kiełczewska, D.; Kirejczyk, M.; Kisiel, J.; Kiss, T.; Kleinfelder, S.; Kobayashi, T.; Kolesnikov, V. I.; Kolev, D.; Kondratiev, V. P.; Korzenev, A.; Kovesarki, P.; Kowalski, S.; Krasnoperov, A.; Kurepin, A.; Larsen, D.; László, A.; Lyubushkin, V. V.; Maćkowiak-Pawłowska, M.; Majka, Z.; Maksiak, B.; Malakhov, A. I.; Manić, D.; Marcinek, A.; Marin, V.; Marton, K.; Mathes, H.-J.; Matulewicz, T.; Matveev, V.; Melkumov, G. L.; Mrówczyński, St.; Murphy, S.; Nakadaira, T.; Nirkko, M.; Nishikawa, K.; Palczewski, T.; Palla, G.; Panagiotou, A. D.; Paul, T.; Pistillo, C.; Peryt, W.; Petukhov, O.; Płaneta, R.; Pluta, J.; Popov, B. A.; Posiadała, M.; Puławski, S.; Puzović, J.; Rauch, W.; Ravonel, M.; Redij, A.; Renfordt, R.; Robert, A.; Röhrich, D.; Rondio, E.; Roth, M.; Rubbia, A.; Rustamov, A.; Rybczyński, M.; Sadovsky, A.; Sakashita, K.; Savić, M.; Schmidt, K.; Sekiguchi, T.; Seyboth, P.; Sgalaberna, D.; Shibata, M.; Sipos, R.; Skrzypczak, E.; Słodkowski, M.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Ströbele, H.; Šuša, T.; Szuba, M.; Tada, M.; Tereshchenko, V.; Tolyhi, T.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Vassiliou, M.; Veberič, D.; Vechernin, V. V.; Vesztergombi, G.; Vinogradov, L.; Wilczek, A.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.; Wyszyński, O.; Zambelli, L.; Zipper, W.

    2014-03-01

    We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/ c ( 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus-nucleus and proton-nucleus collisions.

  3. Measurement of negatively charged pion spectra in inelastic p+p interactions at $p_{lab}$ = 20, 31, 40, 80 and 158 GeV/c

    CERN Document Server

    Abgrall, N; Ali, Y; Anticic, T; Antoniou, N; Baatar, B; Bay, F; Blondel, A; Blumer, J; Bogomilov, M; Bravar, A; Brzychczyk, J; Bunyatov, S A; Busygina, O; Christakoglou, P; Czopowicz, T; Davis, N; Debieux, S; Dembinski, H; Diakonos, F; Di Luise, S; Dominik, W; Drozhzhova, T; Dumarchez, J; Dynowski, K; Engel, R; Ereditato, A; Feofilov, G A; Fodor, Z; Fulop, A; Gazdzicki, M; Golubeva, M; Grebieszkow, K; Grzeszczuk, A; Guber, F; Haesler, A; Hasegawa, T; Hierholzer, M; Idczak, R; Igolkin, S; Ivashkin, A; Jokovic, D; Kadija, K; Kapoyannis, A; Katrynska, N; Kaptur, E; Kielczewska, D; Kirejczyk, M; Kisiel, J; Kiss, T; Kleinfelder, S; Kobayashi, T; Kolesnikov, V I; Kolev, D; Kondratiev, V P; Korzenev, A; Kovesarki, P; Kowalski, S; Krasnoperov, A; Kurepin, A; Larsen, D; Laszlo, A; Lyubushkin, V V; Mackowiak-Pawlowska, M; Majka, Z; Maksiak, B; Malakhov, A I; Manic, D; Marcinek, A; Marin, V; Marton, K; Mathes, H J; Matulewicz, T; Matveev, V; Melkumov, G.L; Mrowczynski, St; Murphy, S; Nakadaira, T; Nirkko, M; Nishikawa, K; Palczewski, T; Palla, G; Panagiotou, A D; Paul, T; Pistillo, C; Peryt, W; Petukhov, O; Planeta, R; Pluta, J; Popov, B A; Posiadala, M; Pulawski, S; Puzovic, J; Rauch, W; Ravonel, M; Redij, A; Renfordt, R; Robert, A; Rohrich, D; Rondio, E; Roth, M; Rubbia, A; Rustamov, A; Rybczynski, M; Sadovsky, A; Sakashita, K; Savic, M; Schmidt, K; Sekiguchi, T; Seyboth, P; Sgalaberna, D; Shibata, M; Sipos, R; Skrzypczak, E; Slodkowski, M; Staszel, P; Stefanek, G; Stepaniak, J; Strobele, H; Susa, T; Szuba, M; Tada, M; Tereshchenko, V; Tolyhi, T; Tsenov, R; Turko, L; Ulrich, R; Unger, M; Vassiliou, M; Veberic, D; Vechernin, V V; Vesztergombi, G; Vinogradov, L; Wilczek, A; Wlodarczyk, Z; Wojtaszek-Szwarc, A; Wyszynski, O; Zambelli, L; Zipper, W

    2014-01-01

    We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158GeV/c ($\\sqrt{s}$ = 6.3, 7.7, 8.8, 12.3 and 17.3GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly inter...

  4. Triangular flow of negative pions emitted in PbAu collisions at √{sNN} = 17.3 GeV

    Science.gov (United States)

    Adamová, D.; Agakichiev, G.; Andronic, A.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Hering, G.; Holeczek, J.; Kalisky, M.; Karpenko, Iu.; Krobath, G.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Miśkowiec, D.; Panebrattsev, Y.; Petchenova, O.; Petráček, V.; Radomski, S.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Schuchmann, S.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Tsiledakis, G.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Yurevich, S.; Yurevich, V.

    2017-01-01

    Differential triangular flow, v3 (pT), of negative pions is measured at √{sNN} = 17.3 GeV around midrapidity by the CERES/NA45 experiment at CERN in central PbAu collisions in the range 0-30% with a mean centrality of 5.5%. This is the first measurement as a function of transverse momentum of the triangular flow at SPS energies. The pT range extends from about 0.05 GeV/c to more than 2 GeV/c. The triangular flow magnitude, corrected for the HBT effects, is smaller by a factor of about 2 than the one measured by the PHENIX experiment at RHIC and the ALICE experiment at the LHC. Within the analyzed range of central collisions no significant centrality dependence is observed. The data are found to be well described by a viscous hydrodynamic calculation combined with an UrQMD cascade model for the late stages.

  5. Coherent Pions From Neutrino Scattering Off Nuclei

    CERN Document Server

    Valverde, M; Hernandez, E; Nieves, J; Vacas, M J Vicente

    2010-01-01

    We describe a model for pion production off nucleons and coherent pions from nuclei induced by neutrinos in the 1 GeV energy regime. Besides the dominant Delta pole contribution, it takes into account the effect of background terms required by chiral symmetry. Moreover, the model uses a reduced nucleon-to-Delta resonance axial coupling, which leads to coherent pion production cross sections around a factor two smaller than most of the previous theoretical estimates. Nuclear effects like medium corrections on the Delta propagator and final pion distortion are included.

  6. Coherent pion production in neutrino-nucleus collisions

    CERN Document Server

    Alvarez-Ruso, L; Hirenzaki, S; Vacas, M J Vicente

    2007-01-01

    We have investigated the neutrino induced coherent pion production reaction at low and intermediate energies including pion, nucleon and Delta(1232) resonance. Medium effects in the production mechanism and the distortion of the pion wave function are included in the calculation. We find a strong reduction of the cross section due to these effects and also substantial modifications in the energy distributions of the final pion. The dependence on the atomic number is discussed.

  7. Neutrino-induced pion production at low energies and in the small $Q^2$ region

    CERN Document Server

    Paschos, E A

    2012-01-01

    We analyse neutrino-induced reactions in the small $Q^2$ region and for energies covering the production and decay of the delta resonance. One of our results is the agreement with the MiniBooNE data for $1\\pi^+$ and $1\\pi^0$ final states. In addition we present differential cross sections for charged and neutral currents and for proton and neutron targets. Finally, we present cross sections induced by muon and electron type neutrinos, where effects of the lepton masses are visible.

  8. Chiral pions in a magnetic background

    Energy Technology Data Exchange (ETDEWEB)

    Colucci, G., E-mail: colucci@th.physik.uni-frankfurt.de [Institute for Theoretical Physics, J.W. Goethe-University, D-60438 Frankfurt am Main (Germany); Fraga, E.S., E-mail: fraga@if.ufrj.br [Institute for Theoretical Physics, J.W. Goethe-University, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main (Germany); Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21945-970 (Brazil); Sedrakian, A., E-mail: sedrakian@th.physik.uni-frankfurt.de [Institute for Theoretical Physics, J.W. Goethe-University, D-60438 Frankfurt am Main (Germany)

    2014-01-20

    We investigate the modification of the pion self-energy at finite temperature due to its interaction with a low-density, isospin-symmetric nuclear medium embedded in a constant magnetic background. To one loop, for fixed temperature and density, we find that the pion effective mass increases with the magnetic field. For the π{sup −}, interestingly, this happens solely due to the trivial Landau quantization shift ∼|eB|, since the real part of the self-energy is negative in this case. In a scenario in which other charged particle species are present and undergo an analogous trivial shift, the relevant behavior of the effective mass might be determined essentially by the real part of the self-energy. In this case, we find that the pion mass decreases by ∼10% for a magnetic field |eB|∼m{sub π}{sup 2}, which favors pion condensation at high density and low temperatures.

  9. Chiral pions in a magnetic background

    CERN Document Server

    Colucci, Giuseppe; Sedrakian, Armen

    2013-01-01

    We investigate the modification of the pion self-energy at finite temperature due to its interaction with a low-density, isospin-symmetric nuclear medium embedded in a constant magnetic background. To one loop, for fixed temperature and density, we find that the pion effective mass increases with the magnetic field. For the $\\pi^{-}$, interestingly, this happens solely due to the trivial Landau quantization shift $\\sim |eB|$, since the real part of the self-energy is negative in this case. In a scenario in which other charged particle species are present and undergo an analogous trivial shift, the relevant behavior of the effective mass might be determined essentially by the real part of the self-energy. In this case, we find that the pion mass decreases by $\\sim 10%$ for a magnetic field $|eB|\\sim m_\\pi^2$, which favors pion condensation at high density and low temperatures.

  10. Chiral pions in a magnetic background

    Science.gov (United States)

    Colucci, G.; Fraga, E. S.; Sedrakian, A.

    2014-01-01

    We investigate the modification of the pion self-energy at finite temperature due to its interaction with a low-density, isospin-symmetric nuclear medium embedded in a constant magnetic background. To one loop, for fixed temperature and density, we find that the pion effective mass increases with the magnetic field. For the π-, interestingly, this happens solely due to the trivial Landau quantization shift ∼|eB|, since the real part of the self-energy is negative in this case. In a scenario in which other charged particle species are present and undergo an analogous trivial shift, the relevant behavior of the effective mass might be determined essentially by the real part of the self-energy. In this case, we find that the pion mass decreases by ∼10% for a magnetic field |eB|∼mπ2, which favors pion condensation at high density and low temperatures.

  11. Dependence of Nucleon and Pion-Induced Fission Cross Sections on the Level Density Parameter in the Cascade-Exciton Model

    Institute of Scientific and Technical Information of China (English)

    Zafar Yasin

    2009-01-01

    A new method is used to compute the fission cross sections in which a change of the ratio of the level density parameter in fission to neutron emission channels is taken into account with the change of the incident energy of the projectile.It is shown that fission cross sections induced by nucleons and pions depend on the ratio of the level density parameter in the fission and evaporation modes,i.e.αf/αn,respectively.We are unable to describe well the cross sections for fission without using this new method.The computed values exhibit reasonable agreement with the experimental data found in the literature across a wide range of beam energies.

  12. Pion in a Box

    CERN Document Server

    Bietenholz, W; Horsley, R; Nakamura, Y; Pleiter, D; Rakow, P E L; Schierholz, G; Zanotti, J M

    2010-01-01

    The residual mass of the pion in a finite spatial box at vanishing quark masses is computed with two flavors of dynamical clover fermions. The result is compared with predictions of chiral perturbation theory in the delta regime.

  13. Discrepancy and Disliking Do Not Induce Negative Opinion Shifts

    National Research Council Canada - National Science Library

    Takács, Károly; Flache, Andreas; Mäs, Michael

    2016-01-01

    .... Results confirm that similarities induce attraction, but results do not support that discrepancy or disliking entails negative influence. Instead, our findings suggest a robust positive linear relationship between opinion distance and opinion shifts.

  14. Discrepancy and Disliking Do Not Induce Negative Opinion Shifts

    NARCIS (Netherlands)

    Takács, Károly; Flache, Andreas; Maes, Michael

    2016-01-01

    Both classical social psychological theories and recent formal models of opinion differentiation and bi-polarization assign a prominent role to negative social influence. Negative influence is defined as shifts away from the opinion of others and hypothesized to be induced by discrepancy with or

  15. Discrepancy and Disliking Do Not Induce Negative Opinion Shifts

    NARCIS (Netherlands)

    Takacs, Karoly; Flache, Andreas; Maes, Michael

    2016-01-01

    Both classical social psychological theories and recent formal models of opinion differentiation and bi-polarization assign a prominent role to negative social influence. Negative influence is defined as shifts away from the opinion of others and hypothesized to be induced by discrepancy with or dis

  16. Negative Refraction Induced by M\\"{o}bius Topology

    CERN Document Server

    Fang, Y N; Ai, Qing; Sun, C P

    2015-01-01

    We theoretically show the negative refraction existing in M\\"{o}bius molecules. The negative refractive index is induced by the non-trivial topology of the molecules. With the M\\"{o}bius boundary condition, the effective electromagnetic fields felt by the electron in a M\\"{o}bius ring is spatially inhomogeneous. In this regard, the $D_{N}$ symmetry is broken in M\\"{o}bius molecules and thus the magnetic response is induced through the effective magnetic field. Our findings open up a new architecture for negative refractive index materials based on the non-trivial topology of M\\"{o}bius molecules.

  17. Metastable Pions in Dense Media

    CERN Document Server

    Loewe, Marcelo; Villavicencio, Cristian

    2016-01-01

    We study the leptonic decay of charged pions in a compact star environment. Considering leptons as a degenerated Fermi system, pions are tightly constrained to decay into these particles because their Fermi levels are occupied. Thus, pion decay is only possible through thermal fluctuations. Under these circumstances, pion life-time is larger and hence can be considered to reach a metastable state. We explore restrictions under which such a metastability is possible. We also study conditions for pion-lepton chemical equilibrium and obtain the neutrino emissivity from metastable pions. Scenarios which favor this metastable state are protoneutron stars.

  18. Pions in the nuclear medium

    CERN Document Server

    de Melo, J P B C; El-Bennich, Bruno; Rojas, E; Frederico, T

    2014-01-01

    Using the light-front pion wave function based on a Bethe-Salpeter amplitude model, we study the properties of the pion in symmetric nuclear matter. The pion model we adopt is well constrained by previous studies to explain the pion properties in vacuum. In order to consistently incorporate the constituent up and down quarks of the pion immersed in symmetric nuclear matter, we use the quark-meson coupling model, which has been widely applied to various hadronic and nuclear phenomena in a nuclear medium with success. We predict the in-medium modifications of the pion lectromagnetic form factor, charge radius and weak decay constant in symmetric nuclear matter.

  19. Experimental Investigation of Proton Induced Thermal Shocks and Magnetohydrodynamic Effects in Molten Metal Pion Production Targets for a Neutrino Factory

    CERN Document Server

    Schaffarzick, D

    2001-01-01

    Neutrinos are one of the basic subatomic particles among electrons, protons and many more, which build all matter. Neutrinos appear in three different types. Sources of neutrinos are the sun and nuclear power plants. But the type of neutrinos created there is not exactly known and the type changes between their creation to their detection, so only assumptions can be made. This change of type is called “neutrino oscillation”. In order to enable the nuclear physisists to find out more about the neutrinos and the neutrino oscillation, a neutrino factory will be built which will produce a high intensity neutrino beam with exactly known parameters like number of particles and type of neutrinos. This neutrino beam can then be used to investigate the properties of the neutrinos at near and far detectors. In cooperation with other laboratories CERN has started a study of some of the many technological challenges of a neutrino factory. A major issue of the facility is the pion production target where p...

  20. Electron and pion scattering off nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Buss, O.; Mosel, U. [Inst. fuer Theoretische Physik, Univ. Giessen (Germany); Alvarez-Ruso, L. [Dept. de Fisica Teorica and IFIC, Centro Mixto Univ. de Valencia-CSIC (Spain)

    2007-07-01

    We present a treatment of pion and electron scattering off nuclei within the framework of a Boltzmann-Uehling-Uhlenbeck (BUU) transport model. In this approach we realize a full coupled channel treatment and include medium modifications such as mean-field potentials, Fermi motion and width modifications. We have applied the GiBUU model to the description of the double charge exchange (DCX) reaction of pions with different nuclear targets at incident kinetic energies of 120-180 MeV. The DCX process is highly sensitive to details of the interactions of pions with the nuclear medium and, therefore, represents a major benchmark for any model of pion scattering off nuclei at low and intermediate energies. We discuss the impact of surface effects and the dependence on the nuclear mass number. We have achieved a good quantitative agreement with the extensive data set obtained at LAMPF. Furthermore, we present a description of electron induced reactions, i.e. pion production, off nuclei. We consider the scattering of electrons off the bound nucleons in an impulse approximation and investigate medium modifications to exclusive particle production cross sections and compare our results to available data. (orig.)

  1. Density and expansion effects on pion spectra in relativistic heavy-ion collisions

    CERN Document Server

    Ayala, A P; Montaño-Zetina, L M; Ayala, Alejandro; Barreiro, Julio; Montano, Luis M.

    1999-01-01

    We compute the pion inclusive momentum distribution in heavy-ion collisions at AGS energies, assuming thermal equilibrium and accounting for density and expansion effects at the time of decoupling. We compare to data on mid rapidity charged pions produced in central Au + Au collisions and find a very good agreement. The shape of the distribution at low m_t-m is explained in part as an effect arising from the high mean pion density achieved in these reactions. The difference between the positive and negative pion distributions in the same region is attributed in part to the different average yields of each kind of charged pions.

  2. Comparative Energy Dependence of Proton and Pion Degradation in Diamond

    CERN Document Server

    Lazanu, Ionel

    1999-01-01

    A comparative theoretical study of the damages produced by protons and pions, in the energy range 50 MeV - 50 GeV, in diamond, is presented. The concentration of primary defects (CPD) induced by hadron irradiation is used to describe material degradation. The CPD has very different behaviours for protons and pions: the proton degradation is important at low energies and is higher than the pion one in the whole energy range investigated, with the exception of the Delta33 resonance region, where a large maximum of the degradation exists for pions. In comparison with silicon, the most investigated and the most studied material for detectors, diamond theoretically proves to be one order of magnitude more resistant, both to proton and pion irradiation.

  3. [Neuronal mechanisms underlying pain-induced negative emotions].

    Science.gov (United States)

    Minami, Masabumi

    2012-11-01

    Pain consists of sensory-discriminative and negative emotional components. Although the neuronal basis of the sensory component of pain has been studied extensively, the neuronal mechanisms underlying the negative emotional component are not well understood. Recently, behavioral studies using a conditioned place paradigm have successfully elucidated the neuronal circuits and mechanisms underlying the negative emotional component of pain. Excitotoxic lesions of the anterior cingulate cortex (ACC), central amygdaloid nucleus, basolateral amygdaloid nucleus (BLA), or bed nucleus of the stria terminalis (BNST) suppress intraplantar formalin-induced aversive responses. Glutamatergic transmission within the ACC and BLA via N-methyl-D-asparate (NMDA) receptors has been shown to play a critical role in these aversive responses. In the BNST, especially its ventral part, noradrenergic transmission via β-adrenergic receptors has been shown to be important for pain-induced aversion. Because persistent pain is frequently associated with psychological and emotional dysfunctions, studies on the neuronal circuits and molecular mechanisms involved in the negative emotional component of pain may have considerable clinical importance in the treatment of chronic pain. Here, I have reviewed behavioral studies investigating the neuronal mechanisms underlying the negative emotional component of pain and have introduced our data showing the pivotal role of amygdala and BNST in pain-induced aversion.

  4. Streamer chamber: pion decay

    CERN Multimedia

    1992-01-01

    The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

  5. Model Selection for Pion Photoproduction

    CERN Document Server

    Landay, J; Fernández-Ramírez, C; Hu, B; Molina, R

    2016-01-01

    Partial-wave analysis of meson and photon-induced reactions is needed to enable the comparison of many theoretical approaches to data. In both energy-dependent and independent parametrizations of partial waves, the selection of the model amplitude is crucial. Principles of the $S$-matrix are implemented to different degree in different approaches, but a many times overlooked aspect concerns the selection of undetermined coefficients and functional forms for fitting, leading to a minimal yet sufficient parametrization. We present an analysis of low-energy neutral pion photoproduction using the Least Absolute Shrinkage and Selection Operator (LASSO) in combination with criteria from information theory and $K$-fold cross validation. These methods are not yet widely known in the analysis of excited hadrons but will become relevant in the era of precision spectroscopy. The principle is first illustrated with synthetic data, then, its feasibility for real data is demonstrated by analyzing the latest available measu...

  6. Pion production off the nucleon

    CERN Document Server

    Alam, M Rafi; Chauhan, Shikha; Singh, S K

    2016-01-01

    We have studied charged current neutrino/antineutrino induced weak pion production from nucleon. For the present study, contributions from $\\Delta(1232)$-resonant term, non-resonant background terms as well as contribution from higher resonances viz. $P_{11}$(1440), $D_{13}$(1520), $S_{11}$(1535), $S_{11}$(1650) and $P_{13}$(1720) are taken. To write the hadronic current for the non-resonant background terms, a microscopic approach based on SU(2) non-linear sigma model has been used. The vector form factors for the resonances are obtained from the helicity amplitudes provided by MAID. Axial coupling in the case of $\\Delta(1232)$ resonance is obtained by fitting the ANL and BNL $\

  7. Transcription dynamics of inducible genes modulated by negative regulations.

    Science.gov (United States)

    Li, Yanyan; Tang, Moxun; Yu, Jianshe

    2015-06-01

    Gene transcription is a stochastic process in single cells, in which genes transit randomly between active and inactive states. Transcription of many inducible genes is also tightly regulated: It is often stimulated by extracellular signals, activated through signal transduction pathways and later repressed by negative regulations. In this work, we study the nonlinear dynamics of the mean transcription level of inducible genes modulated by the interplay of the intrinsic transcriptional randomness and the repression by negative regulations. In our model, we integrate negative regulations into gene activation process, and make the conventional assumption on the production and degradation of transcripts. We show that, whether or not the basal transcription is temporarily terminated when cells are stimulated, the mean transcription level grows in the typical up and down pattern commonly observed in immune response genes. With the help of numerical simulations, we clarify the delicate impact of the system parameters on the transcription dynamics, and demonstrate how our model generates the distinct temporal gene-induction patterns in mouse fibroblasts discerned in recent experiments.

  8. Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions

    CERN Document Server

    Xiao, Zhi-Gang; Chen, Lie-Wen; Li, Bao-An; Zhang, Ming; Xiao, Guo-Qing; Xu, Nu

    2013-01-01

    The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions especially those induced by radioactive beams but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the pion-/pion+ ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the pion-/pion+ ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the pion-/pion+ ratio are still quite model dependent mostly because of the complexity of modeling pion ...

  9. Can pions created in high-energy heavy-ion collisions produce a Centauro-type effect?

    CERN Document Server

    Martinis, M; Martinis, M; Mikuta-Martinis, V

    1994-01-01

    We study a Centauro-type phenomenon in high-energy heavy-ion collisions by assuming that pions are produced semiclassically both directly and in pairs through the isovector channel. The leading-particle effect and the factorization property of the scattering amplitude in the impact-parameter space are used to define the classical pion field. By analyzing the joint probability function P_{II_{3}}(n_{0},n_{ \\_}) for producing n_{0} neutral and n_{-} negative pions from a definite isospin state II_{3} of the incoming leading-particle system we show that only direct production of pions without isovector pairs favors Centauro-type behavior. The presence of isovector pairs seems to destroy the effect. Our conclusion is supported through the calculation of two pion correlation parameters, f_{2}^{0-} and f_{2}^{00}, and the average number of neutral pions ( \\langle n_{0} \\rangle_{n_{ \\_}}) as a function of negative pions (n_{ \\_}) produced.

  10. Quark and pion effective couplings from polarization effects

    CERN Document Server

    Braghin, Fabio L

    2016-01-01

    A flavor SU(2) effective model for pions and quarks is derived by considering polarization effects departing from the usual quark-quark effective interaction induced by dressed gluon exchange, i.e. a global color model for QCD. For that, the quark field is decomposed into a component that yields light mesons and the quark-antiquark condensate, being integrated out by means of the auxiliary field method, and another component which yields constituent quarks. Within a longwavelength and weak quark field expansion (or large quark effective mass expansion) of a quark determinant, the leading terms are found up to the second order in a zero order derivative expansion, by neglecting vector mesons that are considerably heavier than the pion. Pions are considered in the structureless limit and, besides the chiral invariant pion self interaction terms that reproduce previously derived expressions, symmetry breaking terms are also presented. The leading chiral quark-quark effective couplings are also found correspondin...

  11. Negative thermal expansion induced by intermetallic charge transfer.

    Science.gov (United States)

    Azuma, Masaki; Oka, Kengo; Nabetani, Koichiro

    2015-06-01

    Suppression of thermal expansion is of great importance for industry. Negative thermal expansion (NTE) materials which shrink on heating and expand on cooling are therefore attracting keen attention. Here we provide a brief overview of NTE induced by intermetallic charge transfer in A-site ordered double perovskites SaCu3Fe4O12 and LaCu3Fe4-x Mn x O12, as well as in Bi or Ni substituted BiNiO3. The last compound shows a colossal dilatometric linear thermal expansion coefficient exceeding -70 × 10(-6) K(-1) near room temperature, in the temperature range which can be controlled by substitution.

  12. Strain-induced negative differential resistance in ultrasmall carbon nanotube

    Science.gov (United States)

    Fang, Hui; Zhang, Fei-Peng; Ruan, Xing-Xiang; Huang, Can-Sheng; Jiang, Zhi-Nian; Peng, Jin-Yun; Wang, Ru-Zhi

    2017-08-01

    The transport properties in ultrasmall single-wall carbon nanotubes (SWCNTs) under tensile strain have been theoretically investigated. The regular negative differential resistance (NDR) induced by the strain undergoes a process from enhancement to weakening in the zigzag (3,0) SWCNT. The NDR achieves maximum with applying 4% tensile strain. Compared to the case of (3,0) SWCNT, that NDR cannot be manipulated by applying strain clearly in (4,0) and (5,0) ultrasmall SWCNTs with tensile strain lower than 10%. It proposes this strain-induced NDR effect to demonstrate the possibility of finding potential applications in SWCNT-based NDR nanodevices such as in memory devices, oscillators and fast switching devices.

  13. Membrane Permeabilization Induced by Sphingosine: Effect of Negatively Charged Lipids

    Science.gov (United States)

    Jiménez-Rojo, Noemi; Sot, Jesús; Viguera, Ana R.; Collado, M. Isabel; Torrecillas, Alejandro; Gómez-Fernández, J.C.; Goñi, Félix M.; Alonso, Alicia

    2014-01-01

    Sphingosine [(2S, 3R, 4E)-2-amino-4-octadecen-1, 3-diol] is the most common sphingoid long chain base in sphingolipids. It is the precursor of important cell signaling molecules, such as ceramides. In the last decade it has been shown to act itself as a potent metabolic signaling molecule, by activating a number of protein kinases. Moreover, sphingosine has been found to permeabilize phospholipid bilayers, giving rise to vesicle leakage. The present contribution intends to analyze the mechanism by which this bioactive lipid induces vesicle contents release, and the effect of negatively charged bilayers in the release process. Fluorescence lifetime measurements and confocal fluorescence microscopy have been applied to observe the mechanism of sphingosine efflux from large and giant unilamellar vesicles; a graded-release efflux has been detected. Additionally, stopped-flow measurements have shown that the rate of vesicle permeabilization increases with sphingosine concentration. Because at the physiological pH sphingosine has a net positive charge, its interaction with negatively charged phospholipids (e.g., bilayers containing phosphatidic acid together with sphingomyelins, phosphatidylethanolamine, and cholesterol) gives rise to a release of vesicular contents, faster than with electrically neutral bilayers. Furthermore, phosphorous 31-NMR and x-ray data show the capacity of sphingosine to facilitate the formation of nonbilayer (cubic phase) intermediates in negatively charged membranes. The data might explain the pathogenesis of Niemann-Pick type C1 disease. PMID:24940775

  14. Pion mean fields and heavy baryons

    CERN Document Server

    Yang, Ghil-Seok; Polyakov, Maxim V; Praszałowicz, Michał

    2016-01-01

    We show that the masses of the lowest-lying heavy baryons can be very well described in a pion mean-field approach. We consider a heavy baryon as a system consisting of the $N_c-1$ light quarks that induce the pion mean field, and a heavy quark as a static color source under the influence of this mean field. In this approach we derive a number of \\textit{model-independent} relations and calculate the heavy baryon masses using those of the lowest-lying light baryons as input. The results are in remarkable agreement with the experimental data. In addition, the mass of the $\\Omega_b^*$ baryon is predicted.

  15. Cross sections for neutrino and antineutrino induced pion production on hydrocarbon in the few-GeV region using MINERvA

    CERN Document Server

    McGivern, C L; Eberly, B; Aliaga, L; Altinok, O; Bellantoni, L; Bercellie, A; Betancourt, M; Bodek, A; Bravar, A; Budd, H; Cai, T; Carneiro, M F; Christy, M E; da Motta, H; Dytman, S A; Diaz, G A; Endress, E; Felix, J; Fields, L; Fine, R; Galindo, R; Gallagher, H; Golan, T; Gran, R; Harris, D A; Higuera, A; Hurtado, K; Kiveni, M; Kleykamp, J; Kordosky, M; Maher, E; Manly, S; Mann, W A; Marshall, C M; Caicedo, D A Martinez; McFarland, K S; McGowan, A M; Messerly, B; Miller, J; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Norrick, A; Nuruzzaman,; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Rakotondravohitra, L; Ramirez, M A; Ransome, R D; Ray, H; Ren, L; Rimal, D; Rodrigues, P A; Ruterbories, D; Schellman, H; Schmitz, D W; Simon, C; Salinas, C J Solano; Falero, S Sanchez; Tice, B G; Valencia, E; Walton, T; Wolcott, J; Wospakrik, M; Zhang, D

    2016-01-01

    Separate samples of charged-current pion production events representing two semi-inclusive channels nu_mu-CC(pi+) and anu_mu-CC(pi0) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon muon-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q2, are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the Delta(1232) and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the nu_mu-CC(pi+) (anu_mu-CC(pi0)) sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to-2 sigma. However the generators are able to reproduce the shapes of the differential cross ...

  16. Cross sections for νμ and ν¯μ induced pion production on hydrocarbon in the few-GeV region using MINERvA

    Science.gov (United States)

    McGivern, C. L.; Le, T.; Eberly, B.; Aliaga, L.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Betancourt, M.; Bodek, A.; Bravar, A.; Budd, H.; Cai, T.; Carneiro, M. F.; Christy, M. E.; da Motta, H.; Dytman, S. A.; Díaz, G. A.; Endress, E.; Felix, J.; Fields, L.; Fine, R.; Galindo, R.; Gallagher, H.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Kordosky, M.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; Martinez Caicedo, D. A.; McFarland, K. S.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman; Paolone, V.; Park, J.; Patrick, C. E.; Perdue, G. N.; Rakotondravohitra, L.; Ramirez, M. A.; Ransome, R. D.; Ray, H.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Schmitz, D. W.; Simon, C.; Solano Salinas, C. J.; Sánchez Falero, S.; Tice, B. G.; Valencia, E.; Walton, T.; Wolcott, J.; Wospakrik, M.; Zhang, D.; Minerva Collaboration

    2016-09-01

    Separate samples of charged-current pion production events representing two semi-inclusive channels νμ-CC (π+) and ν¯ μ-CC (π0) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon μ±-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q2 are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the Δ (1232 ) and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the νμ-CC (π+) [ν¯ μ-CC (π0) ] sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to- 2 σ . However the generators are able to reproduce the shapes of the differential cross sections for all kinematic variables of either data set.

  17. Low-energy pions in nuclear matter and 2pi photoproduction within a BUU transport model

    CERN Document Server

    Buss, O; Mosel, U; Mühlich, P; Alvarez-Ruso, Luis; Buss, Oliver; Mosel, Ulrich; Muehlich, Pascal

    2006-01-01

    A description of low-energy scattering of pions and nuclei within a BUU transport model is presented. Implementing different scenarios of medium modifications, the mean free path of pions in nuclear matter at low momenta and pion absorption reactions on nuclei have been studied and compared to data and to results obtained via quantum mechanical scattering theory. We show that even in a regime of a long pionic wave length the semi-classical transport model is still a reliable framework for pion kinetic energies greater than ~20-30 MeV. Results are presented on pion-absorption cross sections in the regime of 10 MeV < E(kin) < 130 MeV and on photon-induced double-pion production at incident beam energies of 400-500 MeV.

  18. Search for coherent charged pion production in neutrino-carbon interactions

    CERN Document Server

    Hasegawa, M; Andringa, S; Aoki, S; Argyriades, J; Asakura, K; Ashie, R; Berns, H; Bhang, H; Blondel, A; Borghi, S; Bouchez, J; Burguet-Castell, J; Casper, D; Cavata, C; Cervera-Villanueva, Anselmo; Chen, S M; Cho, K O; Choi, J H; Dore, U; Espinal, X; Fechner, M; Fernández, E; Fukuda, Y; Gómez-Cadenas, Juan José; Gran, R; Hara, T; Hasegawa, T; Hayashi, K; Hayato, Y; Helmer, R L; Hill, J; Hiraide, K; Hosaka, J; Ichikawa, A K; Iinuma, M; Ikeda, A; Inagaki, T; Ishida, T; Ishihara, K; Ishii, T; Ishitsuka, M; Itow, Y; Iwashita, T; Jang, H I; Jeon, E J; Jeong, I S; Joo, K; Jover, G; Jung, C K; Kajita, T; Kameda, J; Kaneyuki, K; Kato, I; Kearns, E; Kerr, D; Kim, C O; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kim, J Y; Kim, S; Kitching, P; Kobayashi, K; Kobayashi, T; Konaka, A; Koshio, Y; Kropp, W; Kubota, J; Kudenko, Yu G; Kuno, Y; Kutter, T; Learned, J; Likhoded, S; Lim, I T; Loverre, P F; Ludovici, L; Maesaka, H; Mallet, J; Mariani, C; Maruyama, T; Matsuno, S; Matveev, V; Mauger, C; McConnel, K; McGrew, C; Mikheyev, S; Minamino, A; Mine, S; Mineev, O V; Mitsuda, C; Miura, M; Moriguchi, Y; Morita, T; Moriyama, S; Nakadaira, T; Nakahata, M; Nakamura, K; Nakano, I; Nakaya, T; Nakayama, S; Namba, T; Nambu, R; Nawang, S; Nishikawa, K; Nitta, K; Nova, F; Novella, P; Obayashi, Y; Okada, A; Okumura, K; Oser, S M; Oyama, Y; Pac, M Y; Pierre, F; Rodríguez, A; Saji, C; Sakuda, M; Sánchez, F; Sarrat, A; Sasaki, T; Sato, H; Scholberg, K; Schroeter, R; Sekiguchi, M; Sharkey, E; Shiozawa, M; Shiraishi, K; Sitjes, G; Smy, M B; Sobel, H; Stone, J; Sulak, L; Suzuki, A; Suzuki, Y; Takahashi, T; Takenaga, Y; Takeuchi, Y; Taki, K; Takubo, Y; Tamura, N; Tanaka, M; Terri, R; T'Jampens, S; Tornero-Lopez, A; Totsuka, Y; Ueda, S; Vagins, M; Whitehead, L; Walter, C W; Wang, W; Wilkes, R J; Yamada, S; Yamamoto, S; Yanagisawa, C; Yershov, N V; Yokoyama, H; Yokoyama, M; Yoo, J; Yoshida, M; Zalipska, J

    2005-01-01

    We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed and an upper limit of $0.60 \\times 10^{-2}$ is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.

  19. Charged Pion Photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Haiyan Gao, Wei Chen

    2009-12-01

    We extracted the differential cross section for the gn --> pi-p process from a deuterium target using the CLAS detector at Jefferson Lab in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (theta c.m.) between 50 deg. and 115 deg. We confirm a previous indication of a broad enhancement around a c.m. energy (sqrt s) of 2.1 GeV at theta c.m. =90 deg. in the scaled differential cross section, s^7 ds/dt and a rapid fall-off in a center-of-mass energy region of about 400 MeV following the enhancement. Our data show an angular dependence of this enhancement as the suggested scaling region is approached for theta c.m. from 70 deg. to 10 deg.

  20. Pion form factor

    Energy Technology Data Exchange (ETDEWEB)

    Ryong Ji, C.; Pang, A.; Szczepaniak, A. [North Carolina State Univ., Raleigh, NC (United States)

    1994-04-01

    It is pointed out that the correct criterion to define the legal PQCD contribution to the exclusive processes in the lightcone perturbative expansion should be based on the large off-shellness of the lightcone energy in the intermediate states. In the lightcone perturbative QCD calculation of the pion form factor, the authors find that the legal PQCD contribution defined by the lightcone energy cut saturates in the smaller Q{sup 2} region compared to that defined by the gluon four-momentum square cut. This is due to the contribution by the highly off-energy-shell gluons in the end point regions of the phase space, indicating that the gluon four-momentum-square cut may have cut too much to define the legal PQCD.

  1. Backward pion photoproduction

    Energy Technology Data Exchange (ETDEWEB)

    Sibirtsev, A; Haidenbauer, J; Huang, F; Krewald, S; Meissner, U -G

    2009-04-01

    We present a systematic analysis of backward pion photoproduction for the reactions $ \\gamma$ p $ \\rightarrow$ $ \\pi^{0}_{}$ p and $ \\gamma$ p $ \\rightarrow$ $ \\pi^{+}_{}$ n . Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision with older data on $ \\pi^{0}_{}$ - and $ \\pi^{+}_{}$ -photoproduction at $ \\vartheta$ = 180° indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around $ \\sqrt{{s}}$ ≃ 3 GeV. In the energy region of $ \\sqrt{{s}}$ $ \\le$2.5 GeV, covered by the new measurements of $ \\gamma$ p $ \\rightarrow$ $ \\pi^{0}_{}$ p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of excited baryons.

  2. Emotional intelligence and recovering from induced negative emotional state.

    Science.gov (United States)

    Limonero, Joaquín T; Fernández-Castro, Jordi; Soler-Oritja, Jordi; Álvarez-Moleiro, María

    2015-01-01

    The aim of the present study was to examine the relationship between emotional intelligence (EI) and recovering from negative emotions induction, using a performance test to measure EI. Sixty seven undergraduates participated in the procedure, which lasted 75 min and was divided into three stages. At Time 1, subjects answered the State-Trait Anxiety Inventory (STAI)-S, Profile of Mood States (POMS)-A, and EI was assessed by Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). At Time 2, negative emotions were induced by nine pictures taken from the International Affective Picture System and participants were asked to complete a second STAI-S and POMS-B questionnaires. At Time 3 participants were allowed to rest doing a distracting task and participants were asked to complete a third STAI-S and POMS-A questionnaires. Results showed that the branches of the MSCEIT emotional facilitation and emotional understanding are related to previous mood states and mood recovery, but not to mood reactivity. This finding contrasts nicely with studies on which emotional recovery was assessed in relation to EI self-reported measures, highlighting the perception and emotional regulation.

  3. Emotional intelligence and recovering from induced negative emotional state

    Directory of Open Access Journals (Sweden)

    Joaquín T. Limonero

    2015-06-01

    Full Text Available The aim of the present study was to examine the relationship between emotional intelligence and recovering from negative emotions induction, using a performance test to measure Emotional Inteligence (EI. Sixty seven undergraduates participated in the procedure, which lasted 75 minutes and was divided into three stages. At Time 1, subjects answered the STAI-S, POMS-A, and EI was assessed by MSCEIT. At Time 2, negative emotions were induced by 9 pictures taken from the International Affective Picture System (IAPS and participants were asked to complete a second STAI-S and POMS-B questionnaires. At Time 3 participants were allowed to rest doing a distracting task and participants were asked to complete a third STAI-S and POMS-A questionnaires. Results showed that the branches of the MSCEIT emotional facilitation and emotional understanding are related to previous mood states and mood recovery, but not to mood reactivity. This finding contrasts nicely with studies on which emotional recovery was assessed in relation to EI self-reported measures, highlighting the perception and emotional regulation.

  4. Pion production in neutrino interactions with nuclei

    CERN Document Server

    Leitner, T; Buss, O; Mosel, U; Alvarez-Ruso, L

    2009-01-01

    Neutrino-induced pion production on nuclear targets is the major inelastic channel in all present-day neutrino-oscillation experiments. It has to be understood quantitatively in order to be able to reconstruct the neutrino-energy at experiments such as MiniBooNE or K2K and T2K. We report here results of calculations cross sections for both this channel and for quasielastic scattering within the semiclassical GiBUU method. This methods contains scattering, both elastic and inelastic, absorption and side-feeding of channels all in a unitary, common theoretical framework and code. We find that charged current quasielastic scattering (CCQE) and $1 \\pi$ production are closely entangled in actual experiments, due to final state interactions of the scattered nucleons on one hand and of the $\\Delta$ resonances and pions, on the other hand. We discuss the uncertainties in the elementary pion production cross sections from ANL and BNL. We find the surprising result that the recent $1 \\pi$ production cross section data ...

  5. Shape of Pion Distribution Amplitude

    Energy Technology Data Exchange (ETDEWEB)

    Radyushkin, Anatoly

    2009-11-01

    A scenario is investigated in which the leading-twist pion distribution amplitude $\\varphi_\\pi (x)$ is approximated by the pion decay constant $f_\\pi$ for all essential values of the light-cone fraction $x$. A model for the light-front wave function $\\Psi (x, k_\\perp)$ is proposed that produces such a distribution amplitude and has a rapidly decreasing (exponential for definiteness) dependence on the light-front energy combination $ k_\\perp^2/x(1-x)$. It is shown that this model easily reproduces the fit of recent large-$Q^2$ BaBar data on the photon-pion transition form factor. Some aspects of scenario with flat pion distribution amplitude are discussed.

  6. Evaluation of the Axial Vector Commutator Sum Rule for Pion-Pion Scattering

    CERN Document Server

    Adler, Stephen L

    2007-01-01

    We consider the sum rule proposed by one of us (SLA), obtained by taking the expectation value of an axial vector commutator in a state with one pion. The sum rule relates the pion decay constant to integrals of pion-pion cross sections, with one pion off the mass shell. We remark that recent data on pion-pion scattering allow a precise evaluation of the sum rule. We also discuss the related Adler--Weisberger sum rule (obtained by taking the expectation value of the same commutator in a state with one nucleon), especially in connection with the problem of extrapolation of the pion momentum off its mass shell.

  7. Model selection for pion photoproduction

    Science.gov (United States)

    Landay, J.; Döring, M.; Fernández-Ramírez, C.; Hu, B.; Molina, R.

    2017-01-01

    Partial-wave analysis of meson and photon-induced reactions is needed to enable the comparison of many theoretical approaches to data. In both energy-dependent and independent parametrizations of partial waves, the selection of the model amplitude is crucial. Principles of the S matrix are implemented to a different degree in different approaches; but a many times overlooked aspect concerns the selection of undetermined coefficients and functional forms for fitting, leading to a minimal yet sufficient parametrization. We present an analysis of low-energy neutral pion photoproduction using the least absolute shrinkage and selection operator (LASSO) in combination with criteria from information theory and K -fold cross validation. These methods are not yet widely known in the analysis of excited hadrons but will become relevant in the era of precision spectroscopy. The principle is first illustrated with synthetic data; then, its feasibility for real data is demonstrated by analyzing the latest available measurements of differential cross sections (d σ /d Ω ), photon-beam asymmetries (Σ ), and target asymmetry differential cross sections (d σT/d ≡T d σ /d Ω ) in the low-energy regime.

  8. Determination of the pion distribution amplitude

    CERN Document Server

    Huang, Tao; Wu, Xing-Gang

    2013-01-01

    Right now, we have not enough knowledge to determine the hadron distribution amplitudes (DAs) which are universal physical quantities in the high energy processes involving hadron for applying pQCD to exclusive processes. Even for the simplest pion, one can't discriminate from different DA models. Inversely, one expects that processes involving pion can in principle provide strong constraints on the pion DA. For example, the pion-photon transition form factor (TFF) can get accurate information of the pion wave function or DA, due to the single pion in this process. However, the data from Belle and BABAR have a big difference on TFF in high $Q^2$ regions, at present, they are helpless for determining the pion DA. At the present paper, we think it is still possible to determine the pion DA as long as we perform a combined analysis of the most existing data of the processes involving pion such as $\\pi \\to \\mu \\bar{\

  9. Intensity-dependent pion-nucleon coupling in multipion production processes

    CERN Document Server

    Martinis, M

    1996-01-01

    We propose an intensity-dependent pion-nucleon coupling Hamiltonian within a unitary multiparticle-production model of the Auerbach- Avin-Blankenbecler-Sugar (AABS) type in which the pion field is represented by the thermal-density matrix.Using this Hamiltonian, we explain the appearance of the negative-binomial (NB) distribution for pions and the well-known empirical relation, the so-called Wr\\' oblewski relation, in which the dispersion $D$ of the pion- multiplicity distribution is linearly related to the average multiplicity $$ : $D = A + B$, with the coefficient $A < 1$. The Hamiltonian of our model is expressed linearly in terms of the generators of the $SU(1,1)$ group.We also find the generating function for the pion field, which reduces to the generating function of the NB distribution limit $T \\to 0$.

  10. Pions to Quarks

    Science.gov (United States)

    Brown, Laurie Mark; Dresden, Max; Hoddeson, Lillian

    2009-01-01

    Part I. Introduction; 1. Pions to quarks: particle physics in the 1950s Laurie M Brown, Max Dresden and Lillian Hoddeson; 2. Particle physics in the early 1950s Chen Ning Yang; 3. An historian's interest in particle physics J. L. Heilbron; Part II. Particle discoveries in cosmic rays; 4. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957 George D. Rochester; 5. Cosmic-ray work with emulsions in the 1940s and 1950s Donald H. Perkins; Part III. High-energy nuclear physics; Learning about nucleon resonances with pion photoproduction Robert L. Walker; 7. A personal view of nucleon structure as revealed by electron scattering Robert Hofstadter; 8. Comments on electromagnetic form factors of the nucleon Robert G. Sachs and Kameshwar C. Wali; Part IV. The new laboratory; 9. The making of an accelerator physicist Matthew Sands; 10. Accelerator design and construction in the 1950s John P. Blewett; 11. Early history of the Cosmotron and AGS Ernest D. Courant; 12. Panel on accelerators and detectors in the 1950s Lawrence W. Jones, Luis W. Alvarez, Ugo Amaldi, Robert Hofstadter, Donald W. Kerst, Robert R. Wilson; 13. Accelerators and the Midwestern Universities Research Association in the 1950s Donald W. Kerst; 14. Bubbles, sparks and the postwar laboratory Peter Galison; 15. Development of the discharge (spark) chamber in Japan in the 1950s Shuji Fukui; 16. Early work at the Bevatron: a personal account Gerson Goldhaber; 17. The discovery of the antiproton Owen Chamberlain; 18. On the antiproton discovery Oreste Piccioni; Part V. The Strange Particles; 19. The hydrogen bubble chamber and the strange resonances Luis W. Alvarez; 20. A particular view of particle physics in the fifties Jack Steinberger; 21. Strange particles William Chinowsky; 22. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers William B. Fowler; 23. From the 1940s into the 1950s Abraham Pais; Part VI. Detection of the

  11. Pion structure from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Javadi Motaghi, Narjes

    2015-05-12

    In this thesis we use lattice QCD to compute the second Mellin moments of pion generalized parton distributions and pion electromagnetic form factors. For our calculations we are able to analyze a large set of gauge configurations with 2 dynamical flavours using non-perturbatively the improved Wilson-Sheikholeslami-Wohlert fermionic action pion masses ranging down to 151 MeV. By employing improved smearing we were able to suppress excited state contamination. However, our data in the physical quark mass limit show that some excited state contamination remains. We show the non-zero sink momentum is optimal for the computation of the electromagnetic form factors and generalized form factors at finite momenta.

  12. Scrutinizing the pion condensed phase

    Energy Technology Data Exchange (ETDEWEB)

    Carignano, Stefano; Mammarella, Andrea; Mannarelli, Massimo [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Lepori, Luca [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); Universita dell' Aquila, Dipartimento di Scienze Fisiche e Chimiche, Coppito-L' Aquila (Italy); Pagliaroli, Giulia [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Gran Sasso Science Institute, L' Aquila (Italy)

    2017-02-15

    When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. Chiral perturbation theory provides a very powerful tool for studying this phase. However, the formalism that is usually employed in this context does not clarify various aspects of the condensation mechanism and makes the identification of the soft modes problematic. We re-examine the pion condensed phase using different approaches within the chiral perturbation theory framework. As a first step, we perform a low-density expansion of the chiral Lagrangian valid close to the onset of the Bose-Einstein condensation. We obtain an effective theory that can be mapped to a Gross-Pitaevskii Lagrangian in which, remarkably, all the coefficients depend on the isospin chemical potential. The low-density expansion becomes unreliable deep in the pion condensed phase. For this reason, we develop an alternative field expansion deriving a low-energy Lagrangian analog to that of quantum magnets. By integrating out the ''radial'' fluctuations we obtain a soft Lagrangian in terms of the Nambu-Goldstone bosons arising from the breaking of the pion number symmetry. Finally, we test the robustness of the second-order transition between the normal and the pion condensed phase when next-to-leading-order chiral corrections are included. We determine the range of parameters for turning the second-order phase transition into a first-order one, finding that the currently accepted values of these corrections are unlikely to change the order of the phase transition. (orig.)

  13. Comparison of GiBUU calculations with MiniBooNE pion production data

    CERN Document Server

    Lalakulich, Olga

    2013-01-01

    Background. Neutrino-induced pion production can give important informationon the axial coupling to nucleon resonances. Furthermore, pion production represents a major background to quasielastic-like events. Single pion production data from the MiniBooNE in charged current neutrino scattering in mineral oil appeared higher than expected within conventional theoretical approaches. Purpose. We aim to investigate which model parameters affect the calculated cross section and how they do this. Method. The Giessen Boltzmann--Uehling--Uhlenbeck (GiBUU) model is used for an investigation of neutrino-nucleus reactions. Results. Presented are integrated and differential cross sections for 1\\pi^+ and 1\\pi^0 production before and after final state interactions in comparison with the MiniBooNE data. Conclusions. For the MiniBooNE flux all processes (QE, 1\\pi-background, \\Delta, higher resonance production, DIS) contribute to the observed final state with one pion of a given charge. The uncertainty in elementary pion prod...

  14. Multiple scattering induced negative refraction of matter waves

    Science.gov (United States)

    Pinsker, Florian

    2016-01-01

    Starting from fundamental multiple scattering theory it is shown that negative refraction indices are feasible for matter waves passing a well-defined ensemble of scatterers. A simple approach to this topic is presented and explicit examples for systems of scatterers in 1D and 3D are stated that imply negative refraction for a generic incoming quantum wave packet. Essential features of the effective scattering field, densities and frequency spectrum of scatterers are considered. Additionally it is shown that negative refraction indices allow perfect transmission of the wave passing the ensemble of scatterers. Finally the concept of the superlens is discussed, since it is based on negative refraction and can be extended to matter waves utilizing the observations presented in this paper which thus paves the way to ‘untouchable’ quantum systems in analogy to cloaking devices for electromagnetic waves. PMID:26857266

  15. Probing Delta structure with pion electromagnetic production

    CERN Document Server

    Yang, S N; Yang, Shin Nan

    2003-01-01

    The Dubna-Mainz-Taipei dynamical model for pion electromagnetic production, which can describe well the existing data from threshold up to 1 GeV photon lab energy, is presented and used to analyze the recent precision data in the $\\Delta$ region. We find that, within our model, the bare Delta is almost spherical while the physical Delta is oblate. The deformation is almost saturated by the pion cloud effects. We further find that up to Q^2 = 4.0 (GeV/c)^2, the extracted helicity amplitude A_{3/2} and A_{1/2} remain comparable with each other, implying that hadronic helicity is not conserved at this range of Q^2. The ratio E_{1+}/M_{1+} obtained show, starting from a small and negative value at the real photon point, a clear tendency to cross zero, and to become positive with increasing Q^2. This is a possible indication of a very slow approach toward the pQCD region. Finally, we find that the bare helicity amplitude A_{1/2} and S_{1/2}, but not A_{3/2}, starts exhibiting the scaling behavior at about Q^2 \\ge ...

  16. In-Medium Pion Valence Distribution Amplitude

    CERN Document Server

    Tsushima, K

    2016-01-01

    After a brief review of the quark-based model for nuclear matter, and some pion properties in medium presented in our previous works, we report new results for the pion valence wave function as well as the valence distribution amplitude in medium, which are presented in our recent article. We find that both the in-medium pion valence distribution and the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

  17. In-Medium Pion Valence Distribution Amplitude

    Science.gov (United States)

    Tsushima, K.; de Melo, J. P. B. C.

    2017-03-01

    After a brief review of the quark-based model for nuclear matter, and some pion properties in medium presented in our previous works, we report new results for the pion valence wave function as well as the valence distribution amplitude in medium, which are presented in our recent article. We find that both the in-medium pion valence distribution and the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

  18. Scrutinizing the pion condensed phase

    CERN Document Server

    Carignano, Stefano; Mammarella, Andrea; Mannarelli, Massimo; Pagliaroli, Giulia

    2016-01-01

    When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. Chiral perturbation theory provides a very powerful tool for studying this phase. However, the formalism that is usually employed in this context does not clarify various aspects of the condensation mechanism and makes the identification of the soft modes problematic. We re-examine the pion condensed phase using different approaches within the chiral perturbation theory framework. As a first step, we perform a low-density expansion of the chiral Lagrangian valid in the normal phase and close to the onset of the Bose-Einstein condensation. We obtain an effective theory that can be mapped to a Gross-Pitaevskii Lagrangian in which, remarkably, all the coefficients depend on the isospin chemical potential. The low-density expansion becomes unreliable deep in the pion condensed phase. For this reason, we develop an alternative field expansion deriving a low-energy Lagrangian analog to ...

  19. The in-medium isovector pi N amplitude from low energy pion scattering

    CERN Document Server

    Friedman, E; Breitschopf, J; Clement, H; Denz, H; Doroshkevich, E; Erhardt, A; Hofman, G J; Meier, R; Wagner, G J; Yaari, G

    2004-01-01

    Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni and Zr have been measured as part of a study of the pion-nucleus potential across threshold. The `anomalous' repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.

  20. In-medium isovector piN amplitude from low-energy pion scattering.

    Science.gov (United States)

    Friedman, E; Bauer, M; Breitschopf, J; Clement, H; Denz, H; Doroshkevich, E; Erhardt, A; Hofman, G J; Meier, R; Wagner, G J; Yaari, G

    2004-09-17

    Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni, and Zr have been measured as part of a study of the pion-nucleus potential across the threshold. The "anomalous" repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.

  1. The in-medium isovector pi N amplitude from low energy pion scattering

    OpenAIRE

    Friedman, E; Bauer, M.; Breitschopf, J.; H. Clement; Denz, H; Doroshkevich, E.; Erhardt, A.; Hofman, G. J.; Meier, R.; Wagner, G. J.; Yaari, G

    2004-01-01

    Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni and Zr have been measured as part of a study of the pion-nucleus potential across threshold. The `anomalous' repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an e...

  2. In-Medium Isovector πN Amplitude from Low-Energy Pion Scattering

    Science.gov (United States)

    Friedman, E.; Bauer, M.; Breitschopf, J.; Clement, H.; Denz, H.; Doroshkevich, E.; Erhardt, A.; Hofman, G. J.; Meier, R.; Wagner, G. J.; Yaari, G.

    2004-09-01

    Differential cross sections for elastic scattering of 21.5MeV positive and negative pions by Si, Ca, Ni, and Zr have been measured as part of a study of the pion-nucleus potential across the threshold. The “anomalous” repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.

  3. Emotional intelligence and recovering from induced negative emotional state

    OpenAIRE

    Limonero, Joaquín T.; Jordi eFernández-Castro; Jordi eSoler-Oritja; María eÁlvarez

    2015-01-01

    The aim of the present study was to examine the relationship between emotional intelligence (EI) and recovering from negative emotions induction, using a performance test to measure EI. Sixty seven undergraduates participated in the procedure, which lasted 75 min and was divided into three stages. At Time 1, subjects answered the State-Trait Anxiety Inventory (STAI)-S, Profile of Mood States (POMS)-A, and EI was assessed by Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT). At Time 2,...

  4. Research program in nuclear and solid state physics. [including pion absorption spectra and muon spin precession

    Science.gov (United States)

    1974-01-01

    The survey of negative pion absorption reactions on light and medium nuclei was continued. Muon spin precession was studied using an iron target. An impulse approximation model of the pion absorption process implied that the ion will absorb almost exclusively on nucleon pairs, single nucleon absorption being suppressed by energy and momentum conservation requirements. For measurements on both paramagnetic and ferromagnetic iron, the external magnetic field was supplied by a large C-type electromagnet carrying a current of about 100 amperes.

  5. Negative refractive index induced by percolation in disordered metamaterials

    CERN Document Server

    Slovick, Brian A

    2016-01-01

    An effective medium model is developed for disordered metamaterials containing a spatially random distribution of dielectric spheres. Similar to effective medium models for ordered metamaterials, this model predicts resonances in the effective permeability and permittivity arising from electric- and magnetic-dipole Mie resonances in the spheres. In addition, the model predicts a redshift of the electric resonance with increasing particle loading. Interestingly, when the particle loading exceeds the percolation threshold of 33\\%, the model predicts that the electric resonance overlaps with the magnetic resonance, resulting in a negative refractive index.

  6. Negative refractive index induced by percolation in disordered metamaterials

    Science.gov (United States)

    Slovick, Brian A.

    2017-03-01

    An effective medium model is developed for disordered metamaterials containing a spatially random distribution of dielectric spheres. Similar to effective medium models for ordered metamaterials, this model predicts resonances in the effective permeability and permittivity arising from electric- and magnetic-dipole Mie resonances in the spheres. In addition, the model predicts a redshift of the electric resonance with increasing particle loading. Interestingly, when the particle loading exceeds the percolation threshold of 33%, the model predicts that the electric resonance overlaps with the magnetic resonance, resulting in a negative refractive index.

  7. Three pion nucleon coupling constants

    CERN Document Server

    Arriola, E Ruiz; Perez, R Navarro

    2016-01-01

    There exist four pion nucleon coupling constants, $f_{\\pi^0, pp}$, $-f_{\\pi^0, nn}$, $f_{\\pi^+, pn} /\\sqrt{2}$ and $ f_{\\pi^-, np} /\\sqrt{2}$ which coincide when up and down quark masses are identical and the electron charge is zero. While there is no reason why the pion-nucleon-nucleon coupling constants should be identical in the real world, one expects that the small differences might be pinned down from a sufficiently large number of independent and mutually consistent data. Our discussion provides a rationale for our recent determination $$f_p^2 = 0.0759(4) \\, , \\quad f_{0}^2 = 0.079(1) \\,, \\quad f_{c}^2 = 0.0763(6) \\, , $$ based on a partial wave analysis of the $3\\sigma$ self-consistent nucleon-nucleon Granada-2013 database comprising 6713 published data in the period 1950-2013.

  8. Double pion photoproduction in nuclei

    CERN Document Server

    Vicente-Vacas, M J; Gómez-Tejedor, J A; Vicente-Vacas, M J; Oset, E; Gómez Tejedor, J A

    1994-01-01

    Abstract: The inclusive A(gamma,pi+ pi-)X reaction is studied theoretically. A sizeable enhancement of the cross section is found, in comparison with the scaling of the deuteron cross section (sigma_deuteron * A/2). This enhancement is due to the modifications in the nuclear medium of the gamma N ----> pi pi N amplitude and the pion dispersion relation. The enhancement is found to be bigger than the one already observed in the (pi,pi pi) reaction in nuclei.

  9. Two-meson and multi-pion final states from 600 gev pion interactions

    CERN Document Server

    Moinester, M A

    1994-01-01

    This report describes the transitions pion ---> meson_1 + meson_2 and also pion ----> multi-pion for high energy pions interacting with target nuclei (Z,A). The physics interests are: A) Nuclear inelastic coherent diffraction cross sections for pions, for studies of size fluctuations in the pion wave function. B) Radiative widths of excited meson states, for tests of vector dominance and quark models. C) Experimental determination of the pi- + rho -----> pi- + gamma total reaction rate for gamma production above 0.7 GeV, needed for background studies of quark-gluon plasma formation experiments. D) Investigation of the gamma ---->3 pi vertex in pion pair production by a pion, for a significantly improved test of the hypothesis of chiral anomalies. The physics interest and associated bibliography are summarized here; with particular reference to the 200-600 GeV beams available at FNAL and CERN. Complementary GEANT simulations and trigger studies are needed.

  10. How strange is pion electroproduction?

    CERN Document Server

    Gorchtein, Mikhail; Zhang, Xilin

    2015-01-01

    We consider pion production in parity-violating electron scattering (PVES) in the presence of nucleon strangeness in the framework of partial wave analysis with unitarity. Using the experimental bounds on the strange form factors obtained in elastic PVES, we study the sensitivity of the parity-violating asymmetry to strange nucleon form factors. For forward kinematics and electron energies above 1 GeV, we observe that this sensitivity may reach about 20\\% in the threshold region. With parity-violating asymmetries being as large as tens p.p.m., this study suggests that threshold pion production in PVES can be used as a promising way to better constrain strangeness contributions. Using this model for the neutral current pion production, we update the estimate for the dispersive $\\gamma Z$-box correction to the weak charge of the proton. In the kinematics of the Qweak experiment, our new prediction reads Re$\\,\\Box_{\\gamma Z}^V(E=1.165\\,{\\rm GeV}) = (5.58\\pm1.41)\\times10^{-3}$, an improvement over the previous un...

  11. Gram negative bacteria and contact lens induced acute red eye

    Directory of Open Access Journals (Sweden)

    Sankaridurg Padmaja

    1996-01-01

    Full Text Available Two patients using hydrogel contact lenses on a daily wear schedule slept overnight with the lenses and woke up with a Contact Lens Induced Acute Red Eye (CLARE. The contact lenses recovered aseptically at the time of the event grew significant colonies of Pseudomonas aeruginosa and Aeromonas hydrophila in patient A and Pseudomonas aeruginosa and Serratia liquefaciens from patient B. Similar organisams from the contact lenses were recovered from the lens case and lens care solutions of patient B. In both the patients the condition resolved on discontinuation of lens wear. Patient compliance as a requirement for successful contact lens wear is highlighted with the illustration of these cases.

  12. Total cross sections for pion charge exchange on the proton

    Energy Technology Data Exchange (ETDEWEB)

    Breitschopf, J.

    2006-04-28

    This work describes the measurement of total SCX cross sections employing a new 4{pi} scintillation counter to perform transmission measurements in the incident pion energy range from about 38 to 250 MeV. A small 4{pi} detector box consisting of thin plastic scintillators has been constructed. The transmission technique, which was used, relates the number of transmitted charged pions to that of incident beam pions and this way effectively counts events with neutral products. The incoming negative pions were counted by three beam defining counters before they hit a target of very well known size and chemical composition. The target was placed in the box detector which was not sensitive to the neutral particles resulting from the SCX. The total cross section for emerging neutral particles was derived from the comparison of the numbers of the incoming and transmitted charged particles. The total SCX cross section on hydrogen was derived from the transmissions of a CH{sub 2} target, a carbon target and an empty target. For a detailed offline analysis all TDC, QDC and FADC information was recorded in an event by event mode for each triggered beam event. Various corrections had to be applied to the data, such as random correction, the detection of neutrals in the detector, Dalitz decay, pion decay and the radiative pion capture. This measurement covers, as the only experiment, the whole {delta}-resonance and the sp-interference region in one single experimental setup and improves the available data base for the SCX reaction. It is shown that the description of the SCX cross sections is improved if the s-wave amplitudes, that have been fixed essentially by elastic pion-nucleon scattering data, is reduced by (4{+-}1.5)%. The exact value depends on the SCX literature data included and on the parameters of the {delta}{sup 0} Breit-Wigner resonance describing the p{sub 33}-waves. This shows that p-wave as well as s-wave effects should be considered in studies of isospin

  13. Pion production in neutrino-nucleus collisions

    CERN Document Server

    Hernández, E; Vacas, M J Vicente

    2013-01-01

    We compare our pion production results with recent MiniBooNE data measured in mineral oil. Our total cross sections lie below experimental data for neutrino energies above 1 GeV. Differential cross sections show our model produces too few high energy pions in the forward direction as compared to data. The agreement with experiment improves by artificially removing pion final state interaction.

  14. Experimental study of rare charged pion decays

    CERN Document Server

    Pocanic, Dinko; van der Schaaf, Andries

    2014-01-01

    The combination of simple dynamics, small number of available decay channels, and extremely well controlled radiative and loop corrections, make charged pion decays a sensitive means for testing the underlying symmetries and the universality of weak fermion couplings, as well as for improving our understanding of pion structure and chiral dynamics. This paper reviews the current state of experimental study of the allowed rare decays of charged pions: (a) leptonic, $\\pi^+ \\to e^+\

  15. Systematics of pion double charge exchange

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, R.A.

    1985-10-01

    Differential cross sections have been measured for pion-induced double-charge-exchange (DCX) reactions leading to double-isobaric-analog states (DIAS) and low-lying nonanalog states in the residual nuclei. A description of the experimental details and data analysis is presented. The experimentally observed systematics of reactions leading to DIAS, to nonanalog ground states, and to low-lying 2 states are described. Lowest-order optical-model calculations of DIAS DCX are compared to the data. Efforts to understand the anomalies by invoking additional reaction-mechanism amplitudes and a higher-order optical potential are described. Calculations of nonanalog DCX reactions leading to J/sup / = 0 states were performed within a distorted-wave impulse-approximation framework. The sensitivities of these calculations to input parameters are discussed. 58 refs., 41 figs., 16 tabs.

  16. Negative regulation of DSS-induced experimental colitis by PILRα.

    Science.gov (United States)

    Kishida, Kazuki; Kohyama, Masako; Kurashima, Yosuke; Kogure, Yuta; Wang, Jing; Hirayasu, Kouyuki; Suenaga, Tadahiro; Kiyono, Hiroshi; Kunisawa, Jun; Arase, Hisashi

    2015-06-01

    Inflammatory bowel disease is thought to be a complex multifactorial disease, in which an increased inflammatory response plays an important role. Paired immunoglobulin-like type 2 receptor α (PILRα), well conserved in almost all mammals, is an inhibitory receptor containing immunoreceptor tyrosine-based inhibitory motifs in the cytoplasmic domain. PILRα is mainly expressed on myeloid cells and plays an important role in the regulation of inflammation. In the present study, we investigated the function of PILRα in inflammatory bowel disease using PILRα-deficient mice. When mice were orally administered dextran sulfate sodium (DSS), colonic mucosal injury and inflammation were significantly exacerbated in DSS-treated PILRα-deficient mice compared with wild-type (WT) mice. Flow cytometric analysis revealed that neutrophil and macrophage cell numbers were higher in the colons of DSS-treated PILRα-deficient mice than in those of WT mice. Blockade of CXCR2 expressed on neutrophils using a CXCR2 inhibitor decreased the severity of colitis observed in PILRα-deficient mice. These results suggest that PILRα negatively regulates inflammatory colitis by regulating the infiltration of inflammatory cells such as neutrophils and macrophages.

  17. New high precision data on the differential cross sections of the pion-proton elastic scattering

    Directory of Open Access Journals (Sweden)

    Alekseev I. G.

    2014-01-01

    Full Text Available The EPECUR collaboration presents new high precision data on the pion-proton elastic scattering in the second resonance region. The experiment EPECUR is placed on the universal beam channel of the accelerator ITEP. The setup features 0.1% beam pion momentum tagging system, 25 cm long liquid hydrogen target, placed in mylar container and beryllium outer shell, low material wire drift chambers and high performance DAQ. More than 3 billions of triggers have been collected. The data cover pion beam momentum range 0.8 - 1.3 GeV/c and 40-120 degrees center-of-mass scattering angle range for both positive and negative pions. The measured differential cross section has 2% statistical accuracy in 2 degrees angle and 5 MeV/c momentum intervals.

  18. Measurement of Pion and Proton Longitudinal Shower Profiles up to 20 Nuclear Interaction Lengths with the ATLAS Tile Calorimeter

    CERN Document Server

    Hakobyan, H; Carli, T; Henriques-Correia, A M

    2006-01-01

    The response of pions and protons in the energy range of 20 to 180 GeV produced at CERN's SPS H8 test beam line in the ATLAS Iron-Scintillator Tile hadron calorimeter has been measured. The testbeam configuration allowed to measure the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It is found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are laterally to the direction of the impinging particle wider. Including the measured total energy response, the pion to proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion induced showers. The data are compared with Geant4 simulations using several hadronic physics lists. The measured longitudinal shower profiles are described by an analytical shower parameterisation within an accuracy of 5-10 %.

  19. Determination of the pion-nucleon coupling constant and scattering lengths

    CERN Document Server

    Ericson, Torleif Eric Oskar; Thomas, A W

    2002-01-01

    We critically evaluate the isovector GMO sum rule for forward pion-nucleon scattering using the recent precision measurements of negatively charged pion-proton and pion-deuteron scattering lengths from pionic atoms. We deduce the charged-pion-nucleon coupling constant, with careful attention to systematic and statistical uncertainties. This determination gives, directly from data a pseudoscalar coupling constant of 14.17+-0.05(statistical)+-0.19(systematic) or a pseudovector one of 0.0786(11). This value is intermediate between that of indirect methods and the direct determination from backward neutron-proton differential scattering cross sections. We also use the pionic atom data to deduce the coherent symmetric and antisymmetric sums of the negatively charged pion-proton and pion-neutron scattering lengths with high precision. The symmetric sum gives 0.0017+-0.0002(statistical)+-0.0008 (systematic) and the antisymmetric one 0.0900+-0.0003(statistical)+-0.0013(systematic), both in units of inverse charged pi...

  20. Feedback-induced glutamate spillover enhances negative feedback from horizontal cells to cones

    NARCIS (Netherlands)

    Vroman, Rozan; Kamermans, M.

    2015-01-01

    KEY POINTS: In the retina, horizontal cells feed back negatively to cone photoreceptors. Glutamate released from cones can spill over to neighbouring cones. Here we show that cone glutamate release induced by negative feedback can also spill over to neighbouring cones. This glutamate activates the g

  1. Charged Current Coherent Pion Production in Neutrino Scattering

    CERN Document Server

    Martins, Paul

    2016-01-01

    We summarise here the main differences of three models of neutrino-induced coherent pion production, namely the Rein-Sehgal and Berger-Sehgal models based on the Partially Conserved Axial Current theorem and the Alvarez-Ruso \\textit{et al.} model which is using a microscopic approach. Their predictions in the event generators are compared against recent experimental measurements for a neutrino energy from 0.5 to 20 GeV.

  2. Pion Structure in Qcd: from Theory to Lattice to Experimental Data

    Science.gov (United States)

    Bakulev, A. P.; Mikhailov, S. V.; Pimikov, A. V.; Stefanis, N. G.

    We describe the present status of the pion distribution amplitude (DA) as it originates from several sources: (i) a nonperturbative approach based on QCD sum rules with nonlocal condensates, (ii) an O(as) QCD analysis of the CLEO data on Fgg*p(Q2) with asymptotic and renormalon models for higher twists and (iii) recent high-precision lattice QCD calculations of the second moment of the pion DA. We show predictions for the pion electromagnetic form factor, obtained in analytic QCD perturbation theory, and compare it with the JLab data on Fp(Q2). We also discuss in this context an improved model for nonlocal condensates in QCD and show its consequences for the pion DA and the gg*p transition form factor. We include a brief analysis of meson-induced massive lepton (muon) Drell-Yan production for the process p-Nm+m-X, considering both an unpolarized nucleon target and longitudinally polarized protons.

  3. Pion polarizabilities: Theory vs Experiment

    CERN Document Server

    Ivanov, Mikhail A

    2015-01-01

    The values of charged pion polarizabilities obtained in the framework of chiral perturbation theory at the level of two-loop accuracy are compared with the experimental result recently reported by COMPASS Collaboration. It is found that the calculated value for the dipole polarizabilities $(\\alpha-\\beta)_{\\pi^\\pm}= (5.7\\pm 1.0)\\times 10^{-4}\\,{\\rm fm}^3$ fits quite well the experimental result $(\\alpha-\\beta)_{\\pi^\\pm} = (4.0 \\pm 1.2_{\\rm stat} \\pm 1.4_{\\rm syst}) \\times 10^{-4}\\,{\\rm fm}^3$.

  4. Double pion photoproduction in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Tejedor, J.A. [Departamento de Fisica Teorica, Valencia (Spain); Vicente-Vacas, M.J. [Departamento de Fisica Teorica, Valencia (Spain); Oset, E. [Departamento de Fisica Teorica, Valencia (Spain)

    1995-06-19

    The inclusive A({gamma},{pi}{sup +}{pi}{sup -})X reaction is studied theoretically. A sizable enhancement of the cross section is found, in comparison with the scaling of the deuteron cross section ({sigma}{sub d} A/2). This enhancement is due to the modifications in the nuclear medium of the {gamma}N {yields}{pi}{pi}N amplitude and the pion dispersion relation. The enhancement is found to be bigger than the one already observed in the ({pi},{pi}{pi}) reaction in nuclei. ((orig.)).

  5. Covariant formulation of pion-nucleon scattering

    Science.gov (United States)

    Lahiff, A. D.; Afnan, I. R.

    A covariant model of elastic pion-nucleon scattering based on the Bethe-Salpeter equation is presented. The kernel consists of s- and u-channel nucleon and delta poles, along with rho and sigma exchange in the t-channel. A good fit is obtained to the s- and p-wave phase shifts up to the two-pion production threshold.

  6. Single pion production in neutrino nucleus scattering

    CERN Document Server

    Hernández, E; Vacas, M J Vicente

    2013-01-01

    We study one pion production in both charged and neutral current neutrino nucleus scattering for neutrino energies below 2 GeV. We use a theoretical model for one pion production at the nucleon level that we correct for medium effects. The results are incorporated into a cascade program that apart from production also includes the pion final state interaction inside the nucleus. Besides, in some specific channels coherent pion production is also possible and we evaluate its contribution as well. Our results for total and differential cross sections are compared with recent data from the MiniBooNE Collaboration. The model provides an overall acceptable description of data, better for NC than for CC channels, although theory is systematically below data. Differential cross sections, folded with the full neutrino flux, show that most of the missing pions lie on the forward direction and at high energies.

  7. On the dissipation of negative excess porewater pressure induced by excavation in soft soil

    Institute of Scientific and Technical Information of China (English)

    LI Yu-qi; YING Hong-wei; XIE Kang-he

    2005-01-01

    Unloading induces negative excess porewater pressure in soil mass around a foundation pit during excavation. In this work, the dissipation rule of negative excess porewater pressure after excavation was studied. Analytical formulas for calculating the negative excess porewater pressures and the effective stresses were derived based on one-dimensional consolidation theory and Terzaghi's effective stress principle. The influence of the dissipation of negative excess porewater pressure on earth pressure inside and outside a foundation pit and the stability of the retaining structure were analyzed through a numerical example. It was indicated that the dissipation of negative excess porewater pressure is harmful to the stability of the retaining structure and that rapid construction can make full use of the negative porewater pressure.

  8. Lorentz-violating neutral-pion decays in isotropic modified Maxwell theory

    CERN Document Server

    Klinkhamer, F R

    2016-01-01

    We consider an extension of the Standard Model with isotropic nonbirefringent Lorentz violation in the photon sector and specialize to the case of a "fast" photon with a phase velocity larger than the maximum attainable velocity of the fermions. With our conventions, this case corresponds to a negative Lorentz-violating parameter $\\kappa$ in the action. The decay rate of a neutral pion into two photons is calculated as a function of the 3-momentum of the initial pion and the negative Lorentz-violating parameter $\\kappa$ of the final photons.

  9. Tragedy or tragicomedy: Mixed feelings induced by positive and negative emotional events.

    Science.gov (United States)

    Xia, Mu; Chen, Jie; Li, Hong

    2016-08-01

    Based on the theory of appraisal, we predicted that positive and negative events happening to the same people or things in a specific chronological order (i.e., a negative event following a positive event) would induce different mixed feelings than the same events happening to different people or things. Pairs of emotional pictures with different captions were used to create two event groups. In the "tragic event" group, the positive and negative events happened to the same person or things, and in the "tragicomic event" group, the positive and negative events happened to different people or things. We designed two experiments to explore and compare the generation of mixed feelings in those two groups. In Experiment 1, the negative event was shown first, and in Experiment 2, the negative event was shown second (although the chronological order of the depicted events was the same). The participants were 381 undergraduates: 195 in Experiment 1 and 186 in Experiment 2. In both experiments, we found that tragic events introduced less intense mixed feelings than did tragicomic events due to fewer pleasurable feelings induced by the tragic events. There was no significant difference in the report of negative emotions between the groups. Appraisal theory and negative bias effects may explain these results.

  10. Evaluation on Geant4 Hadronic Models for Pion Minus, Pion Plus and Neutron Particles as Major Antiproton Annihilation Products.

    Science.gov (United States)

    Tavakoli, Mohammad Bagher; Mohammadi, Mohammad Mehdi; Reiazi, Reza; Jabbari, Keyvan

    2015-01-01

    Geant4 is an open source simulation toolkit based on C++, which its advantages progressively lead to applications in research domains especially modeling the biological effects of ionizing radiation at the sub-cellular scale. However, it was shown that Geant4 does not give a reasonable result in the prediction of antiproton dose especially in Bragg peak. One of the reasons could be lack of reliable physic model to predict the final states of annihilation products like pions. Considering the fact that most of the antiproton deposited dose is resulted from high-LET nuclear fragments following pion interaction in surrounding nucleons, we reproduced depth dose curves of most probable energy range of pions and neutron particle using Geant4. We consider this work one of the steps to understand the origin of the error and finally verification of Geant4 for antiproton tracking. Geant4 toolkit version 9.4.6.p01 and Fluka version 2006.3 were used to reproduce the depth dose curves of 220 MeV pions (both negative and positive) and 70 MeV neutrons. The geometry applied in the simulations consist a 20 × 20 × 20 cm(3) water tank, similar to that used in CERN for antiproton relative dose measurements. Different physic lists including Quark-Gluon String Precompound (QGSP)_Binary Cascade (BIC)_HP, the recommended setting for hadron therapy, were used. In the case of pions, Geant4 resulted in at least 5% dose discrepancy between different physic lists at depth close to the entrance point. Even up to 15% discrepancy was found in some cases like QBBC compared to QGSP_BIC_HP. A significant difference was observed in dose profiles of different Geant4 physic list at small depths for a beam of pions. In the case of neutrons, large dose discrepancy was observed when LHEP or LHEP_EMV lists were applied. The magnitude of this dose discrepancy could be even 50% greater than the dose calculated by LHEP (or LHEP_EMV) at larger depths. We found that effect different Geant4 physic list in

  11. Evaluation on Geant4 Hadronic Models for Pion Minus, Pion Plus and Neutron Particles as Major Antiproton Annihilation Products

    Science.gov (United States)

    Tavakoli, Mohammad Bagher; Mohammadi, Mohammad Mehdi; Reiazi, Reza; Jabbari, Keyvan

    2015-01-01

    Geant4 is an open source simulation toolkit based on C++, which its advantages progressively lead to applications in research domains especially modeling the biological effects of ionizing radiation at the sub-cellular scale. However, it was shown that Geant4 does not give a reasonable result in the prediction of antiproton dose especially in Bragg peak. One of the reasons could be lack of reliable physic model to predict the final states of annihilation products like pions. Considering the fact that most of the antiproton deposited dose is resulted from high-LET nuclear fragments following pion interaction in surrounding nucleons, we reproduced depth dose curves of most probable energy range of pions and neutron particle using Geant4. We consider this work one of the steps to understand the origin of the error and finally verification of Geant4 for antiproton tracking. Geant4 toolkit version 9.4.6.p01 and Fluka version 2006.3 were used to reproduce the depth dose curves of 220 MeV pions (both negative and positive) and 70 MeV neutrons. The geometry applied in the simulations consist a 20 × 20 × 20 cm3 water tank, similar to that used in CERN for antiproton relative dose measurements. Different physic lists including Quark-Gluon String Precompound (QGSP)_Binary Cascade (BIC)_HP, the recommended setting for hadron therapy, were used. In the case of pions, Geant4 resulted in at least 5% dose discrepancy between different physic lists at depth close to the entrance point. Even up to 15% discrepancy was found in some cases like QBBC compared to QGSP_BIC_HP. A significant difference was observed in dose profiles of different Geant4 physic list at small depths for a beam of pions. In the case of neutrons, large dose discrepancy was observed when LHEP or LHEP_EMV lists were applied. The magnitude of this dose discrepancy could be even 50% greater than the dose calculated by LHEP (or LHEP_EMV) at larger depths. We found that effect different Geant4 physic list in

  12. Study of the Two-pion Photoproduction on the Deuteron

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Lewis P. [Univ. of South Carolina, Columbia, SC (United States)

    2012-12-01

    Acceptance Spectrometer (CLAS), the hadronic products are detected in coincidence with the incident scattered photon on a deuterium target. This makes it possible to measure the single differential cross sections and the decay angular distributions for the production of two pion final states. The measured cross sections will contribute significantly to a better understanding of the coupling strengths that govern the baryonic and mesonic resonances which will push the knowledge of the strong interaction to a next level. We use CLAS to study the two pion channel from the eg3 data set, for resonance production, specifically investigating the exclusive reaction of yd --> p pi^+pi^?n, and comparing the relevant cross sections to already existing data sets. The eg3 data set provided an excellent data set for investigating photo-induced baryonic and mesonic resonances. It contains a large photon tagging range from 1.1 to 5.5 GeV in the study of photo-coupling strengths, as well as an available two pion reaction channel for resonant decay study. These measurements provide unique and coherent results from tagged photons over a broad range of energy, and represent the only two pion production data above 5 GeV at this present time. We found that the data produced good comparable single-differentials cross sections to other existing CLAS (gll dataset) two pion differential cross sections, and an excellent comparable total cross section to published (ELSA and ABBHHM) two pion total cross sections.

  13. Negative Pressure Pulmonary Edema after Reversing Rocuronium-Induced Neuromuscular Blockade by Sugammadex

    Directory of Open Access Journals (Sweden)

    Manzo Suzuki

    2014-01-01

    Full Text Available Negative pressure pulmonary edema (NPPE is a rare complication that accompanies general anesthesia, especially after extubation. We experienced a case of negative pressure pulmonary edema after tracheal extubation following reversal of rocuronium-induced neuromuscular blockade by sugammadex. In this case, the contribution of residual muscular block on the upper airway muscle as well as large inspiratory forces created by the respiratory muscle which has a low response to muscle relaxants, is suspected as the cause.

  14. Chiral Dynamics in Pion-Photon Reactions Habilitation

    CERN Document Server

    Friedrich, Jan Michael

    As the lightest particle of the strong force, the pion plays a central role in the field of strong interactions, and understanding its properties is of prime relevance for understanding the strong interaction in general. The low-energy behaviour of pions is of particular interest. Although the quark-gluon substructure and their quantum chromodynamics is not apparent then, this specific inner structure causes the presence of approximate symmetries in pion-pion interactions and in pion decays, which gives rise to the systematic description of processes involving pions in terms of few low-energy constants. Specifically, the chiral symmetry and its spontaneous and explicit breaking, treated in chiral perturbation theory (ChPT), leads to firm predictions for low-energy properties of the pion. To those belong the electromagnetic polarisabilities of the pion, describing the leading-order structure effect in pion Compton scattering. The research presented in this work is concerned with the interaction of pions and ph...

  15. Inducing negative affect increases the reward value of appetizing foods in dieters.

    Science.gov (United States)

    Wagner, Dylan D; Boswell, Rebecca G; Kelley, William M; Heatherton, Todd F

    2012-07-01

    Experiencing negative affect frequently precedes lapses in self-control for dieters, smokers, and drug addicts. Laboratory research has similarly shown that inducing negative emotional distress increases the consumption of food or drugs. One hypothesis for this finding is that emotional distress sensitizes the brain's reward system to appetitive stimuli. Using functional neuroimaging, we demonstrate that inducing negative affect in chronic dieters increases activity in brain regions representing the reward value of appetitive stimuli when viewing appetizing food cues. Thirty female chronic dieters were randomly assigned to receive either a negative (n = 15) or neutral mood induction (n = 15) immediately followed by exposure to images of appetizing foods and natural scenes during fMRI. Compared with chronic dieters in a neutral mood, those receiving a negative mood induction showed increased activity in the OFC to appetizing food images. In addition, activity to food images in the OFC and ventral striatum was correlated with individual differences in the degree to which the negative mood induction decreased participants' self-esteem. These findings suggest that distress sensitizes the brain's reward system to appetitive cues, thereby offering a mechanism for the oft-observed relationship between negative affect and disinhibited eating.

  16. Parton-to-Pion Fragmentation Reloaded

    CERN Document Server

    de Florian, D; Epele, M; Hernandez-Pinto, R J; Stratmann, M

    2014-01-01

    We present a new, comprehensive global analysis of parton-to-pion fragmentation functions at next-to-leading order accuracy in QCD. The obtained results are based on the latest experimental information on single-inclusive pion production in electron-positron annihilation, lepton-nucleon deep-inelastic scattering, and proton-proton collisions. An excellent description of all data sets is achieved, and the remaining uncertainties in parton-to-pion fragmentation functions are estimated based on the Hessian method. Extensive comparisons to the results from our previous global analysis are performed.

  17. Backward pion-nucleon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F. [Univ. of Georgia, Athens, GA (United States); Sibirtsev, Alex [Helmholtz-Institut furr Strahlen- und Kernphysik (Theorie) und Bethe Center for Theoretical Physics, Universitat Bonn, D-53115 Bonn, Germany; Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Haidenbauer, Johann [Forschungszentrum Julich (Germany); Meissner, Ulf-G. [Helmholtz-Institut fur Strahlen- und Kernphysik (Theorie) und Bethe Center for Theoretical Physics, Universitat Bonn, Bonn, Germany; Forschungszentrum Julich (Germany)

    2010-02-01

    A global analysis of the world data on differential cross sections and polarization asymmetries of backward pion-nucleon scattering for invariant collision energies above 3 GeV is performed in a Regge model. Including the $N_\\alpha$, $N_\\gamma$, $\\Delta_\\delta$ and $\\Delta_\\beta$ trajectories, we reproduce both angular distributions and polarization data for small values of the Mandelstam variable $u$, in contrast to previous analyses. The model amplitude is used to obtain evidence for baryon resonances with mass below 3 GeV. Our analysis suggests a $G_{39}$ resonance with a mass of 2.83 GeV as member of the $\\Delta_{\\beta}$ trajectory from the corresponding Chew-Frautschi plot.

  18. Hydralazine Induced Lupus Syndrome Presenting with Recurrent Pericardial Effusion and a Negative Antinuclear Antibody

    OpenAIRE

    Praneet Iyer; Ahmed Dirweesh; Ritika Zijoo

    2017-01-01

    Drug induced lupus erythematosus (DIL or DILE) is an autoimmune disorder caused by chronic use of certain drugs. We report a unique case of hydralazine induced lupus syndrome (HILS) with a negative antinuclear antibody in a female patient who was on hydralazine for a period of 1.5–2 years and developed recurrent pericardial effusion as a result of it. Initially her condition was managed with a pericardial window. The recurrence of a massive pericardial effusion necessitated a right hemiperica...

  19. Quark and pion effective couplings from polarization effects

    Energy Technology Data Exchange (ETDEWEB)

    Braghin, Fabio L. [Federal University of Goias, Instituto de Fisica, Goiania, GO (Brazil)

    2016-05-15

    A flavor SU(2) effective model for pions and quarks is derived by considering polarization effects departing from the usual quark-quark effective interaction induced by dressed gluon exchange, i.e. a global color model for QCD. For that, the quark field is decomposed into a component that yields light mesons and the quark-antiquark condensate, being integrated out by means of the auxiliary field method, and another component which yields constituent quarks, which is basically a background quark field. Within a long-wavelength and weak quark field expansion (or large quark effective mass expansion) of a quark determinant, the leading terms are found up to the second order in a zero-order derivative expansion, by neglecting vector mesons that are considerably heavier than the pion. Pions are considered in the structureless limit and, besides the chiral invariant terms that reproduce previously derived expressions, symmetry breaking terms are also presented. The leading chiral quark-quark effective couplings are also found corresponding to a NJL and a vector-NJL couplings. All the resulting effective coupling constants and parameters are expressed in terms of the current and constituent quark masses and of the coupling g. (orig.)

  20. Experiments on the Nuclear Interactions of Pions and Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Ralph C. Minehart

    2005-04-15

    This is the final technical report. Yearly Progress Reports were submitted throughout the duration of the project. Along with our publications, these reports provide a detailed record of our accomplishments. This report largely consists of a summary of the technical activities carried out during last 2-1/2 years of the project, along with a list of papers published in the period from 2002-2005. Our work during this period involved the following: 1. Electro-production of excited states of the nucleon through the analysis of exclusive single pion production reactions induced by polarized electrons incident on both polarized and unpolarized nucleon targets. (JLab) 2. Measurement of proton and deuteron spin structure functions in and above the nucleon resonance region at low and moderate $Q^2$, using inclusive electron-proton and electron deuteron scattering (JLAB). 3. Contributions to the PRIMEX experiment (JLab). 4. A precise measurement of the branching ratio for pion beta decay was carried out along with other members of the PIBETA collaboration (PSI). The first three, labeled JLab, were experiments made with the CLAS detector at the Thomas Jefferson Laboratory in Newport News, VA. The PIBETA experiment was carried out using a low energy pion beam at the Paul Scherrer Institute in Villigen, Switzerland.

  1. Precise analysis of pion-pion scattering data from Roy equations and forward dispersion relations

    CERN Document Server

    Peláez, J R; Kaminski, R; Ynduráin, F J

    2008-01-01

    We review our recent analysis of pion-pion scattering data in terms of Roy equations and Forward Dispersion Relations, and present some preliminary results in terms of a new set of once-subtracted coupled equations for partial waves. The first analysis consists of independent fits to the different pion-pion channels that satisfies rather well the dispersive representation. In the second analysis we constrain the fit with the dispersion relations. The latter provides a very precise and model independent description of data using just analyticity, causality and crossing.

  2. Anomalous electromagnetism of pions and magnons

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, U.-J. [Institute for Theoretical Physics, Bern University Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2005-04-15

    Pions and magnons - the Goldstone bosons of the strong interactions and of magnetism - share a number of common features. Pion and magnon fields couple anomalously to electromagnetism through the conserved Goldstone-Wilczek current of their topological Skyrmion excitations. In the pion case, this coupling gives rise to the decay of the neutral pion into two photons. In the magnon case, the anomalous coupling leads to photonmagnon conversion in an external magnetic field. A measurement of the conversion rate in quantum Hall ferromagnets determines the anyon statistics angle of baby-Skyrmions. If photon-magnon conversion also occurs in antiferromagnets, baby-Skyrmions carry electric charge and may represent the Cooper-pairs of high-temperature superconductors.

  3. Pion valence-quark parton distribution function

    Directory of Open Access Journals (Sweden)

    Lei Chang

    2015-10-01

    Full Text Available Within the Dyson–Schwinger equation formulation of QCD, a rainbow ladder truncation is used to calculate the pion valence-quark distribution function (PDF. The gap equation is renormalized at a typical hadronic scale, of order 0.5 GeV, which is also set as the default initial scale for the pion PDF. We implement a corrected leading-order expression for the PDF which ensures that the valence-quarks carry all of the pion's light-front momentum at the initial scale. The scaling behavior of the pion PDF at a typical partonic scale of order 5.2 GeV is found to be (1−xν, with ν≃1.6, as x approaches one.

  4. Pion production in nucleon-nucleon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Afnan, I.R.

    1982-01-01

    A model describing pion production in proton-proton interactions is presented. The model includes both single nucleon and two nucleon mechanisms. A system of equations representing the reaction is derived and results calculated using these equations are presented.

  5. Numerical and Experimental Study on Negative Buoyance Induced Vortices in N-Butane Jet Flames

    KAUST Repository

    Xiong, Yuan

    2015-07-26

    Near nozzle flow field in flickering n-butane diffusion jet flames was investigated with a special focus on transient flow patterns of negative buoyance induced vortices. The flow structures were obtained through Mie scattering imaging with seed particles in a fuel stream using continuous-wave (CW) Argon-ion laser. Velocity fields were also quantified with particle mage velocimetry (PIV) system having kHz repetition rate. The results showed that the dynamic motion of negative buoyance induced vortices near the nozzle exit was coupled strongly with a flame flickering instability. Typically during the flame flickering, the negative buoyant vortices oscillated at the flickering frequency. The vortices were distorted by the flickering motion and exhibited complicated transient vortical patterns, such as tilting and stretching. Numerical simulations were also implemented based on an open source C++ package, LaminarSMOKE, for further validations.

  6. Low Energy Pion-Hyperon Interaction

    CERN Document Server

    Hama, Y

    2001-01-01

    We study the low energy pion-hyperon interaction considering effective non-linear chiral invariant Lagrangians including pions, rho mesons, hyperons and corresponding resonances. Then we calculate the S- and P-wave phase-shifts, total cross sections, angular distributions and polarizations for the momentum in the center-of-mass frame up to k=400 MeV. With these results we discuss the CP violation in the csi-> pi-lambda and omega-> pi-csi weak decays.

  7. Measurement of the K{sup 0} inclusive cross section in pion-induced reactions at 1.15 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Benabderrahmane, M.L.

    2007-04-18

    The K{sup 0} production cross section and the phase-space distributions were measured in the reaction {pi}{sup -}+ nucleus at an incident momentum of 1.15 GeV/c for C, Al, Cu, Sn and Pb. For the first time the system-size (A) dependence of the K{sup 0} production cross section has been measured and shows an A{sup 2/3} dependence. The experimental ratio of the K{sup 0} momentum distribution produced in Lead to that in Carbon shows a suppression at low momenta. A comparison to the corresponding ratio of K{sup +} measured in proton-induced reactions shows a good agreement, which indicates the sensitivity of this observable to the K{sup 0}N potential. Comparisons to HSD transport model calculations show that this model is not able to describe momentum and rapidity distributions of the K{sup 0} as well as the behaviour of the inclusive cross section as a function of A. Microscopic calculations of the K{sup 0} cross section in nuclear matter including the KN potential in the final state interaction are in good agreement with the measurements. (orig.)

  8. Two- and three-pion quantum statistics correlations in Pb-Pb collisions at $\\sqrt{s_{NN}}$=2.76 TeV at the CERN Large Hadron Collider

    CERN Document Server

    Abelev, Betty Bezverkhny; Adamova, Dagmar; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agocs, Andras Gabor; Agostinelli, Andrea; Agrawal, Neelima; Ahammed, Zubayer; Ahmad, Nazeer; Ahmad, Arshad; Ahmed, Ijaz; Ahn, Sang Un; Ahn, Sul-Ah; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altini, Valerio; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arbor, Nicolas; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Awes, Terry; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bairathi, Vipul; Bala, Renu; Baldisseri, Alberto; Baltasar Dos Santos Pedrosa, Fernando; Ban, Jaroslav; Baral, Rama Chandra; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartke, Jerzy Gustaw; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batyunya, Boris; Batzing, Paul Christoph; Baumann, Christoph Heinrich; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bellwied, Rene; Belmont Moreno, Ernesto; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Berger, Martin Emanuel; Bergognon, Anais Annick Erica; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Boehmer, Felix Valentin; Bogdanov, Alexey; Boggild, Hans; Bogolyubskiy, Mikhail; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Bornschein, Joerg; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Canoa Roman, Veronica; Carena, Francesco; Carena, Wisla; Carminati, Federico; Casanova Diaz, Amaya Ofelia; Castillo Castellanos, Javier Ernesto; Casula, Ester Anna Rita; Catanescu, Vasile Ioan; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contin, Giacomo; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortese, Pietro; Cortes Maldonado, Ismael; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dainese, Andrea; Dang, Ruina; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Kushal; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; Delagrange, Hugues; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Oliveira Valeriano De Barros, Gabriel; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; De Rooij, Raoul Stefan; Diaz Corchero, Miguel Angel; Dietel, Thomas; Divia, Roberto; Di Bari, Domenico; Di Liberto, Sergio; Di Mauro, Antonio; Di Nezza, Pasquale; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni

    2014-02-26

    Correlations induced by quantum statistics are sensitive to the spatio-temporal extent as well as dynamics of particle emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two and three-pion correlations of same and mixed-charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at $\\sqrt{s_{NN}}$= 2.76 TeV at the LHC with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission.The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged pion emission of 22% +- 12%.

  9. Mouth reversal extinguishes mismatch negativity induced by the McGurk illusion

    DEFF Research Database (Denmark)

    Eskelund, Kasper; Andersen, Tobias

    2013-01-01

    The sight of articulatory mouth movements (visual speech) influences auditory speech perception. This is demonstrated by the McGurk illusion in which incongruent visual speech alters the auditory phonetic percept. In behavioral studies, reversal of the vertical mouth direction has been reported...... cortex. Mismatch Negativity (MMN) is a component in the auditory Event-Related Potential (ERP) that is elicited by a change in the auditory percept. It has been shown that the McGurk illusion can induce a MMN. We conducted an experiment in which the MMN could be elicited by the McGurk illusion induced...... by visual speech with either upright (unaltered) or vertically reversed mouth area. In a preliminary analysis, we found a Mismatch Negativity component induced by the McGurk illusion for 6 of 17 participants at electrode Cz when the mouth area was upright. In comparison, these participants produced...

  10. Tamm plasmon-polariton with negative group velocity induced by a negative index meta-material capping layer at metal-Bragg reflector interface.

    Science.gov (United States)

    Liu, Cunding; Kong, Mingdong; Li, Bincheng

    2014-05-05

    Influence of a negative refractive index meta-material (NIM) capping layer on properties of Tamm plasmon-polariton at the interface of metal-Bragg reflector structure is investigated. Conditions for excitation of the plasmon-polariton is determined from reflectivity mapping calculation and analyzed with cavity mode theory. For specific thicknesses of capping layers, Tamm plasmon-polariton with negative group velocity is revealed in a wide region of frequency. Different from backward optical propagation induced by negative effective-group-refractive-index in dispersive media, negative group velocity of Tamm plasmon-polariton results from opposite signs of cross-section-integrated field energy and Poynting vector.

  11. Low-energy pions in nuclear matter and pi pi photoproduction within a BUU transport model

    CERN Document Server

    Buss, O; Mühlich, P; Mosel, U; Shyam, R; Buss, Oliver; Alvarez-Ruso, Luis; Muehlich, Pascal; Mosel, Ulrich; Shyam, Radhey

    2006-01-01

    In the present paper we investigate a method to describe low-energy scattering events of pions and nuclei within a Boltzmann-Uehling-Uhlenbeck (BUU) transport model. Implementing different scenarios of medium modifications, we studied the mean free path of pions in nuclear matter at low momenta and compared pion absorption simulations to data. Pursuing these studies we have shown, that also in a regime of a long pionic wave length the semi-classical BUU model still generates reasonable results. We present results on pi-induced events in the regime of 10 MeV < Tkin < 130 MeV and photo-induced pi pi production at incident beam energies of 400-460 MeV.

  12. Concern-induced negative affect is associated with the occurrence and content of mind-wandering.

    Science.gov (United States)

    Stawarczyk, David; Majerus, Steve; D'Argembeau, Arnaud

    2013-06-01

    Previous research has shown that the content and frequency of mind-wandering episodes--the occurrence of thoughts that are both stimulus-independent and task-unrelated--are closely related to an individual's future-related concerns. Whether this relationship is shaped by the affective changes that are usually associated with future-related concerns still remains unclear, however. In this study, we induced the anticipation of a negatively valenced event and examined whether the ensuing affective changes were related to the occurrence and content of mind-wandering during an unrelated attentional task. We found that the increase in negative affect following concern induction predicted the general frequency of mind-wandering episodes. Furthermore, mind-wandering episodes specifically directed at the induced concern were related to a lower decrease in negative affect during the attentional task. These results suggest that the negative emotional impact of future-related concerns is an important factor to be taken into consideration for the subsequent occurrence of mind-wandering episodes, which might in turn be involved in the maintenance of negative affect over time.

  13. Pion-Muon Concentrating System for Detectors of Highly Enriched Uranium

    CERN Document Server

    Kurennoy, Sergey; Blind, Barbara; Jason, Andrew J; Neri, Filippo

    2005-01-01

    One of many possible applications of low-energy antiprotons collected in a Penning trap can be a portable muon source. Released antiprotons annihilate on impact with normal matter producing on average about 3 charged pions per antiproton, which in turn decay into muons. Existence of such negative-muon sources of sufficient intensity would bring into play, for example, detectors of highly enriched uranium based on muonic X-rays. We explore options of collecting and focusing pions and resulting muons to enhance the muon flux toward the detector. Simulations with MARS and MAFIA are used to choose the target material and parameters of the magnetic system consisting of a few solenoids.

  14. The observation of charge exchange of pions captured in several nuclei

    Science.gov (United States)

    Bassalleck, B.; Corriveau, F.; Hasinoff, M. D.; Marks, T.; Measday, D. F.; Poutissou, J.-M.; Salomon, M.

    1981-06-01

    We have measured for the first time the branching ratios of the charge exchange of stopped negative pions in targets of 6Li, Al, Ti, Cu, Nb and Pb. These branching ratios are of the order of 10 -6, about an order of magnitude smaller than the upper limit previously established. Using the branching ratio for radiative pion capture in 6Li to the ground state of 6He we obtain the Panofsky ratio in 6Li, P6 = (8.7 ± 2.3) × 10 -4.

  15. Elastic and inelastic pion reactions on few nucleon systems

    Energy Technology Data Exchange (ETDEWEB)

    Lensky, V.

    2007-09-29

    In the present work, we are studying elastic and inelastic pion reactions on few-body systems within the framework of chiral effective theory. We consider two specific reactions involving pions on few-nucleon systems, namely pion production in nucleon-nucleon collisions, and incoherent pion photoproduction on the deuteron. These two reactions are closely related to the issue of dispersive and absorptive corrections to the pion-deuteron scattering length, which we also consider in our analysis. The incoherent pion photoproduction is also considered as the possible source for a high-precision determination of the neutron-neutron scattering length. (orig.)

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

    CERN Document Server

    Hoferichter, Martin; Hanhart, Christoph; Kubis, Bastian; Nogga, Andreas; Phillips, Daniel R

    2012-01-01

    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}.

  17. Systematics of pion emission in heavy ion collisions in the 1A GeV regime

    CERN Document Server

    Reisdorf, W; Barret, V; Basrak, Z; Bastid, N; Benabderrahmane, M L; Caplar, R; Crochet, P; Dupieux, P; Dzelalija, M; Fodor, Z; Grishkin, Y; Hartmann, O N; Herrmann, N; Hildenbrand, K D; Hong, B; Kang, T I; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Kis, M; Koczón, P; Korolija, M; Kotte, R; Kress, T; Lebedev, A; Leifels, Y; López, X; Matulewicz, T; Merschmeyer, M; Neubert, W; Petrovici, M; Rami, F; Ryu, M S; Schüttauf, A; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V; Stockmeier, M R; Stoicea, G; Tyminski, Z; Wisniewski, K; Wohlfarth, D; Xiao, Z G; Xu, H S; Yushmanov, I; Zhilin, A; al, et

    2006-01-01

    Using the large acceptance apparatus FOPI, we study pion emission in the reactions (energies in GeV/nucleon are given in parentheses): 40Ca+40Ca (0.4, 0.6, 0.8, 1.0, 1.5, 1.93), 96Ru+96Ru (0.4, 1.0, 1.5), 96Zr+96Zr (0.4, 1.0, 1.5), 197Au+197Au (0.4, 0.6, 0.8, 1.0, 1.2, 1.5). The observables include longitudinal and transverse rapidity distributions and stopping, polar anisotropies, pion multiplicities, transverse momentum spectra, ratios for positively and negatively charged pions of average transverse momenta and of yields, directed flow, elliptic flow. The data are compared to earlier data where possible and to transport model simulations.

  18. Galangin Abrogates Ovalbumin-Induced Airway Inflammation via Negative Regulation of NF-κB

    Directory of Open Access Journals (Sweden)

    Wang-Jian Zha

    2013-01-01

    Full Text Available Persistent activation of nuclear factor κB (NF-κB has been associated with the development of asthma. Galangin, the active pharmacological ingredient from Alpinia galanga, is reported to have a variety of anti-inflammatory properties in vitro via negative regulation of NF-κB. This study aimed to investigate whether galangin can abrogate ovalbumin- (OVA- induced airway inflammation by negative regulation of NF-κB. BALB/c mice sensitized and challenged with OVA developed airway hyperresponsiveness (AHR and inflammation. Galangin dose dependently inhibited OVA-induced increases in total cell counts, eosinophil counts, and interleukin-(IL- 4, IL-5, and IL-13 levels in bronchoalveolar lavage fluid, and reduced serum level of OVA-specific IgE. Galangin also attenuated AHR, reduced eosinophil infiltration and goblet cell hyperplasia, and reduced expression of inducible nitric oxide synthase and vascular cell adhesion protein-1 (VCAM-1 levels in lung tissue. Additionally, galangin blocked inhibitor of κB degradation, phosphorylation of the p65 subunit of NF-κB, and p65 nuclear translocation from lung tissues of OVA-sensitized mice. Similarly, in normal human airway smooth muscle cells, galangin blocked tumor necrosis factor-α induced p65 nuclear translocation and expression of monocyte chemoattractant protein-1, eotaxin, CXCL10, and VCAM-1. These results suggest that galangin can attenuate ovalbumin-induced airway inflammation by inhibiting the NF-κB pathway.

  19. Electric field cancellation on quartz: a Rb adsorbate induced negative electron affinity surface

    CERN Document Server

    Sedlacek, J A; Rittenhouse, S T; Weck, P F; Sadeghpour, H R; Shaffer, J P

    2015-01-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric fields resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the adsorbed Rb induces a negative electron affinity (NEA) on the quartz surface. The NEA surface allows low energy electrons to bind to the surface and cancel the electric field from the Rb adsorbates. Our results are important for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface.

  20. Hydralazine Induced Lupus Syndrome Presenting with Recurrent Pericardial Effusion and a Negative Antinuclear Antibody

    Science.gov (United States)

    Iyer, Praneet; Zijoo, Ritika

    2017-01-01

    Drug induced lupus erythematosus (DIL or DILE) is an autoimmune disorder caused by chronic use of certain drugs. We report a unique case of hydralazine induced lupus syndrome (HILS) with a negative antinuclear antibody in a female patient who was on hydralazine for a period of 1.5–2 years and developed recurrent pericardial effusion as a result of it. Initially her condition was managed with a pericardial window. The recurrence of a massive pericardial effusion necessitated a right hemipericardiectomy. After hydralazine was stopped, she never had any further episodes of pericardial effusion or tamponade. PMID:28194293

  1. Hydralazine Induced Lupus Syndrome Presenting with Recurrent Pericardial Effusion and a Negative Antinuclear Antibody

    Directory of Open Access Journals (Sweden)

    Praneet Iyer

    2017-01-01

    Full Text Available Drug induced lupus erythematosus (DIL or DILE is an autoimmune disorder caused by chronic use of certain drugs. We report a unique case of hydralazine induced lupus syndrome (HILS with a negative antinuclear antibody in a female patient who was on hydralazine for a period of 1.5–2 years and developed recurrent pericardial effusion as a result of it. Initially her condition was managed with a pericardial window. The recurrence of a massive pericardial effusion necessitated a right hemipericardiectomy. After hydralazine was stopped, she never had any further episodes of pericardial effusion or tamponade.

  2. Visible light induced ocular delayed bioluminescence as a possible origin of negative afterimage

    CERN Document Server

    Bokkon, I; Wang, C; Dai, J; Salari, V; Grass, F; Antal, I

    2011-01-01

    The delayed luminescence of biological tissues is an ultraweak reemission of absorbed photons after exposure to external monochromatic or white light illumination. Recently, Wang, B\\'okkon, Dai and Antal (Brain Res. 2011) presented the first experimental proof of the existence of spontaneous ultraweak biophoton emission and visible light induced delayed ultraweak photon emission from in vitro freshly isolated rat's whole eye, lens, vitreous humor and retina. Here, we suggest that the photobiophysical source of negative afterimage can also occur within the eye by delayed bioluminescent photons. In other words, when we stare at a colored (or white) image for few seconds, external photons can induce excited electronic states within different parts of the eye that is followed by a delayed reemission of absorbed photons for several seconds. Finally, these reemitted photons can be absorbed by nonbleached photoreceptors that produce a negative afterimage. Although this suggests the photobiophysical source of negativ...

  3. Ceramide and ceramide 1-phosphate are negative regulators of TNF-α production induced by lipopolysaccharide.

    Science.gov (United States)

    Józefowski, Szczepan; Czerkies, Maciej; Łukasik, Anna; Bielawska, Alicja; Bielawski, Jacek; Kwiatkowska, Katarzyna; Sobota, Andrzej

    2010-12-01

    LPS is a constituent of cell walls of Gram-negative bacteria that, acting through the CD14/TLR4 receptor complex, causes strong proinflammatory activation of macrophages. In murine peritoneal macrophages and J774 cells, LPS at 1-2 ng/ml induced maximal TNF-α and MIP-2 release, and higher LPS concentrations were less effective, which suggested a negative control of LPS action. While studying the mechanism of this negative regulation, we found that in J774 cells, LPS activated both acid sphingomyelinase and neutral sphingomyelinase and moderately elevated ceramide, ceramide 1-phosphate, and sphingosine levels. Lowering of the acid sphingomyelinase and neutral sphingomyelinase activities using inhibitors or gene silencing upregulated TNF-α and MIP-2 production in J774 cells and macrophages. Accordingly, treatment of those cells with exogenous C8-ceramide diminished TNF-α and MIP-2 production after LPS stimulation. Exposure of J774 cells to bacterial sphingomyelinase or interference with ceramide hydrolysis using inhibitors of ceramidases also lowered the LPS-induced TNF-α production. The latter result indicates that ceramide rather than sphingosine suppresses TNF-α and MIP-2 production. Of these two cytokines, only TNF-α was negatively regulated by ceramide 1-phosphate as was indicated by upregulated TNF-α production after silencing of ceramide kinase gene expression. None of the above treatments diminished NO or RANTES production induced by LPS. Together the data indicate that ceramide negatively regulates production of TNF-α and MIP-2 in response to LPS with the former being sensitive to ceramide 1-phosphate as well. We hypothesize that the ceramide-mediated anti-inflammatory pathway may play a role in preventing endotoxic shock and in limiting inflammation.

  4. Gibberellins negatively regulate light-induced nitrate reductase activity in Arabidopsis seedlings.

    Science.gov (United States)

    Zhang, Yongqiang; Liu, Zhongjuan; Liu, Rongzhi; Wang, Liguang; Bi, Yurong

    2011-12-15

    In the present study, the role of phytohormone gibberellins (GAs) on regulating the nitrate reductase (NR) activity was tested in Arabidopsis seedlings. The NR activity in light-grown Col-0 seedlings was reduced by exogenous GA₃ (an active form of GAs), but enhanced by exogenous paclobutrazol (PAC, a gibberellin biosynthesis inhibitor), suggesting that GAs negatively regulate the NR activity in light-grown seedlings. Light is known to influence the NR activity through both photosynthesis and phytochromes. When etiolated seedlings were transferred to white or red light, both exogenously applied GA₃ and PAC were found to function on the NR activity only in the presence of sucrose, implying that GAs are not involved in light signaling-induced but negatively regulate photoproducts-induced NR activity. NR is regulated by light mainly at two levels: transcript level and post-translational level. Our reverse transcription (RT)-PCR assays showed that GAs did not affect the transcript levels of NIA1 and NIA2, two genes that encode NR proteins. But the divalent cations (especially Mg²⁺) were required for GAs negative regulation of NR activity, in view of the importance of divalent cations during the process of post-translational regulation of NR activity, which indicates that GAs very likely regulate the NR activity at the post-translational level. In the following dark-light shift analyses, GAs were found to accelerate dark-induced decrease, but retard light-induced increase of the NR activity. Furthermore, it was observed that application of G₃ or PAC could impair diurnal variation of the NR activity. These results collectively indicate that GAs play a negative role during light regulation of NR activity in nature.

  5. Negative Photoconductivity Induced by Surface Plasmon Polaritons in the Kretschmann Configuration

    Institute of Scientific and Technical Information of China (English)

    郑京镐; 孙家林; 薛平

    2011-01-01

    Prism coupling in the Kretschmann configuration is a well-known method for the excitation of surface plasmon polaritons(SPPs)in thin films bounded from one side by a prism and from the other side by air.Based on the Kretschmann configuration,we experimentally study the transport properties of a silver thin film with a thickness of 55nm and a width of 500μm undergoing total internal reflection.We observe considerable negative photoconductivity in the film induced by the SPPs excited in this configuration and find that both SPP-electron interactions and SPP-induced heating have contributions to the negative photoconductivity.We believe that the new phenomena,which result from the combination of photonics and electronics,will be useful in relative technical applications and scientific research.%Prism coupling in the Krctschmann configuration is a well-known method for the excitation of surface plasmon polaritons (SPPs) in thin films bounded from one side by a prism and from the other side by air. Based on the Kretschmann configuration, we experimentally study the transport properties of a silver thin Him with a thickness of 55nm and a width of 500μm undergoing total internal reflection. We observe considerable negative photoconductivity in the film induced by the SPPs excited in this configuration and find that both SPP-electron interactions and SPP-induced heating have contributions to the negative photoconductivity. We believe that the new phenomena, which result from the combination of photonics and electronics, will be useful in relative technical applications and scientific research.

  6. Investigation on financial crises with the negative-information-propagation-induced model

    Science.gov (United States)

    Fan, Feng-Hua; Deng, Yanbin; Huang, Yong-Chang

    2017-03-01

    We first argue about the similarity between the propagation phenomenon of negative information about potential deterioration of economic situation in group of investors and the propagation phenomenon of infectious disease in crowd Applying the negative-information-propagation-induced model built based on above argument, we investigate the relationship between the generation of financial crises and propagation effects of negative information We introduce the discrimination parameter to distinguish whether or not negative information will be propagated extensively in group of investors. We also introduce the target critical value of financial crises. By comparing the theoretically predicted ratio of the long term projected number of total investors to the total number of investors at some time as initial time with target critical value of financial crises, the model can provide real-time monitoring of whether the curve of total number of investors is progressing toward the direction of generating financial crises or running on track of financial markets safety. If at some time this ratio is computed to be less than the target critical value of financial crises, governments can take relevant measures to prevent the generation of financial crises in advance Governments' interference helps to recover the confidence of investors so that they never will again believe in negative information to continue their investment. Results from theoretical and numerical analysis show that the number of investors who hold the belief of potential deterioration of economic situation, and the number of investors who withdraw capital and depart from financial markets for avoiding business loss when governments make appropriate interference are lowered compared to that without appropriate governments' interference. The results show the effectiveness of governments in preventing financial crises from the viewpoint of the negative information-propagation-induced model, namely governments

  7. Role of induced negative and positive emotions in sensitivity to itch and pain in women.

    Science.gov (United States)

    van Laarhoven, A I M; Walker, A L; Wilder-Smith, O H; Kroeze, S; van Riel, P L C M; van de Kerkhof, P C M; Kraaimaat, F W; Evers, A W M

    2012-08-01

    Itch and pain are common symptoms in skin disease. It has been suggested that negative emotions may play a role in itch and pain. To date, however, the role of emotions has only been studied for pain in experimental studies, not yet for itch. To investigate the effects of negative and positive emotions on the sensitivity to itch and pain. Film fragments were used to induce a negative or positive emotional state in healthy women. Itch and pain were induced using the following somatosensory stimuli: electrical stimulation, histamine iontophoresis and the cold pressor test. Results showed that the scores for itch and pain evoked by histamine and the cold pressor test, respectively, were significantly higher in the negative than in the positive emotion condition, whereas tolerance thresholds to electrical stimulation and the cold pressor test, and stimulus unpleasantness scores did not differ between the two conditions. These findings for the first time indicate in an experimental design that emotions play a role in sensitivity to somatosensory sensations of both itch and pain. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  8. Analysis of shower shapes of pions and protons from the tungsten analogue hadronic calorimeter

    CERN Document Server

    Burger, Angela Maria

    2014-01-01

    In this report, analysis results of test-beam data taken with the CALICE tungsten analogue hadronic calorimeter prototype are presented. Proton and pion-induced showers originating from a particle beam of an momentum range of 25-150 GeV are examined. As a first part of the study, a comparison between data and two GEANT4 Monte-Carlo simulations with regard to variables describing hadronic shower fluctuations is performed. In the second part of this report, the separation potential of the W-AHCAL for protons and pions is discussed.

  9. Present Status of Single Pion Production in Neutrino-Nucleus Reactions

    CERN Document Server

    Alvarez-Ruso, L; Nieves, J; Vacas, M J Vicente

    2016-01-01

    Some of the recent progress in the physics of pion production induced by neutrinos on nucleons and nuclei is reviewed from a theoretical perspective. The importance of Watson's theorem to reconcile ANL and BNL data with the off-diagonal Goldberger-Treiman relation for the $\\Delta(1232)$ is discussed. The disagreement between MiniBooNE data and theoretical calculations is presented in the light of the new MINERvA data. The coherent pion production data on $^{12}$C obtained by MINERvA are also compared to different microscopic and PCAC models.

  10. Constraining pion interactions at very high energies by cosmic ray data

    CERN Document Server

    Ostapchenko, Sergey

    2016-01-01

    We demonstrate that a substantial part of the present uncertainties in model predictions for the average maximum depth of cosmic ray-induced extensive air showers is related to very high energy pion-air collisions. Our analysis shows that the position of the maximum of the muon production profile in air showers is strongly sensitive to the properties of such interactions. Therefore, the measurements of the maximal muon production depth by cosmic ray experiments provide a unique opportunity to constrain the treatment of pion-air interactions at very high energies and to reduce thereby model-related uncertainties for the shower maximum depth.

  11. Low-energy pions in nuclear matter and {pi}{pi} photoproduction within a BUU transport model

    Energy Technology Data Exchange (ETDEWEB)

    Buss, O.; Alvarez-Ruso, L.; Muehlich, P.; Mosel, U. [Universitaet Giessen, Institut fuer Theoretische Physik (Germany)

    2006-08-15

    A description of the low-energy scattering of pions and nuclei within a BUU transport model is presented. Implementing different scenarios of medium modifications, the mean free path of pions in nuclear matter at low momenta and pion absorption reactions on nuclei have been studied and compared to data and to results obtained via quantum-mechanical scattering theory. We show that even in a regime of a long pionic wavelength the semi-classical transport model is still a reliable framework for pion kinetic energies greater than {approx}20-30 MeV. Results are presented on {pi}-absorption cross-sections in the regime of 10 MeV{<=}T{sup {pi}}{sub kin}{<=}130 MeV and on photon-induced {pi}{pi} production at incident beam energies of 400-500 MeV. (orig.)

  12. Measurement of Collins asymmetry in inclusive production of pion pairs at BaBar

    Directory of Open Access Journals (Sweden)

    Garzia Isabella

    2015-01-01

    Full Text Available We present a measurement of the azimuthal asymmetries induced by the Collins effect in inclusive production of pion pairs in the e+e− → ππX annihilation process, where two charged pion pairs are produced in opposite hemispheres. The data collected by the BABAR detector at the SLAC Linear Accelerator Laboratory allows the determination of the Collins fragmentation function as a function of the pion fractional energies and transverse momenta, as well as the determination of its behavior in a 4-dimensional space. These results can be combined with semi-inclusive deep inelastic scattering data to extract the transversity parton distribution function, which is the least known leading-twist component of the QCD description of the nucleon.

  13. Spectator induced electromagnetic effect on directed flow in heavy ion collisions

    CERN Document Server

    Rybicki, Andrzej

    2013-01-01

    We estimate the electromagnetic effect of the spectator charge on azimuthal anisotropies observed in heavy ion collisions. For peripheral Pb+Pb reactions at the top energy of the CERN Super Proton Synchrotron, $\\sqrt{s_{NN}}=17.3$ GeV, we predict this effect to bring very large distortions to the observed directed flow, $v_1$, of positive and negative pions emitted close to beam rapidity. The overall magnitude of this effect is comparable to values of $v_1$ reported by the WA98 experiment. We argue that also at lower rapidities, the spectator induced electromagnetic effect may result in the splitting of values of $v_1$ observed for positive and negative pions. Such a splitting is visible in the data reported by the STAR Collaboration from the RHIC Beam Energy Scan. Both effects are sensitive to the space-time scenario assumed for pion emission. Therefore, they bring new information on the collision dynamics.

  14. nuSTORM Pion Beamline Design Update

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A. [Indiana U.; Bross, A. [Fermilab; Neuffer, D. [Fermilab; Lee, S. Y. [Indiana U.

    2013-09-01

    A facility producing neutrinos from muons that decay in a racetrack ring can provide extremely well understood neutrino beams for oscillation physics and the search for sterile neutrinos. The “neutrinos from STORed Muons” (nuSTORM) facility based on this idea has been introduced by Bross, Neuffer et al. The design of the nuSTORM facility and the particle tracking have been presented in the paper of Liu, et al. This paper demonstrates the recent optimization results of the pion beamline, with G4beamline simulations. The optimum choice of pion beam center momentum, a new algorithm on fitting bivariate Gaussian distribution to the pion phase space data at the downstream side of the horn, and the comparison of the beamline performance with the optics designed based on Graphite and Inconel targets are also described.

  15. Pion and Kaon Electromagnetic Form Factors

    CERN Document Server

    Bijnens, J; Bijnens, Johan; Talavera, Pere

    2002-01-01

    We study the electromagnetic form factor of the pion and kaons at low-energies with the use of Chiral Perturbation Theory. The analysis is performed within the three flavour framework and at next-to-next-to-leading order. We explain carefully all the relevant consistency checks on the expressions, present full analytical results for the pion form factor and describe all the assumptions in the analysis. From the phenomenological point of view we make use of our expression and the available data to obtain the charge radius of the pion obtaining $_V^\\pi=(0.452+-0.013) fm^2$, as well as the low-energy constant $L_9^r(m_\\rho)= (5.93+-0.43)10^{-3}$. We also obtain experimental values for 3 combinations of order $p^6$ constants.

  16. Semiclassical model for pion production by neutrons on nuclei

    CERN Document Server

    Sparrow, D A; Sternheim, M M

    1974-01-01

    A model for pion production by neutrons on nuclei is derived by a straightforward extension of the semiclassical model for pion production by protons, previously described by two of the present authors, Silbar and Sternheim (1973). Both models are then applied to compute pion production cross sections for nucleons incident on Pb, Cu and Al, and pion absorption cross sections in nuclear matter. Results are consistent with (unpublished) experimental data from CERN. (10 refs).

  17. PKC{eta} is a negative regulator of AKT inhibiting the IGF-I induced proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shahaf, Galit; Rotem-Dai, Noa; Koifman, Gabriela; Raveh-Amit, Hadas; Frost, Sigal A.; Livneh, Etta, E-mail: etta@bgu.ac.il

    2012-04-15

    The PI3K-AKT pathway is frequently activated in human cancers, including breast cancer, and its activation appears to be critical for tumor maintenance. Some malignant cells are dependent on activated AKT for their survival; tumors exhibiting elevated AKT activity show sensitivity to its inhibition, providing an Achilles heel for their treatment. Here we show that the PKC{eta} isoform is a negative regulator of the AKT signaling pathway. The IGF-I induced phosphorylation on Ser473 of AKT was inhibited by the PKC{eta}-induced expression in MCF-7 breast adenocarcinoma cancer cells. This was further confirmed in shRNA PKC{eta}-knocked-down MCF-7 cells, demonstrating elevated phosphorylation on AKT Ser473. While PKC{eta} exhibited negative regulation on AKT phosphorylation it did not alter the IGF-I induced ERK phosphorylation. However, it enhanced ERK phosphorylation when stimulated by PDGF. Moreover, its effects on IGF-I/AKT and PDGF/ERK pathways were in correlation with cell proliferation. We further show that both PKC{eta} and IGF-I confer protection against UV-induced apoptosis and cell death having additive effects. Although the protective effect of IGF-I involved activation of AKT, it was not affected by PKC{eta} expression, suggesting that PKC{eta} acts through a different route to increase cell survival. Hence, our studies show that PKC{eta} provides negative control on AKT pathway leading to reduced cell proliferation, and further suggest that its presence/absence in breast cancer cells will affect cell death, which could be of therapeutic value.

  18. Pions in the nuclear medium and Drell-Yan scattering

    NARCIS (Netherlands)

    Dieperink, AEL; Korpa, CL

    1997-01-01

    We investigate the modification of the pion cloud in the nuclear medium and its effect on the nuclear Drell-Yan process. The pion's in-medium self-energy is calculated in a self-consistent delta-hole model, with particle-hole contributions also included. Both the imaginary and real parts of the pion

  19. Medium Effects of Low Energy Pions

    Science.gov (United States)

    Friedman, E.

    2004-03-01

    Fits of pion--nucleus potentials to large sets of pionic atom data reveal departures of parameter values from the corresponding free π N parameters. These medium effects can be quantitatively reproduced by a chiral-motivated model where the pion decay constant is modified in the medium or by including the empirical on-shell energy dependence of the amplitudes. No consistency is obtained between pionic atoms and the free π N interaction when an extreme off-shell chiral model is used. The role of the size of data sets is briefly discussed.

  20. Cyclooxygenase-2 regulates TGFβ-induced cancer stemness in triple-negative breast cancer

    Science.gov (United States)

    Tian, Jun; Hachim, Mahmood Y.; Hachim, Ibrahim Y.; Dai, Meiou; Lo, Chieh; Raffa, Fatmah Al; Ali, Suhad; Lebrun, Jean Jacques

    2017-01-01

    Triple negative breast cancer (TNBC), an aggressive subtype of breast cancer, display poor prognosis and exhibit resistance to conventional therapies, partly due to an enrichment in breast cancer stem cells (BCSCs). Here, we investigated the role of the cyclooxygenase-2 (COX-2), a downstream target of TGFβ, in regulating BCSCs in TNBC. Bioinformatics analysis revealed that COX-2 is highly expressed in TNBC and that its expression correlated with poor survival outcome in basal subtype of breast cancer. We also found TGFβ-mediated COX-2 expression to be Smad3-dependent and to be required for BCSC self-renewal and expansion in TNBCs. Knocking down COX-2 expression strikingly blocked TGFβ-induced tumorsphere formation and TGFβ-induced enrichment of the two stem-like cell populations, CD24lowCD44high and ALDH+ BCSCs. Blocking COX-2 activity, using a pharmacological inhibitor also prevented TGFβ-induced BCSC self-renewal. Moreover, we found COX-2 to be required for TGFβ-induced expression of mesenchymal and basal breast cancer markers. In particular, we found that TGFβ-induced expression of fibronectin plays a central role in TGFβ-mediated breast cancer stemness. Together, our results describe a novel role for COX-2 in mediating the TGFβ effects on BCSC properties and imply that targeting the COX-2 pathway may prove useful for the treatment of TNBC by eliminating BCSCs. PMID:28054666

  1. Bending-induced mode non-degeneracy and coupling in chalcogenide negative curvature fibers.

    Science.gov (United States)

    Wei, Chengli; Menyuk, Curtis R; Hu, Jonathan

    2016-05-30

    We study bend loss in chalcogenide negative curvature fibers with different polarizations, different tube wall thicknesses, and different bend directions relative to the mode polarization. The coupling between the core mode and tube modes induces bend loss peaks in the two non-degenerate modes at the same bend radius. There is as much as a factor of 28 difference between the losses of the two polarization modes. The fiber with a larger tube wall thickness, corresponding to a smaller inner tube diameter, can sustain a smaller bend radius. The bend loss is sensitive to the bend direction when coupling occurs between the core mode and tube modes. A bend loss of 0.2 dB/m at a bend radius of 16 cm, corresponding to 0.2 dB/turn, can be achieved in a chalcogenide negative curvature fiber.

  2. Endothelium negatively modulates the vascular relaxation induced by nitric oxide donor, due to uncoupling NO synthase.

    Science.gov (United States)

    Bonaventura, Daniella; Lunardi, Claure N; Rodrigues, Gerson J; Neto, Mário A; Vercesi, Juliana A; de Lima, Renata G; da Silva, Roberto S; Bendhack, Lusiane M

    2009-10-01

    Nitrosyl ruthenium complexes have been characterized as nitric oxide (NO) donors that induce relaxation in the denuded rat aorta. There are some differences in their vascular relaxation mechanisms compared with sodium nitroprusside. This study investigates whether the endothelium could interfere with the [Ru(terpy)(bdq)NO](3+)-TERPY-induced vascular relaxation, by analyzing the maximal relaxation (Emax) and potency (pD(2)) of TERPY. Vascular reactivity experiments showed that the endothelium negatively modulates (pD(2): 6.17+/-0.07) the TERPY relaxation in intact rat aortic rings compared with the denuded rat aorta (pD(2): 6.65+/-0.07). This effect is abolished by a non-selective NO-synthase (NOS) inhibitor L-NAME (pD(2): 6.46+/-0.10), by the superoxide anion (O(2)(-)) scavenger TIRON (pD(2): 6.49+/-0.08), and by an NOS cofactor BH(4) (pD(2): 6.80+/-0.10). The selective dye for O(2)(-) (DHE) shows that TERPY enhances O(2)(-) concentration in isolated endothelial cells (intensity of fluorescence (IF):11258.00+/-317.75) compared with the basal concentration (IF: 7760.67+/-381.50), and this enhancement is blocked by L-NAME (IF: 8892.33+/-1074.41). Similar results were observed in vascular smooth muscle cells (concentration of superoxide after TERPY: 2.63+/-0.17% and after TERPY+L-NAME: -4.63+/-0.14%). Considering that TERPY could induce uncoupling NOS, thus producing O(2)(-), we have also investigated the involvement of prostanoids in the negative modulation of the endothelium. The non-selective cyclooxygenase (COX) inhibitor indomethacin and the selective tromboxane (TXA(2)) receptor antagonist SQ29548 reduce the effect of the endothelium on TERPY relaxation (pD(2) INDO: 6.80+/-0.17 and SQ29548: 6.85+/-0.15, respectively). However, a selective prostaglandin F(2alpha) receptor antagonist (AH6809) does not change the endothelium effect. Moreover, TERPY enhances the concentration of TXA(2) stable metabolite (TXB(2)), but this effect is blocked by L-NAME and TIRON. The

  3. Low Energy Pion-Pion Elastic Scattering in Sakai-Sugimoto Model

    CERN Document Server

    Parthasarathy, R

    2008-01-01

    We have considered the holographic large $N_c$ QCD model proposed by Sakai and Sugimoto and evaluated the non-Abelian DBI-action on the D8-brane upto $(\\alpha')^4$ terms. Restricting to the pion sector, these corrections give rise to four derivative contact terms for the pion field. We derive the Weinberg's phenemenological lagrangian. The coefficients of the four derivative terms are determined in terms of $g_{YM}^2$. The low energy pion-pion scattering amplitudes are evaluated. Numerical results are presented with the choice of $M_{KK}=0.94 GeV$ and $N_c=11$. The results are compared with the amplitudes calculated using the experimental phase shifts. The agreement with the experimental data is found to be satisfactory.

  4. Quark-Hadron Duality for the Pion: a Phenomenological Study

    Energy Technology Data Exchange (ETDEWEB)

    Wally Melnitchouk

    2002-08-01

    We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition region at intermediate Q{sup 2}. Combining Drell-Yan data on the leading twist quark distribution in the pion with a model for the resonance region at large x, we calculate QCD moments of the pion structure function over a range of Q{sup 2}, and quantify the role of higher twist corrections. Using a parameterization of the pion elastic form factor and phenomenological models for the pi --> p transition form factor, we test the extent to which local duality may be valid for the pion.

  5. Dropping Sigma-Meson Mass and In-Medium S-Wave pion-pion Correlations

    CERN Document Server

    Aouissat, Z; Schuck, P; Wambach, J

    1999-01-01

    The influence of a dropping sigma-meson mass on previously calculated in-medium pion-pion correlations in the J=I=0 (sigma-meson) channel is investigated. It is found that the invariant-mass distribution around the vacuum threshold experiences a further strong enhancement with respect to standard many-body effects. The relevance of this result for the explanation of recent $A(\\pi,2\\pi)X$ data is pointed out.

  6. Proton-pion and two-pion correlations in eA interactions

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, P.V. [ITEP, Moscow (Russian Federation); Doroshkevich, E.A. [ITEP, Moscow (Russian Federation); Kurzenkov, A.A. [ITEP, Moscow (Russian Federation); Leksin, G.A. [ITEP, Moscow (Russian Federation); Stavinsky, A.V. [ITEP, Moscow (Russian Federation); Vlassov, A.V. [ITEP, Moscow (Russian Federation)

    1997-05-01

    We report here the results on studying of proton-pion and two-pion correlations in eA interactions at 5 GeV. Kinematic correlations were studied as a function of the two-particle opening angle, their momenta and proton multiplicity. The universal properties of correlation functions were found with respect to different particle species. Interferometry method was used to determine the size of the interaction region. (orig.). With 2 figs.

  7. Electric field cancellation on quartz by Rb adsorbate-induced negative electron affinity

    Science.gov (United States)

    Shaffer, James

    2016-05-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric fields resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the adsorbed Rb induces a negative electron affinity (NEA) on the quartz surface. The NEA surface allows low energy electrons to bind to the surface and cancel the electric field from the Rb adsorbates. Our results are important for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface. This work was supported by the DARPA Quasar program by a Grant through ARO (60181-PH-DRP) and the AFOSR (FA9550-12-1-0282),.

  8. Aging. Aging-induced type I interferon response at the choroid plexus negatively affects brain function.

    Science.gov (United States)

    Baruch, Kuti; Deczkowska, Aleksandra; David, Eyal; Castellano, Joseph M; Miller, Omer; Kertser, Alexander; Berkutzki, Tamara; Barnett-Itzhaki, Zohar; Bezalel, Dana; Wyss-Coray, Tony; Amit, Ido; Schwartz, Michal

    2014-10-03

    Aging-associated cognitive decline is affected by factors produced inside and outside the brain. By using multiorgan genome-wide analysis of aged mice, we found that the choroid plexus, an interface between the brain and the circulation, shows a type I interferon (IFN-I)-dependent gene expression profile that was also found in aged human brains. In aged mice, this response was induced by brain-derived signals, present in the cerebrospinal fluid. Blocking IFN-I signaling within the aged brain partially restored cognitive function and hippocampal neurogenesis and reestablished IFN-II-dependent choroid plexus activity, which is lost in aging. Our data identify a chronic aging-induced IFN-I signature, often associated with antiviral response, at the brain's choroid plexus and demonstrate its negative influence on brain function, thereby suggesting a target for ameliorating cognitive decline in aging.

  9. Distorted waves in pion- (Kaon-) nucleus reactions

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, E.R.; Thaler, R.M.

    1978-10-02

    The difference between the Schroedinger and Klein-Gordon wave functions is calculated for 100--200-MeV pions. The same optical-model potential is used in each case. The differences in the distorted waves so calculated are shown to be significant even though the elastic scattering phase shifts re nearly identical.

  10. Isospin violation in pion-kaon scattering

    CERN Document Server

    Kubis, B; Kubis, Bastian; Mei{\\ss}ner, Ulf-G.

    2002-01-01

    We consider strong and electromagnetic isospin violation in near-threshold pion-kaon scattering. At tree level, such effects are small for all physical channels. We work out the complete one-loop corrections to the process pi^- K^+ -> pi^0 K^0. They come out rather small. We also show that the corresponding radiative cross section is highly suppressed at threshold.

  11. Pion decay constants in dense skyrmion matter

    Directory of Open Access Journals (Sweden)

    Lee H.-J.

    2010-10-01

    Full Text Available According to the QCD, the hadronic matter can have various phases with matter density and temperature. In general, when there is phase transition in a matter, it is known that a symmetry in the matter changes. In case of the hadronic matter, the chiral symmetry in the matter is expected to be restored when the matter density (or temperature increases. The actual order parameter with respect to the chiral symmetry in the hadronic matter is known as the quark condensate from the QCD, but the pion decay constant, corresponding to the radius of the chiral circle, plays the role of the order parameter in an effective field theoretical approach to the QCD. In this paper, by using the skyrmion model which is an effective theory to the QCD, we construct the skyrmion matter as a model of the hadronic matter (nuclear matter and calculate the pion decay constant in the matter. Because of presence of the matter, the pion decay constant is split into the two components, the temporal component and the spatial component. We discuss the phase transition in the skyrmion matter and behavior of the two components of the decay constant for massless pion with density of the skyrmion matter.

  12. Measurement of the Charged-Pion Polarizability

    CERN Document Server

    Adolph, C; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dinkelbach, A.M.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Guthorl, T.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Hoppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kroumchtein, Z.V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.K.; Marchand, C.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M.A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peshekhonov, D.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Rocco, E.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rychter, A.; Samoylenko, V.D.; Sandacz, A.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-01-01

    The COMPASS collaboration at CERN has investigated pion Compton scattering, $\\pi^-\\gamma\\rightarrow \\pi^-\\gamma$, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction $\\pi^-\\mathrm{Ni}\\rightarrow\\pi^-\\gamma\\;\\mathrm{Ni}$, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, $Q^2<0.0015$ (GeV/$c$)$^2$. From a sample of 63 000 events the pion electric polarisability is determined to be $\\alpha_\\pi = (2.0 \\pm 0.6_{\\mbox{stat}} \\pm 0.7_{\\mbox{syst}}) \\times 10^{-4} \\mbox{fm}^3$ under the assumption $\\alpha_\\pi=-\\beta_\\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is fou...

  13. High purity pion beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Blecher, M. [Physics Department, Virginia Tech., Blacksburg, VA 24061 (United States); Bryman, D.A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Comfort, J. [Arizona State University, Tempe, AZ 85287 (United States); Doornbos, J.; Doria, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Hussein, A. [University of Northern British Columbia, Prince George, BC, V2N 4Z9 (Canada); Ito, N. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kettell, S. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Kurchaninov, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Malbrunot, C. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Marshall, G.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Numao, T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)], E-mail: toshio@triumf.ca; Poutissou, R.; Sher, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Walker, B. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Yamada, K. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +}{yields}e{sup +}{nu} is also described.

  14. High Purity Pion Beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Kettell, S.; Kettell, S.; Aguilar-Arevalo, A.; Blecher, M.; Bryman, D.A.; Comfort, J.; Doornbos, J.; Doria, L.; Hussein, A.; Ito, N.; et al.

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +} {yields} e{sup +}{nu} is also described.

  15. Exclusive electroproduction of two pions at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, H. [Tel Aviv Univ. (Israel). School of Physics; Max Planck Institute for Physics, Munich (Germany); Abt, I. [Max Planck Institute for Physics, Munich (Germany); Adamczyk, L. [AGH-Univ. of Science and Technology, Krakow (PL). Faculty of Physics and Applied Computer Science] (and others)

    2011-11-15

    The exclusive electroproduction of two pions in the mass range 0.4< M{sub {pi}}{sub {pi}} <2.5 GeV has been studied with the ZEUS detector at HERA using an integrated luminosity of 82 pb{sup -1}. The analysis was carried out in the kinematic range of 2< Q{sup 2}<80 GeV{sup 2}, 32pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, vertical stroke F(M{sub {pi}}{sub {pi}}) vertical stroke, assuming that the studied mass range includes the contributions of the {rho}, {rho}{sup '} and {rho}'' vector-meson states. The masses and widths of the resonances were obtained and the Q{sup 2} dependence of the cross-section ratios {sigma}({rho}{sup '} {yields} {pi}{pi})/{sigma}({rho}) and {sigma}({rho}'' {yields} {pi}{pi})/{sigma}({rho}) was extracted. The pion form factor obtained in the present analysis is compared to that obtained in e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -}. (orig.)

  16. Probing neutron-proton dynamics by pions

    CERN Document Server

    Ikeno, Natsumi; Nara, Yasushi; Ohnishi, Akira

    2016-01-01

    In order to investigate the nuclear symmetry energy at high density, we study the pion production in central collisions of neutron-rich nuclei ${}^{132}\\mathrm{Sn}+{}^{124}\\mathrm{Sn}$ at 300 MeV/nucleon using a new approach by combining the antisymmetrized molecular dynamics (AMD) and a hadronic cascade model (JAM). The dynamics of neutrons and protons is solved by AMD, and then pions and $\\Delta$ resonances in the reaction process are handled by JAM. We see the mechanism how the $\\Delta$ resonance and pions are produced reflecting the dynamics of neutrons and protons. We also investigate the impacts of cluster correlations as well as of the high-density symmetry energy on the nucleon dynamics and consequently on the pion ratio. We find that the $\\Delta^-/\\Delta^{++}$ production ratio agrees very well with the neutron-proton squared ratio $(N/Z)^2$ in the high-density and high-momentum region. We show quantitatively that $\\Delta$ production ratio, and therefore $(N/Z)^2$, are directly reflected in the $\\pi^-...

  17. Exclusive electroproduction of two pions at HERA

    CERN Document Server

    Abramowicz, H

    2012-01-01

    The exclusive electroproduction of two pions in the mass range 0.4 < M{\\pi}{\\pi} < 2.5 GeV has been studied with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The analysis was carried out in the kinematic range of 2 < Q2 < 80 GeV2, 32 < W < 180 GeV and |t| < 0.6 GeV2, where Q2 is the photon virtuality, W is the photon-proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The two-pion invariant-mass distribution is interpreted in terms of the pion electromagnetic form factor, |F(M{\\pi}{\\pi})|, assuming that the studied mass range includes the contributions of the {\\rho}, {\\rho}' and {\\rho}" vector-meson states. The masses and widths of the resonances were obtained and the Q2 dependence of the cross-section ratios {\\sigma}({\\rho}' \\rightarrow {\\pi}{\\pi})/{\\sigma}({\\rho}) and {\\sigma}({\\rho}" \\rightarrow {\\pi}{\\pi})/{\\sigma}({\\rho}) was extracted. The pion form factor obtained in the present analysis is compared to that obtained...

  18. Temperature effect on negative bias-induced instability of HfInZnO amorphous oxide thin film transistor

    Science.gov (United States)

    Kwon, Dae Woong; Kim, Jang Hyun; Chang, Ji Soo; Kim, Sang Wan; Kim, Wandong; Park, Jae Chul; Song, Ihun; Kim, Chang Jung; Jung, U. In; Park, Byung-Gook

    2011-02-01

    Negative bias-induced instability of amorphous hafnium indium zinc oxide (α-HIZO) thin film transistors (TFTs) was investigated at various temperatures. In order to examine temperature-induced effects, fabricated TFTs with different combinations of gate insulator and gate metal were stressed by a negative gate bias at various temperatures. As a result, it is proved that negative bias-induced hole-trapping in the gate insulators and temperature-enhanced electron injection from the gate metals occurs at the same time at all temperatures, and the instability of HIZO TFT is more affected by the dominant factor out of the two mechanisms.

  19. Negative regulation of TGFβ-induced lens epithelial to mesenchymal transition (EMT) by RTK antagonists.

    Science.gov (United States)

    Zhao, Guannan; Wojciechowski, Magdalena C; Jee, Seonah; Boros, Jessica; McAvoy, John W; Lovicu, Frank J

    2015-03-01

    An eclectic range of ocular growth factors with differing actions are present within the aqueous and vitreous humors that bathe the lens. Growth factors that exert their actions via receptor tyrosine kinases (RTKs), such as FGF, play a normal regulatory role in lens; whereas other factors, such as TGFβ, can lead to an epithelial to mesenchymal transition (EMT) that underlies several forms of cataract. The respective downstream intracellular signaling pathways of these factors are in turn tightly regulated. One level of negative regulation is thought to be through RTK-antagonists, namely, Sprouty (Spry), Sef and Spred that are all expressed in the lens. In this study, we tested these different negative regulators and compared their ability to block TGFβ-induced EMT in rat lens epithelial cells. Spred expression within the rodent eye was confirmed using RT-PCR, western blotting and immunofluorescence. Rat lens epithelial explants were used to examine the morphological changes associated with TGFβ-induced EMT over 3 days of culture, as well as α-smooth muscle actin (α-sma) immunolabeling. Cells in lens epithelial explants were transfected with either a reporter (EGFP) vector (pLXSG), or with plasmids also coding for different RTK-antagonists (i.e. pLSXG-Spry1, pLSXG-Spry2, pLXSG-Sef, pLSXG-Spred1, pLSXG-Spred2, pLSXG-Spred3), before treating with TGFβ for up to 3 days. The percentages of transfected cells that underwent TGFβ-induced morphological changes consistent with an EMT were determined using cell counts and validated with a paired two-tailed t-test. Explants transfected with pLXSG demonstrated a distinct transition in cell morphology after TGFβ treatment, with ∼60% of the cells undergoing fibrotic-like cell elongation. This percentage was significantly reduced in cells overexpressing the different antagonists, indicative of a block in lens EMT. Of the antagonists tested under these in vitro conditions, Spred1 was the most potent demonstrating the

  20. The pion: an enigma within the Standard Model

    CERN Document Server

    Horn, Tanja

    2016-01-01

    Almost 50 years after the discovery of gluons & quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: neutrons, protons, and the pions that bind them. QCD is characterised by two emergent phenomena: confinement & dynamical chiral symmetry breaking (DCSB). They are expressed with great force in the character of the pion. In turn, pion properties suggest that confinement & DCSB are closely connected. As both a Nambu-Goldstone boson and a quark-antiquark bound-state, the pion is unique in Nature. Developing an understanding of its properties is thus critical to revealing basic features of the Standard Model. We describe experimental progress in this direction, made using electromagnetic probes, highlighting both improvements in the precision of charged-pion form factor data, achieved in the past decade, and new results on the neutral-pion transition form factor. Both challenge existing notions of pion structure. We also provide a theoretical context for these em...

  1. Negative regulation of NaF-induced apoptosis by Bad-CAII complex.

    Science.gov (United States)

    Otsuki, S; Sugiyama, K; Amano, O; Yasui, T; Sakagami, H

    2011-09-05

    Fluoride is used to prevent caries in dentistry. However, its mechanism of cytotoxicity induction is unclear. This study was undertaken to determine whether sodium fluoride (NaF) induces apoptosis in human oral cells and if so, whether Bad protein is involved in the process. NaF showed higher cytotoxicity and apoptosis-inducing activity against human oral squamous cell carcinoma cells (HSC-2) than against human gingival fibroblasts (HGF). Western blot analysis showed that NaF enhanced the expression and dephosphorylation of Bad protein. This study demonstrates for the first time that Bad protein forms a complex with carbonic anhydrase II (CAII), and NaF stimulates the detachment of CAII from the Bad-CAII complex and the replacement by the formation of Bad-Bcl-2 complex. Knockdown of Bad and CAII mRNA by siRNA inhibited and enhanced the NaF-induced caspase activation, respectively. The present study suggests that CAII negatively regulates the NaF-induced apoptosis by forming a complex with Bad.

  2. Brief owner absence does not induce negative judgement bias in pet dogs.

    Science.gov (United States)

    Müller, Corsin A; Riemer, Stefanie; Rosam, Claudia M; Schößwender, Julia; Range, Friederike; Huber, Ludwig

    2012-09-01

    Humans in a negative emotional state are more likely to judge ambiguous stimuli as negative. In recent years, similar judgement biases have been found in some non-human animals that were exposed to long-term or short-term treatments aimed at influencing their affective states. Here we tested pet dogs in the presence and absence of their owners in a judgement bias test with an established go/no-go procedure. Even though owner absence is thought to induce a state of anxiety in dogs that have formed an attachment bond with their primary caretakers, we found no difference between the dogs' responses to ambiguous stimuli in the presence or absence of their owners. This result may be explained by the absence of anxiety in dogs that are accustomed to brief periods of separation from their owners, or by a sensitivity limit of the customary judgement bias tests in non-human animals when only a moderate, short-term state of anxiety is induced. In addition, we found significant differences between individuals and populations in the responses to ambiguous stimuli, which give impetus for further research.

  3. Antinuclear antibody-negative, drug-induced lupus caused by lisinopril.

    Science.gov (United States)

    Carter, J D; Valeriano-Marcet, J; Kanik, K S; Vasey, F B

    2001-11-01

    The clinical symptoms of drug-induced lupus (DIL) are similar to those of idiopathic systemic lupus erythematosus. The literature indicates that in patients with DIL, sera generally contain antinuclear antibodies (ANAs); however, ANA-negative DIL has been reported. The list of medications implicated as etiologic agents in DIL continues to grow. This list includes two different types of angiotensin-converting enzyme inhibitors--captopril and enalapril. We report the first case of DIL caused by lisinopril. Our patient had negative results on ANA testing and had histone antibodies (IgG anti-[H2A-H2B]-DNA) mirroring the disease course. Antibodies to the (H2A-H2B)-DNA complex are seen in more than 90% of patients with active DIL, excluding those with DIL due to hydralazine. Thus, it is important to recognize the clinical significance of IgG anti-(H2A-H2B)-DNA antibodies and that negative ANA test results do not preclude the diagnosis of DIL.

  4. The pion: an enigma within the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Tanja; Roberts, Craig D.

    2016-05-27

    Almost 50 years after the discovery of gluons & quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: neutrons, protons, and the pions that bind them. QCD is characterised by two emergent phenomena: confinement & dynamical chiral symmetry breaking (DCSB). They are expressed with great force in the character of the pion. In turn, pion properties suggest that confinement & DCSB are closely connected. As both a Nambu-Goldstone boson and a quark-antiquark bound-state, the pion is unique in Nature. Developing an understanding of its properties is thus critical to revealing basic features of the Standard Model. We describe experimental progress in this direction, made using electromagnetic probes, highlighting both improvements in the precision of charged-pion form factor data, achieved in the past decade, and new results on the neutral-pion transition form factor. Both challenge existing notions of pion structure. We also provide a theoretical context for these empirical advances, first explaining how DCSB works to guarantee that the pion is unnaturally light; but also, nevertheless, ensures the pion is key to revealing the mechanisms that generate nearly all the mass of hadrons. Our discussion unifies the charged-pion elastic and neutral-pion transition form factors, and the pion's twist-2 parton distribution amplitude. It also indicates how studies of the charged-kaon form factor can provide significant contributions. Importantly, recent predictions for the large-$Q^2$ behaviour of the pion form factor can be tested by experiments planned at JLab 12. Those experiments will extend precise charged-pion form factor data to momenta that can potentially serve in validating factorisation theorems in QCD, exposing the transition between the nonperturbative and perturbative domains, and thereby reaching a goal that has long driven hadro-particle physics.

  5. Photon-to-pion transition form factor and pion distribution amplitude from holographic QCD

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Fen [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Chinese Academy of Sciences, Theoretical Physics Research Center for Science Facilities, Beijing (China); Istituto Nazionale di Fisica Nucleare, Secione di Bari, Bari (Italy); Huang, Tao [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Chinese Academy of Sciences, Theoretical Physics Research Center for Science Facilities, Beijing (China)

    2012-01-15

    We try to understand the recently observed anomalous behavior of the photon-to-pion transition form factor in the holographic QCD approach. First the holographic description of the anomalous {gamma}{sup *}{gamma}{sup *}{pi}{sup 0} form factor is reviewed and applied to various models. It is pointed out that the holographic identification of the pion mode from the 5D gauge field strength rather than the gauge potential, as first made by Sakai and Sugimoto, naturally reproduces the scaling behavior of various pion form factors. It is also illustrated that in describing the anomalous form factor, the holographic approach is asymptotically dual to the perturbative QCD (pQCD) framework, with the pion mode {pi}(z){proportional_to}z corresponding to the asymptotic pion distribution amplitude. This indicates some inconsistency in light-front holography, since {pi}(z){proportional_to}z would be dual to {phi}(x){proportional_to}{radical}(x(1-x)) there. This apparently contradictory can be attributed to the fact that the holographic wave functions are effective ones, as observed early by Radyushkin. After clarifying these subtleties, we employ the relation between the holographic and the perturbative expressions to study possible asymptotic violation of the transition form factor. It is found that if one require that the asymptotic form factor possess a pQCD-like expression, the pion mode can only be ultraviolet-enhanced by logarithmic factors. The minimally deformed pion mode will then be of the form {pi}(z){proportional_to}zln(z{lambda}){sup -1}. We suppose that this deformation may be due to the coupling of the pion with a nontrivial open string tachyon field, and then the parameter {lambda} will be related to the quark condensate. Interestingly, this pion mode leads immediately to Radyushkin's logarithmic model, which fitted very well the experimental data in the large-Q{sup 2} region. On the other side, the pQCD interpretation with a flat-like pion distribution

  6. Pion absorption on 3He at low energies

    Science.gov (United States)

    Hahn, H.; Altman, A.; Ashery, D.; Gefen, G.; Gill, D. R.; Johnson, R. R.; Levy-Nathansohn, R.; Moinester, M. A.; Sevior, M.; Trelle, R. P.

    1996-03-01

    The reactions 3He(π+,pp)p and 3He(π-,pn)n were studied at 37.0 MeV by coincidence detection of two nucleons. The differential cross sections were separated to two-nucleon (σ2N), three-nucleon (σ3N), and final-state interaction (σFSI) components. For π+, the σ2N angular distribution is symmetric about 90°, and the total cross section is 1.5 times the cross section measured for d(π+,pp). For π-, the angular distribution is asymmetric (backward peaked). The asymmetry increases with decreasing energy, indicating increasing pion s-wave contribution at lower energies. The fraction of the cross section induced by s-wave pions as calculated by a partial wave amplitude analysis is 13%. The measured total cross sections are σ2N(π-)=0.85+/-0.08 mb and σ2N(π+)=7.9+/-0.5 mb; σ3N(π-)=1.6+/-0.7 mb and σ3N(π+)=1.3+/-0.3 mb. A new evaluation of σ3N at Tπ=62.5 and 82.8 MeV is given, using data from an earlier experiment. The cross sections leading to the two-nucleon final-state interaction at Tπ=37.0 MeV are also estimated.

  7. Benchmark Analysis of Pion Contribution from Galactic Cosmic Rays

    Science.gov (United States)

    Aghara, Sukesh K.; Blattnig, Steve R.; Norbury, John W.; Singleterry, Robert C., Jr.

    2008-01-01

    Shielding strategies for extended stays in space must include a comprehensive resolution of the secondary radiation environment inside the spacecraft induced by the primary, external radiation. The distribution of absorbed dose and dose equivalent is a function of the type, energy and population of these secondary products. A systematic verification and validation effort is underway for HZETRN, which is a space radiation transport code currently used by NASA. It performs neutron, proton and heavy ion transport explicitly, but it does not take into account the production and transport of mesons, photons and leptons. The question naturally arises as to what is the contribution of these particles to space radiation. The pion has a production kinetic energy threshold of about 280 MeV. The Galactic cosmic ray (GCR) spectra, coincidentally, reaches flux maxima in the hundreds of MeV range, corresponding to the pion production threshold. We present results from the Monte Carlo code MCNPX, showing the effect of lepton and meson physics when produced and transported explicitly in a GCR environment.

  8. Dispositional optimism and stress-induced changes in immunity and negative mood.

    Science.gov (United States)

    Brydon, Lena; Walker, Cicely; Wawrzyniak, Andrew J; Chart, Henrik; Steptoe, Andrew

    2009-08-01

    Evidence suggests that optimism may be protective for health during times of heightened stress, yet the mechanisms involved remain unclear. In a double-blind placebo-controlled study, we recently showed that acute psychological stress and an immune stimulus (Typhim-Vi typhoid vaccine) synergistically increased serum levels of interleukin-6 (IL-6) and negative mood in 59 healthy men. Here we carried out further analysis of this sample to investigate the relationship between dispositional optimism and stress-induced changes in immunity and mood. Volunteers were randomly assigned to one of four experimental conditions in which they received either typhoid vaccine or saline placebo, and then rested or completed two mental tasks. In the stress condition, optimism was inversely related to IL-6 responses, independent of age, BMI, trait CES-D depression and baseline IL-6. This relationship was present across both stress groups (combining vaccine and placebo) and was not present in the vaccine/stress group alone, suggesting that optimism protects against the inflammatory effects of stress rather than vaccine per se. Typhoid vaccine induced a significant increase in participants' circulating anti-Vi antibody levels. Stress had no effect on antibody responses overall. However, in the vaccine/stress group, there was a strong positive association between optimism and antibody responses, indicating that stress accentuated the antibody response to vaccine in optimists. Across the complete sample, more optimistic individuals had smaller increases in negative mood and less reduction in mental vigour. Together these findings suggest that optimism may promote health, by counteracting stress-induced increases in inflammation and boosting the adjuvant effects of acute stress.

  9. Thymic involution perturbs negative selection leading to autoreactive T cells that induce chronic inflammation.

    Science.gov (United States)

    Coder, Brandon D; Wang, Hongjun; Ruan, Linhui; Su, Dong-Ming

    2015-06-15

    Thymic involution and the subsequent amplified release of autoreactive T cells increase the susceptibility toward developing autoimmunity, but whether they induce chronic inflammation with advanced age remains unclear. The presence of chronic low-level proinflammatory factors in elderly individuals (termed inflammaging) is a significant risk factor for morbidity and mortality in virtually every chronic age-related disease. To determine how thymic involution leads to the persistent release and activation of autoreactive T cells capable of inducing inflammaging, we used a Foxn1 conditional knockout mouse model that induces accelerated thymic involution while maintaining a young periphery. We found that thymic involution leads to T cell activation shortly after thymic egress, which is accompanied by a chronic inflammatory phenotype consisting of cellular infiltration into non-lymphoid tissues, increased TNF-α production, and elevated serum IL-6. Autoreactive T cell clones were detected in the periphery of Foxn1 conditional knockout mice. A failure of negative selection, facilitated by decreased expression of Aire rather than impaired regulatory T cell generation, led to autoreactive T cell generation. Furthermore, the young environment can reverse age-related regulatory T cell accumulation in naturally aged mice, but not inflammatory infiltration. Taken together, these findings identify thymic involution and the persistent activation of autoreactive T cells as a contributing source of chronic inflammation (inflammaging).

  10. Cold-induced precipitation of a monoclonal IgM: a negative activation enthalpy reaction.

    Science.gov (United States)

    Meliga, Stefano C; Farrugia, William; Ramsland, Paul A; Falconer, Robert J

    2013-01-17

    Cold-induced precipitation of a monoclonal IgM cryoglobulin isolated from a patient with Waldenström's macroglobulinemia was observed to have a negative activation enthalpy. The rate of the reaction increased, as the temperature decreased. Differential scanning calorimetry of the monoclonal IgM showed precipitation as an inverted peak during a downward temperature scan. The transition temperature was between 14 and 15 °C and was possibly concentration dependent. At temperatures below the transition the precipitation was best described by second-order kinetics. The difference in change in enthalpy between precipitation and disassociation suggests that cold-induced precipitation had a fast precipitation stage followed by a slower consolidation reaction. Negligible curvature of the Eyring plot suggested the precipitation reaction was dominated by van der Waal forces and hydrogen bonding. Conversely, during an upward temperature scan, disassociation was observed as a positive enthalpy peak. This reaction had two stages, a reaction undoing consolidation followed by heat-induced disassociation that had first-order kinetics.

  11. Mean pion multiplicities in Ar+Sc collisions

    CERN Document Server

    Naskręt, Michał

    2016-01-01

    Preliminary results for mean negatively charged pion multiplicities $\\langle \\pi^- \\rangle$ using the $h^-$ method are presented for central Ar+Sc collisions at 13, 19, 30, 40, 75 and 150\\textit{A} GeV/c beam momentum. The data were recorded by the NA61/SHINE detector at the CERN SPS. Starting with rapidity distributions ${dn}/{dy}$ the procedure of obtaining total multiplicities is presented. The mean number of wounded nucleons $\\langle W\\rangle$ extracted from the Glissando MC model is used to calculate the ratio $\\langle \\pi^- \\rangle/\\langle W\\rangle.$ The results are compared to those from other experiments and their dependence on colliding systems and collision energy is discussed.

  12. Two- and three-pion quantum statistics correlations in Pb-Pb collisions at s N N = 2.76 TeV at the CERN Large Hadron Collider

    NARCIS (Netherlands)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agocs, A. G.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Masoodi, A. Ahmad; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bairathi, V.; Bala, R.; Baldisseri, A.; Pedrosa, F. Baltasar Dos Santos; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bergognon, A. A E; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Boehmer, F. V.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Villar, E. Calvo; Camerini, P.; Roman, V. Canoa; Carena, F.; Carena, W.; Carminati, F.; Díaz, A. Casanova; Castellanos, J. Castillo; Casula, E. A R; Catanescu, V.; Cavicchioli, C.; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; Conesa Del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Cortese, P.; Maldonado, I. Cortés; Cosentino, M. R.; Costa, F.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; De, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; De Barros, G. O V; De Caro, A.; De Cataldo, G.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; De Rooij, R.; Corchero, M. A Diaz; Dietel, T.; Divià, R.; Bari, D. Di; Liberto, S. Di; Mauro, A. Di; Nezza, P. Di; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Gimenez, D. Domenicis; Dönigus, B.; Dordic, O.; Dorheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Majumdar, A. K Dutta; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A S; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Girard, M. Fusco; Gaardhøje, J. J.; Gagliardi, M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J. Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, I.M.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.

    2014-01-01

    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correl

  13. Gram-negative endotoxin lipopolysaccharide induces cardiac hypertrophy: detrimental role of Na(+)-Ca(2+) exchanger.

    Science.gov (United States)

    Magi, Simona; Nasti, Annamaria Assunta; Gratteri, Santo; Castaldo, Pasqualina; Bompadre, Stefano; Amoroso, Salvatore; Lariccia, Vincenzo

    2015-01-05

    Several molecular pathways involved in the development of cardiac hypertrophy are triggered by perturbation of intracellular Ca(2+) homeostasis. Within the heart, Na(+)/Ca(2+) exchanger 1 (NCX1) is one of the main determinant in controlling Ca(2+) homeostasis. In cardiac hypertrophy and heart failure NCX1 expression and activity have been reported to be altered. It has been shown that chronic bacterial infections (sepsis, endocarditis, and myocarditis) can promote cardiac hypertrophy. Bacterial stressors, such as the Gram-negative endotoxin lipopolysaccharide (LPS), can directly or indirectly affect intracellular Ca(2+) homeostasis in the heart and induce the development of cardiac hypertrophy. The present study aimed at evaluating the potential link between the signal pathways activated in LPS-exposed myocytes and NCX1. In the whole rat heart, LPS perfusion induced an early hypertrophy response during which NCX1 expression significantly increased. Notably, all these changes were completely prevented by the NCX inhibitor SN-6. We further dissect the role of NCX1 in the LPS-induced hypertrophic response in an in vitro cardiac model based on two H9c2 cardiomyoblast clones, namely H9c2-WT (lacking endogenous NCX1 expression) and H9c2-NCX1 (stably transfected with a functional NCX1). H9c2-NCX1 were more susceptible than H9c2-WT to develop a hypertrophic phenotype, and they displayed a significant increase in NCX1 expression and function after LPS treatment. SN-6 completely counteracted both hypertrophic response and exchanger alterations induced by LPS in H9c2-NCX1 cells, but it had no effects on H9c2-WT. Collectively, our results suggest that NCX1 plays a critical role in promoting myocardial hypertrophy triggered by LPS. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. A novel curcumin-like dienone induces apoptosis in triple-negative breast cancer cells

    Science.gov (United States)

    Robles-Escajeda, Elisa; Das, Umashankar; Ortega, Nora M.; Parra, Karla; Francia, Giulio; Dimmock, Jonathan R.; Varela-Ramirez, Armando; Aguilera, Renato J.

    2016-01-01

    Purpose According to the World Health Organization (WHO), breast cancer is the most common cancer affecting women worldwide. In the USA ~12.3 % of all women are expected to be diagnosed with various types of breast cancer, exhibiting varying degrees of therapeutic response rates. Therefore, the identification of novel anti-breast cancer drugs is of paramount importance. Methods The 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore was incorporated into a number of cytotoxins. Three of the resulting dienones, 2a, 2b and 2c, were tested for their antineoplastic potencies in a variety of human breast cancer-derived cell lines, including the triple negative MDA-MB-231 cell line and its metastatic variant, using a live-cell bio-imaging method. Special emphasis was put on dienone 2c, since its anti-cancer activity and its mode of inflicting cell death have so far not been reported. Results We found that all three dienones exhibited potent cytotoxicities towards the breast cancer-derived cell lines tested, whereas significantly lower toxicities were observed towards the non-cancerous human breast cell line MCF-10A. The dienones 2b and 2c exhibited the greatest selective cytotoxicity at submicromolar concentration levels. We found that these two dienones induced phosphatidylserine externalization in MDA-MB-231 cells in a concentration-dependent manner, suggesting that their cytotoxic effect might be mediated by apoptosis. This possibility was confirmed by our observation that the dienone 2c can induce mitochondrial depolarization, caspase-3 activation, cell cycle disruption and DNA fragmentation in MDA-MB-231 cells. Conclusion Our findings indicate that dienone 2c uses the mitochondrial/intrinsic pathway to inflict apoptosis in triple negative MDA-MB-231 breast cancer-derived cells. This observation warrants further assessment of dienone 2c as a potential anti-breast cancer drug. PMID:26920032

  15. Vector meson condensation in a pion superfluid

    Science.gov (United States)

    Brauner, Tomáš; Huang, Xu-Guang

    2016-11-01

    We revisit the suggestion that charged ρ -mesons undergo Bose-Einstein condensation in isospin-rich nuclear matter. Using a simple version of the Nambu-Jona-Lasinio (NJL) model, we conclude that ρ -meson condensation is either avoided or postponed to isospin chemical potentials much higher than the ρ -meson mass as a consequence of the repulsive interaction with the preformed pion condensate. In order to support our numerical results, we work out a linear sigma model for pions and ρ -mesons, showing that the two models lead to similar patterns of medium dependence of meson masses. As a byproduct, we analyze in detail the mapping between the NJL model and the linear sigma model, focusing on conditions that must be satisfied for a quantitative agreement between the models.

  16. Pion contamination in the MICE muon beam

    CERN Document Server

    Bogomilov, M.; Vankova-Kirilova, G.; Bertoni, R.; Bonesini, M.; Chignoli, F.; Mazza, R.; Palladino, V.; de Bari, A.; Cecchet, G.; Capponi, M.; Iaciofano, A.; Orestano, D.; Pastore, F.; Tortora, L.; Kuno, Y.; Sakamoto, H.; Ishimoto, S.; Japan, Ibaraki; Filthaut, F.; Hansen, O.M.; Ramberger, S.; Vretenar, M.; Asfandiyarov, R.; Blondel, A.; Drielsma, F.; Karadzhov, Y.; Charnley, G.; Collomb, N.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Oates, A.; Owens, P.; Stokes, G.; Warburton, P.; White, C.; Adams, D.; Barclay, P.; Bayliss, V.; Bradshaw, T.W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Watson, S.; Wilson, A.; Bayes, R.; Nugent, J.C.; Soler, F.J.P.; Cooke, P.; Gamet, R.; Alekou, A.; Apollonio, M.; Barber, G.; Colling, D.; Dobbs, A.; Dornan, P.; Hunt, C.; Lagrange, J-B.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Santos, E.; Savidge, T.; Uchida, M.A.; Blackmore, V.J.; Carlisle, T.; Cobb, J.H.; Lau, W.; Rayner, M.A.; Tunnell, C.D.; Booth, C.N.; Hodgson, P.; Langlands, J.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P.J.; Dick, A.; Ronald, K.; Speirs, D.; Whyte, C.G.; Young, A.; Boyd, S.; Franchini, P.; Greis, J.R.; Pidcott, C.; Taylor, I.; Gardener, R.; Kyberd, P.; Littlefield, M.; Nebrensky, J.J.; Bross, A.D.; Fitzpatrick, T.; Leonova, M.; Moretti, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; Rucinski, R.; Roberts, T.J.; Bowring, D.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.; Zisman, M.; Drews, M.; Hanlet, P.; Kafka, G.; Kaplan, D.M.; Rajaram, D.; Snopok, P.; Torun, Y.; Winter, M.; Blot, S.; Kim, Y.K.; Bravar, U.; Onel, Y.; Cremaldi, L.M.; Hart, T.L.; Luo, T.; Sanders, D.A.; Summers, D.J.; Cline, D.; Yang, X.; Coney, L.; Hanson, G.G.; Heidt, C.

    2016-01-01

    The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than $\\sim$1\\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $f_\\pi < 1.4\\%$ at 90\\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

  17. Vector meson condensation in a pion superfluid

    CERN Document Server

    Brauner, Tomas

    2016-01-01

    We revisit the suggestion that charged rho-mesons undergo Bose-Einstein condensation in isospin-rich nuclear matter. Using a simple version of the Nambu-Jona-Lasinio (NJL) model, we conclude that rho-meson condensation is either avoided or postponed to isospin chemical potentials much higher than the rho-meson mass as a consequence of the repulsive interaction with the preformed pion condensate. In order to support our numerical results, we work out a linear sigma model for pions and rho-mesons, showing that the two models lead to similar patterns of medium dependence of meson masses. As a byproduct, we analyze in detail the mapping between the NJL model and the linear sigma model, focusing on conditions that must be satisfied for a quantitative agreement between the models.

  18. Pion Distribution Amplitude from Lattice QCD

    CERN Document Server

    Braun, V M; Göckeler, M; Pérez-Rubio, P; Schäfer, A; Schiel, R W; Sternbeck, A

    2015-01-01

    We have calculated the second moment of the pion light-cone distribution amplitude using two flavors of dynamical (clover) fermions on lattices of different volumes, lattice spacings between $0.06 \\, \\mathrm {fm}$ and $0.08 \\, \\mathrm {fm}$ and pion masses down to $m_\\pi\\sim 150 \\, \\mathrm {MeV}$. Our result for the second Gegenbauer coefficient is $a_2 = 0.1364(154)(145)$ and for the width parameter $\\langle \\xi^2 \\rangle = 0.2361(41)(39)$. Both numbers refer to the scale $\\mu=2 \\, \\mathrm {GeV}$in the $\\overline{\\text{MS}}$ scheme, the first error is statistical including the uncertainty of the chiral extrapolation, and the second error is the estimated uncertainty coming from the nonperturbatively determined renormalization factors.

  19. Pion contamination in the MICE muon beam

    Science.gov (United States)

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V. J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C. N.; Bowring, D.; Boyd, S.; Brashaw, T. W.; Bravar, U.; Bross, A. D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, C.; Chignoli, F.; Cline, D.; Cobb, J. H.; Colling, G.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L. M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Drews, M.; Drielsma, F.; Filthaut, F.; Fitzpatrick, T.; Franchini, P.; Francis, V.; Fry, L.; Gallagher, A.; Gamet, R.; Gardener, R.; Gourlay, S.; Grant, A.; Greis, J. R.; Griffiths, S.; Hanlet, P.; Hansen, O. M.; Hanson, G. G.; Hart, T. L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Hunt, C.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D. M.; Karadzhov, Y.; Kim, Y. K.; Kuno, Y.; Kyberd, P.; Lagrange, J.-B.; Langlands, J.; Lau, W.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Mazza, R.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J. J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J. C.; Oates, A.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M. A.; Ricciardi, S.; Roberts, T. J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, P.; Sakamato, H.; Sanders, D. A.; Santos, E.; Savidge, T.; Smith, P. J.; Snopok, P.; Soler, F. J. P.; Speirs, D.; Stanley, T.; Stokes, G.; Summers, D. J.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C. D.; Uchida, M. A.; Vankova-Kirilova, G.; Virostek, S.; Vretenar, M.; Warburton, P.; Watson, S.; White, C.; Whyte, C. G.; Wilson, A.; Winter, M.; Yang, X.; Young, A.; Zisman, M.

    2016-03-01

    The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240 MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than ~1% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is fπ < 1.4% at 90% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling.

  20. Form Factors in radiative pion decay

    CERN Document Server

    Mateu, V

    2007-01-01

    We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions VVP and VAP, and by demanding the smoothing of the form factors at high transfer of momentum. A comparison between theoretical and experimental determinations of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic incertitudes, the search for New Physics in this process is not feasible.

  1. Pion-Nucleus potentials in the energy range of 0-80 MeV

    Science.gov (United States)

    Meirav, O.; Friedman, E.; Altman, A.; Hannah, M.; Johnson, R. R.; Gill, D. R.

    1987-12-01

    Data for the elastic scattering of 30-80 MeV positive and negative pions by a wide range of nuclei is analysed with an Ericson-Ericson MSU type optical potential. By use of consistent sets of data for π+ and π- and of experimental results for total reaction cross sections we obtain for the first time optical potentials that describe well all the data without the need of introducing non-standard charge-dependent effects.

  2. Negative particle production at the CERN intersecting storage rings

    CERN Document Server

    Bertin, A; Cristallini, A; D'Agostino-Bruno, M; Ellis, R J; Giacomelli, G; Maroni, C; Mercatali, F; Rossi, A M; Vannini, G

    1972-01-01

    Preliminary results on the production of negative particles in inclusive reactions at intermediate angles (80-200 mrad) at the CERN ISR are reported. Pion production, is still the dominant process; within experimental errors, scaling holds for negative pions or alternatively a limiting distribution is reached at relatively low energies. However the antiproton production cross-sections are apparently larger than smaller energies. (14 refs).

  3. Loop corrections to pion and kaon neutrinoproduction

    CERN Document Server

    Siddikov, Marat

    2016-01-01

    In this paper we study the next-to-leading order corrections to deeply virtual pion and kaon production in neutrino experiments. We estimate these corrections in the kinematics of the Minerva experiment at FERMILAB, and find that they are sizable and increase the leading order cross-section by up to a factor of two. We provide a code, which can be used for the evaluation of the cross-sections, taking into account these corrections and employing various GPD models.

  4. Modeling the pion Generalized Parton Distribution

    CERN Document Server

    Mezrag, C

    2015-01-01

    We compute the pion Generalized Parton Distribution (GPD) in a valence dressed quarks approach. We model the Mellin moments of the GPD using Ans\\"atze for Green functions inspired by the numerical solutions of the Dyson-Schwinger Equations (DSE) and the Bethe-Salpeter Equation (BSE). Then, the GPD is reconstructed from its Mellin moment using the Double Distribution (DD) formalism. The agreement with available experimental data is very good.

  5. Theory of the scattering of pions from nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, E.R.; Thaler, R.M.

    1978-09-15

    A nonrelativistic quantum field theoretic formulation of pion--nucleus scattering is presented. A nonrelativistic boson--complex-target Low equation is developed, in which the coupling between the incident boson and target constituent particles is completely general. This development is then particularized to the case where the bosons are pions and the target is a nucleus of A nucleons. Special detailed attention is paid to the case where the pion--nucleon coupling is linear. The pion--nucleus Low equation is decomposed into a finite series of A terms, referred to as a spectator expansion, of which the first term involves one active particle and (a-1) spectators and the higher terms involve an increasingly larger number of active target particles. Within the framework of the nonrelativistic pion--nucleus Low equation, a formal definition of the pion--nucleus optical potential is also given.

  6. Measurement of the charged-pion polarisability at COMPASS

    CERN Document Server

    CERN. Geneva

    2015-01-01

    For more than a decade, COMPASS has been tackling the measurement of the electromagnetic polarizability of the charged pion, which describes the stiffness of the pion against deformation in electromagnetic fields. Previous experiments date back to the 1980's in Serpukhov (Russia), where the Primakoff method for realizing interactions of charged pions with quasi-real photons was first employed. Later also other techniques in photon-nucleon and photon-photon collisions were carried out at different machines. The COMPASS measurement demonstrates that the charged-pion polarizability is significantly smaller than the previous results, roughly by a factor two, with the smallest uncertainties realized so far. The pion polarisability is of fundamental interest in the low-energy sector of quantum chromodynamics. It is directly linked to the quark-gluon substructure and dynamics of the pion, the lightest bound system of strong interaction.

  7. Mesenchymal Stem Cell-Induced Doxorubicin Resistance in Triple Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    Dar-Ren Chen

    2014-01-01

    Full Text Available Triple negative breast cancer (TNBC is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs, tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM, noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.

  8. Mesenchymal stem cell-induced doxorubicin resistance in triple negative breast cancer.

    Science.gov (United States)

    Chen, Dar-Ren; Lu, Dah-Yuu; Lin, Hui-Yi; Yeh, Wei-Lan

    2014-01-01

    Triple negative breast cancer (TNBC) is an aggressive histological subtype with limited treatment options and a worse clinical outcome compared with other breast cancer subtypes. Doxorubicin is considered to be one of the most effective agents in the treatment of TNBC. Unfortunately, resistance to this agent is common. In some drug-resistant cells, drug efflux is mediated by adenosine triphosphate-dependent membrane transporter termed adenosine triphosphate-binding cassette (ABC) transporter, which can drive the substrates across membranes against concentration gradient. In the tumor microenvironment, upon interaction with mesenchymal stem cells (MSCs), tumor cells exhibit altered biological functions of certain gene clusters, hence increasing stemness of tumor cells, migration ability, angiogenesis, and drug resistance. In our present study, we investigated the mechanism of TNBC drug resistance induced by adipose-derived MSCs. Upon exposure of TNBC to MSC-secreted conditioned medium (CM), noticeable drug resistance against doxorubicin with markedly increased BCRP protein expression was observed. Intracellular doxorubicin accumulation of TNBC was also decreased by MSC-secreted CM. Furthermore, we found that doxorubicin resistance of TNBC was mediated by IL-8 presented in the MSC-secreted CM. These findings may enrich the list of potential targets for overcoming drug resistance induced by MSCs in TNBC patients.

  9. Nicotine induces negative energy balance through hypothalamic AMP-activated protein kinase.

    Science.gov (United States)

    Martínez de Morentin, Pablo B; Whittle, Andrew J; Fernø, Johan; Nogueiras, Rubén; Diéguez, Carlos; Vidal-Puig, Antonio; López, Miguel

    2012-04-01

    Smokers around the world commonly report increased body weight after smoking cessation as a major factor that interferes with their attempts to quit. Numerous controlled studies in both humans and rodents have reported that nicotine exerts a marked anorectic action. The effects of nicotine on energy homeostasis have been mostly pinpointed in the central nervous system, but the molecular mechanisms controlling its action are still not fully understood. The aim of this study was to investigate the effect of nicotine on hypothalamic AMP-activated protein kinase (AMPK) and its effect on energy balance. Here we demonstrate that nicotine-induced weight loss is associated with inactivation of hypothalamic AMPK, decreased orexigenic signaling in the hypothalamus, increased energy expenditure as a result of increased locomotor activity, increased thermogenesis in brown adipose tissue (BAT), and alterations in fuel substrate utilization. Conversely, nicotine withdrawal or genetic activation of hypothalamic AMPK in the ventromedial nucleus of the hypothalamus reversed nicotine-induced negative energy balance. Overall these data demonstrate that the effects of nicotine on energy balance involve specific modulation of the hypothalamic AMPK-BAT axis. These targets may be relevant for the development of new therapies for human obesity.

  10. Half-filled energy bands induced negative differential resistance in nitrogen-doped graphene.

    Science.gov (United States)

    Li, Xiao-Fei; Lian, Ke-Yan; Qiu, Qi; Luo, Yi

    2015-03-07

    Nitrogen-doping brings novel properties and promising applications into graphene, but the underlying mechanism is still in debate. To determine the key factor in motivating the negative differential resistance (NDR) behaviour of nitrogen-doped graphene, the electronic structure and transport properties of an 11-dimer wide nitrogen-doped armchair graphene nanoribbon (N-AGNR) were systematically studied by first principles calculations. Both the effect of interaction between N-dopants and the effect of doping-sublattice on the NDR were examined for the first time. Taking into account the two effects, N-AGNR becomes metallic or semiconducting depending on the doping configuration, and its Fermi level varies in a large range. NDR was firmly verified not to be intrinsic for N-AGNRs. However, it is totally determined by whether nitrogen-doping induces half-filled energy bands (HFEBs) because it is HFEBs that cross the Fermi level and determine the transport properties of N-AGNR under low biases. With the bias increasing, the transmission spectrum near the Fermi level showed a flag shape, and therefore, the corresponding transport channel is totally suppressed at a certain bias, resulting in the NDR behaviour with a configuration-dependent peak-to-valley current ratio (PVCR) up to 10(4). Our findings give new insights into the microscopic mechanism of chemical doping induced NDR behaviour and will be useful in building NDR-based nanodevices in the future.

  11. Precision tracking and electromagnetic calorimetry towards a measurement of the pion polarisabilities at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Dinkelbach, Anna-Maria Elisabeth

    2010-07-20

    In 2004 the COMPASS experiment at CERN SPS measured soft reactions with a beam of negatively charged pions on various nuclear targets. For this measurement, a silicon micro-strip telescope was installed in the target region. For the first time 5 silicon detector stations were operated simultaneously in the COMPASS experiment. A novel method of time calibration, with a clustering algorithm accordingly adapted, and refined alignment corrections were implemented in the analysis software. The spatial resolution of a silicon detector was determined to be 5 - 14 {mu}m and the time resolution 2 - 3 ns. Combining the time information of all stations, a track time resolution of 530 ps from the silicon telescope could be reached. One of the key points of this experiment was the observation of Primakoff events, namely pions scattering off quasi-real photons in the Coulomb field of a heavy nucleus. The production of real photons corresponds to pion Compton scattering in inverse kinematics which is sensitive to the pion polarisabilities {alpha}{sub {pi}} and {beta}{sub {pi}}. Key ingredient for such measurements is a precise knowledge of the performance of the electromagnetic calorimeter. This includes a study of the instabilities of calorimeter cells and an improved reconstruction algorithm. A data-driven shower model was developed, which was used for a timedependent recalibration of the calorimeter. A new cluster refitting method was used to recover position and energy of clusters containing passive or saturated cells and detects double-hit clusters. The latter are important, as the main background to the Primakoff Compton events stems from neutral pions misinterpreted as single-photon hits. The physics analysis comprised the selection of Primakoff events and the necessary steps to obtain the pionic polarisabilities. The measurement was limited by systematic effects of the apparatus also determined within this thesis. (orig.)

  12. Photoproduction of Rho' Mesons in Reactions Photon -p --> (P2((+)PION))(2(-)PION) and Photon-P --> P((+)PION)(( -)PION)2((0)PION) at 20 GEV.

    Science.gov (United States)

    Dingus, Peter John

    From over 300,000 hadronic events gathered by the BC72/73 collaboration, which directed a 20GeV photon beam onto a liquid hydrogen target, the reaction gamma p to pp ^' was isolated in the channels gamma p to p2pi^+2pi^- and gamma p to ppi^+pi^-2pi^0 . Subsequently various Monte Carlo models of the rho^' decaying into four pions in the charge states 2pi^+2 pi^- and pi^+ pi^-2pi^0 were fit to the data in all pertinent kinematic variables along with the decay angular distributions and various assumed backgrounds that had not been disentangled. The results of this analysis are: (1) The Photoproduced rho^' conserves S channel helicity, this is shown by an analysis of the angle Phi, as described in the text, and by the Density Matrix Elements, (DME), of the rho^' in the channel gamma p to p2pi^+2pi^-. The DMEs, through the Parity Asymmetry, also show the rho^' production to be mostly due to natural parity exchange in the t channel. (2) The dominant decay mode of the rho^' is via rho^' to pi A_1, this is shown by the absence of a rho^0 signal in the channel gamma p to ppi^+pi ^-2pi^0 and by the approximate equality of the rho^' cross sections in the two channels. The rho ^' cross section in the channel gamma p to p2pi^+2pi^- is measured to be 0.944 +/- 0.05 mu b and the rho^' cross section in the channel gamma p to ppi^+ pi^-2pi^0 is measured to be 1.19 +/- 0.089mu b. (3) The rho^' mass and width in the channel gamma p to p2pi^+2 pi^- are determined to be 1.20 +/- 0.05GeV and 0.535 +/- 0.04GeV respectively. In the channel gamma p to ppi^+ pi^-2pi^0 the rho^' mass and width are determined to be 1.25 +/- 0.1GeV and 0.53 +/- 0.06GeV respectively.

  13. Multi-pion production in deuteron-proton collisions at COSY-ANKE

    Energy Technology Data Exchange (ETDEWEB)

    Mielke, Malte Marius

    2014-07-01

    The presented work is a contribution to the research on two- and three pion production in deuteron-proton collisions. Whereas the latter has received very little attention so far, the former is attracting the interest of particle physicists since several decades. An important reason for this is the appearance of the so-called ABC effect, a striking enhancement in the two-pion invariant mass spectrum near its threshold. There is strong evidence that this is related to the presence of nucleons and in the context of recent investigations it is even linked to an excitation of dibaryon resonances. The here presented results from an exclusive measurement of the dp→{sup 3}Heπ{sup +}π{sup -} reaction with the COSY-ANKE facility at an excess energy of 265 MeV benefit from high statistics as well as a good momentum resolution. Events with coincidentally detected {sup 3}Heπ{sup ±} and {sup 3}Heπ{sup +}π{sup -} combinations were used for the analysis. Various selection steps led to a very clean data sample. The limited geometrical acceptance of the ANKE detector was studied in detail in order to successfully elaborate a reliable correction method. Based on this, it was possible to determine differential and double differential cross sections for a large fraction of the backward {sup 3}He hemisphere. The derived invariant mass distributions do allow to illuminate further details of the two-pion production processes. Besides the prominent ABC enhancement, they reveal a significant difference in the behaviour of the positively and negatively charged pions, which is interpreted to be caused by π{sup +}π{sup -} isovector contributions. The total results are successfully described in terms of a N{sup *}(1440)→Δ(1232)→N decay chain. However, the isobar model surprisingly underestimates the charge difference at low two-pion invariant masses, indicating further contribution to the isovector channel. Investigations on the simultaneously measured dp→{sup 3}Heπ{sup +}

  14. Crossing symmetric potential model of pion-nucleon scattering

    CERN Document Server

    Blankleider, B; Skawronski, T

    2010-01-01

    A crossing symmetric $\\pi N$ scattering amplitude is constructed through a complete attachment of two external pions to the dressed nucleon propagator of an underlying $\\pi N$ potential model. Our formulation automatically provides expressions also for the crossing symmetric and gauge invariant pion photoproduction and Compton scattering amplitudes. We show that our amplitudes are unitary if they coincide on-shell with the amplitudes obtained by attaching one pion to the dressed $\\pi NN$ vertex of the same potential model.

  15. The pion form factor from analyticity and unitarity

    Indian Academy of Sciences (India)

    B Ananthanarayan; Irinel Caprini; I Sentitemsu Imsong

    2012-11-01

    Analyticity and unitarity techniques are employed to estimate Taylor coefficients of the pion electromagnetic form factor at = 0 by exploiting the recently evaluated two-pion contribution to the muon ( − 2) and the phase of the pion electromagnetic form factor in the elastic region, known from scattering by Fermi–Watson theorem and the values of the form factor at several points in the space-like region. Regions in the complex -plane are isolated where the form factor cannot have zeros.

  16. Design and simulation of the nuSTORM pion beamline

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A., E-mail: aoliu@fnal.gov; Neuffer, D.; Bross, A.

    2015-11-21

    The nuSTORM (neutrinos from STORed Muons) proposal presents a detailed design for a neutrino facility based on a muon storage ring, with muon decay in the production straight section of the ring providing well defined neutrino beams. The facility includes a primary high-energy proton beam line, a target station with pion production and collection, and a pion beamline for pion transportation and injection into a muon decay ring. The nuSTORM design uses “stochastic injection”, in which pions are directed by a chicane, referred to as the Orbit Combination Section (OCS), into the production straight section of the storage ring. Pions that decay within that straight section provide muons within the circulating acceptance of the ring. The design enables injection without kickers or a separate pion decay transport line. The beam line that the pions traverse before being extracted from the decay ring is referred to as the pion beamline. This paper describes the design and simulation of the pion beamline, and includes full beam dynamics simulations of the system.

  17. Pion production and absorption in relativistic nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Senger, P. [GSI Planckstr.1, Darmstadt (Germany)

    1993-12-31

    In a relativistic nucleus-nucleus collision the projectile kinetic energy is not only converted into thermal and compressional energy of the nucleonic system, but also into internal excitation energy of the nucleons. At bombarding energies around 1 GeV/nucleon a substantial amount of baryonic resonances is produced which decay predominantly into pions. Thus the pion multiplicity, momentum and angular distributions provide information on the space time dynamics of the nuclear reaction system. In this paper the authors report on experiments which try to measure the `primordial` delta or pion abundancy. The idea is to compare the pion yields measured in a heavy and a light system: in the first case pion final-state interactions should happen much more frequently than in the second case. Both inclusive pion cross sections and pion multiplicities per participant nucleon are measured. In addition the authors study the pion emission pattern with respect to the reaction plane to sort out pions which are less affected by absorption and rescattering even in a heavy collision system.

  18. A dynamical model for pion electroproduction on the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    George L. Caia; Louis E. Wright; Vladimir Pascalutsa

    2005-06-01

    We develop a Lorenz- and gauge-invariant dynamical model for pion electroproduction in the resonance region. The model is based on solving of the Salpeter (instantaneous) equation for the pion-nucleon interaction with a hadron-exchange potential. We find that the one-particle-exchange kernel of the Salpeter equation for pion electroproduction develops an unphysical singularity for a finite value of Q{sup 2}. We analyze two methods of dealing with this problem. Results of our model are compared with recent single-polarization data for pion electroproduction.

  19. Inelastic electron-pion scattering at FNAL (SELEX)

    CERN Document Server

    Moinester, M A; Steiner, V; Moinester, Murray A.; Ocherashvili, Aharon; Steiner, Victor

    1999-01-01

    In this report we describe the analysis status of electron-pion inelastic scattering $\\pi e \\to \\pi' e' \\gamma$ and $\\pi e \\to \\pi' e' \\pi^0$ reaction data, measured in inverse pion-electron scattering at 590 GeV/c at FNAL. The data give information on reactions that were never previously measured: (1) radiative width from a measurement of the transition form factor near zero momentum transfer, (2) $ \\pi e \\to e' \\pi' \\pi^0$ scattering near threshold for a determination of the chiral anomaly transition form factor and the $\\gamma field is Compton scattered on the pion, for a determination of the never previously measured generalized pion polarizabilities.

  20. High transverse mass pion and proton correlations in central PbPb collisions at 17GeV/nucleon

    CERN Document Server

    Bearden, I G; Boissevain, J G; Christiansen, P H L; Conin, L; Dodd, J; Erazmus, B; Esumi, S; Fabjan, Christian Wolfgang; Ferenc, D; Franz, A; Gaardhøje, J J; Hansen, A G; Hansen, O; Hardtke, D; van Hecke, H; Holzer, E B; Humanic, T J; Hummel, P; Jacak, B V; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M; Leltchouk, M; Ljubicic, A; Lörstad, B; Maeda, N; Martin, L; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Potekhin, M V; Poulard, G; Reichhold, D M; Sakaguchi, A; Schmidt-Sørensen, J; Simon-Gillo, J; Sondheim, W E; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K; Xu, N; Zachary, D S

    2003-01-01

    For central PbPb collisions at a center of mass energy of 17.3 GeV/nucleon we have made the first two-dimensional measurement of the pp correlation function. These data extend the range of previous studies of HBT radii by a factor of two in transverse mass. They are consistent with a hydrodynamic interpretation and microscopic models that include hadronic rescattering and transverse expansion. We also report new data on pion correlations. The two particle correlations of negative pions at a transverse mass of 0.92 GeV imply source radii that are smaller than typical hydrodynamic fits and transport model simulations. It is possible that these fast pions may have left the source before the build up of hydrodynamic flow.

  1. Music-induced mood modulates the strength of emotional negativity bias: an ERP study.

    Science.gov (United States)

    Chen, Jie; Yuan, Jiajin; Huang, He; Chen, Changming; Li, Hong

    2008-11-14

    The present study investigated the effect of music-elicited moods on the subsequent affective processing through a music-primed valence categorization task. Event-related potentials were recorded for positive and negative emotional pictures that were primed by happy or sad music excerpts. The reaction time data revealed longer reaction times (RTs) for pictures following negative versus positive music pieces, irrespective of the valence of the picture. Additionally, positive pictures elicited faster response latencies than negative pictures, irrespective of the valence of the musical prime. Moreover, the main effect of picture valence, and the music by picture valence interaction effect were both significant for P2 amplitudes and for the averaged amplitudes at 500-700ms interval. Negative pictures elicited smaller P2 amplitudes than positive pictures, and the amplitude differences between negative and positive pictures were larger with negative musical primes than with positive musical primes. Similarly, compared to positive pictures, negative pictures elicited more negative deflections during the 500-700ms interval across prime types. The amplitude differences between negative and positive pictures were again larger under negative versus positive music primes at this interval. Therefore, the present study observed a clear emotional negativity bias during either prime condition, and extended the previous findings by showing increased strength of the negative bias under negative mood primes. This suggests that the neural sensitivity of the brain to negative stimuli varies with individuals' mood states, and this bias is particularly intensified by negative mood states.

  2. Efflux Transporters Regulate Arsenite Induced Genotoxicity in Double Negative and Double Positive T Cells.

    Science.gov (United States)

    Xu, Huan; Medina, Sebastian; Lauer, Fredine T; Douillet, Christelle; Jian Liu, Ke; Hudson, Laurie G; Stýblo, Miroslav; Aleksunes, Lauren M; Burchiel, Scott W

    2017-04-29

    Arsenite (As+3) exposure is known to cause immunotoxicity in human and animal models. Our previous studies demonstrated that As+3 at 50 to 500 nM concentrations induced both genotoxicity and non-genotoxicity in mouse thymus cells. Developing T cells at CD4-CD8- double negative (DN) stage, the first stage after early T cells are transported from bone marrow to thymus, were found to be more sensitive to As+3 toxicity than the T cells at CD4+CD8+ double positive (DP) stage in vitro. Induction of Mdr1 (Abcb1) and Mrp1 (Abcc1), two multidrug resistance transporters and exporters of As+3, was associated with the reversal of As+3-induced double strand breaks and DNA damage. In order to confirm that the thymus cell populations have different sensitivity to As+3in vivo, male C57BL/6J mice were exposed to 0, 100 and 500 ppb As+3 in drinking water for 30 d. A significant decrease in DN cell percentage was observed with exposure to 500 ppb As+3. Low to moderate concentrations of As+3 were shown to induce higher genotoxicity in sorted DN cells than DP cells in vitro. Calcein AM uptake and Mdr1/Mrp1 mRNA quantification results revealed that DN cells not only had limited As+3 exporter activity, but also lacked the ability to activate these exporters with As+3 treatments, resulting in a higher accumulation of intracellular As+3. Knockdown study of As+3 exporters in the DN thymic cell line, D1 using siRNA, demonstrated that Mdr1 and Mrp1 regulate intracellular As+3 accumulation and genotoxicity. Taken together, the results indicate that transporter regulation is an important mechanism for differential genotoxicity induced by As+3 in thymocytes at different developmental stages. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Negative Modulation of NO for Diaphragmatic Contractile Reduction Induced by Sepsis and Restraint Position

    Institute of Scientific and Technical Information of China (English)

    XIANG Jian; GUAN Su-dong; SONG Xiang-he; WANG Hui-yun; GU Zhen-yong

    2014-01-01

    In practice of forensic medicine, potential disease can be associated with fatal asphyxia in re-straint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and punc-ture (CLP) under the condition of restraint position. The results showed that in the CLP12-18 h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dtmax, -dT/dtmax, CT, Po, force over the full range of the force-frequency relationship and fatigue resistance ) declined progressive-ly; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

  4. Generation of a Retinoblastoma (Rb)1-inducible dominant-negative (DN) mouse model.

    Science.gov (United States)

    Tarang, Shikha; Doi, Songila M S R; Gurumurthy, Channabasavaiah B; Harms, Donald; Quadros, Rolen; Rocha-Sanchez, Sonia M

    2015-01-01

    Retinoblastoma 1 (Rb1) is an essential gene regulating cellular proliferation, differentiation, and homeostasis. To exert these functions, Rb1 is recruited and physically interacts with a growing variety of signaling pathways. While Rb1 does not appear to be ubiquitously expressed, its expression has been confirmed in a variety of hematopoietic and neuronal-derived cells, including the inner ear hair cells (HCs). Studies in transgenic mice demonstrate that complete germline or conditional Rb1 deletion leads to abnormal cell proliferation, followed by massive apoptosis; making it difficult to fully address Rb1's biochemical activities. To overcome these limitations, we developed a tetracycline-inducible TetO-CB-myc6-Rb1 (CBRb) mouse model to achieve transient and inducible dominant-negative (DN) inhibition of the endogenous RB1 protein. Our strategy involved fusing the Rb1 gene to the lysosomal protease pre-procathepsin B (CB), thus allowing for further routing of the DN-CBRb fusion protein and its interacting complexes for proteolytic degradation. Moreover, reversibility of the system is achieved upon suppression of doxycycline (Dox) administration. Preliminary characterization of DN-CBRb mice bred to a ubiquitous rtTA mouse line demonstrated a significant inhibition of the endogenous RB1 protein in the inner ear and in a number of other organs where RB1 is expressed. Examination of the postnatal (P) DN-CBRb mice inner ear at P10 and P28 showed the presence of supernumerary inner HCs (IHCs) in the lower turns of the cochleae, which corresponds to the described expression domain of the endogenous Rb1 gene. Selective and reversible suppression of gene expression is both an experimental tool for defining function and a potential means to medical therapy. Given the limitations associated with Rb1-null mice lethality, this model provides a valuable resource for understanding RB1 activity, relative contribution to HC regeneration and its potential therapeutic application.

  5. Electromagnetic chirality-induced negative refraction with the same amplitude and anti-phase of the two chirality coefficients

    Institute of Scientific and Technical Information of China (English)

    Zhao Shun-Cai; Liu Zheng-Dong; Zheng Jun; Li Gen

    2011-01-01

    This paper suggests a scheme of electromagnetic chirality-induced negative refraction utilizing magneto-electric cross coupling in a four-level atomic system. The negative refraction can be achieved with the two chirality coefficients having the same amplitude but the opposite phase, without requiring the simultaneous presence of an electric-dipole and a magnetic-dipole transition near the same transition frequency.

  6. The pion: an enigma within the Standard Model

    Science.gov (United States)

    Horn, Tanja; Roberts, Craig D.

    2016-07-01

    Quantum chromodynamics (QCDs) is the strongly interacting part of the Standard Model. It is supposed to describe all of nuclear physics; and yet, almost 50 years after the discovery of gluons and quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: neutrons and protons, and the pions that bind them together. QCD is characterised by two emergent phenomena: confinement and dynamical chiral symmetry breaking (DCSB). They have far-reaching consequences, expressed with great force in the character of the pion; and pion properties, in turn, suggest that confinement and DCSB are intimately connected. Indeed, since the pion is both a Nambu-Goldstone boson and a quark-antiquark bound-state, it holds a unique position in nature and, consequently, developing an understanding of its properties is critical to revealing some very basic features of the Standard Model. We describe experimental progress toward meeting this challenge that has been made using electromagnetic probes, highlighting both dramatic improvements in the precision of charged-pion form factor data that have been achieved in the past decade and new results on the neutral-pion transition form factor, both of which challenge existing notions of pion structure. We also provide a theoretical context for these empirical advances, which begins with an explanation of how DCSB works to guarantee that the pion is un-naturally light; but also, nevertheless, ensures that the pion is the best object to study in order to reveal the mechanisms that generate nearly all the mass of hadrons. In canvassing advances in these areas, our discussion unifies many aspects of pion structure and interactions, connecting the charged-pion elastic form factor, the neutral-pion transition form factor and the pion's leading-twist parton distribution amplitude. It also sketches novel ways in which experimental and theoretical studies of the charged-kaon electromagnetic form factor can provide

  7. The pion: an enigma within the Standard Model

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Tanja; Roberts, Craig D.

    2016-05-27

    Quantum chromodynamics (QCDs) is the strongly interacting part of the Standard Model. It is supposed to describe all of nuclear physics; and yet, almost 50 years after the discovery of gluons and quarks, we are only just beginning to understand how QCD builds the basic bricks for nuclei: neutrons and protons, and the pions that bind them together. QCD is characterised by two emergent phenomena: confinement and dynamical chiral symmetry breaking (DCSB). They have far-reaching consequences, expressed with great force in the character of the pion; and pion properties, in turn, suggest that confinement and DCSB are intimately connected. Indeed, since the pion is both a Nambu–Goldstone boson and a quark–antiquark bound-state, it holds a unique position in nature and, consequently, developing an understanding of its properties is critical to revealing some very basic features of the Standard Model. We describe experimental progress toward meeting this challenge that has been made using electromagnetic probes, highlighting both dramatic improvements in the precision of charged-pion form factor data that have been achieved in the past decade and new results on the neutral-pion transition form factor, both of which challenge existing notions of pion structure. We also provide a theoretical context for these empirical advances, which begins with an explanation of how DCSB works to guarantee that the pion is un-naturally light; but also, nevertheless, ensures that the pion is the best object to study in order to reveal the mechanisms that generate nearly all the mass of hadrons. In canvassing advances in these areas, our discussion unifies many aspects of pion structure and interactions, connecting the charged-pion elastic form factor, the neutral-pion transition form factor and the pion's leading-twist parton distribution amplitude. It also sketches novel ways in which experimental and theoretical studies of the charged-kaon electromagnetic form factor can provide

  8. Pion and proton showers in the CALICE scintillator-steel analogue hadron calorimeter

    CERN Document Server

    Bilki, B.; Xia, L.; Eigen, G.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Blazey, G.C.; Dyshkant, A.; Francis, K.; Lima, J.G.R.; Salcido, R.; Zutshi, V.; Salvatore, F.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Suehara, T.; Tomita, T.; Ueno, H.; Yoshioka, T.; Apostolakis, J.; Dannheim, D.; Folger, G.; Ivantchenko, V.; Klempt, W.; Lucaci-Timoce, A. -I.; Ribon, A.; Schlatter, D.; Sicking, E.; Uzhinskiy, V.; Giraud, J.; Grondin, D.; Hostachy, J. -Y.; Morin, L.; Brianne, E.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Tran, H.L.; Buhmann, P.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Schultz-Coulon, H. -Ch.; Shen, W.; Stamen, R.; Norbeck, E.; Northacker, D.; van Doren, B.; Wilson, G.W.; Wing, M.; Combaret, C.; Caponetto, L.; Eté, R.; Grenier, G.; Han, R.; Ianigro, J.C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Antequera, J. Berenguer; Calvo Alamillo, E.; Fouz, M. -C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Corriveau, F.; Bobchenko, B.; Chistov, R.; Chadeeva, M.; Danilov, M.; Drutskoy, A.; Epifantsev, A.; Markin, O.; Mironov, D.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Besson, D.; Buzhan, P.; Ilyin, A.; Popova, E.; Gabriel, M.; Kiesling, C.; van der Kolk, N.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Conforti Di Lorenzo, S.; Cornebise, P.; Dulucq, F.; Fleury, J.; Frisson, T.; Martin-Chassard, G.; Poschl, R.; Raux, L.; Richard, F.; Pöschl, R.; Rouëné, J.; Seguin-Moreau, N.; de la Taille, Ch.; Anduze, M.; Boudry, V.; Brient, J-C.; Clerc, C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Matthieu, A.; Mora de Freitas, P.; Musat, G.; Ruan, M.; Videau, H.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Jeans, D.; Weber, S.

    2015-01-01

    Showers produced by positive hadrons in the highly granular CALICE scintillatorsteel analogue hadronic calorimeter were studied. The experimental data were collected at CERN and FNAL for single particles with initial momenta from 10 to 80 GeV/c. The calorimeter response and resolution and spatial characteristics of shower development for proton- and pion-induced showers for test beam data and simulations using GEANT4 version 9.6 are compared.

  9. N-Delta(1232) axial form factors from weak pion production

    CERN Document Server

    Hernandez, E; Valverde, M; Vicente-Vacas, M J

    2010-01-01

    The N-Delta axial form factors are determined from neutrino induced pion production ANL & BNL data by using a state of the art theoretical model, which accounts both for background mechanisms and deuteron effects. We find violations of the off diagonal Goldberger-Treiman relation at the level of 2 sigma which might have an impact in background calculations for T2K and MiniBooNE low energy neutrino oscillation precision experiments.

  10. Excess pions in Drell-Yan and deep inelastic scattering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Florian, D. de (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Epele, L.N. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Fanchiotti, H. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Garcia Canal, C.A. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina)); Sassot, R. (Lab. de Fisica Teorica, Dept. de Fisica, Univ. Nacional de La Plata (Argentina))

    1994-10-01

    Recent data on Drell-Yan processes induced by protons on nuclear targets gives non trivial information about nuclear effects. A very simple model for excess pions in nuclei reproduces the main features of these data, and also of those coming from deep inelastic experiments. This simple scheme gives an unified treatment of nuclear effects highlighting its importance in the deuteron and provides a precise prediction for future p - p and p - d Drell-Yan experiments. (orig.)

  11. Gap state charge induced spin-dependent negative differential resistance in tunnel junctions

    Science.gov (United States)

    Jiang, Jun; Zhang, X.-G.; Han, X. F.

    2016-04-01

    We propose and demonstrate through first-principles calculation a new spin-dependent negative differential resistance (NDR) mechanism in magnetic tunnel junctions (MTJ) with cubic cation disordered crystals (CCDC) AlO x or Mg1-x Al x O as barrier materials. The CCDC is a class of insulators whose band gap can be changed by cation doping. The gap becomes arched in an ultrathin layer due to the space charge formed from metal-induced gap states. With an appropriate combination of an arched gap and a bias voltage, NDR can be produced in either spin channel. This mechanism is applicable to 2D and 3D ultrathin junctions with a sufficiently small band gap that forms a large space charge. It provides a new way of controlling the spin-dependent transport in spintronic devices by an electric field. A generalized Simmons formula for tunneling current through junction with an arched gap is derived to show the general conditions under which ultrathin junctions may exhibit NDR.

  12. Light-induced negative differential resistance in graphene/Si-quantum-dot tunneling diodes.

    Science.gov (United States)

    Lee, Kyeong Won; Jang, Chan Wook; Shin, Dong Hee; Kim, Jong Min; Kang, Soo Seok; Lee, Dae Hun; Kim, Sung; Choi, Suk-Ho; Hwang, Euyheon

    2016-01-01

    One of the interesing tunneling phenomena is negative differential resistance (NDR), the basic principle of resonant-tunneling diodes. NDR has been utilized in various semiconductor devices such as frequency multipliers, oscillators, relfection amplifiers, logic switches, and memories. The NDR in graphene has been also reported theoretically as well as experimentally, but should be further studied to fully understand its mechanism, useful for practical device applications. Especially, there has been no observation about light-induced NDR (LNDR) in graphene-related structures despite very few reports on the LNDR in GaAs-based heterostructures. Here, we report first observation of LNDR in graphene/Si quantum dots-embedded SiO2 (SQDs:SiO2) multilayers (MLs) tunneling diodes. The LNDR strongly depends on temperature (T) as well as on SQD size, and the T dependence is consistent with photocurrent (PC)-decay behaviors. With increasing light power, the PC-voltage curves are more structured with peak-to-valley ratios over 2 at room temperature. The physical mechanism of the LNDR, governed by resonant tunneling of charge carriers through the minibands formed across the graphene/SQDs:SiO2 MLs and by their nonresonant phonon-assisted tunneling, is discussed based on theoretical considerations.

  13. Light-induced negative differential resistance in graphene/Si-quantum-dot tunneling diodes

    Science.gov (United States)

    Lee, Kyeong Won; Jang, Chan Wook; Shin, Dong Hee; Kim, Jong Min; Kang, Soo Seok; Lee, Dae Hun; Kim, Sung; Choi, Suk-Ho; Hwang, Euyheon

    2016-07-01

    One of the interesing tunneling phenomena is negative differential resistance (NDR), the basic principle of resonant-tunneling diodes. NDR has been utilized in various semiconductor devices such as frequency multipliers, oscillators, relfection amplifiers, logic switches, and memories. The NDR in graphene has been also reported theoretically as well as experimentally, but should be further studied to fully understand its mechanism, useful for practical device applications. Especially, there has been no observation about light-induced NDR (LNDR) in graphene-related structures despite very few reports on the LNDR in GaAs-based heterostructures. Here, we report first observation of LNDR in graphene/Si quantum dots-embedded SiO2 (SQDs:SiO2) multilayers (MLs) tunneling diodes. The LNDR strongly depends on temperature (T) as well as on SQD size, and the T dependence is consistent with photocurrent (PC)-decay behaviors. With increasing light power, the PC-voltage curves are more structured with peak-to-valley ratios over 2 at room temperature. The physical mechanism of the LNDR, governed by resonant tunneling of charge carriers through the minibands formed across the graphene/SQDs:SiO2 MLs and by their nonresonant phonon-assisted tunneling, is discussed based on theoretical considerations.

  14. Low energy electron induced reactions in fluorinated acetamide - probing negative ions and neutral stable counterparts*

    Science.gov (United States)

    Kopyra, Janina; König-Lehmann, Constanze; Illenberger, Eugen; Warneke, Jonas; Swiderek, Petra

    2016-06-01

    Electron impact to trifluoroacetamide (CF3CONH2, TFAA) in the energy range 0-12 eV leads to a variety of negative fragment ions which are formed via dissociative electron attachment (DEA). The underlying reactions range from single bond cleavages to remarkably complex reactions that lead to loss of the neutral units HF, H2O and HNCO as deduced from their directly observed ionic counterparts (M - H2O)-, (M - HF)- and (M - HNCO)-. Also formed are the pseudo-halogen ions CN- and OCN-. All these reactions proceed dominantly via a resonance located near 1 eV, i.e., electrons at subexcitation energies trigger reactions involving multiple bond cleavages. The electron induced generation of the neutral molecules HF, H2O and HNCO in condensed TFAA films is probed by temperature controlled thermal desorption spectrometry (TDS) which can be viewed as a complementary techniques to gas-phase experiments in DEA to directly probe the neutral counterparts. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  15. Measurement of the charged pion mass using a low-density target of light atoms

    Directory of Open Access Journals (Sweden)

    Trassinelli M.

    2016-01-01

    Full Text Available We present a new evaluation of the negatively charged pion mass based on the simultaneous spectroscopy of pionic nitrogen and muonic oxygen transitions using a gaseous target composed by a N2/O2 mixture at 1.4 bar. We present the experimental set-up and the methods for deriving the pion mass value from the spatial separation from the 5g − 4f πN transition line and the 5g − 4f μO transition line used as reference. Moreover, we discuss the importance to use dilute targets in order to minimize the influence of additional spectral lines from the presence of remaining electrons during the radiative emission. The occurrence of possible satellite lines is investigated via hypothesis testing methods using the Bayes factor.

  16. Measurement of the charged pion mass using a low-density target of light atoms

    CERN Document Server

    Trassinelli, M; Borchert, G; Dax, A; Egger, J -P; Gotta, D; Hennebach, M; Indelicato, P; Liu, Y -W; Manil, B; Nelms, N; Simons, L M; Wells, A

    2016-01-01

    We present a new evaluation of the negatively charged pion mass based on the simultaneous spec-troscopy of pionic nitrogen and muonic oxygen transitions using a gaseous target composed by a N 2 /O 2 mixture at 1.4 bar. We present the experimental setup and the methods for deriving the pion mass value from the spatial separation from the 5g -- 4 f $\\pi$N transition line and the 5g -- 4 f $\\mu$O transition line used as reference. Moreover, we discuss the importance to use dilute targets in order to minimize the influence of additional spectral lines from the presence of remaining electrons during the radiative emission. The occurrence of possible satellite lines is investigated via hypothesis testing methods using the Bayes factor.

  17. The KARMEN time anomaly search for a neutral particle of mass 339 Me V in pion decay

    CERN Document Server

    Kettle, P R; Janousch, M; Koglin, J; Pocanic, D; Schottmüller, J; Wigger, C; Zhao, Z G

    2001-01-01

    We have searched the muon momentum spectrum from pion decay-in-flight for evidence of a hitherto unknown neutral particle X, with a mass of 33.905 MeV. This process was suggested by the KARMEN collaboration as an explanation for a 'long-standing' anomaly in their data of neutrino induced reactions originating from stopped pion and muon decays. Using the advantages of a decay-in-flight experiment to kinematically separate muons associated with an X-particle from those originating from normal pion decay, we find no evidence for such a process and place an upper limit on the branching fraction eta

  18. Pion absorption on {sup 3}He at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, H.; Altman, A.; Ashery, D.; Gefen, G.; Gill, D.R.; Johnson, R.R.; Levy-Nathansohn, R.; Moinester, M.A.; Sevior, M.; Trelle, R.P. [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel Aviv University, 69978 Ramat Aviv (Israel)]|[TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (CANADA)]|[Department of Physics, University of British Columbia, Vancouver, British Columbia, V6T 2A6 (CANADA)

    1996-03-01

    The reactions {sup 3}He({pi}{sup +},{ital pp}){ital p} and {sup 3}He({pi}{sup {minus}},{ital pn}){ital n} were studied at 37.0 MeV by coincidence detection of two nucleons. The differential cross sections were separated to two-nucleon ({sigma}{sub 2{ital N}}), three-nucleon ({sigma}{sub 3{ital N}}), and final-state interaction ({sigma}{sub FSI}) components. For {pi}{sup +}, the {sigma}{sub 2{ital N}} angular distribution is symmetric about 90{degree}, and the total cross section is 1.5 times the cross section measured for {ital d}({pi}{sup +},{ital pp}). For {pi}{sup {minus}}, the angular distribution is asymmetric (backward peaked). The asymmetry increases with decreasing energy, indicating increasing pion {ital s}-wave contribution at lower energies. The fraction of the cross section induced by {ital s}-wave pions as calculated by a partial wave amplitude analysis is 13{percent}. The measured total cross sections are {sigma}{sub 2{ital N}}({pi}{sup {minus}})=0.85{plus_minus}0.08 mb and {sigma}{sub 2{ital N}}({pi}{sup +})=7.9{plus_minus}0.5 mb; {sigma}{sub 3{ital N}}({pi}{sup {minus}})=1.6{plus_minus}0.7 mb and {sigma}{sub 3{ital N}}({pi}{sup +})=1.3{plus_minus}0.3 mb. A new evaluation of {sigma}{sub 3{ital N}} at {ital T}{sub {pi}}=62.5 and 82.8 MeV is given, using data from an earlier experiment. The cross sections leading to the two-nucleon final-state interaction at {ital T}{sub {pi}}=37.0 MeV are also estimated. {copyright} {ital 1996 The American Physical Society.}

  19. Pion electric polarizability from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Alexandru, Andrei; Lujan, Michael; Freeman, Walter; Lee, Frank [The George Washington University, 725 21st St. NW, Washington DC, 20052 (United States)

    2016-01-22

    Electromagnetic polarizabilities are important parameters for understanding the interaction between photons and hadrons. For pions these quantities are poorly constrained experimentally since they can only be measured indirectly. New experiments at CERN and Jefferson Lab are planned that will measure the polarizabilities more precisely. Lattice QCD can be used to compute these quantities directly in terms of quark and gluons degrees of freedom, using the background field method. We present results for the electric polarizability for two different quark masses, light enough to connect to chiral perturbation theory. These are currently the lightest quark masses used in polarizability studies.

  20. Pion showers in highly granular calorimeters

    Indian Academy of Sciences (India)

    Jaroslav Cvach; on behalf of the CALICE Collaboration

    2012-10-01

    New results on properties of hadron showers created by pion beam at 8–80 GeV in high granular electromagnetic and hadron calorimeters are presented. Data were used for the first time to investigate the separation of the neutral and charged hadron showers. The result is important to verify the prediction of the PFA algorithm based up to now on the simulated data only. Next, the properties of hadron showers were compared to different physics lists of GEANT4 version 9.3.

  1. Photoproduction of Neutral Pions off Protons

    CERN Document Server

    Crede, V; Wilson, A; Anisovich, A V; Bacelar, J C S; Bantes, R; Bartholomy, O; Bayadilov, D; Beck, R; Beloglazov, Y A; Castelijns, R; Dutz, H; Elsner, D; Ewald, R; Frommberger, F; Funke, Chr; Gregor, R; Gridnev, A; Gutz, E; Hillert, W; Hoffmeister, P; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Kammer, S; Klein, Frank; Klein, Friedrich; Klempt, E; Kotulla, M; Krusche, B; Loehner, H; Lopatin, I V; Lugert, S; Menze, D; Mertens, T; Messchendorp, J G; Metag, V; Nanova, M; Nikonov, V A; Novinski, D; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Sarantsev, A V; Schadmand, S; Schmidt, C; Schmieden, H; Schoch, B; Shende, S; Sokhoyan, V; Suele, A; Sumachev, V V; Szczepanek, T; Thoma, U; Trnka, D; Varma, R; Walther, D; Wendel, Ch

    2011-01-01

    Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction $\\gamma p\\to p\\pi^0$ for photon energies between 0.85 and 2.50 GeV. The $\\pi^0$ mesons are observed in their dominant neutral decay mode: $\\pi^0\\to\\gamma\\gamma$. For the first time, the differential cross sections cover the very forward region, $\\theta_{\\rm c.m.}<60^\\circ$. A partial-wave analysis of these data within the Bonn-Gatchina framework observes the high-mass resonances: $G_{17}$(2190), $D_{13}$(2080), and $D_{15}$(2070).

  2. Rare kaon, muon, and pion decay

    Energy Technology Data Exchange (ETDEWEB)

    Littenberg, L.

    1998-12-01

    The author discusses the status of and prospects for the study of rare decays of kaons, muons, and pions. Studies of rare kaon decays are entering an interesting new phase wherein they can deliver important short-distance information. It should be possible to construct an alternative unitarity triangle to that determined in the B sector, and thus perform a critical check of the Standard Model by comparing the two. Rare muon decays are beginning to constrain supersymmetric models in a significant way, and future experiments should reach sensitivities which this kind of model must show effects, or become far less appealing.

  3. Threshold Neutral Pion Photoproduction on the Proton

    CERN Document Server

    Blin, Astrid Hiller; Ledwig, Tim

    2015-01-01

    The neutral pion photoproduction on the proton near threshold has a very small scattering cross section when compared to the charged channels, which in ChPT is explained by strong cancellations between the lowest order pieces. Therefore it is very sensitive to higher-order corrections of chiral perturbation theory. We perform a fully covariant calculation up to chiral order p^3 and we investigate the effect of the inclusion of the Delta(1232) resonance as an explicit degree of freedom. We show that the convergence improves, leading to a much better agreement with data at a wide range of energies.

  4. Photoproduction of neutral pions off protons

    Science.gov (United States)

    Crede, V.; Sparks, N.; Wilson, A.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, R.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Funke, Chr.; Gregor, R.; Gridnev, A.; Gutz, E.; Hillert, W.; Hoffmeister, P.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Löhner, H.; Lopatin, I. V.; Lugert, S.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Nanova, M.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Sarantsev, A. V.; Schadmand, S.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Sokhoyan, V.; Süle, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch.

    2011-11-01

    Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction γp→pπ0 for photon energies between 0.85 and 2.50 GeV. The π0 mesons are observed in their dominant neutral decay mode: π0→γγ. For the first time, the differential cross sections cover the very forward region, θc.m.<60∘. A partial-wave analysis of these data within the Bonn-Gatchina framework observes the high-mass resonances G17(2190), D13(2080), and D15(2070).

  5. Quark dynamics and pion-nucleon coupling

    Science.gov (United States)

    Weise, W.; Werner, E.

    1981-05-01

    In the framework of nonperturbative QCD phenomenology we discuss: (1) The elementary process for the creation of color-singlet qq-pairs inside a hadron. (2) The interaction of the qq-pair with the surrounding quark-gluon medium. An important consequence of these discussions is that meson emission takes place preferentially, if the primary qq-pair is created in the surface region of the hadron. For the case of pseudoscalar coupling we employ PCAC to obtain the coupling of the qq-pair to the pion. The resulting form and coupling strength of the πNN vertex is consistent with the phenomenological OPEP.

  6. Nuclear transparencies from photoinduced pion production

    Energy Technology Data Exchange (ETDEWEB)

    W. Cosyn; M.C. Martinez; J. Ryckebusch; B. Van Overmeire

    2006-12-01

    We present a relativistic and cross-section factorized framework for computing nuclear transparencies extracted from A({gamma}, {pi} N) reactions at intermediate energies. The proposed quantum mechanical model adopts a relativistic extension to the multiple-scattering Glauber approximation to account for the final state interactions of the ejected nucleon and pion. The theoretical predictions are compared against the experimental {sup 4}He({gamma},p {pi}{sup -}) data from Jefferson Lab. For those data, our results show no conclusive evidence for the onset of mechanisms related to color transparency.

  7. Preliminary results of fission induced by (1068 MeV) pi in Cu, Sn, Au and Bi using CR-39 detectors

    CERN Document Server

    Khan, H A; Shahzad, M I; Manzoor, S; Farooq, M A; Sher, G; Khan, E U; Peterson, R J

    1999-01-01

    Fission probabilities in pion induced reactions exhibit characteristic variations with respect to pion energies and target fissility values. At incident energies well above the pion-nucleon resonances, the statistical model seems to give good description of the observed data. We have used negative pions of energy 1068 MeV, in order to study fission induced in four target materials with fissility values [(Z-1)2/A] ranging from 12 to 32. All targets were arranged in a single stack in such a way that each target coated on a CR-39 detector was sandwiched by another uncoated CR-39 detector plate. The stack was irradiated at the AGS of Brookhaven National Laboratory (USA). This set-up ensures solid angle coverage of almost 4 pi degrees, so that for each fission event one of the fission fragments is expected to be trapped by the forward detector and one by the detector covering backward hemisphere. The effect of pion momentum transfer to the struck nucleus was observed in the form of asymmetry between events counted...

  8. Single neutral pion production by charged-current $\\bar{\

    CERN Document Server

    Aliaga, L; Bercellie, A; Bodek, A; Bravar, A; Brooks, W K; Butkevich, A; Caicedo, D A Martinez; Carneiro, M F; Christy, M E; Chvojka, J; da Motta, H; Devan, J; Dytman, S A; Díaz, G A; Eberly, B; Felix, J; Fields, L; Fine, R; Gago, A M; Gallagher, H; Gran, R; Harris, D A; Higuera, A; Hurtado, K; Kordosky, M; Le, T; Maher, E; Manly, S; Mann, W A; Marshall, C M; McFarland, K S; McGivern, C L; McGowan, A M; Miller, J; Morfín, J G; Mousseau, J; Nelson, J K; Norrick, A; Osta, J; Palomino, J L; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Rakotondravohitra, L; Ramirez, M A; Ransome, R D; Ray, H; Ren, L; Rodrigues, P A; Ruterbories, D; Schellman, H; Schmitz, D W; Sobczyk, J T; Salinas, C J Solano; Tagg, N; Tice, B G; Valencia, E; Walton, T; Wolcott, J; Yepes-Ramirez, H; Zavala, G; Zhang, D; Ziemer, B P

    2015-01-01

    Single neutral pion production via muon antineutrino charged-current interactions in plastic scintillator (CH) is studied using the \\minerva detector exposed to the NuMI low-energy, wideband antineutrino beam at Fermilab. Measurement of this process constrains models of neutral pion production in nuclei, which is important because the neutral-current analog is a background for $\\bar{\

  9. Limits on Lorentz violation from charged-pion decay

    NARCIS (Netherlands)

    P. Noordmans, J.; K. Vos, K.

    2014-01-01

    Charged-pion decay offers many opportunities to study Lorentz violation. Using an effective field theory approach, we study Lorentz violation in the lepton, W-boson, and quark sectors and derive the differential pion-decay rate, including muon polarization. Using coordinate redefinitions we are able

  10. Pion Electromagnetic Form Factor in Virtuality Distribution Formalism

    Energy Technology Data Exchange (ETDEWEB)

    Radyushkin, Anatoly V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Old Dominion Univ., Norfolk, VA (United States)

    2016-01-01

    We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion {\\it transverse momentum distribution amplitude} (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asymptotic pQCD predictions and show that in the $Q^2 \\lesssim 10$ GeV$^2$ region there is essentially no sensitivity to the shape of the pion distribution amplitude. Furthermore, the magnitude of the one-gluon exchange contribution in this region is estimated to be an order of magnitude below the Jefferson Lab data, thus leaving the Feynman mechanism as the only one relevant to the pion electromagnetic form factor behavior for accessible $Q^2$.

  11. Optimization of Experiment Detecting Kaon and Pion Internal Structure

    Science.gov (United States)

    Wacht, Jacob

    2016-09-01

    Pions and kaons are the lightest two-quark systems in Nature. Scientists believe that the rules governing the strong interaction are chirally, symmetric. If this were true, the pion would have no mass. The chiral symmetry is broken dynamically by quark-gluon interactions, giving the pion mass. The pion is thus seen as the key to confirm the mechanism that dynamically generates nearly all of the mass of hadrons and central to the effort to understand hadron structure. The most prominent observables are the meson form factors. Experiments are planned at the 12 GeV Jefferson Lab. An experiment aimed at shedding light on the kaon's internal structure is scheduled to run in 2017. The experimental setup has been optimized for detecting kaons, but it may allow for detecting pions between values of Q2 of 0.4 and 5.5 GeV2. Measurements of the separated pion cross section and exploratory extraction of the pion form factor from electroproduction at low Q2 could be compared to earlier e-pi scattering data, and thus help validating the method. At high Q2, these measurements provide the first L/T separated cross sections and could help guide planned dedicated pion experiments. I will present possible parasitic studies with the upcoming kaon experiment. This work was supported in part by NSF Grant PHY-1306227.

  12. Some remarks on pion condensation in relativistic heavy ion collisions

    CERN Document Server

    Greiner, C; Müller, B

    1993-01-01

    Recently it was pointed out that coherent or condensated states of pions may account for the explanation of the Centauro events observed in cosmic ray showers. We argue that an occurrence of condensed pions requires that the system evolves far out of thermal equilibrium. Besides an unusual charge ratio distribution we show that such a produced state also would lead to strong isospin correlations.

  13. Further comment on pion electroproduction and the axial form factor

    CERN Document Server

    Bernard, V; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.

    2001-01-01

    We show that a recent claim (H.Haberzettl, Phys. Rev. Lett. 85 (2000) 3576) that one cannot extract the nucleon weak axial form factor G_A (t) from charged pion threshold electroproduction is incorrect. Thus previous calculations remain valid and threshold charged pion electroproduction experiments can indeed be used to determine G_A (t), and they should certainly be pursued.

  14. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    Directory of Open Access Journals (Sweden)

    Katia Maalouf

    2011-02-01

    further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines.Conclusion: In conclusion, kefir is effective in inhibiting proliferation and inducing apoptosis of HTLV-1-negative malignant T-lymphocytes. Therefore, further in vivo investigation is highly recommended.Keywords: apoptosis, cancer, CEM, Jurkat, kefir, leukemia

  15. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes.

    Science.gov (United States)

    Maalouf, Katia; Baydoun, Elias; Rizk, Sandra

    2011-02-14

    Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer. The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes. Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry. The maximum cytotoxicity recorded after 48-hours treatment with 80 μg/μL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF-β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG(1) phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines. In conclusion, kefir is effective in inhibiting proliferation and inducing

  16. QCD factorization for the pion diffractive dissociation to two jets

    CERN Document Server

    Braun, V M; Schäfer, A; Szymanowski, L

    2001-01-01

    We calculate the cross section of a pion diffraction dissociation in two jets with large transverse momenta originating from a hard gluon exchange between the pion constituents. To the leading logarithmic accuracy (in energy), the contribution coming from small transverse separations between the quark and the antiquark in the pion acquires the expected factorized form, the longitudinal momentum distribution of the jets being proportional to the pion distribution amplitude. The hard gluon exchange can in this case be considered as a part of the unintegrated gluon distribution. Beyond the leading logarithms (in energy) this proportionality does not hold. Moreover, the collinear factorization appears to be broken by the end-point singularities. Remarkably enough, the longitudinal momentum distribution of the jets for the non-factorizable contribution is calculable, and turns out to be the same as for the factorizable contribution with the asymptotic pion distribution amplitude.

  17. Subthreshold production of pions in coincidence with light particles

    Energy Technology Data Exchange (ETDEWEB)

    Barbera, R.; Badala, A.; Adorno, A.; Bonasera, A.; Di Toro, M.; Palmeri, A.; Pappalardo, G.S.; Riggi, F.; Russo, G. (Istituto Nazionale di Fisica Nucleare, Catania (Italy)); Bizard, G.; Durand, D.; Laville, J.L. (Caen Univ., 14 (France). Lab. de Physique Corpusculaire); Jin, G.M. (Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)); Rosato, E. (Naples Univ. (Italy). Dipt. di Scienze Fisiche Istituto Nazionale di Fisica Nucleare, Naples (Italy))

    1990-12-03

    He ions have been detected in coincidence with charged pions in the reaction {sup 16}O on {sup 27}Al at E{sub lab}=94 MeV/u. We analyse velocity spectra and cross-sections of He ions emitted in the angular range 4deg/150deg in coincidence with charged pions detected at 90deg. A two source emission mechanism of the helium particles and a pion statistical production from an equilibrated participant zone is stressed. The absolute yields at different angles are compared with results of a theoretical model for medium energy heavy ion reactions in the frame of a participant-spectator picture. A comparison of the pion energy spectra with Boltzmann-Nordheim-Vlasov calculations and a discussion on the time scale for pion emission is also presented. (orig.).

  18. RB1 deficiency in triple-negative breast cancer induces mitochondrial protein translation

    Science.gov (United States)

    Jones, Robert A.; Robinson, Tyler J.; Liu, Jeff C.; Shrestha, Mariusz; Voisin, Veronique; Ju, YoungJun; Chung, Philip E.D.; Pellecchia, Giovanna; Fell, Victoria L.; Bae, SooIn; Muthuswamy, Lakshmi; Egan, Sean E.; Jiang, Zhe; Leone, Gustavo; Bader, Gary D.; Schimmer, Aaron

    2016-01-01

    Triple-negative breast cancer (TNBC) includes basal-like and claudin-low subtypes for which no specific treatment is currently available. Although the retinoblastoma tumor-suppressor gene (RB1) is frequently lost together with TP53 in TNBC, it is not directly targetable. There is thus great interest in identifying vulnerabilities downstream of RB1 that can be therapeutically exploited. Here, we determined that combined inactivation of murine Rb and p53 in diverse mammary epithelial cells induced claudin-low–like TNBC with Met, Birc2/3-Mmp13-Yap1, and Pvt1-Myc amplifications. Gene set enrichment analysis revealed that Rb/p53-deficient tumors showed elevated expression of the mitochondrial protein translation (MPT) gene pathway relative to tumors harboring p53 deletion alone. Accordingly, bioinformatic, functional, and biochemical analyses showed that RB1-E2F complexes bind to MPT gene promoters to regulate transcription and control MPT. Additionally, a screen of US Food and Drug Administration–approved (FDA-approved) drugs identified the MPT antagonist tigecycline (TIG) as a potent inhibitor of Rb/p53-deficient tumor cell proliferation. TIG preferentially suppressed RB1-deficient TNBC cell proliferation, targeted both the bulk and cancer stem cell fraction, and strongly attenuated xenograft growth. It also cooperated with sulfasalazine, an FDA-approved inhibitor of cystine xCT antiporter, in culture and xenograft assays. Our results suggest that RB1 deficiency promotes cancer cell proliferation in part by enhancing mitochondrial function and identify TIG as a clinically approved drug for RB1-deficient TNBC. PMID:27571409

  19. Double pion photoproduction off {sup 40}Ca

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, F.; Kotulla, M.; Krusche, B. [University of Basel, Department of Physics and Astronomy, Basel (Switzerland); Ahrens, J.; Beck, R.; Hornidge, D.; Rost, M.; Thomas, A. [Johannes-Gutenberg-Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Fog, L.S.; McGeorge, J.C.; MacGregor, I.J.D.; Owens, R.O.; Sanderson, R.; Watts, D.P. [University of Glasgow, Department of Physics and Astronomy, Glasgow (United Kingdom); Janssen, S.; Messchendorp, J.G.; Metag, V.; Novotny, R.; Pfeiffer, M.; Schadmand, S. [Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany)

    2007-05-15

    The photoproduction of {pi} {sup 0} {pi} {sup 0} and {pi} {sup 0} {pi} {sup {+-}} pairs off {sup 40}Ca has been investigated with the TAPS detector using the Glasgow photon tagging spectrometer at the Mainz MAMI accelerator. Data have been taken for incident photon energies in the energy range from 200-820 MeV. Total cross-sections have been extracted from threshold up to the maximum photon energy and invariant-mass distributions of the pion pairs have been obtained for incident photon energies between 400-500 MeV and 500-550 MeV. The double {pi} {sup 0} invariant-mass distributions show some relative enhancement with respect to the mixed charge channel at small invariant masses. The effects are smaller than previously observed for lead nuclei and the distributions do not significantly deviate from carbon data. The data are in good agreement with the results of recent calculations in the framework of the BUU model, with careful treatment of final-state interaction effects but without an explicit in-medium modification of scalar, iso-scalar pion pairs. This means that for Ca most of the experimentally observed effect can be explained by final-state interactions. Only at low incident photon energies there is still a small low mass enhancement of the double {pi} {sup 0} data over the BUU results. (orig.)

  20. Pion inelastic scattering from sup 20 Ne

    Energy Technology Data Exchange (ETDEWEB)

    Burlein, M. (Pennsylvania Univ., Philadelphia, PA (USA). Dept. of Physics)

    1989-12-01

    Angular distributions for {sup 20}Ne({pi}{sup {plus minus}}, {pi}{sup {plus minus}}{prime}) were measured on the Energetic Pion Channel and Spectrometer (EPICS) at the Clinton P. Anderson Meson Physics Facility (LAMPF). Data were taken with both {pi}{sup {plus}} and {pi}{sup {minus}} over an angular range of 12{degree} to 90{degree} for T{sub {pi}}=180 MeV and with {pi}{sup +} from 15{degree} to 90{degree} for T{sub {pi}}=120 MeV. The data were analyzed using both the distorted-wave impulse approximation (DWIA) and the coupled-channels impulse approximation (CCIA) with collective transition densities. In addition, microscopic transition densities were used in the DWIA analysis for states in the lowest rotational bands. The transitions to the 6.73-MeV 0{sup +} and several 1{sup {minus}} states, including the states at 5.79 MeV and 8.71 MeV, were studied using several models for the transition density. Strong evidence for the importance of two-step routes in pion inelastic scattering was seen in several angular distributions, including the 5.79-MeV 1{sup {minus}}, the first three 4{sup +} states, and the 8.78-MeV 6{sup +}. 100 refs., 81 figs., 33 tabs.

  1. Near-threshold pion production with radioactive beams at the Rare Isotope Accelerator

    CERN Document Server

    Li, B A; Zuo, W; Li, Bao-An; Yong, Gao-Chan; Zuo, Wei

    2005-01-01

    Using an isospin- and momentum-dependent transport model we study near-threshold pion production in heavy-ion collisions induced by radioactive beams at the planned Rare Isotope Accelerator (RIA). We revisit the question of probing the high density behavior of nuclear symmetry energy $E_{sym}(\\rho)$ using the $\\pi^-/\\pi^+$ ratio. It is found that both the total and differential $\\pi^-/\\pi^+$ ratios remain sensitive to the $E_{sym}(\\rho)$ when the momentum-dependence of both the isoscalar and isovector potentials are consistently taken into account. Moreover, the multiplicity and spectrum of $\\pi^-$ mesons are found more sensitive to the $E_{sym}(\\rho)$ than those of $\\pi^+$ mesons. Finally, effects of the Coulomb potential on the pion spectra and $\\pi^-/\\pi^+$ ratio are also discussed.

  2. Improved input for multi-reaction hadronic analyses from elastic pion-nucleon scattering

    Science.gov (United States)

    Revier, Joseph; Roenchen, Deborah; Doering, Michael; Workman`, Ronald

    2017-01-01

    In the search for missing baryonic resonances, many analyses include data from a variety of pion and photon induced reactions. For elastic πN scattering, however, usually the partial waves of the SAID or other groups are fitted, instead of data. We provide the partial-wave covariance matrices needed to perform correlated χ2 fits, in which the obtained χ2 equals the actual χ2 up to non-linear and normalization corrections. For any analysis relying on partial waves extracted from elastic pion scattering, this is a prerequisite to assess the significance of resonance signals and to assign any uncertainty on results. The compilation of the necessary data to improve hadronic analyses is presented in detail. Supported by the U.S. Department of Energy Grant DE-SC0014133, contract DE-AC05-06OR23177, and by the National Science Foundation (CAREER grant No. 1452055, PIF Grant No. 1415459).

  3. Role of induced negative and positive emotions in sensitivity to itch and pain in women.

    NARCIS (Netherlands)

    Laarhoven, A.I.M. van; Walker, A.L.; Wilder-Smith, O.H.G.; Kroeze, S.; Riel, P.L.C.M. van; Kerkhof, P.C.M. van de; Kraaimaat, F.W.; Evers, A.W.M.

    2012-01-01

    Background Itch and pain are common symptoms in skin disease. It has been suggested that negative emotions may play a role in itch and pain. To date, however, the role of emotions has only been studied for pain in experimental studies, not yet for itch. Objectives To investigate the effects of negat

  4. Role of induced negative and positive emotions in sensitivity to itch and pain in women.

    NARCIS (Netherlands)

    Laarhoven, A.I.M. van; Walker, A.L.; Wilder-Smith, O.H.G.; Kroeze, S.; Riel, P.L.C.M. van; Kerkhof, P.C.M. van de; Kraaimaat, F.W.; Evers, A.W.M.

    2012-01-01

    Background Itch and pain are common symptoms in skin disease. It has been suggested that negative emotions may play a role in itch and pain. To date, however, the role of emotions has only been studied for pain in experimental studies, not yet for itch. Objectives To investigate the effects of negat

  5. Lattice calculation of Delta isospin = 3/2 kaon decays to pion pion decay amplitude with interacting two pions

    Science.gov (United States)

    Kim, Changhoan

    We report the results of a calculation of the K → pipi matrix elements of the DeltaI = 3/2 operators. Relying on the 3-flavor effective Hamiltonian, we calculate the low energy contribution to the matrix elements in quenched lattice QCD with the DBW2 action using domain wall fermions, while the high energy contribution is included in the Wilson coefficients. In order to generate interacting pipi states with non-zero relative momentum in lattice, we apply anti-periodic boundary conditions on pions. Since only the magnitude of the overlap of our interpolating operators with the initial and final state is determined, we can calculate only the magnitude of the matrix elements. From the comparison with the experimental result, however, we find some degree of discrepancy. This discrepancy might be ascribed to the unphysical kinematics we choose in this report.

  6. Dilepton bremsstrahlung from pion-pion scattering in a relativistic OBE model

    CERN Document Server

    Eggers, H C; Gale, C; Haglin, K L

    1996-01-01

    We have made a detailed and quantitative study of dilepton production via bremsstrahlung of a virtual photon during pion-pion collisions. Most calculations of electromagnetic radiation from strong interaction processes rely on the soft photon approximation (SPA). The conditions underlying this approximation are generally violated when dilepton spectra are calculated in terms of their invariant mass, so that an approach going beyond the SPA becomes necessary. Superseding previous derivations, we derive an exact formula for the bremsstrahlung cross section. The resulting formulation is compared to various forms based on the SPA, the two-particle phase space approximation and R\\"uckl's formula using a relativistic One Boson Exchange (OBE) model. Within the OBE approach, we show that approximations to the bremsstrahlung dilepton cross sections often differ greatly from the exact result; discrepancies become greater both with rising temperature and with invariant mass. Integrated dilepton production rates are over...

  7. Development of the pion tracker for HADES spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Lalik, Rafal [Excellence Cluster ' ' Universe' ' , TU Muenchen, Boltzmannstr.2, 85748 Garching (Germany); Collaboration: HADES-Collaboration

    2014-07-01

    The beam detector for experiments with pion beams at the HADES spectrometer in GSI Darmstadt has been developed. The main goal of this development is to provide efficient event by event reconstruction of secondary pion momenta. Pions are created impacting nitrogen or proton beams on a secondary beryllium target and are then delivered through a chicane to the experimental areas. The expected momentum spread of the secondary pion beam is about 8% whereas simulated resolution of reconstructed momenta is below 0.5%. The challenging issue is to achieve an accurate measurement (on order of per-mile) of each pion in a high intensity (10{sup 8} part./spill) environment along the pion-bean chicane. This translates into a rate of 10{sup 6} pion/spill with a kinetic energy of 1-2 GeV at the HADES target point. The tracking system is based on double-sided silicon strips sensors build in radiation hardness technology, and a n-XYTER ASIC front-end readout. The trigger logic is implemented in the TRB3 boards. The whole system is designed as a standalone, easy scalable and portable. In this talk we are showing status and performance of the system, and recent results obtained in the laboratory and with proton beams at COSY with 2 GeV protons.

  8. Development of the pion tracker for HADES spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Lalik, Rafal [Technische Univ. Muenchen, Garching (Germany). Excellence Cluster Universe; Collaboration: HADES-Collaboration

    2013-07-01

    We are working on the development of the beam detector for experiments with pion beams at HADES spectrometer in GSI Darmstadt. Pions are created impacting nitrogen or proton beams on a secondary beryllium target and are then delivered through a chicane to the experimental areas. The expected momentum spread of the secondary pion beam is about 8 % and the main goal of this beam detector is to deliver information about the pion momentum for each beam particle. The challenging issue is to achieve an accurate measurement (∼ % fj) of each pion in a high intensity (10{sup 8} part./spill) environment along the pion-bean chicane. This translates into a rate of 10{sup 6} pion/spill with a kinetic energy of 1-2 GeV at the HADES target point. We are currently testing a tracker system, based on double-sided silicon strips detectors with higher radiation hardness and n-XYTER ASIC readout. For prototyping we have prepared the acquisition system compatible with the CBM data acquisition system, for the future employment with HADES we are currently working on acquisition based on the novel TRB3 board. In this talk we are showing current status and performance of the system, and recent results obtained in the laboratory and with proton beams.

  9. Nucleon and pion structure with lattice QCD simulations at physical value of the pion mass

    CERN Document Server

    Abdel-Rehim, A; Constantinou, M; Dimopoulos, P; Frezzotti, R; Hadjiyiannakou, K; Jansen, K; Kallidonis, Ch; Kostrzewa, B; Koutsou, G; Mangin-Brinet, M; Oehm, M; Rossi, G C; Urbach, C; Wenger, U

    2015-01-01

    We present results on the nucleon scalar, axial and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key observables is carried out using lattice QCD simulations at a physical value of the pion mass. The evaluation is based on gauge configurations generated with two degenerate sea quarks of twisted mass fermions with a clover term. We investigate excited states contributions with the nucleon quantum numbers by analyzing three sink-source time separations. We find that, for the scalar charge, excited states contribute significantly and to a less degree to the nucleon momentum fraction and helicity moment. Our analysis yields a value for the nucleon axial charge agrees with the experimental value and we predict a value of 1.027(62) in the $\\overline{\\text{MS}}$ scheme at 2 GeV for the isovector nucleon tensor charge directly at the physical point. The pion momentum fraction is found to be $\\langl...

  10. Neutrinos from PIon Beam Line, nuPIL

    Energy Technology Data Exchange (ETDEWEB)

    Lagrange, J. B. [Imperial Coll., London; Pasternak, J. [Imperial Coll., London; Bross, A. [Fermilab; Liu, A. [Fermilab

    2016-05-05

    LBNF-DUNE (Long Baseline Neutrino Facilities - Deep Underground Neutrino Experiment) is a project based at Fermilab to study neutrino oscillations. The current baseline regarding the neutrino production considers the conventional approach: a high energy proton beam hits a target, producing pions that are collected by a horn and that decay in a decay pipe. An alternative solution, called nuPIL (neutrinos from a Pion beam Line) consists of using a beam line to guide the pions to clean the beam and to put instrumentation to monitor it. This paper presents the concept and the first preliminary results.

  11. Influence of Multiple Scattering on Two-Pion Correlation Measurements

    Institute of Scientific and Technical Information of China (English)

    TANG Gui-Xin; ZHANG Wei-Ning; LIU Yi-Ming; HUO Lei; ZHANG Jing-Bo

    2004-01-01

    @@ Using the relativistic quantum molecular dynamics model, we study the influence of multiple scattering on the result of two-pion correlation measurements. The scales of pion spatial distribution are larger at thermal freezeout than at chemical freeze-out. By varying the value of the parameter of cross section from 0 to 90mb, we find that the sizes of pion source measured by two-particle correlation functions are almost independent of the parameter of cross section. However, λ parameters are sensitive to the parameter of cross section.

  12. Remarks on the pion-nucleon sigma-term

    CERN Document Server

    Hoferichter, Martin; Kubis, Bastian; Meißner, Ulf-G

    2016-01-01

    The pion-nucleon $\\sigma$-term can be stringently constrained by the combination of analyticity, unitarity, and crossing symmetry with phenomenological information on the pion-nucleon scattering lengths. Recently, lattice calculations at the physical point have been reported that find lower values by about $3\\sigma$ with respect to the phenomenological determination. We point out that a lattice measurement of the pion-nucleon scattering lengths could help resolve the situation by testing the values extracted from spectroscopy measurements in pionic atoms.

  13. Thermal and Nonthermal Pion Enhancements with Chiral Symmetry Restoration

    CERN Document Server

    Zhuang, P

    2001-01-01

    The pion production by sigma decay and its relation with chiral symmetry restoration in a hot and dense matter are investigated in the framework of the Nambu-Jona-Lasinio model. The decay rate for the process sigma -> 2pion to the lowest order in a 1/N_c expansion is calculated as a function of temperature T and chemical potential mu. The thermal and nonthermal enhancements of pions generated by the decay before and after the freeze-out present only in the crossover region of the chiral symmetry transition. The strongest nonthermal enhancement is located in the vicinity of the endpoint of the first-order transition.

  14. Pion-nucleon scattering inside the Mandelstam triangle

    CERN Document Server

    Büttiker, P; Büttiker, Paul; Meissner, Ulf-G.

    2000-01-01

    We study the third order pion-nucleon scattering amplitude obtained from heavy baryon chiral perturbation theory inside the Mandelstam triangle. We reconstruct the pion-nucleon amplitude in the unphysical region by use of dispersion relations and determine the pertinent low-energy constants by a fit to this amplitude. A detailed comparison with values obtained from phase shift analysis is given. Our analysis leads to a pion-nucleon sigma-term of sigma(0)=40 MeV based on the Karlsruhe partial wave analysis. We have repeated the same procedure using the latest solution of the VPI group and find a much larger value for sigma(0).

  15. Two-pion interferometry for a partially coherent evolution source

    Institute of Scientific and Technical Information of China (English)

    LI Jian-Wei; YU Li-Li; ZHANG Wei-Ning

    2008-01-01

    We give the formulas of two-pion Hanbury-Brown-Twiss (HBT) correlation function for a partially coherent evolution pion-emitting source,using quantum probability amplitudes in a path-integral formalism.The multiple scattering of the particles in the source is taken into consideration based on Glauber scattering theory.Two-pion interferometry with effects of the multiple scattering and source collective expansion is examined for a partially coherent source of hadronic gas with a finite baryon density and evolving hydrodynamically.We do not find observable effect of either the multiple scattering or the source collective expansion on HBT chaotic parameter.

  16. Pion Effect of Nuclear Matter in a Chiral Sigma Model

    Institute of Scientific and Technical Information of China (English)

    HU Jin-niu; Y.Ogawa; H.Toki; A.Hosaka; SHEN Hong

    2009-01-01

    We develop a new framework for the study of the nuclear matter based on the linear sigma model.We introduce a completely new viewpoint on the treatment of the nuclear matter with the inclusion of the pion.We extend the relativistic chiral mean field model by using the similar method in the tensor optimized shell model.We also regulate the pion-nucleon interaction by considering the form-factor and short range repulsion effects.We obtain the equation of state of nuclear matter and study the importance of the pion effect.

  17. Azimuthal Dependence of Pion Interferometry at the AGS

    CERN Document Server

    Lisa, M A; Alexander, J M; Anderson, M; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D; Chance, J L; Chung, P; Cole, B; Crowe, K M; Das, A C; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A S; Hjort, E L; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J C; Klay, J L; Krofcheck, D; Lacey, R A; Lauret, J; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, Grazyna Janina; Olson, D L; Panitkin, S Y; Pinkenburg, C H; Porile, N T; Rai, G; Ritter, H G; Romero, J L; Scharenberg, R P; Schröder, L; Srivastava, B; Stone, N T B; Symons, T J M; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Zhang Wei Ning

    2000-01-01

    Two-pion correlation functions, measured as a function of azimuthal emission angle with respect to the reaction plane, provide novel information on the anisotropic shape and orientation of the pion-emitting zone formed in heavy ion collisions. We present the first experimental determination of this information, for semi-central Au+Au collisions at 2-6 AGeV. The source extension perpendicular to the reaction plane is greater than the extension in the plane, and tilt of the pion source in coordinate space is found to be opposite its tilt in momentum space.

  18. Pions near the chiral critical point

    Science.gov (United States)

    Hippert, M.; Fraga, E. S.; Santos, E. M.

    2016-04-01

    It is an exciting possibility that the QCD critical point can be found in ultrarelativistic heavy-ion collision experiments (HICs). While quantities such as some event-by-event moments of specific observables should display strong non-monotonic behavior near the critical point and could, hence, be used as signatures of criticality, it is not clear that this behavior could effectively be observed in the highly non-ideal scenario of HICs. We here employ Monte Carlo simulations to test second-order moments of pion observables as possible signatures of the critical point while taking into account some realistic ingredients, similar to the ones found in HICs. We make use of simplified models to introduce spurious contributions and dynamical effects.

  19. Incoherent neutral pion photoproduction on 12C.

    Science.gov (United States)

    Tarbert, C M; Watts, D P; Aguar, P; Ahrens, J; Annand, J R M; Arends, H J; Beck, R; Bekrenev, V; Boillat, B; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R; Downie, E J; Föhl, K; Glazier, D I; Grabmayr, P; Gregor, R; Heid, E; Hornidge, D; Jahn, O; Kashevarov, V L; Knezevic, A; Kondratiev, R; Korolija, M; Kotulla, M; Krambrich, D; Krusche, B; Lang, M; Lisin, V; Livingston, K; Lugert, S; Macgregor, I J D; Manley, D M; Martinez, M; McGeorge, J C; Mekterovic, D; Metag, V; Nefkens, B M K; Nikolaev, A; Novotny, R; Owens, R O; Pedroni, P; Polonski, A; Prakhov, S N; Price, J W; Rosner, G; Rost, M; Rostomyan, T; Schadmand, S; Schumann, S; Sober, D; Starostin, A; Supek, I; Thomas, A; Unverzagt, M; Walcher, Th; Zehr, F

    2008-04-04

    We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The 12C(gamma,pi(0))(12)C*(4.4 MeV) reaction has been studied with the Glasgow photon tagger at MAMI employing a new technique which uses the large solid angle Crystal Ball detector both as a pi(0) spectrometer and to detect decay photons from the excited residual nucleus. The technique has potential applications to a broad range of future nuclear measurements with the Crystal Ball and similar detector systems elsewhere. Such data are sensitive to the propagation of the Delta in the nuclear medium and will give the first information on matter transition form factors from measurements with an electromagnetic probe. The incoherent cross sections are compared to two theoretical predictions including a Delta-hole model.

  20. In-Medium Pion Valence Distributions in a Light-Front Model

    CERN Document Server

    de Melo, J P B C; Ahmed, I

    2016-01-01

    Pion valence distributions in nuclear medium and vacuum are studied in a light-front constituent quark model. The in-medium input for studying the pion properties is calculated by the quark-meson coupling model. We find that the in-medium pion valence distribution, as well as the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

  1. Pion correlations and calorimeter design for high energy heavy ion collisions. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, K.L.

    1997-04-01

    Data analysis is in progress for recent experiments performed by the NA44 collaboration with the first running of 160 A GeV {sup 208}Pb-induced reactions at the CERN SPS. Identified singles spectra were taken for pions, kaons, protons, deuterons, antiprotons and antideuterons. Two-pion interferometry measurements were made for semi-central-triggered {sup 208}Pb + Pb collisions. An updated multi-particle spectrometer allows high statistics data sets of identified particles to be collected near mid-rapidity. A second series of experiments will be performed in the fall of 1995 with more emphasis on identical kaon interferometry and on the measurement of rare particle spectra and correlations. Modest instrumentation upgrades by TAMU are designed to increase the trigger function for better impact parameter selection and improved collection efficiency of valid events. An effort to achieve the highest degree of projectile-target stopping is outlined and it is argued that an excitation function on the SPS is needed to better understand reaction mechanisms. Analysis of experimental results is in the final stages at LBL in the EOS collaboration for two-pion interferometry in the 1.2 A GeV Au + Au reaction, taken with full event characterization.

  2. Pion and kaon correlations in high energy heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, K.L.; Wolf, K.L.

    1996-12-31

    Data analysis is in progress for recent experiments performed by the NA44 collaboration with the first running of 160 A GeV {sup 208}Pb-induced reactions at the CERN SPS. Identified singles spectra were taken for pions, kaons, protons, deuterons, antiprotons and antideuterons. Two-pion interferometry measurements were made for semi-central-triggered {sup 208}Pb + Pb collisions. An upgraded multi-particle spectrometer allows high statistics data sets of identified particles to be collected near mid-rapidity. A second series of experiments will be performed in the fall of 1995 with more emphasis on identical kaon interferometry and on the measurement of rare particle spectra and correlations. Modest instrumentation upgrades by TAMU are designed to increase the trigger function for better impact parameter selection and improved collection efficiency of valid events. An effort to achieve the highest degree of projectile-target stopping is outlined and it is argued that an excitation function on the SPS is needed to better understand reaction mechanisms. Analysis of experimental results is in the final stages at LBL in the EOS collaboration for two-pion interferometry in the 1.2 A GeV Au+Au reaction, taken with full event characterization. 35 refs., 15 figs., 5 tabs.

  3. Beam-spin Asymmetries from Semi-inclusive Pion Electroproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gohn, Wesley P. [University of Connecticut, Storrs, CT (United States); Avakian, Harut A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Joo, Kyungseon [University of Connecticut, Storrs, CT (United States); Ungaro, Maurizio [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-04-01

    We have measured the moment A{sup sin{phi}}{sub LU} corresponding to the polarized electron beam-spin asymmetry in SIDIS. A{sup sin{phi}}{sub LU} is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (pi{sup +}, pi{sup 0} and pi{sup -}) were measured simultaneously over a large range of kinematics within the virtuality range Q{sup 2} ~ 1.0-4.5 GeV{sup 2}. The observable was measured with good statistical precision over a large range of z, P{sub T}, x{sub B}, and Q{sup 2}, which permits comparison with several reaction models. The discussed measurements provide an upgrade in statistics over previous measurements, and serve as the first evidence for the negative sign of the {pi}{sup -} sin{phi} Moment.

  4. The effect of pirenzepine on positive- and negative-lens-induced refractive error and ocular growth in chicks.

    Science.gov (United States)

    Metlapally, Sangeetha; McBrien, Neville A

    2010-11-01

    The selective muscarinic antagonist pirenzepine inhibits experimentally induced myopia in avian and mammalian species, including nonhuman primates and adolescent humans. Transient positive lens defocus has a potent inhibitory effect on negative-lens-induced myopia in avian and mammalian models. The purpose of the present study was to determine the influence of daily treatment with pirenzepine on ocular growth and refractive error in chicks wearing positive lenses. The chicks were allocated to one of eight groups (n = 6 each group) on the basis of whether they wore +10 or -10 D lenses monocularly and whether they received daily intravitreal injections of pirenzepine (700 μg) or vehicle (phosphate-buffered saline) in the lens-defocused eye. In vivo refractive and biometric data were collected, and glycosaminoglycan synthesis in the sclera was assessed. Pirenzepine did not alter the level of positive-lens-induced hyperopia in chicks wearing +10 D lenses compared with that in the vehicle control group (+8.1 ± 0.6 D vs. +8.9 ± 2.4 D, mean ± SEM; P = 0.76). In contrast, pirenzepine caused significant inhibition of negative-lens-induced myopia compared with that in the vehicle group (-1.1 ± 1.5 D vs. -8.8 ± 1.1 D; P = 0.001). Glycosaminoglycan synthesis in the posterior sclera was significantly increased in the negative-lens-treated groups and showed small decreases in the positive-lens-treated groups. The influence of pirenzepine on ocular growth in chicks differed by sign of lens defocus, with pirenzepine blocking negative-lens effects on ocular growth, but not positive-lens effects. The most likely reason that hyperopia was not enhanced by pirenzepine treatment was that the rapid compensatory eye growth associated with positive lenses eliminated the imposed myopic defocus, and the clear retinal image prevented any additional hyperopia from developing.

  5. ST2 negatively regulates TLR2 signaling, but is not required for bacterial lipoprotein-induced tolerance.

    LENUS (Irish Health Repository)

    Liu, Jinghua

    2010-05-15

    Activation of TLR signaling is critical for host innate immunity against bacterial infection. Previous studies reported that the ST2 receptor, a member of the Toll\\/IL-1 receptor superfamily, functions as a negative regulator of TLR4 signaling and maintains LPS tolerance. However, it is undetermined whether ST2 negatively regulates TLR2 signaling and furthermore, whether a TLR2 agonist, bacterial lipoprotein (BLP)-induced tolerance is dependent on ST2. In this study, we show that BLP stimulation-induced production of proinflammatory cytokines and immunocomplex formation of TLR2-MyD88 and MyD88-IL-1R-associated kinase (IRAK) were significantly enhanced in ST2-deficient macrophages compared with those in wild-type controls. Furthermore, overexpression of ST2 dose-dependently attenuated BLP-induced NF-kappaB activation, suggesting a negative regulatory role of ST2 in TLR2 signaling. A moderate but significantly attenuated production of TNF-alpha and IL-6 on a second BLP stimulation was observed in BLP-pretreated, ST2-deficient macrophages, which is associated with substantially reduced IRAK-1 protein expression and downregulated TLR2-MyD88 and MyD88-IRAK immunocomplex formation. ST2-deficient mice, when pretreated with a nonlethal dose of BLP, benefitted from an improved survival against a subsequent lethal BLP challenge, indicating BLP tolerance develops in the absence of the ST2 receptor. Taken together, our results demonstrate that ST2 acts as a negative regulator of TLR2 signaling, but is not required for BLP-induced tolerance.

  6. Gene expression profiling analysis of bisphenol A-induced perturbation in biological processes in ER-negative HEK293 cells.

    Directory of Open Access Journals (Sweden)

    Rong Yin

    Full Text Available Bisphenol A (BPA is an environmental endocrine disruptor which has been detected in human bodies. Many studies have implied that BPA exposure is harmful to human health. Previous studies mainly focused on BPA effects on estrogen receptor (ER-positive cells. Genome-wide impacts of BPA on gene expression in ER-negative cells is unclear. In this study, we performed RNA-seq to characterize BPA-induced cellular and molecular impacts on ER-negative HEK293 cells. The microscopic observation showed that low-dose BPA exposure did not affect cell viability and morphology. Gene expression profiling analysis identified a list of differentially expressed genes in response to BPA exposure in HEK293 cells. These genes were involved in variable important biological processes including ion transport, cysteine metabolic process, apoptosis, DNA damage repair, etc. Notably, BPA up-regulated the expression of ERCC5 encoding a DNA endonuclease for nucleotide-excision repair. Further electrochemical experiment showed that BPA induced significant DNA damage in ER-positive MCF-7 cells but not in ER-negative HEK293 cells. Collectively, our study revealed that ER-negative HEK293 cells employed mechanisms in response to BPA exposure different from ER-positive cells.

  7. Gene expression profiling analysis of bisphenol A-induced perturbation in biological processes in ER-negative HEK293 cells.

    Science.gov (United States)

    Yin, Rong; Gu, Liang; Li, Min; Jiang, Cizhong; Cao, Tongcheng; Zhang, Xiaobai

    2014-01-01

    Bisphenol A (BPA) is an environmental endocrine disruptor which has been detected in human bodies. Many studies have implied that BPA exposure is harmful to human health. Previous studies mainly focused on BPA effects on estrogen receptor (ER)-positive cells. Genome-wide impacts of BPA on gene expression in ER-negative cells is unclear. In this study, we performed RNA-seq to characterize BPA-induced cellular and molecular impacts on ER-negative HEK293 cells. The microscopic observation showed that low-dose BPA exposure did not affect cell viability and morphology. Gene expression profiling analysis identified a list of differentially expressed genes in response to BPA exposure in HEK293 cells. These genes were involved in variable important biological processes including ion transport, cysteine metabolic process, apoptosis, DNA damage repair, etc. Notably, BPA up-regulated the expression of ERCC5 encoding a DNA endonuclease for nucleotide-excision repair. Further electrochemical experiment showed that BPA induced significant DNA damage in ER-positive MCF-7 cells but not in ER-negative HEK293 cells. Collectively, our study revealed that ER-negative HEK293 cells employed mechanisms in response to BPA exposure different from ER-positive cells.

  8. Glucocorticoids induce CCN5/WISP-2 expression and attenuate invasion in oestrogen receptor-negative human breast cancer cells.

    Science.gov (United States)

    Ferrand, Nathalie; Stragier, Emilien; Redeuilh, Gérard; Sabbah, Michèle

    2012-10-01

    CCN5 (cysteine-rich 61/connective tissue growth factor/nephroblastoma overexpressed 5)/WISP-2 [WNT1 (wingless-type MMTV integration site family, member 1)-inducible signalling pathway protein 2] is an oestrogen-regulated member of the CCN family. CCN5 is a transcriptional repressor of genes associated with the EMT (epithelial-mesenchymal transition) and plays an important role in maintenance of the differentiated phenotype in ER (oestrogen receptor)-positive breast cancer cells. In contrast, CCN5 is undetectable in more aggressive ER-negative breast cancer cells. We now report that CCN5 is induced in ER-negative breast cancer cells such as MDA-MB-231 following glucocorticoid exposure, due to interaction of the endogenous glucocorticoid receptor with a functional glucocorticoid-response element in the CCN5 gene promoter. Glucocorticoid treatment of MDA-MB-231 cells is accompanied by morphological alterations, decreased invasiveness and attenuated expression of mesenchymal markers, including vimentin, cadherin 11 and ZEB1 (zinc finger E-box binding homeobox 1). Interestingly, glucocorticoid exposure did not increase CCN5 expression in ER-positive breast cancer cells, but rather down-regulated ER expression, thereby attenuating oestrogen pathway signalling. Taken together, our results indicate that glucocorticoid treatment of ER-negative breast cancer cells induces high levels of CCN5 expression and is accompanied by the appearance of a more differentiated and less invasive epithelial phenotype. These findings propose a novel therapeutic strategy for high-risk breast cancer patients.

  9. Isospin breaking in the pion-nucleon scattering lengths

    CERN Document Server

    Hoferichter, Martin; Meißner, Ulf-G

    2009-01-01

    We analyze isospin breaking through quark mass differences and virtual photons in the pion-nucleon scattering lengths in all physical channels in the framework of covariant baryon chiral perturbation theory.

  10. Amplitude analysis of resonant production in three pions

    CERN Document Server

    Jackura, Andrew; Szczepaniak, Adam

    2016-01-01

    We present some results on the analysis of three pion resonances. The analyses are motivated by the recent release of the largest data set on diffractively produced three pions by the COMPASS collaboration. We construct reaction amplitudes that satisfy fundamental $S$-matrix principles, which allows the use of models that have physical constraints to be used in fitting data. The models are motivated by the isobar model that satisfy unitarity constraints. The model consist of a Deck production amplitude with which final state interactions are constrained by unitarity. We employ the isobar model where two of the pions form a quasi-stable particle. The analysis is performed in the high-energy, single Regge limit. We specifically discuss the examples of the three pion $J^{PC}=2^{-+}$ resonance in the $\\rho\\pi$ and $f_2\\pi$ channels.

  11. Charged Pion Energy Reconstruction in the ATLAS Barrel Calorimeter

    CERN Document Server

    Bosman, M; Nessi, Marzio

    2000-01-01

    The intrinsic performance of the ATLAS barrel and extended barrelcalorimeters for the measurement of charged pions is presented. Pion energyscans (E = 20, 50, 200, 400 and 1000 GeV) at two pseudo-rapidity points ($\\eta$= 0.3 and 1.3) and pseudorapidity scans ($-0.2 < \\eta < 1.8$) with pions ofconstant transverse energy ($E_T = 20$ and 50 GeV) are analysed. A simpleapproach, that accounts in first order for non-compensation and dead materialeffects, is used for the pion energy reconstruction. The intrinsic performancesof the calorimeter are studied: resolution, linearity, effect of dead material,tails in the energy distribution. The effect of electronic noise, cell energycuts and restricted cone size are investigated.

  12. Amplitude analysis of resonant production in three pions

    Directory of Open Access Journals (Sweden)

    Jackura Andrew

    2016-01-01

    Full Text Available We present some results on the analysis of three pion resonances. The analyses are motivated by the recent release of the largest data set on diffractively produced three pions by the COMPASS collaboration. We construct reaction amplitudes that satisfy fundamental S -matrix principles, which allows the use of models that have physical constraints to be used in fitting data. The models are motivated by the isobar model that satisfy unitarity constraints. The model consist of a Deck production amplitude with which final state interactions are constrained by unitarity. We employ the isobar model where two of the pions form a quasi-stable particle. The analysis is performed in the high-energy, single Regge limit. We specifically discuss the examples of the three pion JPC = 2−+ resonance in the ρπ and f2π channels.

  13. On the role of secondary pions in spallation targets

    Energy Technology Data Exchange (ETDEWEB)

    Mancusi, Davide [Paris-Saclay Univ., Gif-sur-Yvette (France). Den-Service d' Etude des Reacteurs et de Mathematiques Appliquees (SERMA); Lo Meo, Sergio [ENEA, Research Centre ' ' Ezio Clementel' ' , Bologna (Italy); INFN, Bologna (Italy); Colonna, Nicola [INFN, Bari (Italy); Boudard, Alain; David, Jean-Christophe; Leray, Sylvie [Paris-Saclay Univ., Gif-sur-Yvette (France). IRFU, CEA; Cortes-Giraldo, Miguel Antonio; Lerendegui-Marco, Jorge [Sevilla Univ. (Spain). Facultad de Fisica; Cugnon, Joseph [Liege Univ. (Belgium). AGO Dept.; Massimi, Cristian [INFN, Bologna (Italy); Bologna Univ. (Italy). Physics and Astronomy Dept.; Vlachoudis, Vasilis [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

    2017-05-15

    We use particle-transport simulations to show that secondary pions play a crucial role for the development of the hadronic cascade and therefore for the production of neutrons and photons from thick spallation targets. In particular, for the nTOF lead spallation target, irradiated with 20 GeV/c protons, neutral pions are involved in the production of ∝ 90% of the high-energy photons; charged pions participate in ∝ 40% of the integral neutron yield. Nevertheless, photon and neutron yields are shown to be relatively insensitive to large changes of the average pion multiplicity in the individual spallation reactions. We characterize this robustness as a peculiar property of hadronic cascades in thick targets. (orig.)

  14. Dynamical model of electroweak pion production in the resonance region

    CERN Document Server

    Sato, T; Kubodera, K; Lee, T S H

    2006-01-01

    In this report, we will briefly review the dynamical model of pion electroweak production reactions in the $\\Delta$ resonance region and report on our study of neutrino-nucleus reactions based on this model.

  15. Cumulative pion production via successive collisions in nuclear medium

    CERN Document Server

    Motornenko, A

    2016-01-01

    Production of pions in proton-nucleus (p+A) reactions outside of a kinematical boundary of proton-nucleon collisions, the so-called cumulative effect, is studied. The kinematical restrictions on pions emitted in backward direction in the target rest frame are analyzed. It is shown that cumulative pion production requires a presence of massive baryonic resonances that are produced during successive collisions of projectile with nuclear nucleons. After each successive collision the mass of created resonance may increase and, simultaneously, its longitudinal velocity decreases. Simulations within Ultra relativistic Quantum Molecular Dynamics model reveals that successive collisions of baryonic resonances with nuclear nucleons plays the dominant role in cumulative pion production in p+A reactions.

  16. Study of $\\tau$ Decays to Six Pions and Neutrino

    CERN Document Server

    Anastassov, A; Eckhart, E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pedlar, T K; Schwarthoff, H; Thayer, J B; Von Törne, E; Zoeller, M M; Richichi, S J; Severini, H; Skubic, P L; Undrus, A; Chen, S; Fast, J; Hinson, J W; Lee, J; Miller, D H; Shibata, E I; Shipsey, I P J; Pavlunin, V; Cronin-Hennessy, D; Lyon, A L; Thorndike, E H; Jessop, C P; Savinov, V; Coan, T E; Fadeev, V; Maravin, Y; Narsky, I; Stroynowski, R; Ye, J; Wlodek, T; Artuso, M; Ayad, R; Boulahouache, C; Bukin, K; Dambasuren, E; Karamov, S; Majumder, G; Moneti, G C; Mountain, R; Schuh, S; Skwarnicki, T; Stone, S; Viehhauser, G; Wang, J C; Wolf, A; Wu, J; Kopp, S E; Mahmood, A H; Csorna, S E; Danko, I; McLean, K W; Xu, Z; Godang, R; Bonvicini, G; Cinabro, D; Dubrovin, M; McGee, S; Zhou, G J; Lipeles, E; Pappas, S P; Schmidtler, M; Shapiro, A; Sun, W M; Weinstein, A J; Würthwein, F; Jaffe, D E; Masek, G E; Paar, H P; Potter, E M; Prell, S; Asner, D M; Eppich, A; Hill, T S; Morrison, R J; Briere, R A; Chen, G P; Ford, W T; Gritsan, A; Roy, J D; Smith, J G; Alexander, J P; Baker, R; Bebek, C; Berger, B E; Berkelman, K; Blanc, F; Boisvert, V; Cassel, David G; Drell, P S; Ecklund, K M; Ehrlich, R; Foland, A D; Gaidarev, P B; Galik, R S; Gibbons, L K; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hopman, P I; Hsu, L; Jones, C D; Kreinick, D L; Lohner, M; Magerkurth, A; Meyer, T O; Mistry, N B; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Romano, A; Thayer, J G; Urner, D; Valant-Spaight, B L; Warburton, A; Avery, P; Prescott, C; Rubiera, A I; Stöck, H; Yelton, J; Brandenburg, G; Ershov, A; Gao, Y S; Kim, D Y J; Wilson, R; Bergfeld, T; Eisenstein, B I; Ernst, J; Gladding, G E; Gollin, G D; Hans, R M; Johnson, E; Karliner, I; Marsh, M A; Palmer, M; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Janicek, R; Patel, P M; Sadoff, A J; Ammar, R; Bean, A; Besson, D; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Mahapatra, R; O'Neill, J J; Poling, R A; Riehle, T; Smith, A; Stepaniak, C J; Urheim, J; Ahmed, S; Alam, M S; Athar, S B; Jian, L; Ling, L; Saleem, M; Timm, S; Wappler, F

    2001-01-01

    The $\\tau$ decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are ${\\cal B}(\\tau^-\\to 2\\pi^-\\pi^+3\\pi^0\

  17. On the role of secondary pions in spallation targets

    CERN Document Server

    Mancusi, Davide; Colonna, Nicola; Boudard, Alain; Cortés-Giraldo, Miguel Antonio; Cugnon, Joseph; David, Jean-Christophe; Leray, Sylvie; Lerendegui-Marco, Jorge; Massimi, Cristian; Vlachoudis, Vasilis

    2016-01-01

    We use particle-transport simulations to show that secondary pions play a crucial role for the development of the hadronic cascade and therefore for the production of neutrons and photons from thick spallation targets. In particular, for the n_TOF lead spallation target, irradiated with 20-GeV/c protons, neutral pions are involved in the production of ~90% of the high-energy photons; charged pions participate in ~40% of the integral neutron yield. Nevertheless, photon and neutron yields are shown to be relatively insensitive to large changes of the average pion multiplicity in the individual spallation reactions. We characterize this robustness as a peculiar property of hadronic cascades in thick targets.

  18. Roy-Steiner-equation analysis of pion-nucleon scattering

    Science.gov (United States)

    Meißner, U.-G.; Ruiz de Elvira, J.; Hoferichter, M.; Kubis, B.

    2017-03-01

    Low-energy pion-nucleon scattering is relevant for many areas in nuclear and hadronic physics, ranging from the scalar couplings of the nucleon to the long-range part of two-pion-exchange potentials and three-nucleon forces in Chiral Effective Field Theory. In this talk, we show how the fruitful combination of dispersion-theoretical methods, in particular in the form of Roy-Steiner equations, with modern high-precision data on hadronic atoms allows one to determine the pion-nucleon scattering amplitudes at low energies with unprecedented accuracy. Special attention will be paid to the extraction of the pion-nucleon σ-term, and we discuss in detail the current tension with recent lattice results, as well as the determination of the low-energy constants of chiral perturbation theory.c

  19. Amplitude analysis of resonant production in three pions

    Science.gov (United States)

    Jackura, Andrew; Mikhasenko, Mikhail; Szczepaniak, Adam

    2016-11-01

    We present some results on the analysis of three pion resonances. The analyses are motivated by the recent release of the largest data set on diffractively produced three pions by the COMPASS collaboration. We construct reaction amplitudes that satisfy fundamental S -matrix principles, which allows the use of models that have physical constraints to be used in fitting data. The models are motivated by the isobar model that satisfy unitarity constraints. The model consist of a Deck production amplitude with which final state interactions are constrained by unitarity. We employ the isobar model where two of the pions form a quasi-stable particle. The analysis is performed in the high-energy, single Regge limit. We specifically discuss the examples of the three pion JPC = 2-+ resonance in the ρπ and f2π channels.

  20. Amplitude analysis of resonant production in three pions

    Energy Technology Data Exchange (ETDEWEB)

    Jackura, Andrew [Indiana Univ., Bloomington, IN (United States); Mikhasenko, Mikhail [Univ. of Bonn (Germany); Szczepaniak, Adam [Indiana Univ., Bloomington, IN (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-11-29

    We present some results on the analysis of three pion resonances. The analyses are motivated by the recent release of the largest data set on diffractively produced three pions by the COMPASS collaboration. We construct reaction amplitudes that satisfy fundamental $S$-matrix principles, which allows the use of models that have physical constraints to be used in fitting data. The models are motivated by the isobar model that satisfy unitarity constraints. The model consist of a Deck production amplitude with which final state interactions are constrained by unitarity. We employ the isobar model where two of the pions form a quasi-stable particle. The analysis is performed in the high-energy, single Regge limit. We specifically discuss the examples of the three pion $J^{PC}=2^{-+}$ resonance in the $\\rho\\pi$ and $f_2\\pi$ channels.

  1. Plastic and evolutionary responses to heat stress in a temperate dung fly: negative correlation between basal and induced heat tolerance?

    Science.gov (United States)

    Esperk, T; Kjaersgaard, A; Walters, R J; Berger, D; Blanckenhorn, W U

    2016-05-01

    Extreme weather events such as heat waves are becoming more frequent and intense. Populations can cope with elevated heat stress by evolving higher basal heat tolerance (evolutionary response) and/or stronger induced heat tolerance (plastic response). However, there is ongoing debate about whether basal and induced heat tolerance are negatively correlated and whether adaptive potential in heat tolerance is sufficient under ongoing climate warming. To evaluate the evolutionary potential of basal and induced heat tolerance, we performed experimental evolution on a temperate source population of the dung fly Sepsis punctum. Offspring of flies adapted to three thermal selection regimes (Hot, Cold and Reference) were subjected to acute heat stress after having been exposed to either a hot-acclimation or non-acclimation pretreatment. As different traits may respond differently to temperature stress, several physiological and life history traits were assessed. Condition dependence of the response was evaluated by exposing juveniles to different levels of developmental (food restriction/rearing density) stress. Heat knockdown times were highest, whereas acclimation effects were lowest in the Hot selection regime, indicating a negative association between basal and induced heat tolerance. However, survival, adult longevity, fecundity and fertility did not show such a pattern. Acclimation had positive effects in heat-shocked flies, but in the absence of heat stress hot-acclimated flies had reduced life spans relative to non-acclimated ones, thereby revealing a potential cost of acclimation. Moreover, body size positively affected heat tolerance and unstressed individuals were less prone to heat stress than stressed flies, offering support for energetic costs associated with heat tolerance. Overall, our results indicate that heat tolerance of temperate insects can evolve under rising temperatures, but this response could be limited by a negative relationship between basal and

  2. Spin effects in the pion holographic light-front wavefunction

    CERN Document Server

    Ahmady, Mohammad; Sandapen, Ruben

    2016-01-01

    We account for dynamical spin effects in the holographic light-front wavefunction of the pion in order to predict its mean charge radius, decay constant, spacelike electromagnetic form factor, twist-2 Distribution Amplitude and the photon-to-pion transition form factor. Using a universal fundamental AdS/QCD scale of 523 MeV and a constituent quark mass of 330 MeV, we find a remarkable improvement in describing all observables.

  3. Coulomb dissociation of a fast pion into two jets

    CERN Document Server

    Ivanov, D Yu

    2001-01-01

    We calculate the electromagnetic contribution to the scattering amplitude of pion diffractive dissociation into di-jets which is described by one photon exchange. The result shows that the factorization procedure known for the description of exclusive reactions holds also for this quasi-exclusive process. We find that the longitudinal momentum distribution of di-jets does not depend on the form of the pion distribution amplitude. We discuss the magnitude of the cross section.

  4. Determination of the pion and kaon structure functions

    Energy Technology Data Exchange (ETDEWEB)

    Aitkenhead, W.; Barton, D.S.; Brandenburg, G.W.; Busza, W.; Dobrowolski, T.; Friedman, J.I.; Kendall, H.W.; Lyons, T.; Nelson, B.; Rosenson, L.; Toy, W.; Verdier, R.; Votta, L.; Chiaradia, M.T.; DeMarzo, C.; Favuzzi, C.; Germinario, G.; Guerriero, L.; LaVopa, P.; Maggi, G.; Posa, F.; Selvaggi, G.; Spinelli, P.; Waldner, F.; Brenner, A.E.; Carey, D.C.; Elias, J.E.; Garbincius, P.H.; Mikenberg, G.; Polychronakos, V.A.; Meunier, R.; Cutts, D.; Dulude, R.S.; Lanou, R.E. Jr.; Massimo, J.T.

    1980-07-21

    Quark structure functions have been extracted from low-p/sub T/ inclusive hadron production data for the pion and kaon with use of the recombination model. n/sup ..pi../=1.0 +- 0.1 and n/sup K/=2.5 +- 0.6 is obtained, where n is the leading (1-x) power of the nonstrange--valence-quark distribution. Both the pion and kaon nonstrange--sea-quark functions have napprox. =3.5.

  5. Di-photon resonance and Dark Matter as heavy pions

    CERN Document Server

    Redi, Michele; Tesi, Andrea; Vigiani, Elena

    2016-05-13

    We analyse confining gauge theories where the 750 GeV di-photon resonance is a composite techni-pion that undergoes anomalous decays into SM vectors. These scenarios naturally contain accidentally stable techni-pions Dark Matter candidates. The di-photon resonance can acquire a larger width by decaying into Dark Matter through the CP-violating $\\theta$-term of the new gauge theory reproducing the cosmological Dark Matter density as thermal relic.

  6. The Onset of Quark-Hadron Duality in Pion Electroproduction

    CERN Document Server

    Navasardyan, T; Ahmidouch, A; Angelescu, T; Arrington, J; Asaturyan, R; Baker, O K; Benmouna, N; Bertoncini, C; Blok, H P; Bosted, P E; Breuer, H; Böglin, W; Christy, M E; Connell, S H; Cui, Y; Dalton, M M; Danagulyan, S; Day, D; Dodario, T; Dunne, J A; Dutta, D; Ent, R; Fenker, H C; Frolov, V V; Gan, L; Gaskell, D; Hafidi, K; Hinton, W; Holt, R J; Horn, T; Huber, G M; Hungerford, E; Jiang, X; Jones, M; Joo, K; Kalantarians, N; Kelly, J J; Keppel, C E; Khayari, N E; Kinney, E R; Kubarovski, V; Li, Y; Liang, Y; Malace, S; Markowitz, P; McGrath, E; McKee, P; Meekins, D G; Mkrtchyan, H; Moziak, B; Niculescu, G; Niculescu, I; Opper, A K; Ostapenko, T; Reimer, P; Reinhold, J; Roche, J; Rock, S E; Schulte, E; Segbefia, E; Smith, C; Smith, G R; Stoler, P; Tadevosyan, V; Tang, L; Ungaro, M; Uzzle, A; Vidakovic, S; Villano, A; Vulcan, W F; Wang, M; Warren, G; Wesselmann, F; Wojtsekhowski, B; Wood, S A; Xu, C; Yuan, L; Zheng, X; Zhu, H

    2007-01-01

    A large data set of charged-pion electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-to- pion production mechanisms.

  7. The Electromagnetic Mass Differences of Pions and Kaons

    CERN Document Server

    Donoghue, J F; Donoghue, John F.; Perez, Antonio F.

    1997-01-01

    We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy and experimental data in between are used in the dispersion relation. We find excellent agreement with experiment for the pion mass difference. The kaon mass difference exhibits a strong violation of the lowest order prediction of Dashen's theorem, in qualitative agreement with several other recent calculations.

  8. Effects of Nonlocal One-Pion-Exchange Potential in Deuteron

    OpenAIRE

    Forest, J. L.

    1999-01-01

    The off-shell aspects of the one-pion-exchange potential (OPEP) are discussed. Relativistic Hamiltonians containing relativistic kinetic energy, relativistic OPEP with various off-shell behaviors and Argonne $v_{18}$ short-range parameterization are used to study the deuteron properties. The OPEP off-shell behaviors depend on whether a pseudovector or pseudoscalar pion-nucleon coupling is used and are characterized by a parameter $\\mu$. We study potentials having $\\mu$=-1, 0 and +1 and we fin...

  9. The transverse spin structure of the pion at short distances

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Szymanowski, Lech [Soltan Inst. for Nuclear Studies, Warsaw (Poland); Ecole Polytechnique, CNRS, Palaiseau (France). Centre de Physique Theorique; Paris-Sud Univ., CNRS, Orsay (France). Lab. de Physique Theorique

    2010-03-15

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q{sup 2}. It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the dominant terms at high Q{sup 2} and illustrate them numerically. (orig.)

  10. Stopping pions in high-energy nuclear cascades.

    Science.gov (United States)

    Jones, W. V.; Johnson, D. P.; Thompson, J. A.

    1973-01-01

    Results of Monte Carlo calculations for the number and energy spectra of charged pions from nuclear-electromagnetic cascades developing in rock are presented for primary hadron energies ranging from 3 to 3000 GeV. These spectra are given as functions of the longitudinal depth in the absorber and the lateral distance from the cascade axis. The number of charged pions which stop in the absorber increases with the primary energy of the hadron initiating the cascade.

  11. HBT correlations and charge ratios in multiple production of pions

    CERN Document Server

    Bialas, A

    1999-01-01

    The influence of the HBT effect on the multiplicity distribution and charge ratios of independently produced pions is studied. It is shown that, for a wide class of models, there is a critical point, where the average number of pions becomes very large and the multiplicity distibution becomes very broad. In this regime unusual charge ratios ("centauros", "anticentauros") are strongly enhanced. The prospects for reaching this regime are discussed.

  12. Di-photon resonance and Dark Matter as heavy pions

    CERN Document Server

    Redi, Michele; Tesi, Andrea; Vigiani, Elena

    2016-01-01

    We analyse confining gauge theories where the 750 GeV di-photon resonance is a composite techni-pion that undergoes anomalous decays into SM vectors. These scenarios naturally contain accidentally stable techni-pions Dark Matter candidates. The di-photon resonance can acquire a larger width by decaying into Dark Matter through the CP-violating $\\theta$-term of the new gauge theory reproducing the cosmological Dark Matter density as thermal relic.

  13. The transverse spin structure of the pion at short distances

    CERN Document Server

    Diehl, Markus

    2010-01-01

    We study the form factors of the quark tensor currents in the pion at large squared momentum transfer Q^2. It turns out that certain form factors can be evaluated using collinear factorization, whereas others receive important contributions from the end-point regions of the longitudinal quark momenta in the pion. We derive simple analytic expressions for the dominant terms at high Q^2 and illustrate them numerically.

  14. Measurement of the charged pion mass using X-ray spectroscopy of exotic atoms

    CERN Document Server

    Trassinelli, M; Borchert, G; Dax, A; Egger, J P; Gotta, D; Hennebach, M; Indelicato, P; Liu, Y -W; Manil, B; Nelms, N; Simons, L M; Wells, A

    2016-01-01

    The $5g-4f$ transitions in pionic nitrogen and muonic oxygen were measured simultaneously by using a gaseous nitrogen-oxygen mixture at 1.4\\,bar. Due to the precise knowledge of the muon mass the muonic line provides the energy calibration for the pionic transition. A value of (139.57077\\,$\\pm$\\,0.00018)\\,MeV/c$^{2}$ ($\\pm$\\,1.3ppm) is derived for the mass of the negatively charged pion, which is 4.2ppm larger than the present world average.

  15. Local Structural Distortion Induced Uniaxial Negative Thermal Expansion in Nanosized Semimetal Bismuth.

    Science.gov (United States)

    Li, Qiang; Zhu, He; Zheng, Lirong; Fan, Longlong; Ren, Yang; Chen, Jun; Deng, Jinxia; Xing, Xianran

    2016-11-01

    The corrugated layer structure bismuth has been successfully tailored into negative thermal expansion along c axis by size effect. Pair distribution function and extended X-ray absorption fine structure are combined to reveal the local structural distortion for nanosized bismuth. The comprehensive method to identify the local structure of nanomaterials can benefit the regulating and controlling of thermal expansion in nanodivices.

  16. Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Verheul, A.; Gram, Lone;

    1997-01-01

    carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

  17. Sex steroid induced negative mood may be explained by the paradoxical effect mediated by GABAA modulators.

    NARCIS (Netherlands)

    Andreen, L.; Nyberg, S.; Turkmen, S.; Wingen, G.A. van; Fernandez, G.S.E.; Backstrom, T.

    2009-01-01

    Certain women experience negative mood symptoms as a result of progesterone during the luteal phase of the menstrual cycle, progestagens in hormonal contraceptives, or the addition of progesterone or progestagens in sequential hormone therapy (HT). This phenomenon is believed to be mediated via the

  18. Diet induced weight loss accelerates onset of negative alliesthesia in obese women

    Directory of Open Access Journals (Sweden)

    Frankham Patrick

    2005-10-01

    Full Text Available Abstract Background The physiological and behavioral responses to hypocaloric diet are to increase energy intake to defend a steady body weight. We utilized the method of "negative alliesthesia" for measuring the hedonic reponse to sweet stimulus before (Initial session and 3 months after entering a weight loss program. The negative alliesthesia test is known by physiologists but few clinical data exist. It is based on the observation that repeated pleasant gustatory stimuli turn into unpleasantness in the process of alliesthesia. At first visit participants repeatedly ingested sweet stimuli until they found them unpleasant and rated quantitatively on a linear analogue scale their hedonic experience. This procedure was repeated every 3 min until participants felt displeasure to end the session. The same protocol was followed after three months of following a weight loss diet. Dieting energy intake was from 1400 – 2000 kcal/d for 8 wk. Energy composition was 50% carb:25% prot: 25% lipid. After 8 wk caloric intake increased by 50 kcal/wk, to reach daily intake of 1800 – 2400 kcal/d. Energy composition was 50% carb:22% prot: 27% lipid. We report results on the effect of slow weight loss on negative alliesthesia in ten obese female participants enrolled in a commercial diet program based on Canada's Food Guide (Mincavi®. Results Results showed that diet lowered the mean BMI (Initial session 36.8 +/- 1.8 vs. 3 mo 34.9 +/- 1.8 kg/m2. At 3 mo the onset of negative alliesthesia, time to abandon experimental session, was shortened (Initial session 33 vs. 3 mo 24 min. The same trend was observed in the time to reach indifference (Initial session 21.9 +/- 3.8 vs. 3 mo 16.2 +/-2.4 min. There was no observed difference in maximum (Initial session +79.5 +/- 11.7; 3 mo +94.5 +/- 9.9 mm and minimum (Initial session -90.0 +/- 14.4; 3 mo -106 +/- 11.1 mm hedonic rating. Conclusion Earlier onset of negative alliesthesia, as seen in our participants, is not

  19. Pion transverse charge density from timelike form factor data

    Energy Technology Data Exchange (ETDEWEB)

    Gerald Miller, Mark Strikman, Christian Weiss

    2011-01-01

    The transverse charge density in the pion can be represented as a dispersion integral of the imaginary part of the pion form factor in the timelike region. This formulation incorporates information from e+e- annihilation experiments and allows one to reconstruct the transverse density much more accurately than from the spacelike pion form factor data alone. We calculate the transverse density using an empirical parametrization of the timelike pion form factor and estimate that it is determined to an accuracy of ~10% at a distance b ~ 0.1 fm, and significantly better at larger distances. The density is found to be close to that obtained from a zero-width rho meson pole over a wide range and shows a pronounced rise at small distances. The resulting two-dimensional image of the fast-moving pion can be interpreted in terms of its partonic structure in QCD. We argue that the singular behavior of the charge density at the center requires a substantial presence of pointlike configurations in the pion's partonic wave function, which can be probed in other high-momentum transfer processes.

  20. Single pion electro- and neutrino production on heavy targets

    Energy Technology Data Exchange (ETDEWEB)

    Paschos, E. A. [Theoretische Physik III, University of Dortmund, D-44221 Dortmund (Germany); Schienbein, I. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier/CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France); Yu, J.Y. [Southern Methodist University, Dallas, Texas 75275 (United States)

    2007-04-15

    We present a calculation of single pion electroproduction cross sections on heavy targets in the kinematic region of the {delta}(1232) resonance. Final state interactions of the pions are taken into account using the pion multiple scattering model of Adler, Nussinov and Paschos (ANP model). For electroproduction and neutral current reactions we obtain results for carbon, oxygen, argon and iron targets and find a significant reduction of the W-spectra for {pi}{sup 0} as compared to the free nucleon case. On the other hand, the charged pion spectra are only little affected by final state interactions. Measurements of such cross sections with the CLAS detector at JLAB could help to improve our understanding of pion rescattering effects and serve as important/valuable input for calculations of single pion neutrino production on heavy targets relevant for current and future long baseline neutrino experiments. Two ratios, in Eq. (3.8) and (3.10), will test important properties of the model. (authors)

  1. Pion Electromagnetic Form Factor in Virtuality Distribution Formalism

    CERN Document Server

    Radyushkin, A V

    2015-01-01

    We discuss two applications of the {\\it Virtuality Distribution Amplitudes} (VDA) formalism developed in our recent papers. We start with an overview of the main properties of the pion distribution amplitude emphasizing the quantitative measures of its width, and possibility to access them through the pion transition form factor studies. We formulate the basic concepts of the VDA approach and introduce the pion transverse momentum distribution amplitude (TMDA) which plays, in a covariant Lagrangian formulation, a role similar to that of the pion wave function in the 3-dimensional Hamiltonian light-front approach. We propose simple factorized models for soft TMDAs, and use them to describe existing data on the pion transition form factor, thus fixing the scale determining the size of the transverse-momentum effects. Finally, we apply the VDA approach to the one-gluon exchange contribution for the pion electromagnetic form factor. We observe a very late $Q^2 \\gtrsim 20$ GeV$^2$ onset of transition to the asympt...

  2. Gravitational wave from dark sector with dark pion

    Science.gov (United States)

    Tsumura, Koji; Yamada, Masatoshi; Yamaguchi, Yuya

    2017-07-01

    In this work, we investigate the spectra of gravitational waves produced by chiral symmetry breaking in dark quantum chromodynamics (dQCD) sector. The dark pion (π) can be a dark matter candidate as weakly interacting massive particle (WIMP) or strongly interacting massive particle (SIMP). For a WIMP scenario, we introduce the dQCD sector coupled to the standard model (SM) sector with classical scale invariance and investigate the annihilation process of the dark pion via the 2π → 2 SM process. For a SIMP scenario, we investigate the 3π → 2π annihilation process of the dark pion as a SIMP using chiral perturbation theory. We find that in the WIMP scenario the gravitational wave background spectra can be observed by future space gravitational wave antennas. On the other hand, when the dark pion is the SIMP dark matter with the constraints for the chiral perturbative limit and pion-pion scattering cross section, the chiral phase transition becomes crossover and then the gravitational waves are not produced.

  3. Orphan Nuclear Receptor ERRα Controls Macrophage Metabolic Signaling and A20 Expression to Negatively Regulate TLR-Induced Inflammation.

    Science.gov (United States)

    Yuk, Jae-Min; Kim, Tae Sung; Kim, Soo Yeon; Lee, Hye-Mi; Han, Jeongsu; Dufour, Catherine Rosa; Kim, Jin Kyung; Jin, Hyo Sun; Yang, Chul-Su; Park, Ki-Sun; Lee, Chul-Ho; Kim, Jin-Man; Kweon, Gi Ryang; Choi, Hueng-Sik; Vanacker, Jean-Marc; Moore, David D; Giguère, Vincent; Jo, Eun-Kyeong

    2015-07-21

    The orphan nuclear receptor estrogen-related receptor α (ERRα; NR3B1) is a key metabolic regulator, but its function in regulating inflammation remains largely unknown. Here, we demonstrate that ERRα negatively regulates Toll-like receptor (TLR)-induced inflammation by promoting Tnfaip3 transcription and fine-tuning of metabolic reprogramming in macrophages. ERRα-deficient (Esrra(-/-)) mice showed increased susceptibility to endotoxin-induced septic shock, leading to more severe pro-inflammatory responses than control mice. ERRα regulated macrophage inflammatory responses by directly binding the promoter region of Tnfaip3, a deubiquitinating enzyme in TLR signaling. In addition, Esrra(-/-) macrophages showed an increased glycolysis, but impaired mitochondrial respiratory function and biogenesis. Further, ERRα was required for the regulation of NF-κB signaling by controlling p65 acetylation via maintenance of NAD(+) levels and sirtuin 1 activation. These findings unravel a previously unappreciated role for ERRα as a negative regulator of TLR-induced inflammatory responses through inducing Tnfaip3 transcription and controlling the metabolic reprogramming.

  4. Truncated forms of BNIP3 act as dominant negatives inhibiting hypoxia-induced cell death

    Science.gov (United States)

    Bristow, Nicolle; Burton, Teralee R; Henson, Elizabeth S; Ong-Justiniano, Coleen; Brown, Michelle; Gibson, Spencer B

    2011-01-01

    BNIP3 (Bcl-2/adenovirus E1B Ninteen Kilodalton Interacting Protein) is a pro-cell death member of the Bcl-2 family of proteins. Its expression is induced by the transcription factor Hypoxia Inducible Factor-1 (HIF-1) under conditions of low oxygen (hypoxia) and is found over expressed in hypoxic regions of many tumors. When over expressed, BNIP3 induces cell death through induction of mitochondrial dysfunction that is dependant on the presence of BNIP3’s TM domain. Herein, we have determined that the SkOv3 ovarian cancer cell line expresses a truncated BNIP3 protein, which results in the elimination of the transmembrane domain. Truncation that eliminates all four domains of BNIP3 protein also inhibits hypoxia-induced cell death in SkOv3, HEK293, U251 and MCF-7 cells. Three different mutations in a BNIP3 expression vector that lead to a truncated BNIP3 protein, lacking TM domain only, or lacking CD, BH3, and TM domains resulted in inhibition of hypoxia-induced cell death when transfected into HEK293 cells. We found that truncated BNIP3 failed to associate with the mitochondria and the truncated BNIP3 lacking all four domains can bind to wild type BNIP3. Taken together, truncation of BNIP3 could be a novel mechanism for cancer cells to avoid hypoxia-induced cell death mediated by BNIP3 over expression. PMID:21138765

  5. KISS1R induces invasiveness of estrogen receptor-negative human mammary epithelial and breast cancer cells.

    Science.gov (United States)

    Cvetkovic, Donna; Dragan, Magdalena; Leith, Sean J; Mir, Zuhaib M; Leong, Hon S; Pampillo, Macarena; Lewis, John D; Babwah, Andy V; Bhattacharya, Moshmi

    2013-06-01

    Kisspeptins (KPs), peptide products of the KISS1 metastasis-suppressor gene, are endogenous ligands for a G protein-coupled receptor (KISS1R). KISS1 acts as a metastasis suppressor in numerous human cancers. However, recent studies have demonstrated that an increase in KISS1 and KISS1R expression in patient breast tumors correlates with higher tumor grade and metastatic potential. We have shown that KP-10 stimulates invasion of estrogen receptor α (ERα)-negative MDA-MB-231 breast cancer cells via transactivation of the epidermal growth factor receptor (EGFR). Here, we report that either KP-10 treatment of ERα-negative nonmalignant mammary epithelial MCF10A cells or expression of KISS1R in MCF10A cells induced a mesenchymal phenotype and stimulated invasiveness. Similarly, exogenous expression of KISS1R in ERα-negative SKBR3 breast cancer cells was sufficient to trigger invasion and induced extravasation in vivo. In contrast, KP-10 failed to transactivate EGFR or stimulate invasiveness in the ERα-positive MCF7 and T47D breast cancer cells. This suggested that ERα negatively regulates KISS1R-dependent breast cancer cell migration, invasion, and EGFR transactivation. In support of this, we found that these KP-10-induced effects were ablated upon exogenous expression of ERα in the MDA-MB-231 cells, by down-regulating KISS1R expression. Lastly, we have identified IQGAP1, an actin cytoskeletal binding protein as a novel binding partner of KISS1R, and have shown that KISS1R regulates EGFR transactivation in breast cancer cells in an IQGAP1-dependent manner. Overall, our data strongly suggest that the ERα status of mammary cells dictates whether KISS1R may be a novel clinical target for treating breast cancer metastasis.

  6. Anomalous decays of eta' and eta into four pions

    CERN Document Server

    Guo, Feng-Kun; Wirzba, Andreas

    2011-01-01

    We calculate the branching ratios of the yet unmeasured eta' decays into four pions, based on a combination of chiral perturbation theory and vector-meson dominance. The decays eta' --> 2(pi+ pi-) and eta' --> pi+ pi- 2pi0 are P-wave dominated and can largely be thought to proceed via two rho resonances; we predict branching fractions of (1.0+-0.3)*10^-4 and (2.4+-0.7)*10^-4, respectively, not much lower than the current experimental upper limits. The decays eta' --> 4pi0 and eta --> 4pi0, in contrast, are D-wave driven as long as conservation of CP symmetry is assumed, and are significantly further suppressed; any experimental evidence for the decay eta --> 4pi0 could almost certainly be interpreted as a signal of CP violation. We also calculate the CP-violating amplitudes for eta' --> 4pi0 and eta --> 4pi0 induced by the QCD theta-term.

  7. Differential flux measurement of atmospheric pion, muon, electron and positron energy spectra at balloon altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Grimani, C.; Brunetti, M.T.; Codino, A. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F.; Finetti, N. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Stephens, S.A. [Tata Institute of Fundamental Researc, Bombay (International Commission on Radiation Units and Measurements); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ. Las Cruces, NM (United States). Particle Astrophysics Lab.

    1995-09-01

    The fluxes of atmospheric electrons, positrons, positive and negative muons and negative pions have been determined using the NMSU Wizard-MASS2 balloons-borne instrument. The instrument was launched from Fort Sumner, New Mexico, (geomagnetic cut-off about 4.5 GV/c) on september 23, 1991. The flight lasted 9.8 hours and remained above 100.000 ft. Muons and negative pions were observed and their momenta were determined. Since these particles are not a part of the primary component, the measurement of their fluxes provides information regarding production and propagation of secondary particles in the atmosphere. Similarly, observations of electrons and positrons well below the geomagnetic cut-off provides insight into electromagnetic cascade processes in the upper atmosphere. In addition, the determination of the energy spectra of rare particles such as positrons can be used for background subtraction for cosmic ray experiments gathering data below a few g/cm{sup 2} of overlying atmosphere.

  8. Water spray-induced grooming is negatively correlated with depressive behavior in the forced swimming test in rats.

    Science.gov (United States)

    Shiota, Noboru; Narikiyo, Kimiya; Masuda, Akira; Aou, Shuji

    2016-05-01

    Rodents show grooming, a typical self-care behavior, under stress and non-stress conditions. Previous studies revealed that grooming under stress conditions such as the open-field test (OFT) or the elevated plus-maze test (EPM) is associated with anxiety, but the roles of grooming under non-stress conditions are not well understood. Here, we examined spray-induced grooming as a model of grooming under a non-stress condition to investigate the relationship between this grooming and depression-like behavior in the forced swim test (FST) and tail suspension test, and we compared spray-induced grooming with OFT- and EPM-induced grooming. The main finding was that the duration of spray-induced grooming, but not that of OFT/EPM-induced grooming, was negatively correlated with the duration of immobility in the FST, an index of depression-like behavior. The results suggest that spray-induced grooming is functionally different from the grooming in the OFT and EPM and is related to reduction of depressive behavior.

  9. Phosphodiesterase 2 negatively regulates adenosine-induced transcription of the tyrosine hydroxylase gene in PC12 rat pheochromocytoma cells.

    Science.gov (United States)

    Makuch, Edyta; Kuropatwa, Marianna; Kurowska, Ewa; Ciekot, Jaroslaw; Klopotowska, Dagmara; Matuszyk, Janusz

    2014-07-05

    Adenosine induces expression of the tyrosine hydroxylase (TH) gene in PC12 cells. However, it is suggested that atrial natriuretic peptide (ANP) inhibits expression of this gene. Using real-time PCR and luciferase reporter assays we found that ANP significantly decreases the adenosine-induced transcription of the TH gene. Results of measurements of cyclic nucleotide concentrations indicated that ANP-induced accumulation of cGMP inhibits the adenosine-induced increase in cAMP level. Using selective phosphodiesterase 2 (PDE2) inhibitors and a synthetic cGMP analog activating PDE2, we found that PDE2 is involved in coupling the ANP-triggered signal to the cAMP metabolism. We have established that ANP-induced elevated levels of cGMP as well as cGMP analog stimulate hydrolytic activity of PDE2, leading to inhibition of adenosine-induced transcription of the TH gene. We conclude that ANP mediates negative regulation of TH gene expression via stimulation of PDE2-dependent cAMP breakdown in PC12 cells.

  10. Giant negative magnetoresistance induced by the chiral anomaly in individual Cd3As2 nanowires

    Science.gov (United States)

    Li, Cai-Zhen; Wang, Li-Xian; Liu, Haiwen; Wang, Jian; Liao, Zhi-Min; Yu, Da-Peng

    2015-12-01

    Dirac electronic materials beyond graphene and topological insulators have recently attracted considerable attention. Cd3As2 is a Dirac semimetal with linear dispersion along all three momentum directions and can be viewed as a three-dimensional analogue of graphene. By breaking of either time-reversal symmetry or spatial inversion symmetry, the Dirac semimetal is believed to transform into a Weyl semimetal with an exotic chiral anomaly effect, however the experimental evidence of the chiral anomaly is still missing in Cd3As2. Here we show a large negative magnetoresistance with magnitude of -63% at 60 K and -11% at 300 K in individual Cd3As2 nanowires. The negative magnetoresistance can be modulated by gate voltage and temperature through tuning the density of chiral states at the Fermi level and the inter-valley scatterings between Weyl nodes. The results give evidence of the chiral anomaly effect and are valuable for understanding the Weyl fermions in Dirac semimetals.

  11. CARD9 negatively regulates NLRP3-induced IL-1β production on Salmonella infection of macrophages.

    Science.gov (United States)

    Pereira, Milton; Tourlomousis, Panagiotis; Wright, John; P Monie, Tom; Bryant, Clare E

    2016-09-27

    Interleukin-1β (IL-1β) is a proinflammatory cytokine required for host control of bacterial infections, and its production must be tightly regulated to prevent excessive inflammation. Here we show that caspase recruitment domain-containing protein 9 (CARD9), a protein associated with induction of proinflammatory cytokines by fungi, has a negative role on IL-1β production during bacterial infection. Specifically, in response to activation of the nucleotide oligomerization domain receptor pyrin-domain containing protein 3 (NLRP3) by Salmonella infection, CARD9 negatively regulates IL-1β by fine-tuning pro-IL-1β expression, spleen tyrosine kinase (SYK)-mediated NLRP3 activation and repressing inflammasome-associated caspase-8 activity. CARD9 is suppressed during Salmonella enterica serovar Typhimurium infection, facilitating increased IL-1β production. CARD9 is, therefore, a central signalling hub that coordinates a pathogen-specific host inflammatory response.

  12. CARD9 negatively regulates NLRP3-induced IL-1β production on Salmonella infection of macrophages

    Science.gov (United States)

    Pereira, Milton; Tourlomousis, Panagiotis; Wright, John; P. Monie, Tom; Bryant, Clare E.

    2016-01-01

    Interleukin-1β (IL-1β) is a proinflammatory cytokine required for host control of bacterial infections, and its production must be tightly regulated to prevent excessive inflammation. Here we show that caspase recruitment domain-containing protein 9 (CARD9), a protein associated with induction of proinflammatory cytokines by fungi, has a negative role on IL-1β production during bacterial infection. Specifically, in response to activation of the nucleotide oligomerization domain receptor pyrin-domain containing protein 3 (NLRP3) by Salmonella infection, CARD9 negatively regulates IL-1β by fine-tuning pro-IL-1β expression, spleen tyrosine kinase (SYK)-mediated NLRP3 activation and repressing inflammasome-associated caspase-8 activity. CARD9 is suppressed during Salmonella enterica serovar Typhimurium infection, facilitating increased IL-1β production. CARD9 is, therefore, a central signalling hub that coordinates a pathogen-specific host inflammatory response. PMID:27670879

  13. Dispositional optimism and stress-induced changes in immunity and negative mood

    OpenAIRE

    Brydon, L; Walker, C; Wawrzyniak, A. J.; Chart, H.; Steptoe, A.

    2009-01-01

    Evidence suggests that optimism may be protective for health during times of heightened stress, yet the mechanisms involved remain unclear. in a double-blind placebo-controlled study, we recently showed that acute psychological stress and an immune stimulus (Typhim-Vi typhoid vaccine) synergistically increased serum levels of interleukin-6 (IL-6) and negative mood in 59 healthy men. Here we carried out further analysis of this sample to investigate the relationship between dispositional optim...

  14. Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer.

    Science.gov (United States)

    Azuma, Masaki; Chen, Wei-tin; Seki, Hayato; Czapski, Michal; Olga, Smirnova; Oka, Kengo; Mizumaki, Masaichiro; Watanuki, Tetsu; Ishimatsu, Naoki; Kawamura, Naomi; Ishiwata, Shintaro; Tucker, Matthew G; Shimakawa, Yuichi; Attfield, J Paul

    2011-06-14

    The unusual property of negative thermal expansion is of fundamental interest and may be used to fabricate composites with zero or other controlled thermal expansion values. Here we report that colossal negative thermal expansion (defined as linear expansion transfer transitions. BiNiO(3) shows a 2.6% volume reduction under pressure due to a Bi/Ni charge transfer that is shifted to ambient pressure through lanthanum substitution for Bi. Changing proportions of coexisting low- and high-temperature phases leads to smooth volume shrinkage on heating. The crystallographic linear expansion coefficient for Bi(0.95)La(0.05)NiO(3) is -137×10(-6) K(-1) and a value of -82×10(-6) K(-1) is observed between 320 and 380 K from a dilatometric measurement on a ceramic pellet. Colossal negative thermal expansion materials operating at ambient conditions may also be accessible through metal-insulator transitions driven by other phenomena such as ferroelectric orders.

  15. Colossal negative thermal expansion in BiNiO3 induced by intermetallic charge transfer

    Science.gov (United States)

    Azuma, Masaki; Chen, Wei-tin; Seki, Hayato; Czapski, Michal; Olga, Smirnova; Oka, Kengo; Mizumaki, Masaichiro; Watanuki, Tetsu; Ishimatsu, Naoki; Kawamura, Naomi; Ishiwata, Shintaro; Tucker, Matthew G.; Shimakawa, Yuichi; Attfield, J. Paul

    2011-01-01

    The unusual property of negative thermal expansion is of fundamental interest and may be used to fabricate composites with zero or other controlled thermal expansion values. Here we report that colossal negative thermal expansion (defined as linear expansion <−10−4 K−1 over a temperature range ~100 K) is accessible in perovskite oxides showing charge-transfer transitions. BiNiO3 shows a 2.6% volume reduction under pressure due to a Bi/Ni charge transfer that is shifted to ambient pressure through lanthanum substitution for Bi. Changing proportions of coexisting low- and high-temperature phases leads to smooth volume shrinkage on heating. The crystallographic linear expansion coefficient for Bi0.95La0.05NiO3 is −137×10−6 K−1 and a value of −82×10−6 K−1 is observed between 320 and 380 K from a dilatometric measurement on a ceramic pellet. Colossal negative thermal expansion materials operating at ambient conditions may also be accessible through metal-insulator transitions driven by other phenomena such as ferroelectric orders. PMID:21673668

  16. Measurement of Pion and Proton Response and Longitudinal Shower Profiles up to 20 Nuclear Interaction Lengths with the ATLAS Tile Calorimeter

    CERN Document Server

    Adragna, P; Anderson, K; Antonaki, A; Arabidze, A; Batkova, L; Batusov, V; Beck, H P; Bergeaas Kuutmann, E; Biscarat, C; Blanchot, G; Bogush, A; Bohm, C; Boldea, V; Bosman, M; Bromberg, C; Budagov, J; Burckhart-Chromek, D; Caprini, M; Caloba, L; Calvet, D; Carli, T; Carvalho, J; Cascella, M; Castelo, J; Castillo, M V; Cavalli-Sforza, M; Cavasinni, V; Cerqueira, A S; Clement, C; Cobal, M; Cogswell, F; Constantinescu, S; Costanzo, D; Corso-Radu, A; Cuenca, C; Damazio, D O; Davidek, T; De, K; Del Prete, T; Di Girolamo, B; Dita, S; Djobava, T; Dobson, M; Dotti, A; Downing, R; Efthymiopoulos, I; Eriksson, D; Errede, D; Errede, S; Farbin, A; Fassouliotis, D; Febbraro, R; Fenyuk, A; Ferdi, C; Ferrer, A; Flaminio, V; Francis, D; Fullana, E; Gadomski, S; Gameiro, S; Garde, V; Gellerstedt, K; Giakoumopoulou, V; Gildemeister, O; Gilewsky, V; Giokaris, N; Gollub, N; Gomes, A; Gonzalez, V; Gorini, B; Grenier, P; Gris, P; Gruwe, M; Guarino, V; Guicheney, C; Gupta, A; Haeberli, C; Hakobyan, H; Haney, M; Hellman, S; Henriques, A; Higon, E; Holmgren, S; Hurwitz, M; Huston, J; Iglesias, C; Isaev, A; Jen-La Plante, I; Jon-And, K; Joos, M; Junk, T; Karyukhin, A; Kazarov, A; Khandanyan, H; Khramov, J; Khubua, J; Kolos, S; Korolkov, I; Krivkova, P; Kulchitsky, Y; Kurochkin, Yu; Kuzhir, P; LeCompte, T; Lefevre, R; Lehmann, G; Leitner, R; Lembesi, M; Lesser, J; Li, J; Liablin, M; Lokajicek, M; Lomakin, Y; Lupi, A; Maidanchik, C; Maio, A; Makouski, M; Maliukov, S; Manousakis, A; Mapelli, L; Marques, C; Marroquim, F; Martin, F; Mazzoni, E; Merritt, F; Miagkov, A; Miller, R; Minashvili, I; Miralles, L; Montarou, G; Mosidze, M; Myagkov, A; Nemecek, S; Nessi, M; Nodulman, L; Nordkvist, B; Norniella, O; Novakova, J; Onofre, A; Oreglia, M; Pallin, D; Pantea, D; Petersen, J; Pilcher, J; Pina, J; Pinhao, J; Podlyski, F; Portell Bueso, X; Poveda, J; Pribyl, L; Price, L E; Proudfoot, J; Ramstedt, M; Richards, R; Roda, C; Romanov, V; Rosnet, P; Roy, P; Ruiz, A; Rumiantsev, V; Russakovich, N; Salto, O; Salvachua, B; Sanchis, E; Sanders, H; Santoni, C; Saraiva, J G; Sarri, F; Satsunkevitch, I; Says, L P; Schlager, G; Schlereth, J; Seixas, J M; Sellden, B; Shalanda, N; Shevtsov, P; Shochet, M; Silva, J; Da Silva, P; Simaitis, V; Simonyan, M; Sissakian, A; Sjolin, J; Solans, C; Solodkov, A; Soloviev, I; Solovyanov, O; Sosebee, M; Spano, F; Stanek, R; Starchenko, E; Starovoitov, P; Stavina, P; Suk, M; Sykora, I; Tang, F; Tas, P; Teuscher, R; Tokar, S; Topilin, N; Torres, J; Tremblet, L; Tsiareshka, P; Tylmad, M; Underwood, D; Unel, G; Usai, G; Valero, A; Valkar, S; Valls, J A; Vartapetian, A; Vazeille, F; Vichou, I; Vinogradov, V; Vivarelli, I; Volpi, M; White, A; Zaitsev, A; Zenine, A; Zenis, T

    2010-01-01

    The response of pions and protons in the energy range of 20 to 180 GeV produced at CERN's SPS H8 test beam line in the ATLAS iron-scintillator Tile hadron calorimeter has been measured. The test-beam configuration allowed to measure the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It is found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion to proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion induced showers. The data are compared with GEANT4 simulations using several hadronic physics lists. The measured longitudinal shower profiles are described by an analytical shower parameterization within an accuracy of 5-10%. The amount of energy leaking out behind the calorimeter is determined and parameterised as a function of the b...

  17. Measurement of pion and proton response and longitudinal shower profiles up to 20 nuclear interaction lengths with the ATLAS Tile calorimeter

    Science.gov (United States)

    Adragna, P.; Alexa, C.; Anderson, K.; Antonaki, A.; Arabidze, A.; Batkova, L.; Batusov, V.; Beck, H. P.; Bergeaas Kuutmann, E.; Biscarat, C.; Blanchot, G.; Bogush, A.; Bohm, C.; Boldea, V.; Bosman, M.; Bromberg, C.; Budagov, J.; Burckhart-Chromek, D.; Caprini, M.; Caloba, L.; Calvet, D.; Carli, T.; Carvalho, J.; Cascella, M.; Castelo, J.; Castillo, M. V.; Cavalli-Sforza, M.; Cavasinni, V.; Cerqueira, A. S.; Clement, C.; Cobal, M.; Cogswell, F.; Constantinescu, S.; Costanzo, D.; Corso-Radu, A.; Cuenca, C.; Damazio, D. O.; Davidek, T.; De, K.; Del Prete, T.; Di Girolamo, B.; Dita, S.; Djobava, T.; Dobson, M.; Dotti, A.; Downing, R.; Efthymiopoulos, I.; Eriksson, D.; Errede, D.; Errede, S.; Farbin, A.; Fassouliotis, D.; Febbraro, R.; Fenyuk, A.; Ferdi, C.; Ferrer, A.; Flaminio, V.; Francis, D.; Fullana, E.; Gadomski, S.; Gameiro, S.; Garde, V.; Gellerstedt, K.; Giakoumopoulou, V.; Gildemeister, O.; Gilewsky, V.; Giokaris, N.; Gollub, N.; Gomes, A.; Gonzalez, V.; Gorini, B.; Grenier, P.; Gris, P.; Gruwe, M.; Guarino, V.; Guicheney, C.; Gupta, A.; Haeberli, C.; Hakobyan, H.; Haney, M.; Hellman, S.; Henriques, A.; Higon, E.; Holmgren, S.; Hurwitz, M.; Huston, J.; Iglesias, C.; Isaev, A.; Jen-La Plante, I.; Jon-And, K.; Joos, M.; Junk, T.; Karyukhin, A.; Kazarov, A.; Khandanyan, H.; Khramov, J.; Khubua, J.; Kolos, S.; Korolkov, I.; Krivkova, P.; Kulchitsky, Y.; Kurochkin, Yu.; Kuzhir, P.; Le Compte, T.; Lefevre, R.; Lehmann, G.; Leitner, R.; Lembesi, M.; Lesser, J.; Li, J.; Liablin, M.; Lokajicek, M.; Lomakin, Y.; Lupi, A.; Maidanchik, C.; Maio, A.; Makouski, M.; Maliukov, S.; Manousakis, A.; Mapelli, L.; Marques, C.; Marroquim, F.; Martin, F.; Mazzoni, E.; Merritt, F.; Miagkov, A.; Miller, R.; Minashvili, I.; Miralles, L.; Montarou, G.; Mosidze, M.; Myagkov, A.; Nemecek, S.; Nessi, M.; Nodulman, L.; Nordkvist, B.; Norniella, O.; Novakova, J.; Onofre, A.; Oreglia, M.; Pallin, D.; Pantea, D.; Petersen, J.; Pilcher, J.; Pina, J.; Pinhão, J.; Podlyski, F.; Portell, X.; Poveda, J.; Pribyl, L.; Price, L. E.; Proudfoot, J.; Ramstedt, M.; Richards, R.; Roda, C.; Romanov, V.; Rosnet, P.; Roy, P.; Ruiz, A.; Rumiantsev, V.; Russakovich, N.; Saltó, O.; Salvachua, B.; Sanchis, E.; Sanders, H.; Santoni, C.; Saraiva, J. G.; Sarri, F.; Satsunkevitch, I.; Says, L.-P.; Schlager, G.; Schlereth, J.; Seixas, J. M.; Selldèn, B.; Shalanda, N.; Shevtsov, P.; Shochet, M.; Silva, J.; Da Silva, P.; Simaitis, V.; Simonyan, M.; Sissakian, A.; Sjölin, J.; Solans, C.; Solodkov, A.; Soloviev, I.; Solovyanov, O.; Sosebee, M.; Spanò, F.; Stanek, R.; Starchenko, E.; Starovoitov, P.; Stavina, P.; Suk, M.; Sykora, I.; Tang, F.; Tas, P.; Teuscher, R.; Tokar, S.; Topilin, N.; Torres, J.; Tremblet, L.; Tsiareshka, P.; Tylmad, M.; Underwood, D.; Unel, G.; Usai, G.; Valero, A.; Valkar, S.; Valls, J. A.; Vartapetian, A.; Vazeille, F.; Vichou, I.; Vinogradov, V.; Vivarelli, I.; Volpi, M.; White, A.; Zaitsev, A.; Zenine, A.; Zenis, T.

    2010-04-01

    The response of pions and protons in the energy range of 20-180 GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron-scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion-to-proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion-induced showers. The data are compared with GEANT4 simulations using several hadronic physics lists. The measured longitudinal shower profiles are described by an analytical shower parametrization within an accuracy of 5-10%. The amount of energy leaking out behind the calorimeter is determined and parametrized as a function of the beam energy and the calorimeter depth. This allows for a leakage correction of test-beam results in the standard projective geometry.

  18. Dissociable neural systems underwrite logical reasoning in the context of induced emotions with positive and negative valence.

    Science.gov (United States)

    Smith, Kathleen W; Vartanian, Oshin; Goel, Vinod

    2014-01-01

    How emotions influence syllogistic reasoning is not well understood. fMRI was employed to investigate the effects of induced positive or negative emotion on syllogistic reasoning. Specifically, on a trial-by-trial basis participants were exposed to a positive, negative, or neutral picture, immediately prior to engagement in a reasoning task. After viewing and rating the valence and intensity of each picture, participants indicated by keypress whether or not the conclusion of the syllogism followed logically from the premises. The content of all syllogisms was neutral, and the influence of belief-bias was controlled for in the study design. Emotion did not affect reasoning performance, although there was a trend in the expected direction based on accuracy rates for the positive (63%) and negative (64%) versus neutral (70%) condition. Nevertheless, exposure to positive and negative pictures led to dissociable patterns of neural activation during reasoning. Therefore, the neural basis of deductive reasoning differs as a function of the valence of the context.

  19. Dissociable neural systems underwrite logical reasoning in the context of induced emotions with positive and negative valence

    Directory of Open Access Journals (Sweden)

    Kathleen Walton Smith

    2014-09-01

    Full Text Available How emotions influence syllogistic reasoning is not well understood. fMRI was employed to investigate the effects of induced positive or negative emotion on syllogistic reasoning. Specifically, on a trial-by-trial basis participants were exposed to a positive, negative, or neutral picture, immediately prior to engagement in a reasoning task. After viewing and rating the valence and intensity of each picture, participants indicated by keypress whether or not the conclusion of the syllogism followed logically from the premises. The content of all syllogisms was neutral, and the influence of belief-bias was controlled for in the study design. Emotion did not affect reasoning performance, although there was a trend in the expected direction based on accuracy rates for the positive (63% and negative (64% versus neutral (70% condition. Nevertheless, exposure to positive and negative pictures led to dissociable patterns of neural activation during reasoning. Therefore, the neural basis of deductive reasoning differs as a function of the valence of the context.

  20. Two-pion interferometry at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    Chen Xiao-Fan; Yang Xue-Dong; Hah Ling

    2004-01-01

    A two-pion correlation function at small relative momentum for pion sources with transverse and longitudinal expansions in relativistic heavy ion collisions is obtained using two-pion interferometry at small relative momentum,and the relations between the real and apparent parameters of the pion source are given. The relations can be used to extract both the temperature and the transverse and longitudinal expansion velocities of pion sources and to verify the correctness of relativistic transformation T' = T√1- v2 of temperature in relativistic statistical mechanics and thermodynamics.

  1. Pion Form Factor in Chiral Limit of Hard-Wall AdS/QCD Model

    Energy Technology Data Exchange (ETDEWEB)

    Anatoly Radyushkin; Hovhannes Grigoryan

    2007-12-01

    We develop a formalism to calculate form factor and charge density distribution of pion in the chiral limit using the holographic dual model of QCD with hard-wall cutoff. We introduce two conjugate pion wave functions and present analytic expressions for these functions and for the pion form factor. They allow to relate such observables as the pion decay constant and the pion charge electric radius to the values of chiral condensate and hard-wall cutoff scale. The evolution of the pion form factor to large values of the momentum transfer is discussed, and results are compared to existing experimental data.

  2. Punishment sensitivity modulates the processing of negative feedback but not error-induced learning

    Directory of Open Access Journals (Sweden)

    Kerstin eUnger

    2012-06-01

    Full Text Available Accumulating evidence suggests that individual differences in punishment and reward sensitivity are associated with functional alterations in neural systems underlying error and feedback processing. In particular, individuals highly sensitive to punishment have been found to be characterized by larger midfrontal error signals as reflected in the error negativity (Ne/ERN and the FRN (feedback-related negativity. By contrast, reward sensitivity has been shown to relate to the error positivity (Pe. Given that Ne/ERN, FRN, and Pe have been functionally linked to flexible behavioral adaptation, the aim of the present research was to examine how these electrophysiological reflections of error and feedback processing vary as a function of punishment and reward sensitivity during reinforcement learning. We applied a probabilistic learning task that involved three different conditions of feedback validity (100%, 80%, and 50%. In contrast to prior studies using response competition tasks, we did not find reliable correlations between punishment sensitivity and the Ne/ERN. Instead, higher punishment sensitivity predicted larger FRN amplitudes, irrespective of feedback validity. Moreover, higher reward sensitivity was associated with a larger Pe. However, only reward sensitivity was related to better overall learning performance and higher post-error accuracy, whereas highly punishment sensitive participants showed impaired learning performance, suggesting that larger negative feedback-related error signals were not beneficial for learning or even reflected maladaptive information processing in these individuals. Thus, although our findings indicate that individual differences in reward and punishment sensitivity are related to electrophysiological correlates of error and feedback processing, we found less evidence for influences of these personality characteristics on the relation between performance monitoring and feedback-based learning.

  3. Effects of experimentally induced low back pain on the sit-to-stand movement and electroencephalographic contingent negative variation.

    Science.gov (United States)

    Jacobs, Jesse V; Yaguchi, Chie; Kaida, Chizuru; Irei, Mariko; Naka, Masami; Henry, Sharon M; Fujiwara, Katsuo

    2011-11-01

    It is becoming increasingly evident that people with chronic, recurrent low back pain (LBP) exhibit changes in cerebrocortical activity that associate with altered postural coordination, suggesting a need for a better understanding of how the experience of LBP alters postural coordination and cerebrocortical activity. To characterize changes in postural coordination and pre-movement cerebrocortical activity related to the experience of acutely induced LBP, 14 healthy participants with no history of LBP performed sit-to-stand movements in 3 sequential conditions: (1) without experimentally induced LBP; NoPain1, (2) with movement-associated LBP induced by electrocutaneous stimulation; Pain, and (3) again without induced LBP; NoPain2. The Pain condition elicited altered muscle activation and redistributed forces under the seat and feet prior to movement, decreased peak vertical force exerted under the feet during weight transfer, longer movement times, as well as decreased and earlier peak hip extension. Stepwise regression models demonstrated that electroencephalographic amplitudes of contingent negative variation during the Pain condition significantly correlated with the participants' change in sit-to-stand measures between the NoPain1 and Pain conditions, as well as with the subsequent difference in sit-to-stand measures between the NoPain1 and NoPain2 conditions. The results, therefore, identify the contingent negative variation as a correlate for the extent of an individual's LBP-related movement modifications and to the subsequent change in movement patterns from before to after the experience of acutely induced LBP, thereby providing a direction for future studies aimed to understand the neural mechanisms underlying the development of altered movement patterns with LBP.

  4. Multiply Charged Negative Ions of Hydrogen Induced by Superintense Laser Fields

    Energy Technology Data Exchange (ETDEWEB)

    van Duijn, E.; Gavrila, M.; Muller, H.G. [FOM--Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam (The Netherlands)

    1996-10-01

    Using the high-frequency Floquet theory of laser-atom interactions we predict that in superintense fields a proton can bind more than two electrons. For linear polarization, a self-consistent solution of the structure equation shows that H{sup 2{minus}} becomes bound for {alpha}{sub 0}=155 a.u. The fields and frequencies needed for binding H{sup 2{minus}} are within reach of lasers under construction. By choosing appropriately polarized bichromatic radiation, the production of more highly charged negative ions also lies within experimental reach. The ions are (adiabatically) stabilized against ionization, from their very appearance. {copyright} {ital 1996 The American Physical Society.}

  5. Substance P Receptor Signaling Mediates Doxorubicin-Induced Cardiomyocyte Apoptosis and Triple-Negative Breast Cancer Chemoresistance.

    Science.gov (United States)

    Robinson, Prema; Kasembeli, Moses; Bharadwaj, Uddalak; Engineer, Nikita; Eckols, Kris T; Tweardy, David J

    2016-01-01

    Doxorubicin (DOX), an anthracycline, is broadly considered the most active single agent available for treating breast cancer but has been known to induce cardiotoxicity. Although DOX is highly effective in treating triple-negative breast cancer (TNBC), DOX can have poor outcomes owing to induction of chemoresistance. There is an urgent need to develop new therapies for TNBC aimed at improving DOX outcome and DOX-induced cardiotoxicity. Substance P (SP), a neuropeptide involved in pain transmission is known to stimulate production of reactive oxygen species (ROS). Elevated cardiac ROS is linked with heart injury and failure. We investigated the role of SP in chemotherapy-associated death of cardiomyocytes and chemoresistance. We showed that pretreating a cardiomyocyte cell line (H9C2) and a TNBC cell line (MDA-MB 231) with aprepitant, a SP receptor antagonist that is routinely used to treat chemotherapy-associated associated nausea, decreased DOX-induced reduction of cell viability, apoptotic cell death, and ROS production in cardiomyocytes and increased DOX-induced reduction of cell viability, apoptotic cell death, and ROS production in TNBC cells compared with cells treated with DOX alone. Our findings demonstrate the ability of aprepitant to decrease DOX-induced killing of cardiomyocytes and to increase cancer cell sensitivity to DOX, which has tremendous clinical significance.

  6. Substance P Receptor Signaling Mediates Doxorubicin-Induced Cardiomyocyte Apoptosis and Triple-Negative Breast Cancer Chemoresistance

    Directory of Open Access Journals (Sweden)

    Prema Robinson

    2016-01-01

    Full Text Available Doxorubicin (DOX, an anthracycline, is broadly considered the most active single agent available for treating breast cancer but has been known to induce cardiotoxicity. Although DOX is highly effective in treating triple-negative breast cancer (TNBC, DOX can have poor outcomes owing to induction of chemoresistance. There is an urgent need to develop new therapies for TNBC aimed at improving DOX outcome and DOX-induced cardiotoxicity. Substance P (SP, a neuropeptide involved in pain transmission is known to stimulate production of reactive oxygen species (ROS. Elevated cardiac ROS is linked with heart injury and failure. We investigated the role of SP in chemotherapy-associated death of cardiomyocytes and chemoresistance. We showed that pretreating a cardiomyocyte cell line (H9C2 and a TNBC cell line (MDA-MB 231 with aprepitant, a SP receptor antagonist that is routinely used to treat chemotherapy-associated associated nausea, decreased DOX-induced reduction of cell viability, apoptotic cell death, and ROS production in cardiomyocytes and increased DOX-induced reduction of cell viability, apoptotic cell death, and ROS production in TNBC cells compared with cells treated with DOX alone. Our findings demonstrate the ability of aprepitant to decrease DOX-induced killing of cardiomyocytes and to increase cancer cell sensitivity to DOX, which has tremendous clinical significance.

  7. Nucleon polarisabilities at and beyond physical pion masses

    Energy Technology Data Exchange (ETDEWEB)

    Griesshammer, Harald W. [The George Washington University, Institute for Nuclear Studies, Department of Physics, Washington, DC (United States); McGovern, Judith A. [The University of Manchester, School of Physics and Astronomy, Manchester (United Kingdom); Phillips, Daniel R. [Ohio University, Department of Physics and Astronomy and Institute of Nuclear and Particle Physics, Athens, OH (United States)

    2016-05-15

    We examine the results of Chiral Effective Field Theory (χEFT) for the scalar- and spin-dipole polarisabilities of the proton and neutron, both for the physical pion mass and as a function of m{sub π}. This provides chiral extrapolations for lattice QCD polarisability computations. We include both the leading and subleading effects of the nucleon's pion cloud, as well as the leading ones of the Δ (1232)-resonance and its pion cloud. The analytic results are complete at N{sup 2}LO in the δ counting for pion masses close to the physical value, and at leading order for pion masses similar to the Delta-nucleon mass splitting. In order to quantify the truncation error of our predictions and fits as 68% degree-of-belief intervals, we use a Bayesian procedure recently adapted to EFT expansions. At the physical point, our predictions for the spin polarisabilities are, within respective errors, in good agreement with alternative extractions using experiments and dispersion-relation theory. At larger pion masses we find that the chiral expansion of all polarisabilities becomes intrinsically unreliable as m{sub π} approaches about 300 MeV -as has already been seen in other observables. χEFT also predicts a substantial isospin splitting above the physical point for both the electric and magnetic scalar polarisabilities; and we speculate on the impact this has on the stability of nucleons. Our results agree very well with emerging lattice computations in the realm where χEFT converges. Curiously, for the central values of some of our predictions, this agreement persists to much higher pion masses. We speculate on whether this might be more than a fortuitous coincidence. (orig.)

  8. Valence-quark distribution functions in the kaon and pion

    Science.gov (United States)

    Chen, Chen; Chang, Lei; Roberts, Craig D.; Wan, Shaolong; Zong, Hong-Shi

    2016-04-01

    We describe expressions for pion and kaon dressed-quark distribution functions that incorporate contributions from gluons which bind quarks into these mesons and hence overcome a flaw of the commonly used handbag approximation. The distributions therewith obtained are purely valence in character, ensuring that dressed quarks carry all the meson's momentum at a characteristic hadronic scale and vanish as (1 -x )2 when Bjorken-x →1 . Comparing such distributions within the pion and kaon, it is apparent that the size of S U (3 ) -flavor symmetry breaking in meson parton distribution functions is modulated by the flavor dependence of dynamical chiral symmetry breaking. Corrections to these leading-order formulas may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea quarks. Working with available empirical information, we build an algebraic framework that is capable of expressing the principal impact of both classes of corrections. This enables a realistic comparison with experiment which allows us to identify and highlight basic features of measurable pion and kaon valence-quark distributions. We find that whereas roughly two thirds of the pion's light-front momentum is carried by valence dressed quarks at a characteristic hadronic scale; this fraction rises to 95% in the kaon; evolving distributions with these features to a scale typical of available Drell-Yan data produces a kaon-to-pion ratio of u -quark distributions that is in agreement with the single existing data set, and predicts a u -quark distribution within the pion that agrees with a modern reappraisal of π N Drell-Yan data. Precise new data are essential in order to validate this reappraisal and because a single modest-quality measurement of the kaon-to-pion ratio cannot be considered definitive.

  9. Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts isolated from strictures in Crohn\\'s disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn\\'s stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.

  10. TNF-α Gene Knockout in Triple Negative Breast Cancer Cell Line Induces Apoptosis

    Directory of Open Access Journals (Sweden)

    Valentina Pileczki

    2012-12-01

    Full Text Available Tumor necrosis factor alpha (TNF-α is a pro-inflammatory cytokine involved in the promotion and progression of cancer, including triple negative breast cancer cells. Thus, there is significant interest in understanding the molecular signaling pathways that connect TNF-α with the survival of tumor cells. In our experiments, we used as an in vitro model for triple negative breast cancer the cell line Hs578T. The purpose of this study is to determine the gene expression profiling of apoptotic signaling networks after blocking TNF-α formation by using specially designed siRNA molecules to target TNF-α messenger RNA. Knockdown of TNF-α gene was associated with cell proliferation inhibition and apoptosis, as observed by monitoring the cell index using the xCELLigence RTCA System and flow cytometry. PCR array technology was used to examine the transcript levels of 84 genes involved in apoptosis. 15 genes were found to be relevant after comparing the treated group with the untreated one of which 3 were down-regulated and 12 up-regulated. The down-regulated genes are all involved in cell survival, whereas the up-regulated ones are involved in and interact with pro-apoptotic pathways. The results described here indicate that the direct target of TNF-α in the Hs578T breast cancer cell line increases the level of certain pro-apoptotic factors that modulate different cellular networks that direct the cells towards death.

  11. Negative differential resistance and rectifying performance induced by doped graphene nanoribbons p–n device

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yuhong; Qiu, Nianxiang; Li, Runwei [Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo 315201 (China); Guo, Zhansheng [Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072 (China); Zhang, Jian; Fang, Junfeng; Huang, Aisheng [Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo 315201 (China); He, Jian [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Zha, Xianhu; Luo, Kan; Yin, Jingshuo; Li, Qiuwu; Bai, Xiaojing; Huang, Qing [Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo 315201 (China); Du, Shiyu, E-mail: dushiyu@nimte.ac.cn [Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo 315201 (China)

    2016-03-06

    Employing nonequilibrium Green's Functions in combination with density functional theory, the electronic transport properties of armchair graphene nanoribbon (GNR) devices with various widths are investigated in this work. In the adopted model, two semi-infinite graphene electrodes are periodically doped with boron or nitrogen atoms. Our calculations reveal that these devices have a striking nonlinear feature and show notable negative differential resistance (NDR). The results also indicate the diode-like properties are reserved and the rectification ratios are high. It is found the electronic transport properties are strongly dependent on the width of doped nanoribbons and the positions of dopants and three distinct families are elucidated for the current armchair GNR devices. The NDR as well as rectifying properties can be well explained by the variation of transmission spectra and the relative shift of discrete energy states with applied bias voltage. These findings suggest that the doped armchair GNR is a promising candidate for the next generation nanoscale device. - Highlights: • The negative differential resistance (NDR) and rectification phenomena have been observed for the B- and N-doping armchair graphene nanoribbon (GNR) devices. • The electronic transport properties are strongly dependent on the width of doped nanoribbons and exhibit three distinct families. • The NDR as well as rectifying properties can be well explained by the variation of transmission spectra and the relative shift of discrete energy states with applied bias voltage.

  12. A Sensitive and Specific Neural Signature for Picture-Induced Negative Affect.

    Directory of Open Access Journals (Sweden)

    Luke J Chang

    2015-06-01

    Full Text Available Neuroimaging has identified many correlates of emotion but has not yet yielded brain representations predictive of the intensity of emotional experiences in individuals. We used machine learning to identify a sensitive and specific signature of emotional responses to aversive images. This signature predicted the intensity of negative emotion in individual participants in cross validation (n =121 and test (n = 61 samples (high-low emotion = 93.5% accuracy. It was unresponsive to physical pain (emotion-pain = 92% discriminative accuracy, demonstrating that it is not a representation of generalized arousal or salience. The signature was comprised of mesoscale patterns spanning multiple cortical and subcortical systems, with no single system necessary or sufficient for predicting experience. Furthermore, it was not reducible to activity in traditional "emotion-related" regions (e.g., amygdala, insula or resting-state networks (e.g., "salience," "default mode". Overall, this work identifies differentiable neural components of negative emotion and pain, providing a basis for new, brain-based taxonomies of affective processes.

  13. Nonlinear Cavity and Frequency Comb Radiations Induced by Negative Frequency Field Effects

    Science.gov (United States)

    Lourés, Cristian Redondo; Faccio, Daniele; Biancalana, Fabio

    2015-11-01

    Optical Kerr frequency combs (KFCs) are an increasingly important optical metrology tool with applications ranging from ultraprecise spectroscopy to time keeping. KFCs may be generated in compact resonators with extremely high quality factors. Here, we show that the same features that lead to high quality frequency combs in these resonators also lead to an enhancement of nonlinear emissions that may be identified as originating from the presence of a negative frequency (NF) component in the optical spectrum. While the negative frequency component of the spectrum is naturally always present in the real-valued optical field, it is not included in the principal theoretical model used to model nonlinear cavities, i.e., the Lugiato-Lefever equation. We therefore extend these equations in order to include the contribution of NF components and show that the predicted emissions may be studied analytically, in excellent agreement with full numerical simulations. These results are of importance for a variety of fields, such as Bose-Einstein condensates, mode-locked lasers, nonlinear plasmonics, and polaritonics.

  14. Vasopressin-induced taurine efflux from rat pituicytes: a potential negative feedback for hormone secretion.

    Science.gov (United States)

    Rosso, Lia; Peteri-Brunbäck, Brigitta; Poujeol, Philippe; Hussy, Nicolas; Mienville, Jean-Marc

    2004-02-01

    Previous work on the whole neurohypophysis has shown that hypotonic conditions increase release of taurine from neurohypophysial astrocytes (pituicytes). The present work confirms that taurine is present in cultured pituicytes, and that its specific release increases in response to a hypotonic shock. We next show that vasopressin (VP) and oxytocin (OT) also specifically release taurine from pituicytes. With an EC(50) of approximately 2 nm, VP is much more potent than OT, and the effects of both hormones are blocked by SR 49059, a V(1a) receptor antagonist. This pharmacological profile matches the one for VP- and OT-evoked calcium signals in pituicytes, consistent with the fact that VP-induced taurine efflux is blocked by BAPTA-AM. However, BAPTA-AM also blocks the taurine efflux induced by a 270 mosmol l(-1) challenge, which per se does not evoke any calcium signal, suggesting a permissive role for calcium in this case. Nevertheless, the fact that structurally unrelated calcium-mobilizing agents and ionomycin are able to induce taurine efflux suggests that calcium may also play a signalling role in this event. It is widely accepted that in hypotonic conditions taurine exits cells through anionic channels. Antagonism by the chloride channel inhibitors 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) suggests the same pathway for VP-induced taurine efflux, which is also blocked in hypertonic conditions (330 mosmol l(-1)). Moreover, it is likely that the osmosensitivity of the taurine channel is up-regulated by calcium. These results, together with our in situ experiments showing stimulation of taurine release by endogenous VP, strengthen the concept of a glial control of neurohormone output.

  15. Caenorhabditis elegans star formation and negative chemotaxis induced by infection with corynebacteria.

    Science.gov (United States)

    Antunes, Camila Azevedo; Clark, Laura; Wanuske, Marie-Therès; Hacker, Elena; Ott, Lisa; Simpson-Louredo, Liliane; de Luna, Maria das Gracas; Hirata, Raphael; Mattos-Guaraldi, Ana Luíza; Hodgkin, Jonathan; Burkovski, Andreas

    2016-01-01

    Caenorhabditis elegans is one of the major model systems in biology based on advantageous properties such as short life span, transparency, genetic tractability and ease of culture using an Escherichia coli diet. In its natural habitat, compost and rotting plant material, this nematode lives on bacteria. However, C. elegans is a predator of bacteria, but can also be infected by nematopathogenic coryneform bacteria such Microbacterium and Leucobacter species, which display intriguing and diverse modes of pathogenicity. Depending on the nematode pathogen, aggregates of worms, termed worm-stars, can be formed, or severe rectal swelling, so-called Dar formation, can be induced. Using the human and animal pathogens Corynebacterium diphtheriae and Corynebacterium ulcerans as well as the non-pathogenic species Corynebacterium glutamicum, we show that these coryneform bacteria can also induce star formation slowly in worms, as well as a severe tail-swelling phenotype. While C. glutamicum had a significant, but minor influence on survival of C. elegans, nematodes were killed after infection with C. diphtheriae and C. ulcerans. The two pathogenic species were avoided by the nematodes and induced aversive learning in C. elegans.

  16. Arabidopsis Phytochrome D Is Involved in Red Light-Induced Negative Gravitropism of Hypocotyles

    Institute of Scientific and Technical Information of China (English)

    LI Jian-ping; HOU Pei; ZHENG Xu; SONG Mei-fang; SU Liang; YANG Jian-ping

    2014-01-01

    The phytochrome gene family, which is in Arabidopsis thaliana, consists of phytochromes A-E (phyA to phyE), regulates plant responses to ambient light environments. PhyA and phyB have been characterized in detail, but studies on phyC to phyE have reported discrepant functions. In this study, we show that phyD regulates the Arabidopsis gravitropic response by inhibiting negative gravitropism of hypocotyls under red light condition. PhyD had only a limited effect on the gravitropic response of roots in red light condition. PhyD also enhanced phyB-regulated gravitropic responses in hypocotyls. Moreover, the regulation of hypocotyl gravitropic responses by phyD was dependent upon the red light lfuence rate.

  17. Startle response and prepulse inhibition modulation by positive- and negative-induced affect.

    Science.gov (United States)

    De la Casa, Luis Gonzalo; Mena, Auxiliadora; Puentes, Andrea

    2014-02-01

    The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional process.

  18. Negative differential resistance and rectifying performance induced by doped graphene nanoribbons p-n device

    Science.gov (United States)

    Zhou, Yuhong; Qiu, Nianxiang; Li, Runwei; Guo, Zhansheng; Zhang, Jian; Fang, Junfeng; Huang, Aisheng; He, Jian; Zha, Xianhu; Luo, Kan; Yin, Jingshuo; Li, Qiuwu; Bai, Xiaojing; Huang, Qing; Du, Shiyu

    2016-03-01

    Employing nonequilibrium Green's Functions in combination with density functional theory, the electronic transport properties of armchair graphene nanoribbon (GNR) devices with various widths are investigated in this work. In the adopted model, two semi-infinite graphene electrodes are periodically doped with boron or nitrogen atoms. Our calculations reveal that these devices have a striking nonlinear feature and show notable negative differential resistance (NDR). The results also indicate the diode-like properties are reserved and the rectification ratios are high. It is found the electronic transport properties are strongly dependent on the width of doped nanoribbons and the positions of dopants and three distinct families are elucidated for the current armchair GNR devices. The NDR as well as rectifying properties can be well explained by the variation of transmission spectra and the relative shift of discrete energy states with applied bias voltage. These findings suggest that the doped armchair GNR is a promising candidate for the next generation nanoscale device.

  19. SEMICONDUCTOR DEVICES Negative bias temperature instability induced single event transient pulse narrowing and broadening

    Science.gov (United States)

    Jianjun, Chen; Shuming, Chen; Bin, Liang; Biwei, Liu

    2010-12-01

    The effect of negative bias temperature instability (NBTI) on a single event transient (SET) has been studied in a 130 nm bulk silicon CMOS process based on 3D TCAD device simulations. The investigation shows that NBTI can result in the pulse width and amplitude of SET narrowing when the heavy ion hits the PMOS in the high-input inverter; but NBTI can result in the pulse width and amplitude of SET broadening when the heavy ion hits the NMOS in the low-input inverter. Based on this study, for the first time we propose that the impact of NBTI on a SET produced by the heavy ion hitting the NMOS has already been a significant reliability issue and should be of wide concern, and the radiation hardened design must consider the impact of NBTI on a SET.

  20. Regge approach to charged-pion photoproduction at invariant energies above 2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Sibirtsev, A; Haidenbauer, J; Krewald, S; Lee, T S.H.; Meissner, U -G; Thomas, A W

    2007-10-01

    A Regge model with absorptive corrections is employed in a global analysis of the world data on positive and negative pion photoproduction for photon energies from 3 to 8~GeV. In this region resonance contributions are expected to be negligible so that the available experimental information on differential cross sections and single polarization observables at $-t{\\leq}2$ GeV$^2$ allows us to determine the non-resonant part of the reaction amplitude reliably. The model amplitude is then used to predict observables for photon energies below $3$ GeV. Differences between our predictions and data in this energy region are systematically examined as possible signals for the presence of excited baryons. We find that the data available for the polarized photon asymmetry show promising resonance signatures at invariant energies around 2~GeV. With regard to differential cross sections the analysis of negative pion photoproduction data, obtained recently at JLab, indicates likewise the presence of resonance structures around 2~GeV.

  1. Phase Transitions in the Early Universe with Negatively Induced Supergravity Cosmological Constant

    Institute of Scientific and Technical Information of China (English)

    EL-NABULSI Ahmad Rami

    2006-01-01

    @@ We consider that the observable cosmological constant is the sum of the vacuum (Avac) and the induced term (Aind - 3m2/4) with m being the ultra-light masses (≈ Hubble parameter) implemented in the theory from supergravities arguments and non-minimal coupling. In the absence of a scalar buildup of matter fields, we study its effects on spontaneous symmetry breaking with a Higgs potential and show how the presence of the ultra-light masses yields some important consequences for the early universe and new constraints on the Higgs and electroweak gauge bosons masses.

  2. Nucleon Polarisabilities at and Beyond Physical Pion Masses

    CERN Document Server

    Griesshammer, Harald W; Phillips, Daniel R

    2015-01-01

    We examine the results of Chiral Effective Field Theory ($\\chi$EFT) for the scalar and spin-dipole polarisabilities of the proton and neutron for the physical pion mass and as a function of $m_\\pi$, thereby providing chiral extrapolations for lattice-QCD polarisability computations. We include both the leading and sub-leading effects of the nucleon's pion cloud, as well as the leading ones of the $\\Delta(1232)$ resonance and its pion cloud. The analytic results are complete at N${}^2$LO in the $\\delta$-counting for pion masses close to the physical value, and at leading order for pion masses similar to the Delta-nucleon mass splitting. In order to quantify the truncation error of our predictions and fits as 68% degree-of-belief confidence intervals, we use a Bayesian procedure recently adapted to EFT expansions. At the physical point, our predictions for the spin polarisabilities are, within respective errors, in good agreement with alternative extractions using experiments and dispersion-relation theory. At ...

  3. Comparisons of pion simulations for the MOLLER experiment

    Science.gov (United States)

    Lunde, Dominic; Moller Collaboration

    2016-09-01

    The MOLLER experiment at Jefferson Lab will measure the parity-violating asymmetry in Møller scattering, the scattering of electrons from electrons. A precise measurement of this parity-violating asymmetry will allow us to determine the weak charge of the electron with a precision that improves over the E158 experiment at SLAC. The experiment will scatter electrons from a 11 GeV beam from atomic electrons in a liquid hydrogen target. The detected particles will include inelastically produced pions, which will be a background to our measurements. In this work we investigate the validity and accuracy of two available pion physics models in order to estimate the uncertainty in the size of the pion background in the simulation. Currently there are two methods of pion models implemented. The LUND model is based on the Pythia event generator and has been used with success in simulations for the SoLID experiment. The Wiser model is based on data from previous pion scattering experiments. Comparison of the rates, cross sections, particle momentum, scattering angles, and other parameters show that both models produce consistent results for the parameters that were studied in this work, within the range of energies and scattering angles of interest to the MOLLER experiment. The work was supported in part by the National Science Foundation under Grant Nos. PHY-1359364 and PHY-1405857.

  4. Sketching the pion's valence-quark generalised parton distribution

    Directory of Open Access Journals (Sweden)

    C. Mezrag

    2015-02-01

    Full Text Available In order to learn effectively from measurements of generalised parton distributions (GPDs, it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL truncation of QCD's Dyson–Schwinger equations and exemplified via the pion's valence dressed-quark GPD, Hπv(x,ξ,t. Our analysis focuses primarily on ξ=0, although we also capitalise on the symmetry-preserving nature of the RL truncation by connecting Hπv(x,ξ=±1,t with the pion's valence-quark parton distribution amplitude. We explain that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for Hπv(x,0,t, expressed as the Radon transform of a single amplitude. Therewith we obtain results for Hπv(x,0,t and the associated impact-parameter dependent distribution, qπv(x,|b→⊥|, which provide a qualitatively sound picture of the pion's dressed-quark structure at a hadronic scale. We evolve the distributions to a scale ζ=2 GeV, so as to facilitate comparisons in future with results from experiment or other nonperturbative methods.

  5. Basic features of the pion valence-quark distribution function

    Directory of Open Access Journals (Sweden)

    Lei Chang

    2014-10-01

    Full Text Available The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the rainbow–ladder truncation, or any practical analogue, carry all the pion's light-front momentum at a characteristic hadronic scale. Corrections to the leading contribution may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea-quarks. Working with available empirical information, we use an algebraic model to express the principal impact of both classes of corrections. This enables a realistic comparison with experiment that allows us to highlight the basic features of the pion's measurable valence-quark distribution, qπ(x; namely, at a characteristic hadronic scale, qπ(x∼(1−x2 for x≳0.85; and the valence-quarks carry approximately two-thirds of the pion's light-front momentum.

  6. Gauge invariance and the electromagnetic current of composite pions

    Energy Technology Data Exchange (ETDEWEB)

    Frank, M.R. [Hampton Univ., VA (United States). Dept. of Physics]|[Continuous Electron Beam Accelerator Facility, Newport News, VA (United States); Tandy, P.C. [Kent State Univ., OH (United States). Center for Nuclear Research

    1993-03-24

    The Global Color-symmetry Model of QCD is extended to deal with a background electromagnetic field, and the associated conserved current is identified for the finite size {bar q}q pion modes at tree level. A well-defined truncation issued that factorizes the bilocal pion field into a local field variable and a hadronic form factor having a ladder Bethe-Salpeter content. The associated pion charge form factor is formulated. These developments are used to provide an illustration of how an effective hadronic action containing form factors may be electromagnetically coupled in a gauge invariant way that is accountable to its field substructure. In particular, the Ward-Takahashi identity for the photon vertex appropriate to the localized pion fields is seen to contain the hadronic form factors. In this context, gauge invariance of the effective hadronic action also requires recognition of the fact that the free inverse propagator for the localized pion field gauge transforms due to the substructure field content that has been absorbed into it.

  7. Binding energy of the $X(3872)$ at unphysical pion masses

    CERN Document Server

    Baru, V; Filin, A A; Gegelia, J; Nefediev, A V

    2015-01-01

    Chiral extrapolation of the $X(3872)$ binding energy is investigated using the modified Weinberg formulation of chiral effective field theory for the $D \\bar{D}^*$ scattering. Given its explicit renormalisability, this approach is particularly useful to explore the interplay of the long- and short-range $D \\bar{D}^*$ forces in the $X(3872)$ from studying the light-quark (pion) mass dependence of its binding energy. In particular, the parameter-free leading-order calculation shows that the $X$-pole disappears for unphysical large pion masses. On the other hand, without contradicting the naive dimensional analysis, the higher-order pion-mass-dependent contact interaction can change the slope of the binding energy at the physical point yielding the opposite scenario of a stronger bound $X$ at pion masses larger than its physical value. An important role of the pion dynamics and of the 3-body $D\\bar{D}\\pi$ effects for chiral extrapolations of the $X$-pole is emphasised. The results of the present study should be ...

  8. Lymphocyte Activation Gene-3 (LAG-3 negatively regulates environmentally-induced autoimmunity.

    Directory of Open Access Journals (Sweden)

    Vibha Jha

    Full Text Available Environmental factors including drugs, mineral oils and heavy metals such as lead, gold and mercury are triggers of autoimmune diseases in animal models or even in occupationally exposed humans. After exposure to subtoxic levels of mercury (Hg, genetically susceptible strains of mice develop an autoimmune disease characterized by the production of highly specific anti-nucleolar autoantibodies, hyperglobulinemia and nephritis. However, mice can be tolerized to the disease by a single low dose administration of Hg. Lymphocyte Activation Gene-3 (LAG-3 is a CD4-related, MHC-class II binding molecule expressed on activated T cells and NK cells which maintains lymphocyte homeostatic balance via various inhibitory mechanisms. In our model, administration of anti-LAG-3 monoclonal antibody broke tolerance to Hg resulting in autoantibody production and an increase in serum IgE level. In addition, LAG-3-deficient B6.SJL mice not only had increased susceptibility to Hg-induced autoimmunity but were also unresponsive to tolerance induction. Conversely, adoptive transfer of wild-type CD4(+ T cells was able to partially rescue LAG-3-deficient mice from the autoimmune disease. Further, in LAG-3-deficient mice, mercury elicited higher amounts of IL-6, IL-4 and IFN-γ, cytokines known to play a critical role in mercury-induced autoimmunity. Therefore, we conclude that LAG-3 exerts an important regulatory effect on autoimmunity elicited by a common environmental pollutant.

  9. TG-interacting factor transcriptionally induced by AKT/FOXO3A is a negative regulator that antagonizes arsenic trioxide-induced cancer cell apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zi-Miao; Tseng, Hong-Yu; Cheng, Ya-Ling [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Yeh, Bi-Wen [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Wu, Wen-Jeng [Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Department of Urology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Huang, Huei-Sheng, E-mail: huanghs@mail.ncku.edu.tw [Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan (China)

    2015-05-15

    Arsenic trioxide (ATO) is a multi-target drug approved by the Food and Drug Administration as the first-line chemotherapeutic agent for the treatment of acute promyelocytic leukemia. In addition, several clinical trials are being conducted with arsenic-based drugs for the treatment of other hematological malignancies and solid tumors. However, ATO's modest clinical efficacy on some cancers, and potential toxic effects on humans have been reported. Determining how best to reduce these adverse effects while increasing its therapeutic efficacy is obviously a critical issue. Previously, we demonstrated that the JNK-induced complex formation of phosphorylated c-Jun and TG-interacting factor (TGIF) antagonizes ERK-induced cyclin-dependent kinase inhibitor CDKN1A (p21{sup WAF1/CIP1}) expression and resultant apoptosis in response to ATO in A431 cells. Surprisingly, at low-concentrations (0.1–0.2 μM), ATO increased cellular proliferation, migration and invasion, involving TGIF expression, however, at high-concentrations (5–20 μM), ATO induced cell apoptosis. Using a promoter analysis, TGIF was transcriptionally regulated by ATO at the FOXO3A binding site (− 1486 to − 1479 bp) via the c-Src/EGFR/AKT pathway. Stable overexpression of TGIF promoted advancing the cell cycle into the S phase, and attenuated 20 μM ATO-induced apoptosis. Furthermore, blockage of the AKT pathway enhanced ATO-induced CDKN1A expression and resultant apoptosis in cancer cells, but overexpression of AKT1 inhibited CDKN1A expression. Therefore, we suggest that TGIF is transcriptionally regulated by the c-Src/EGFR/AKT pathway, which plays a role as a negative regulator in antagonizing ATO-induced CDKN1A expression and resultant apoptosis. Suppression of these antagonistic effects might be a promising therapeutic strategy toward improving clinical efficacy of ATO. - Highlights: • ATO-induced biphasic survival responses of cancer cells depend on low- or high-concentrations. • TGIF

  10. Cbl participates in shikonin-induced apoptosis by negatively regulating phosphoinositide 3-kinase/protein kinase B signaling.

    Science.gov (United States)

    Qu, Dan; Xu, Xiao-Man; Zhang, Meng; Jiang, Ting-Shu; Zhang, Yi; Li, Sheng-Qi

    2015-07-01

    Shikonin, a naturally occurring naphthoquinone, exhibits anti-tumorigenic activity. However, its precise mechanisms of action have remained elusive. In the present study, the involvement in the action of shikonin of the ubiquitin ligases Cbl-b and c-Cbl, which are negative regulators of phosphoinositide 3-kinase (PI3K) activation, was investigated. Shikonin was observed to reduce cell viability and induce apoptosis and G2/M phase arrest in lung cancer cells. In addition, shikonin increased the protein levels of B-cell lymphoma 2 (Bcl-2)-associated X and p53 and reduced those of Bcl-2. Additionally, shikonin inhibited PI3k/Akt activity and upregulated Cbl protein expression. In addition, a specific inhibitor of PI3K, LY294002, was observed to have a synergistic effect on the proliferation inhibition and apoptotic induction of A549 cells with shikonin. In conclusion, the results of the present study suggested that Cbl proteins promote shikonin-induced apoptosis by negatively regulating PI3K/Akt signaling in lung cancer cells.

  11. Root-expressed maize lipoxygenase 3 negatively regulates induced systemic resistance to Colletotrichum graminicola in shoots.

    Science.gov (United States)

    Constantino, Nasie N; Mastouri, Fatemeh; Damarwinasis, Ramadhika; Borrego, Eli J; Moran-Diez, Maria E; Kenerley, Charley M; Gao, Xiquan; Kolomiets, Michael V

    2013-01-01

    We have previously reported that disruption of a maize root-expressed 9-lipoxygenase (9-LOX) gene, ZmLOX3, results in dramatic increase in resistance to diverse leaf and stalk pathogens. Despite evident economic significance of these findings, the mechanism behind this increased resistance remained elusive. In this study, we found that increased resistance of the lox3-4 mutants is due to constitutive activation of induced systemic resistance (ISR) signaling. We showed that ZmLOX3 lacked expression in leaves in response to anthracnose leaf blight pathogen Colletotrichum graminicola, but was expressed constitutively in the roots, thus, prompting our hypothesis: the roots of lox3-4 mutants are the source of increased resistance in leaves. Supporting this hypothesis, treatment of wild-type plants (WT) with xylem sap of lox3-4 mutant induced resistance to C. graminicola to the levels comparable to those observed in lox3-4 mutant. Moreover, treating mutants with the sap collected from WT plants partially restored the susceptibility to C. graminicola. lox3-4 mutants showed primed defense responses upon infection, which included earlier and greater induction of defense-related PAL and GST genes compared to WT. In addition to the greater expression of the octadecanoid pathway genes, lox3-4 mutant responded earlier and with a greater accumulation of H2O2 in response to C. graminicola infection or treatment with alamethicin. These findings suggest that lox3-4 mutants display constitutive ISR-like signaling. In support of this idea, root colonization by Trichoderma virens strain GV29-8 induced the same level of disease resistance in WT as the treatment with the mutant sap, but had no additional resistance effect in lox3-4 mutant. While treatment with T. virens GV29 strongly and rapidly suppressed ZmLOX3 expression in hydroponically grown WT roots, T. virens Δsml mutant, which is deficient in ISR induction, was unable to suppress expression of ZmLOX3, thus, providing genetic

  12. Root-Expressed Maize Lipoxygenase 3 Negatively Regulates Induced Systemic Resistance to Colletotrichum graminicola in Shoots

    Directory of Open Access Journals (Sweden)

    Nasie eConstantino

    2013-12-01

    Full Text Available We have previously reported that disruption of a maize root-expressed 9-lipoxygenase (9-LOX gene, ZmLOX3, results in dramatic increase in resistance to diverse leaf and stalk pathogens. Despite evident economic significance of these findings, the mechanism behind this increased resistance remained elusive. In this study, we show that increased resistance of the lox3-4 mutants is due to constitutive activation of induced systemic resistance (ISR signaling. We showed that ZmLOX3 lacked expression in leaves in response to anthracnose leaf blight pathogen Colletotrichum graminicola, but was expressed constitutively in the roots, thus prompting our hypothesis: the roots of lox3-4 mutants are the source of increased resistance in leaves. Supporting this hypothesis, treatment of wild-type plants (WT with xylem sap of lox3-4 mutant induced resistance to C. graminicola to the levels comparable to those observed in lox3-4 mutant. Moreover, treating mutants with the sap collected from WT plants partially restored the susceptibility to C. graminicola. lox3-4 mutants showed primed defense responses upon infection, which included earlier and greater induction of defense-related PAL and GST genes compared to WT. In addition to the greater expression of the octadecanoid pathway genes, lox3-4 mutant responded earlier and with a greater accumulation of H2O2 in response to C. graminicola infection or treatment with alamethicin. These findings suggest that lox3-4 mutants display constitutive ISR-like signaling. In support of this idea, root colonization by Trichoderma virens strain GV29-8 induced the same level of disease resistance in WT as the treatment with the mutant sap, but had no additional resistance effect in lox3-4 mutant. While treatment with T. virens GV29 strongly and rapidly suppressed ZmLOX3 expression in hydroponically grown WT roots, T. virens Δsml mutant, which is deficient in ISR induction, was unable to suppress expression of ZmLOX3, thus

  13. Carbon-doping-induced negative differential resistance in armchair phosphorene nanoribbons

    Science.gov (United States)

    Guo, Caixia; Xia, Congxin; Wang, Tianxing; Liu, Yufang

    2017-03-01

    By using a combined method of density functional theory and non-equilibrium Green’s function formalism, we investigate the electronic transport properties of carbon-doped armchair phosphorene nanoribbons (APNRs). The results show that C atom doping can strongly affect the electronic transport properties of the APNR and change it from semiconductor to metal. Meanwhile, obvious negative differential resistance (NDR) behaviors are obtained by tuning the doping position and concentration. In particular, with reducing doping concentration, NDR peak position can enter into mV bias range. These results provide a theoretical support to design the related nanodevice by tuning the doping position and concentration in the APNRs. Project supported by the National Natural Science Foundation of China (No. 11274096), the University Science and Technology Innovation Team Support Project of Henan Province (No. 13IRTSTHN016), the University key Science Research Project of Henan Province (No.16A140043). The calculation about this work was supported by the High Performance Computing Center of Henan Normal University.

  14. Negative bias temperature instability of SiC MOSFET induced by interface trap assisted hole trapping

    Science.gov (United States)

    Yen, Cheng-Tyng; Hung, Chien-Chung; Hung, Hsiang-Ting; Lee, Chwan-Ying; Lee, Lurng-Shehng; Huang, Yao-Feng; Hsu, Fu-Jen

    2016-01-01

    We investigated the negative bias temperature instability (NBTI) characteristics of 4H-SiC metal oxide semiconductor field effect transistor (MOSFET) and metal oxide semiconductor capacitor (MOSCAP). The shift of threshold voltage approached saturation with time, and the different magnitude of mid-gap voltage shift with different starting biases observed in capacitance-voltage (CV) curves taken from MOSCAP and MOSFET suggested that the hole trapping was the primary mechanism contributing to the NBTI in this study. The trend of mid-gap voltage shift with starting bias and threshold voltage shift with stress bias showed steep change before -10 V and approached saturation after -10 V which can be explained by a process where the hole trapping was assisted by positively charged interface states. The positively charged interface states may have acted as an intermediate state which reduced the overall energy barrier and facilitated the process of hole trapping. The split-CV sweeps with 0 s and 655 s of hold time were essentially overlapped which was consistent with the time evolution characteristic of hole trapping and supported the interface trap assisted hole trapping mechanism.

  15. Alteration of Duration Mismatch Negativity Induced by Transcranial Magnetic Stimulation Over the Left Parietal Lobe.

    Science.gov (United States)

    Oshima, Hirokazu; Shiga, Tetsuya; Niwa, Shin-Ichi; Enomoto, Hiroyuki; Ugawa, Yoshikazu; Yabe, Hirooki

    2017-01-01

    Mismatch negativity (MMN) is generated by a comparison between an incoming sound and the memory trace of preceding sounds stored in sensory memory without any attention to the sound. N100 (N1) is associated with the afferent response to sound onset and reflects early analysis of stimulus characteristics. MMN generators are present in the temporal and frontal lobe, and N1 generators are present in the temporal lobe. The parietal lobe is involved in MMN generation elicited by a change in duration. The anatomical network connecting these areas, lateralization, and the effect of the side of ear stimulation on MMN remain unknown. Thus, we studied the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the left parietal lobe on MMN and N1 in 10 healthy subjects. Low-frequency rTMS over the left parietal lobe decreased the amplitude of MMN following right ear sound stimulation, but the amplitude was unaffected with left ear sound stimulation. We observed no significant changes in the amplitude of N1 or the latency of MMN or N1. These results suggest that low-frequency rTMS over the left parietal lobe modulates the detection of early auditory changes in duration in healthy subjects. Stimulation that is contralateral to the side of the ear experiencing sound may affect the generation of duration MMN more than ipsilateral stimulation. © EEG and Clinical Neuroscience Society (ECNS) 2016.

  16. Trion-Induced Negative Photoconductivity in Monolayer MoS2

    Science.gov (United States)

    Lui, C. H.; Frenzel, A. J.; Pilon, D. V.; Lee, Y.-H.; Ling, X.; Akselrod, G. M.; Kong, J.; Gedik, N.

    2014-10-01

    Optical excitation typically enhances electrical conduction and low-frequency radiation absorption in semiconductors. We, however, observe a pronounced transient decrease of conductivity in doped monolayer molybdenum disulfide (MoS2), a two-dimensional (2D) semiconductor, using ultrafast optical-pump terahertz-probe spectroscopy. In particular, the conductivity is reduced to only 30% of its equilibrium value at high pump fluence. This anomalous phenomenon arises from the strong many-body interactions in the 2D system, where photoexcited electron-hole pairs join the doping-induced charges to form trions, bound states of two electrons and one hole. The resultant increase of the carrier effective mass substantially diminishes the conductivity.

  17. One-pion production in neutrino-nucleus collisions

    CERN Document Server

    Hernández, E; Vicente-Vacas, M J

    2013-01-01

    We use our model for neutrino pion production on the nucleon to study pion production on a nucleus. The model is conveniently modified to include in-medium corrections and its validity is extended up to 2 GeV neutrino energies by the inclusion of new resonant contributions in the production process. Our results are compared with recent MiniBooNE data measured in mineral oil. Our total cross sections are below data for neutrino energies above 1 GeV. As with other theoretical calculations, the agreement with data improves if we neglect pion final state interaction. This is also the case for differential cross sections convoluted over the neutrino flux.

  18. Low Energy Analyzing Powers in Pion-Proton Elastic Scattering

    CERN Document Server

    Meier, R; Bilger, R; Van den Brandt, B; Breitschopf, J; Clement, H; Comfort, J R; Denz, H; Erhardt, A; Föhl, K; Friedman, E; Gr"ater, J; Hautle, P; Hofman, G J; Konter, J A; Mango, S; P"atzold, J; Pavan, M M; Wagner, G J; Von Wrochem, F

    2004-01-01

    Analyzing powers of pion-proton elastic scattering have been measured at PSI with the Low Energy Pion Spectrometer LEPS as well as a novel polarized scintillator target. Angular distributions between 40 and 120 deg (c.m.) were taken at 45.2, 51.2, 57.2, 68.5, 77.2, and 87.2 MeV incoming pion kinetic energy for pi+ p scattering, and at 67.3 and 87.2 MeV for pi- p scattering. These new measurements constitute a substantial extension of the polarization data base at low energies. Predictions from phase shift analyses are compared with the experimental results, and deviations are observed at low energies.

  19. Inclusive and pion production neutrino-nucleus cross sections

    CERN Document Server

    Martini, M

    2014-01-01

    We analyze the experimental data on the inclusive double differential cross section by neutrinos charged current, measured by T2K, with the same model which was successful for the MiniBooNE quasielastic cross sections. As in our previous analysis the multinucleon component is needed in order to reproduce the data. For the total cross section our evaluation is smaller than the SciBooNE data above 1 GeV. This indicates the opening of a new channel not included in our evaluation, presumably the two pion emission channel. We also check that our description holds for the exclusive single pion production channel by confronting our evaluation with the MiniBooNE double differential cross section for a single charged pion and the Q^2 distribution. Both are compatible with data.

  20. Magnetic catalysis of a finite size pion condensate

    CERN Document Server

    Ayala, Alejandro; Villavicencio, C

    2016-01-01

    We study the Bose-Einstein condensation of a finite size pion gas subject to the influence of a magnetic field. We find the expressions for the critical chemical potential and temperature for the onset of condensation. We show that for values of the external magnetic flux larger than the elemental flux, the critical temperature is larger than the one obtained by considering only finite size effects. We use experimentally reported values of pion source sizes and multiplicities at LHC energies to show that if the magnetic flux, produced initially in peripheral heavy-ion collision, is at least partially preserved up to the hadronic phase, the combined finite size and magnetic field effects give rise to a critical temperature above the kinetic freeze-out temperature. We discuss the implications for the evolution of the pion system created in relativistic heavy-ion collisions.

  1. One-pion production in neutrino-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, E. [Departamento de Física Fundamental e IUFFyM, Universidad de Salamanca, E-37008 Salamanca (Spain); Nieves, J. [Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, Apartado 22085, E-46071 Valencia (Spain); Vicente-Vacas, J. M. [Departamento de Física Teórica e IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Apartado 22085, E-46071 Valencia (Spain)

    2015-05-15

    We use our model for neutrino pion production on the nucleon to study pion production on a nucleus. The model is conveniently modified to include in-medium corrections and its validity is extended up to 2 GeV neutrino energies by the inclusion of new resonant contributions in the production process. Our results are compared with recent MiniBooNE data measured in mineral oil. Our total cross sections are below data for neutrino energies above ≈ 1 GeV. As with other theoretical calculations, the agreement with data improves if we neglect pion final state interaction. This is also the case for differential cross sections convoluted over the neutrino flux.

  2. Magnetic catalysis of a finite-size pion condensate

    Science.gov (United States)

    Ayala, Alejandro; Mercado, Pedro; Villavicencio, C.

    2017-01-01

    We study the Bose-Einstein condensation of a finite-size pion gas subject to the influence of a magnetic field. We find the expressions for the critical chemical potential and temperature for the onset of condensation. We show that for values of the external magnetic flux larger than the elemental flux, the critical temperature is larger than the one obtained by considering only finite-size effects. We use experimentally reported values of pion source sizes and multiplicities at Large Hadron Collider (LHC) energies to show that if the magnetic flux, produced initially in peripheral heavy-ion collisions, is at least partially preserved up to the hadronic phase, the combined finite-size and magnetic field effects give rise to a critical temperature above the kinetic freeze-out temperature. We discuss the implications for the evolution of the pion system created in relativistic heavy-ion collisions.

  3. Ginsparg-Wilson Pions Scattering on a Staggered Sea

    CERN Document Server

    Chen, J W; De van Water, R S; Walker-Loud, A; Chen, Jiunn-Wei; Connell, Donal O'; Water, Ruth S. Van de; Walker-Loud, Andre

    2006-01-01

    In this article, we calculate isospin 2 (I=2) pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We determine the scattering length at threshold for both 2 sea quarks and 2+1 sea quarks in the isospin limit. The scattering length, expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons. Thus, it does not depend upon the parameter, C_Mix, that appears in the chiral Lagrangian of the mixed theory. This result holds for both 2 and 2+1 flavors of sea quarks. Finally, we take the continuum limit of our mixed action results and give expressions for the scattering length in continuum 2 and 2+1 flavor partially quenched chiral perturbation theory.

  4. The pion electromagnetic structure with self-energy

    CERN Document Server

    Mello, Clayton Santos; Frederico, T

    2016-01-01

    We study the electromagnetic structure of the pion in terms of the quantum cromodynamic~(QCD) model on the Breit-frame. We calculated the observables, such as the electromagnetic form factor. The priori to have a calculation covariant need to get the valence term of the eletromagnetic form factor. We use the usual formalism in quantum field theory (QFT) and light-front quantum field theory (LFQFT) in order to test the properties of form factor in nonperturbative QCD. In this particular case, the form factor can be obtained using the pion Light-Front (LF) wave function including self-energy from Lattice-QCD. Specifically, these calculations was performed in LF formalism. We consider a quark-antiquark vertex model having a quark self-energy. Also we can use other models to compare the pion electromagnetic form factor with different wave function and to observe the degree of agreement between them.

  5. Effects of Nonlocal One-Pion-Exchange Potential in Deuteron

    CERN Document Server

    Forest, J L

    2000-01-01

    The off-shell aspects of the one-pion-exchange potential (OPEP) are discussed. Relativistic Hamiltonians containing relativistic kinetic energy, relativistic OPEP with various off-shell behaviors and Argonne $v_{18}$ short-range parameterization are used to study the deuteron properties. The OPEP off-shell behaviors depend on whether a pseudovector or pseudoscalar pion-nucleon coupling is used and are characterized by a parameter $\\mu$. We study potentials having $\\mu$=-1, 0 and +1 and we find that they are nearly unitarily equivalent. We also find that a nonrelativistic Hamiltonian containing local potentials and nonrelativistic kinetic energy provides a good approximation to a Hamiltonian containing a relativistic OPEP based on pseudovector pion-nucleon coupling and relativistic kinetic energy.

  6. Low energy analyzing powers in pion-proton elastic scattering

    Science.gov (United States)

    Meier, R.; Cröni, M.; Bilger, R.; van den Brandt, B.; Breitschopf, J.; Clement, H.; Comfort, J. R.; Denz, H.; Erhardt, A.; Föhl, K.; Friedman, E.; Gräter, J.; Hautle, P.; Hofman, G. J.; Konter, J. A.; Mango, S.; Pätzold, J.; Pavan, M. M.; Wagner, G. J.; von Wrochem, F.

    2004-05-01

    Analyzing powers of pion-proton elastic scattering have been measured at PSI with the Low Energy Pion Spectrometer LEPS and a novel polarized scintillator target. Angular distributions between 40 and 120 deg (c.m.) were taken at 45.2, 51.2, 57.2, 68.5, 77.2, and 87.2 MeV incoming pion kinetic energy for π+p scattering, and at 67.3 and 87.2 MeV for π-p scattering. These new measurements constitute a substantial extension of the polarization data base at low energies. Predictions from phase shift analyses are compared with the experimental results, and deviations are observed at low energies.

  7. Study on Charged Top-Pion Decay Processes

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-Lei; XU Wen-Na; DU Lin-Lin

    2004-01-01

    In the framework of top-color assisted technicolor (TC2) theory, we study the four decay processes of charged top-pion, i.e., П+t → t-b, П+t → c-b, П+t → W+γ П+t → W+ Z0. The decay branching ratio of these modes are calculated. The results show that the main decay channels of charged top-pion are the tree level modes: П+t → t-b and П+t → c-b. Light П+t is easier to be detected than heavy one at future coliders. So, the study provides us with some useful informations to search for charged top-pion.

  8. Measurement of the charged pion polarizability at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Thiemo Christian Ingo

    2012-09-26

    The reaction {pi}{sup -}+Z{yields}{pi}{sup -}+{gamma}+Z in which a photon is produced by a beam pion scattering off a quasi-real photon of the Coulomb field of the target nucleus is identified experimentally by the tiny magnitude of the momentum transfer to the nucleus. This process gives access to the charged pion polarizabilities {alpha}{sub {pi}} and {beta}{sub {pi}} whose experimental determination constitutes an important test of Chiral Perturbation Theory. In this work, the pion polarizability is obtained as {alpha}{sub {pi}}=(1.9{+-}0.7{sub stat.}{+-}0.8{sub syst.}) x 10{sup -4} fm{sup 3} from data taken with 190 GeV/c hadron beam provided by SPS to the COMPASS experiment at CERN in November 2009 and under the assumption of {alpha}{sub {pi}}+{beta}{sub {pi}}=0.

  9. Pion Cloud Effects on △-N Mass Splitting from Quark Models

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-Bing; FENG Qing-Guo

    2002-01-01

    Pion cloud effects on △-N mass splitting are studied based on quark models. Pseudo-scalar pion-quarkcoupling is discussed in the relativistic and nonrelativistic frameworks. We separately calculate the pion cloud effects bythe one-pion exchange potential and by another method which is consistent with the baryon chiral perturbation theory.Remark able discrepancy in the mass splitting between the two methods is shown.

  10. The pion electromagnetic form-factor in a QCD-inspired model

    CERN Document Server

    Pacheco-Bicudo-Cabral de Melo, J; Pace, E; Salmè, G

    2004-01-01

    We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates the vector meson dominance mechanism at the quark level, where the dressed photon with $q^+>0$ decay in an interacting quark-antiquark pair,wich absorbs the initial pion and produces the pion in the final state.

  11. Functional analysis of Arabidopsis immune-related MAPKs uncovers a role for MPK3 as negative regulator of inducible defences

    KAUST Repository

    Frei dit Frey, Nicolas

    2014-06-30

    Background Mitogen-activated protein kinases (MAPKs) are key regulators of immune responses in animals and plants. In Arabidopsis, perception of microbe-associated molecular patterns (MAMPs) activates the MAPKs MPK3, MPK4 and MPK6. Increasing information depicts the molecular events activated by MAMPs in plants, but the specific and cooperative contributions of the MAPKs in these signalling events are largely unclear. Results In this work, we analyse the behaviour of MPK3, MPK4 and MPK6 mutants in early and late immune responses triggered by the MAMP flg22 from bacterial flagellin. A genome-wide transcriptome analysis reveals that 36% of the flg22-upregulated genes and 68% of the flg22-downregulated genes are affected in at least one MAPK mutant. So far MPK4 was considered as a negative regulator of immunity, whereas MPK3 and MPK6 were believed to play partially redundant positive functions in defence. Our work reveals that MPK4 is required for the regulation of approximately 50% of flg22-induced genes and we identify a negative role for MPK3 in regulating defence gene expression, flg22-induced salicylic acid accumulation and disease resistance to Pseudomonas syringae. Among the MAPK-dependent genes, 27% of flg22-upregulated genes and 76% of flg22-downregulated genes require two or three MAPKs for their regulation. The flg22-induced MAPK activities are differentially regulated in MPK3 and MPK6 mutants, both in amplitude and duration, revealing a highly interdependent network. Conclusions These data reveal a new set of distinct functions for MPK3, MPK4 and MPK6 and indicate that the plant immune signalling network is choreographed through the interplay of these three interwoven MAPK pathways.

  12. PIGMI: a design report for Pion Generator for Medical Irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Hansborough, L.D. (comp.)

    1981-09-01

    PIGMI (Pion Generator for Medical Irradiations) is an integrated linear accelerator (linac) system developed under the auspices of the National Cancer Institute for specific application to cancer treatment in a hospital environment. In its full configuration, PIGMI is a proton linac that is far smaller, less expensive, and more reliable than previous machines that produce pions. Subsets of PIGMI technology can be used with equal advantage to generate beams of other particles (such as neutrons, protons, or heavy ions) that may be of interest for radiotherapy, radioisotope production, or other applications. The dramatic performance and cost advantages of this new breed of acceleraor result from a number of improvements. In the low-energy portion of the machine, a new type of low-energy linac (the radio-frequency quadrupole(RFQ)) produces an exceptionally good quality beam, and uses a very simple 30-kV injector. In the second part of the machine (the drift-tube linac (DTL)), high accelerating gradients are now achievable with consequent reductions in machine length. Another new structure (the disk and washer (DAW)) will be used in the third and final section of the accelerator; this portion will also be relatively short and require few power amplifiers. The entire machine is designed for ease of operation and high reliability. The pion-production machine, discussed in this report, accelerates a 100-..mu..A average proton-beam current to 650 MeV; use of an efficient pion-collection channel would result in an average pion flux of over 100 rad/min in a volume of about 1 l. Pion-channel design is not treated in this report. Accelerator construction cost is estimated at $10 million (1980 dollars); site preparation and treatment facility costs would bring the cost of a complete facility to an estimated $25 million.

  13. Valence-quark distribution functions in the kaon and pion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chen; Chang, Lei; Roberts, Craig D.; Wan, Shaolong; Zong, Hong-Shi

    2016-04-18

    We describe expressions for pion and kaon dressed-quark distribution functions that incorporate contributions from gluons which bind quarks into these mesons and hence overcome a flaw of the commonly used handbag approximation. The distributions therewith obtained are purely valence in character, ensuring that dressed quarks carry all the meson’s momentum at a characteristic hadronic scale and vanish as ( 1 - x ) 2 when Bjorken- x → 1 . Comparing such distributions within the pion and kaon, it is apparent that the size of S U ( 3 ) -flavor symmetry breaking in meson parton distribution functions is modulated by the flavor dependence of dynamical chiral symmetry breaking. Corrections to these leading-order formulas may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea quarks. Working with available empirical information, we build an algebraic framework that is capable of expressing the principal impact of both classes of corrections. This enables a realistic comparison with experiment which allows us to identify and highlight basic features of measurable pion and kaon valence-quark distributions. We find that whereas roughly two thirds of the pion’s light-front momentum is carried by valence dressed quarks at a characteristic hadronic scale; this fraction rises to 95% in the kaon; evolving distributions with these features to a scale typical of available Drell-Yan data produces a kaon-to-pion ratio of u -quark distributions that is in agreement with the single existing data set, and predicts a u -quark distribution within the pion that agrees with a modern reappraisal of π N Drell-Yan data. Precise new data are essential in order to validate this reappraisal and because a single modest-quality measurement of the kaon-to-pion ratio cannot be considered definitive.

  14. miR-181b negatively regulates activation-induced cytidine deaminase in B cells.

    Science.gov (United States)

    de Yébenes, Virginia G; Belver, Laura; Pisano, David G; González, Susana; Villasante, Aranzazu; Croce, Carlo; He, Lin; Ramiro, Almudena R

    2008-09-29

    Activated B cells reshape their primary antibody repertoire after antigen encounter by two molecular mechanisms: somatic hypermutation (SHM) and class switch recombination (CSR). SHM and CSR are initiated by activation-induced cytidine deaminase (AID) through the deamination of cytosine residues on the immunoglobulin loci, which leads to the generation of DNA mutations or double-strand break intermediates. As a bystander effect, endogenous AID levels can also promote the generation of chromosome translocations, suggesting that the fine tuning of AID expression may be critical to restrict B cell lymphomagenesis. To determine whether microRNAs (miRNAs) play a role in the regulation of AID expression, we performed a functional screening of an miRNA library and identified miRNAs that regulate CSR. One such miRNA, miR-181b, impairs CSR when expressed in activated B cells, and results in the down-regulation of AID mRNA and protein levels. We found that the AID 3' untranslated region contains multiple putative binding sequences for miR-181b and that these sequences can be directly targeted by miR-181b. Overall, our results provide evidence for a new regulatory mechanism that restricts AID activity and can therefore be relevant to prevent B cell malignant transformation.

  15. Study of the Production of Single Pions in Pion-proton Collisions near Threshold

    CERN Multimedia

    2002-01-01

    This experiment aims at a complete-kinematics measurement of the processes @p|-p @A @p|-@p|+n and @p|+p @A @p|+@p|+n in the region of incident momenta between 300 MeV/c and 460 MeV/c. It uses the Omicron Spectrometer with detectors placed in the magnetic field close to a 12 atm. hydrogen gas target. The apparatus has an acceptance of 4\\% for the processes to be studied. \\\\ \\\\ Their threshold is at 279 MeV/c and pion production in this region is interesting from the point of view of the determination of transformation properties of the chiral-symmetry-breaking part of the Lagrangian.

  16. Scaling study of the pion electroproduction cross sections and the pion form factor

    Energy Technology Data Exchange (ETDEWEB)

    Tanja Horn; Xin Qian; John Arrington; Razmik Asaturyan; Fatiha Benmokthar; Werner Boeglin; Peter Bosted; Antje Bruell; Eric Christy; Eugene Chudakov; Ben Clasie; Mark Dalton; AJI Daniel; Donal Day; Dipangkar Dutta; Lamiaa El Fassi; Rolf Ent; Howard Fenker; J. Ferrer; Nadia Fomin; H. Gao; K Garrow; Dave Gaskell; C Gray; G. Huber; M. Jones; N Kalantarians; C. Keppel; K Kramer; Y Li; Y Liang; A. Lung; S Malace; P. Markowitz; A. Matsumura; D. Meekins; T Mertens; T Miyoshi; H. Mykrtchyan; R. Monson; T. Navasardyan; G. Niculescu; I. Niculescu; Y. Okayasu; A. Opper; C Perdrisat; V. Punjabi; A. Rauf; V. Rodriguez; D. Rohe; J Seely; E Segbefia; G. Smith; M. Sumihama; V. Tadevoyan; L Tang; V. Tvaskis; A. Villano; W. Vulcan; F. Wesselmann; S. Wood; L. Yuan; X. Zheng

    2007-07-12

    The $^{1}$H($e,e^\\prime \\pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component is consistent with the $Q^2$-scaling prediction for hard exclusive processes. This suggests that perturbative QCD concepts are applicable at rather low values of $Q^2$. Pion form factor results, while consistent with the $Q^2$-scaling prediction, are inconsistent in magnitude with perturbative QCD calculations. The extraction of Generalized Parton Distributions from hard exclusive processes assumes the dominance of the longitudinal term. However, transverse contributions to the cross section are still significant at $Q^2$=3.91 GeV$^2$.

  17. Threshold pion electroproduction at large momentum transfers; Threshold Pion-Elektroproduktion bei grossen Energieuebertraegen

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Andreas

    2008-02-15

    We consider pion electroproduction close to threshold for Q{sup 2} in the region 1-10 GeV{sup 2} on a nucleon target. The momentum transfer dependence of the S-wave multipoles at threshold, E{sub 0+} and L{sub 0+}, is calculated in the chiral limit using light-cone sum rules. Predictions for the cross sections in the threshold region are given taking into account P-wave contributions that, as we argue, are model independent to a large extent. The results are compared with the SLAC E136 data on the structure function F{sub 2}(W,Q{sup 2}) in the threshold region. (orig.)

  18. On the Distribution of Neutral and Charged Pions through the Production of a Classical Pion Field

    CERN Document Server

    Anselm, A A; Bander, Myron

    1994-01-01

    High energy reactions may produce a state around the collision point that is best described by a classical pion field. Such a field might be an isospin rotated vacuum of the chiral $\\sigma$-model or, as discussed in this work, a solution of the equations of motion resultinng from the coupling of fields of this model to quarks produced in the collision. In such configurations all directions in isospin space are allowed leading to a sizable probability of events with, essentially, only charged particles (Centauros) or all neutral particles (anti-Centauros). (In more common statistical models of multiparticle production, the probability of such events is suppressed exponentially by the total multiplicity.) We find that the isospin violation due to the mass difference of the up and down quarks has a significant effect on these distributions and enhances the production of events consisting predominantly of neutral particles.

  19. Mass extrapolation of the amplitude for pion production in N-N collision

    Energy Technology Data Exchange (ETDEWEB)

    Afnan, I.R.; Thomas, A.W.

    1977-06-01

    The S-wave pion production process (at q/sub ..pi../ = 0) is calculated as a function of the mass of the produced pion. The invariant matrix element is found to be surprisingly constant over a large range of pion mass.

  20. Soft-pion production in n-n collisions. [n + n. -->. pi. /sup -/ + d

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, A.W. (CERN, Geneva); Afnan, I.R.

    1976-01-01

    The matrix element for s-wave pion production nn ..-->.. ..pi../sup -/d is examined as a function of the external pion mass. Quite unexpectedly, in view of the well-known failure of soft pion theory for this reaction, it is found to be constant within a few per cent. Both the reason for this result and its implications are briefly discussed.

  1. Exclusive near threshold two-pion production with the MOMO experiment at COSY

    Science.gov (United States)

    Bavink, S.; Bellemann, F.; Berg, A.; Bisplinghoff, J.; Bohlscheid, G.; Ernst, J.; Henrich, C.; Hinterberger, F.; Ibald, R.; Jahn, R.; Jarczyk, L.; Joosten, R.; Kozela, A.; Machner, H.; Magiera, A.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Munkel, J.; Neumann-Cosel, P. v.; Rosendaal, D.; Rossen, P. v.; Schnitker, H.; Scho, K.; Smyrski, J.; Strzalkowski, A.; Tölle, R.; Wurzinger, R.

    1998-03-01

    Near threshold two pion production via the reaction pd → 3Heπ +π - was measured kinematically complete with the MOMO experiment at COSY. A remarkable deviation of the obtained two pion invariant mass spectra from phase space as well as a predominant back to back and sidewise emission of the two pions was observed.

  2. Exclusive near threshold two-pion production with the MOMO experiment at COSY

    Energy Technology Data Exchange (ETDEWEB)

    Bavink, S.; Bellemann, F.; Berg, A. [Bonn Univ. (Germany). Inst. fuer Strahlen- und Kernphysik] [and others

    1998-03-02

    Near threshold two pion production via the reaction pd {yields} {sup 3}He{pi}{sup +}{pi}{sup -}was measured kinematically complete with the MOMO experiment at COSY. A remarkable deviation of the obtained two pion invariant mass spectra from phase space as well as a predominant back to back and sidewise emission of the two pions was observed. (orig.). 2 refs.

  3. Muon identification and pion rejection in the 4th concept

    Indian Academy of Sciences (India)

    John Haupton

    2007-12-01

    We describe a completely new way to reconstruct and identify muons with high efficiency and very high pion rejection in the 4th concept detector. The dual-solenoid magnetic field allows the reconstruction and precision momentum measurement of muons down to a few GeV (just the energy loss in the 10-int calorimeter and the coil) and the dual-readout calorimeter provides a new, unique and powerful separation of muons from pions. We use test beam data for the calorimeter and calculations for the magnetic fields

  4. Effective pion mass term and the trace anomaly

    CERN Document Server

    Golterman, Maarten

    2016-01-01

    Recently, we developed an effective theory of pions and a light dilatonic meson for gauge theories with spontaneously broken chiral symmetry that are close to the conformal window. The pion mass term in this effective theory depends on an exponent $y$. We derive the transformation properties under dilatations of the renormalized fermion mass, and use this to rederive $y=3-\\gamma_m^*$, where $\\gamma_m^*$ is fixed-point value of the mass anomalous dimension at the sill of the conformal window. This value for $y$ is consistent with the trace anomaly of the underlying near-conformal gauge theory.

  5. Pion Electromagnetic Form Factor at Lower and Higher Momentum Transfer

    CERN Document Server

    de Melo, J P B C; Tsushima, Kazuo

    2016-01-01

    The pion electromagnetic form factor is calculated at lower and higher momentum transfer in order to explore constituent quark models and the differences among those models. In particular, the light-front constituent quark model is utilized here to calculate the pion electromagnetic form factor at lower and higher energies. The matrix elements of the electromagnetic current, are calculated with both "plus" and "minus" components of the electromagnetic current in the light-front. Further, the electromagnetic form factor is compared with other models in the literature and experimental data.

  6. Pion in the Medium with a Light-Front Model

    CERN Document Server

    de Melo, J P B C; Frederico, Tobias

    2015-01-01

    The pion properties in symmetric nuclear matter are investigated with the Quark-Meson Coupling (QMC) Model plus the light-front constituent quark model~(LFCQM). The LFCQM has been quite successful in describing the properties of pseudoscalar mesons in vacuum, such as the electromagnetic elastic form factors, electromagnetic radii, and decay constants. We study the pion properties in symmetric nuclear matter with the in-medium input recalculated through the QMC model, which provides the in-medium modification of the LFCQM.

  7. Role of pion pole in hard exlusive meson leptoproduction

    CERN Document Server

    Goloskokov, Sergey

    2015-01-01

    We consider the pion pole contribution and transversity effects determined by the $H_T$ and $\\bar E_T$ Generalized Parton Distributions (GPDs) which are essential in hard pseudoscalar and vector meson leptoproduction. We investigate spin effects in the $\\omega$ and $\\rho^0$ reactions. It is shown that the pion pole contribution is very important in the $\\omega$ production. Such effects in the $\\rho^0$ channel are much smaller. Our results on spin asymmetries and spin density matrix elements in these reactions were found to be in good agreement with HERMES data.

  8. Chemical nonequilibrium for interacting bosons: Applications to the pion gas

    Science.gov (United States)

    Fernández-Fraile, D.; Gómez Nicola, A.

    2009-09-01

    We consider an interacting pion gas in a stage of the system evolution where thermal but not chemical equilibrium has been reached, i.e., for temperatures between thermal and chemical freeze-out TtherLuscher and Gell-Mann-Oakes-Renner-type relations. We pay special attention to the comparison with the conventional kinetic theory approach in the dilute regime, which allows for a check of consistency of our approach. Several phenomenological applications are discussed, concerning chiral symmetry restoration, freeze-out conditions, and Bose-Einstein pion condensation.

  9. Parton distributions for the pion in a chiral quark model

    CERN Document Server

    Ruiz-Arriola, E

    2001-01-01

    Parton distributions for the pion are studied in a chiral quark model characterized by a quark propagator for which a spectral representation is assumed. Electromagnetic and chiral symmetry constraints are imposed through the relevant Ward-Takahashi identities for flavoured vertex functions. Finiteness of the theory, requires the spectral function to be non-positive definite. Straightforward calculation yields the result that the pion structure function becomes one in the chiral limit, regardless of the details of the spectral function. LO and NLO evolution provide a satisfactory description of phenomenological parameterizations of the valence distribution functions but fails to describe gluon and sea distributions.

  10. Neutral pion form factor measurement at NA62

    CERN Document Server

    Goudzovski, Evgueni

    2016-01-01

    The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from $1.05\\times10^6$ fully reconstructed $\\pi^0$ Dalitz decay is presented. The limits on dark photon production in $\\pi^0$ decays from the earlier kaon experiment at CERN, NA48/2, are also reported.

  11. Effects of pion-fold-pion diagrams in the energy-independent nucleon-nucleon potential

    Science.gov (United States)

    de Guzman, G.; Kuo, T. T. S.; Holinde, K.; Machleidt, R.; Faessler, A.; Müther, H.

    1985-10-01

    Based on a T-matrix equivalence theory, an energy-independent or locally energy-dependent nucléon-nucléon potential VNN derived from meson exchanges is studied. The potential, given as a series expansion of folded diagrams, is independent of the asymptotic energy of the scattering nucleons. It is, however, locally energy dependent in the sense that its matrix elements depend on the energies associated with its bra and ket states a and b. Our formulation makes use of right-hand-side on-shell T-matrix equivalence of the field-theoretical and potential descriptions when limited to the space of neutrons and protons only. This preserves not only scattering (e.g. phase shifts, projections of wave functions) but also bound-state properties. The matrix elements of V were calculated for two potential models, one based on one-pion exchange (OPEP) and the other on one-boson exchange (OBEP) using {π, ρ, σ, ω, δ, η }. Three types of phase-shift calculations have been carried out to study the viability of constructing an energy-independent potential using the folded-diagram expansion: (A) NN phase shifts for an energy-dependent OPEP and OBEP. For the OBEP we used parameters adjusted to fit experimental data. (B) The same phase shifts for the energy-independent case for both OPEP and OBEP. (C) Repetition of (B) with effects of the two-pion folded diagrams included. Our results show two important points: (i) folded diagrams are of essential importance, and (ii) the first-order folded diagrams contain the dominant effect and the neglect of terms with more than two folds can be regarded as a good approximation. The effects of folded diagrams are large especially for low partial waves and high energies. For high partial waves ( J greater than 2) the folded terms are negligible, and the phase shifts given by (A), (B) and (C) practically coincide.

  12. Siglec-F-dependent negative regulation of allergen-induced eosinophilia depends critically on the experimental model.

    Science.gov (United States)

    McMillan, Sarah J; Richards, Hannah E; Crocker, Paul R

    2014-07-01

    Siglec-8 and siglec-F are paralogous membrane proteins expressed on human and murine eosinophils respectively. They bind similar sialylated and sulphated glycans and mediate eosinophil apoptosis when cross-linked with antibodies or glycan ligands. In models of allergic eosinophilic airway inflammation, siglec-F was shown previously to be important for negatively regulating eosinophilia. It was proposed that this was due to siglec-F-dependent apoptosis, triggered via engagement with ligands that are upregulated on bronchial epithelium. Our aim was to further investigate the functions of siglec-F by comparing two commonly used models of ovalbumin-induced airway inflammation that differ in the dose and route of administration of ovalbumin. In confirmation of published results, siglec-F-deficient mice had enhanced lung tissue eosinophilia in response to intranasal ovalbumin delivered every other day. However, following aerosolised ovalbumin delivered daily, there was no influence of siglec-F deficiency on lung eosinophilia. Expression of siglec-F ligands in lung tissues was similar in both models of allergen induced inflammation. These data demonstrate that siglec-F-dependent regulation of eosinophilia is subtle and depends critically on the model used. The findings also indicate that mechanisms other than ligand-induced apoptosis may be important in siglec-F-dependent suppression of eosinophilia. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Combined negative effect of donor age and time in culture on the reprogramming efficiency into induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Ras Trokovic

    2015-07-01

    Full Text Available Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSC by the forced expression of the transcription factors OCT4, SOX2, KLF4 and c-MYC. Pluripotent reprogramming appears as a slow and inefficient process because of genetic and epigenetic barriers of somatic cells. In this report, we have extended previous observations concerning donor age and passage number of human fibroblasts as critical determinants of the efficiency of iPSC induction. Human fibroblasts from 11 different donors of variable age were reprogrammed by ectopic expression of reprogramming factors. Although all fibroblasts gave rise to iPSC colonies, the reprogramming efficiency correlated negatively and declined rapidly with increasing donor age. In addition, the late passage fibroblasts gave less reprogrammed colonies than the early passage cell counterparts, a finding associated with the cellular senescence-induced upregulation of p21. Knockdown of p21 restored iPSC generation even in long-term passaged fibroblasts of an old donor, highlighting the central role of the p53/p21 pathway in cellular senescence induced by both donor age and culture time.

  14. Combined negative effect of donor age and time in culture on the reprogramming efficiency into induced pluripotent stem cells.

    Science.gov (United States)

    Trokovic, Ras; Weltner, Jere; Noisa, Parinya; Raivio, Taneli; Otonkoski, Timo

    2015-07-01

    Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSC) by the forced expression of the transcription factors OCT4, SOX2, KLF4 and c-MYC. Pluripotent reprogramming appears as a slow and inefficient process because of genetic and epigenetic barriers of somatic cells. In this report, we have extended previous observations concerning donor age and passage number of human fibroblasts as critical determinants of the efficiency of iPSC induction. Human fibroblasts from 11 different donors of variable age were reprogrammed by ectopic expression of reprogramming factors. Although all fibroblasts gave rise to iPSC colonies, the reprogramming efficiency correlated negatively and declined rapidly with increasing donor age. In addition, the late passage fibroblasts gave less reprogrammed colonies than the early passage cell counterparts, a finding associated with the cellular senescence-induced upregulation of p21. Knockdown of p21 restored iPSC generation even in long-term passaged fibroblasts of an old donor, highlighting the central role of the p53/p21 pathway in cellular senescence induced by both donor age and culture time.

  15. NF-κB (p65) negatively regulates myocardin-induced cardiomyocyte hypertrophy through multiple mechanisms.

    Science.gov (United States)

    Liao, Xing-Hua; Wang, Nan; Zhao, Dong-Wei; Zheng, De-Liang; Zheng, Li; Xing, Wen-Jing; Zhou, Hao; Cao, Dong-Sun; Zhang, Tong-Cun

    2014-12-01

    Myocardin is well known to play a key role in the development of cardiomyocyte hypertrophy. But the exact molecular mechanism regulating myocardin stability and transactivity to affect cardiomyocyte hypertrophy has not been studied clearly. We now report that NF-κB (p65) can inhibit myocardin-induced cardiomyocyte hypertrophy. Then we explore the molecular mechanism of this response. First, we show that p65 can functionally repress myocardin transcriptional activity and also reduce the protein expression of myocardin. Second, the function of myocardin can be regulated by epigenetic modifications. Myocardin sumoylation is known to transactivate cardiac genes, but whether p65 can inhibit SUMO modification of myocardin is still not clear. Our data show that p65 weakens myocardin transcriptional activity through attenuating SUMO modification of myocardin by SUMO1/PIAS1, thereby impairing myocardin-mediated cardiomyocyte hypertrophy. Furthermore, the expression of myocardin can be regulated by several microRNAs, which play important roles in the development and function of the heart and muscle. We next investigated potential role of miR-1 in cardiac hypotrophy. Our results show that p65 can upregulate the level of miR-1 and miR-1 can decrease protein expression of myocardin in cardiac myocytes. Notably, miR-1 expression is also controlled by myocardin, leading to a feedback loop. These data thus provide important and novel insights into the function that p65 inhibits myocardin-mediated cardiomyocyte hypertrophy by downregulating the expression and SUMO modification of myocardin and enhancing the expression of miR-1. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. How does pain induce negative emotion? Role of the bed nucleus of the stria terminalis in pain-induced place aversion.

    Science.gov (United States)

    Minami, M; Ide, S

    2015-01-01

    Pain consists of sensory-discriminative and negative-affective components. Neuronal mechanisms for the sensory component of pain have been investigated extensively. On the other hand, neuronal mechanisms for the affective component of pain remain to be investigated. Recent behavioral studies have revealed the brain regions and neuronal mechanisms involved in the affective component of pain. Glutamatergic transmission within the anterior cingulate cortex and basolateral amygdaloid nucleus plays a critical role in pain-induced aversion. Noradrenaline and corticotropin-releasing factor (CRF) within the ventral and dorsolateral parts of the bed nucleus of the stria terminalis (BNST), respectively, play important roles in paininduced aversion. Electrophysiological studies have revealed that both noradrenaline and CRF activate type II BNST neurons, which may inhibit the BNST output neurons. A recent histochemical study showed that most VTA-projecting BNST output neurons are GABAergic neurons, which preferentially make synaptic contact with VTA GABAergic neurons. Therefore, activation of VTA-projecting BNST output neurons should increase the neuronal excitability of VTA dopaminergic (DAergic) neurons through increased inhibitory input to VTA GABAergic neurons, which negatively regulate VTA DAergic neurons. Pain-induced release of noradrenaline and CRF within the BNST may activate type II BNST neurons, which could suppress VTA-projecting BNST output neurons, thereby attenuating the excitatory influence to the VTA DAergic neurons. Recent optogenetic studies suggest that the suppression of VTA DAergic neurons is sufficient to induce place aversion. Pain-induced place aversion may be due to the suppression of VTA DAergic neurons via the processing of nociceptive information within the BNST.

  17. Biochar-induced negative carbon mineralization priming effects in a coastal wetland soil: Roles of soil aggregation and microbial modulation.

    Science.gov (United States)

    Zheng, Hao; Wang, Xiao; Luo, Xianxiang; Wang, Zhenyu; Xing, Baoshan

    2017-08-19

    Biochar can sequestrate carbon (C) in soils and affect native soil organic carbon (SOC) mineralization via priming effects. However, the roles of soil aggregation and microbial regulation in priming effects of biochars on SOC in coastal wetland soils are poorly understood. Thus, a coastal wetland soil (δ(13)C -22‰) was separated into macro-micro aggregates (53-2000μm, MA) and silt-clay fractions (priming effect using two (13)C enriched biochars produced from corn straw (δ(13)C -11.58‰) at 350 and 550°C. The two biochars induced negative priming effect on the native SOC mineralization in the both soil aggregate size fractions, attributed to the enhanced stability of the soil aggregates resulting from the intimate physico-chemical associations between the soil minerals and biochar particles. Additionally, biochar amendments increased soil microbial biomass C and resulted in a lower metabolic quotient, suggesting that microbes in biochar amended aggregates could likely incorporate biomass C rather than mineralize it. Moreover, the biochar amendments induced obvious shifts of the bacterial community towards low C turnover bacteria taxa (e.g., Actinobacteria and Deltaproteobacteria) and the bacteria taxa responsible for stabilizing soil aggregates (e.g., Actinobacteria and Acidobacteria), which also accounted for the negative priming effect. Overall, these results suggested that biochar had considerable merit for stabilizing SOC in the coastal soil and thus has potential to restore and/or enhance "blue C" sink in the degraded coastal wetland ecosystem. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Negative Regulation of Leptin-induced Reactive Oxygen Species (ROS) Formation by Cannabinoid CB1 Receptor Activation in Hypothalamic Neurons.

    Science.gov (United States)

    Palomba, Letizia; Silvestri, Cristoforo; Imperatore, Roberta; Morello, Giovanna; Piscitelli, Fabiana; Martella, Andrea; Cristino, Luigia; Di Marzo, Vincenzo

    2015-05-29

    The adipocyte-derived, anorectic hormone leptin was recently shown to owe part of its regulatory effects on appetite-regulating hypothalamic neuropeptides to the elevation of reactive oxygen species (ROS) levels in arcuate nucleus (ARC) neurons. Leptin is also known to exert a negative regulation on hypothalamic endocannabinoid levels and hence on cannabinoid CB1 receptor activity. Here we investigated the possibility of a negative regulation by CB1 receptors of leptin-mediated ROS formation in the ARC. Through pharmacological and molecular biology experiments we report data showing that leptin-induced ROS accumulation is 1) blunted by arachidonyl-2'-chloroethylamide (ACEA) in a CB1-dependent manner in both the mouse hypothalamic cell line mHypoE-N41 and ARC neuron primary cultures, 2) likewise blocked by a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, troglitazone, in a manner inhibited by T0070907, a PPAR-γ antagonist that also inhibited the ACEA effect on leptin, 3) blunted under conditions of increased endocannabinoid tone due to either pharmacological or genetic inhibition of endocannabinoid degradation in mHypoE-N41 and primary ARC neuronal cultures from MAGL(-/-) mice, respectively, and 4) associated with reduction of both PPAR-γ and catalase activity, which are reversed by both ACEA and troglitazone. We conclude that CB1 activation reverses leptin-induced ROS formation and hence possibly some of the ROS-mediated effects of the hormone by preventing PPAR-γ inhibition by leptin, with subsequent increase of catalase activity. This mechanism might underlie in part CB1 orexigenic actions under physiopathological conditions accompanied by elevated hypothalamic endocannabinoid levels.

  19. Reduced defense of central blood volume during acute lower body negative pressure-induced hypovolemic circulatory stress in aging women.

    Science.gov (United States)

    Lindenberger, Marcus; Länne, Toste

    2012-06-01

    Elderly humans are more vulnerable to trauma and hemorrhage than young and elderly men and respond with decreased defense of central blood volume during acute experimental hypovolemia induced by lower body negative pressure (LBNP). However, these defense mechanisms have not been evaluated in elderly women. The aim of this study was to determine the effectiveness of compensatory responses to defend central blood volume during experimental hypovolemia in elderly and young women. Cardiovascular responses in 34 women, 12 elderly (66 ± 1 years) and 22 young women (23 ± 0.4 years), were studied during experimental hypovolemia induced by LBNP of 11 to 44 mmHg. Air plethysmography was used to assess the capacitance response (redistribution of peripheral venous blood to the central circulation) as well as net capillary fluid transfer from tissue to blood in the arm. Lower body negative pressure seemed to create comparable hypovolemia measured as total calf volume increase in elderly and young women. Heart rate increased less in elderly women (LBNP of 44 mmHg: 20 ± 2 vs. 37 ± 4%; P < 0.01) but with similar (%) increase in forearm vascular resistance. Mobilization of capacitance blood from the peripheral circulation was both slower and decreased by ∼60% in elderly women (P < 0.001), and net capillary fluid absorption from surrounding tissues was reduced by ∼40% (P < 0.01, LBNP of 44 mmHg). Elderly women responded with less increase in heart rate but with equal forearm vascular resistance (%) response during LBNP. Furthermore, the compensatory capacitance response was both slower and substantially decreased, and net capillary fluid absorption considerably reduced, collectively indicating less efficiency to defend central blood volume in elderly than in young women.

  20. Tendon progenitor cells in injured tendons have strong chondrogenic potential: the CD105-negative subpopulation induces chondrogenic degeneration.

    Science.gov (United States)

    Asai, Shuji; Otsuru, Satoru; Candela, Maria Elena; Cantley, Leslie; Uchibe, Kenta; Hofmann, Ted J; Zhang, Kairui; Wapner, Keith L; Soslowsky, Louis J; Horwitz, Edwin M; Enomoto-Iwamoto, Motomi

    2014-12-01

    To study the cellular mechanism of the tendon repair process, we used a mouse Achilles tendon injury model to focus on the cells recruited to the injured site. The cells isolated from injured tendon 1 week after the surgery and uninjured tendons contained the connective tissue progenitor populations as determined by colony-forming capacity, cell surface markers, and multipotency. When the injured tendon-derived progenitor cells (inTPCs) were transplanted into injured Achilles tendons, they were not only integrated in the regenerating area expressing tenogenic phenotype but also trans-differentiated into chondrogenic cells in the degenerative lesion that underwent ectopic endochondral ossification. Surprisingly, the micromass culture of the inTPCs rapidly underwent chondrogenic differentiation even in the absence of exogenous bone morphogenetic proteins or TGFβs. The cells isolated from human ruptured tendon tissues also showed connective tissue progenitor properties and exhibited stronger chondrogenic ability than bone marrow stromal cells. The mouse inTPCs contained two subpopulations one positive and one negative for CD105, a coreceptor of the TGFβ superfamily. The CD105-negative cells showed superior chondrogenic potential in vitro and induced larger chondroid degenerative lesions in mice as compared to the CD105-positive cells. These findings indicate that tendon progenitor cells are recruited to the injured site of tendons and have a strong chondrogenic potential and that the CD105-negative population of these cells would be the cause for chondroid degeneration in injured tendons. The newly identified cells recruited to the injured tendon may provide novel targets to develop therapeutic strategies to facilitate tendon repair. © 2014 AlphaMed Press.

  1. Tendon Progenitor Cells in Injured Tendons Have Strong Chondrogenic Potential: The CD105-Negative Subpopulation Induces Chondrogenic Degeneration

    Science.gov (United States)

    Asai, Shuji; Otsuru, Satoru; Candela, Maria Elena; Cantley, Leslie; Uchibe, Kenta; Hofmann, Ted J.; Zhang, Kairui; Wapner, Keith L.; Soslowsky, Louis J; Horwitz, Edwin M.; Enomoto-Iwamoto, Motomi

    2014-01-01

    To study the cellular mechanism of the tendon repair process, we used a mouse Achilles tendon injury model to focus on the cells recruited to the injured site. The cells isolated from injured tendon 1 week after the surgery and uninjured tendons contained the connective tissue progenitor populations as determined by colony-forming capacity, cell surface markers and multipotency. When the injured tendon-derived progenitor cells (inTPCs) were transplanted into injured Achilles tendons, they were not only integrated in the regenerating area expressing tenogenic phenotype but also trans-differentiated into chondrogenic cells in the degenerative lesion that underwent ectopic endochondral ossification. Surprisingly, the micromass culture of the inTPCs rapidly underwent chondrogenic differentiation even in the absence of exogenous BMPs or TGFβs. The cells isolated from human ruptured tendon tissues also showed connective tissue progenitor properties and exhibited stronger chondrogenic ability than bone marrow stromal cells. The mouse inTPCs contained two subpopulations one positive and one negative for CD105, a co-receptor of the TGFβ superfamily. The CD105-negative cells showed superior chondrogenic potential in vitro and induced larger chondroid degenerative lesions in mice as compared to the CD105-positive cells. These findings indicate that tendon progenitor cells are recruited to the injured site of tendons and have a strong chondrogenic potential and that the CD105-negative population of these cells would be the cause for chondroid degeneration in injured tendons. The newly identified cells recruited to the injured tendon may provide novel targets to develop therapeutic strategies to facilitate tendon repair. PMID:25220576

  2. Collision-induced dissociation analysis of negative atmospheric ion adducts in atmospheric pressure corona discharge ionization mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2013-05-01

    Collision-induced dissociation (CID) experiments were performed on atmospheric ion adducts [M + R](-) formed between various types of organic compounds M and atmospheric negative ions R(-) [such as O2(-), HCO3(-), COO(-)(COOH), NO2(-), NO3(-), and NO3(-)(HNO3)] in negative-ion mode atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. All of the [M + R](-) adducts were fragmented to form deprotonated analytes [M - H](-) and/or atmospheric ions R(-), whose intensities in the CID spectra were dependent on the proton affinities of the [M - H](-) and R(-) fragments. Precursor ions [M + R](-) for which R(-) have higher proton affinities than [M - H](-) formed [M - H](-) as the dominant product. Furthermore, the CID of the adducts with HCO3(-) and NO3(-)(HNO3) led to other product ions such as [M + HO](-) and NO3(-), respectively. The fragmentation behavior of [M + R](-) for each R(-) observed was independent of analyte type (e.g., whether the analyte was aliphatic or aromatic, or possessed certain functional groups).

  3. Longitudinal Lelectroproduction of Charged Pions on Hydrogen, Deuterium, and Helium 3

    Energy Technology Data Exchange (ETDEWEB)

    Gaskell, David [Oregon State Univ., Corvallis, OR (United States)

    2001-03-22

    Conventional pictures of nuclear interactions, in which the pion mediates the long/medium range part of the nuclear force, predict an enhancement of the virtual pion cloud in nuclei relative to that in the free nucleon. Jefferson Lab Experiment E91003 measured charged pion electroproduction from Hydrogen, Deuterium, and Helium-3. The longitudinal cross section, which in the limit of pole dominance can be viewed as the quasifree knockout of a virtual pion, was extracted via a Rosenbluth separation. The longitudinal cross sections from Deuterium and Helium-3 were compared to Hydrogen to look for signatures of the nuclear pions.

  4. Longitudinal Lelectroproduction of Charged Pions on Hydrogen, Deuterium, and Helium 3

    Energy Technology Data Exchange (ETDEWEB)

    David Gaskell

    2001-05-01

    Conventional pictures of nuclear interactions, in which the pion mediates the long/medium range part of the nuclear force, predict an enhancement of the virtual pion cloud in nuclei relative to that in the free nucleon. Jefferson Lab Experiment E91003 measured charged pion electroproduction from Hydrogen, Deuterium, and Helium-3. The longitudinal cross section, which in the limit of pole dominance can be viewed as the quasifree knockout of a virtual pion, was extracted via a Rosenbluth separation. The longitudinal cross sections from Deuterium and Helium-3 were compared to Hydrogen to look for signatures of the nuclear pions.

  5. Measurement of the pion electromagnetic form-factor in the SELEX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dirkes, Guido; /Heidelberg, Max Planck Inst.

    1999-10-01

    This work describes the analysis of pion-electron scattering data of the fix-trage-experiment SELEX at Fermilab with special respects to the pion charge radius. At an average rate of 150 Hz, 215 million candidates for pion-electron elastic scattering were recorded during the fix target run until September 1997. A sample of 24,000 pion-electron scattering events was extracted in the course of several data strips. Monte Carlo studies gave detailed knowledge of acceptance, which is important due to special trigger conditions. Systematics were studied and the pion mean square charge radius was determined.

  6. Three-Pion HBT Correlations in Relativistic Heavy-Ion Collisions from the STAR Experiment

    CERN Document Server

    Adams, J; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Balewski, J T; Barannikova, O Yu; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Mora-Corral, M J; Cramer, J G; Crawford, H J; Derevshchikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Yu; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N D; Gans, J; Gaudichet, L; Germain, M; Geurts, F J M; Ghazikhanian, V; Grachov, O A; Guedon, M; Guertin, S M; Gushin, E; Gutíerrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Leontiev, V M; Le Vine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Ludlam, Thomas W; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnik, Yu M; Meshchanin, A P; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Molnár, L; Moore, C F; Morozov, V; De Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevozchikov, V; Peryt, W; Petrov, V; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E V; Prindle, D J; Pruneau, C A; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Renault, G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V L; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimansky, S S; Simon, F; Skoro, G P; Smirnov, N; Snellings, R; Sørensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, Reinhard; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T S; Underwood, D G; Van Buren, G; Van der Molen, A M; Vasilev, A N; Vigdor, S E; Voloshin, S A; Vznuzdaev, M; Wang, F; Wang, Y; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevsky, Yu V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

    2003-01-01

    Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at $sqrt{s_{NN}}=130$ GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freezeout. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

  7. Pion linac as an energy-tagged ν source

    Directory of Open Access Journals (Sweden)

    T. Goldman

    2008-12-01

    Full Text Available The energy spectrum and flux of neutrinos from a linear pion accelerator are calculated analytically under the assumption of a uniform accelerating gradient. The energy of a neutrino from this source reacting in a detector can be determined from timing and event position information.

  8. Electromagnetic fields and transport coefficients in a hot pion gas

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Nicola, A. [Departamentos de Fisica Teorica I, II, Universidad Complutense, 28040 Madrid (Spain); Fernandez-Fraile, D. [Departamentos de Fisica Teorica I, II, Universidad Complutense, 28040 Madrid (Spain)

    2007-03-15

    We present recent results on finite temperature electromagnetic form factors and the electrical conductivity in a pion gas. The standard Chiral Perturbation Theory power counting needs to be modified for transport coefficients. We pay special attention to unitarity and to possible applications for dilepton and photon production.

  9. Pion and neutron production by cosmic-ray muons underground

    CERN Document Server

    Delorme, J; Ericson, Torleif Eric Oskar; Vogel, P; Delorme, Jean; Ericson, Magda; Ericson, Torleif; Vogel, C

    1995-01-01

    The production of positive pions and neutrons by cosmic muons at underground sites of various depths is investigated. We first test the equivalent photon method in the particular case of \\Delta excitation by the muon. We find that this method, when it neglects the momentum dependence of the transverse response, reproduces remarkably well the theoretical muon cross-section. This success has lead us to apply the method to higher energies, where it has not been tested. We evaluate in this way the production of positive pions in liquid scintillator from known photo-absorption cross-sections. At a shallow depth of 20 meters our estimate reproduces the measurement. As for the neutron emission, we include the obvious sources, such as the giant-resonance excitation, the quasi-deuteron process, the quasi- free pion production as well as neutrons emitted following pion capture. Our evaluation underestimates the number of neutrons produced and finds a too weak dependence on the depth. This suggests that secondary neutro...

  10. Measurement of the pion form factor at higher energies

    Energy Technology Data Exchange (ETDEWEB)

    Mack, D.J. [CEBAF, Newport News, VA (United States)

    1994-04-01

    One of the strongest arguments for increasing the nominal CEBAF beam energy to equal or exceed 6 GeV is that one would be able to make quality high Q{sup 2} measurements of the charged pion form factor.

  11. The Discoveries of Rare Pion Decays at the CERN Synchrocyclotron

    CERN Document Server

    Fidecaro, Giuseppe

    2015-01-01

    In 1957 the CERN 600 MeV Synchrocyclotron started to operate and could detect for the first time already in 1958, and later in 1962, the two still missing β-decays of the charged pion, providing crucial verifications of the universal V–A coupling.

  12. Pion photo- and electroproduction in relativistic baryon ChPT

    Directory of Open Access Journals (Sweden)

    Tiator Lothar

    2014-06-01

    Full Text Available We present a calculation of pion photo- and electroproduction in manifestly Lorentz-invariant baryon chiral perturbation theory up to and including order q4. We fix the low-energy constants by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID.

  13. Pigmi mechanical fabrication. [Pion Generator for Medical Irradiations (PIGMI)

    Energy Technology Data Exchange (ETDEWEB)

    Hart, V.E.

    1976-01-01

    A prime goal of the mechanical design effort associated with the PIGMI (Pion Generator for Medical Irradiations) program is to investigate new materials and fabrication techniques in an effort to obtain increased machine efficiency and reliability at a reasonable cost. A discussion is given dealing with the modeling program that LASL is pursuing for 450-MHz and 1350-MHz PIGMI development.

  14. Renormalization of NN Interaction with Relativistic Chiral Two Pion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Higa, R; Valderrama, M Pavon; Arriola, E Ruiz

    2007-06-14

    The renormalization of the NN interaction with the Chiral Two Pion Exchange Potential computed using relativistic baryon chiral perturbation theory is considered. The short distance singularity reduces the number of counter-terms to about a half as those in the heavy-baryon expansion. Phase shifts and deuteron properties are evaluated and a general overall agreement is observed.

  15. Anomalous electrodynamics of neutral pion matter in strong magnetic fields

    Science.gov (United States)

    Brauner, Tomáš; Kadam, Saurabh V.

    2017-03-01

    The ground state of quantum chromodynamics in sufficiently strong external magnetic fields and at moderate baryon chemical potential is a chiral soliton lattice (CSL) of neutral pions [1]. We investigate the interplay between the CSL structure and dynamical electromagnetic fields. Our main result is that in presence of the CSL background, the two physical photon polarizations and the neutral pion mix, giving rise to two gapped excitations and one gapless mode with a nonrelativistic dispersion relation. The nature of this mode depends on the direction of its propagation, interpolating between a circularly polarized electromagnetic wave [2] and a neutral pion surface wave, which in turn arises from the spontaneously broken translation invariance. Quite remarkably, there is a neutral-pion-like mode that remains gapped even in the chiral limit, in seeming contradiction to the Goldstone theorem. Finally, we have a first look at the effect of thermal fluctuations of the CSL, showing that even the soft nonrelativistic excitation does not lead to the Landau-Peierls instability. However, it leads to an anomalous contribution to pressure that scales with temperature and magnetic field as T 5/2( B/f π )3/2.

  16. Subthreshold Production of Neutral Pions in Heavy Ion Collisions

    CERN Multimedia

    2002-01-01

    The pion production below the threshold at 290 MeV/u (corresponding to the minimum beam velocity at which pions can be produced in nucleon-nucleon collisions) is sensitive to coherent effects in the momentum distribution of the nucleons in the internuclear collision region. Such collective or coherent effects would manifest themselves in an enhancement of the observed cross section with respect to a prediction on the basis of model momentum distributions, e.g. from the Fermi gas model. \\\\ \\\\ With neutral pions such experiments can be extended to rather low energies and rather small cross sections (in the sub-@mb range) due to the fact that the @p|0's leave the composite nuclear system undisturbed by the Coulomb forces and that their decay $\\gamma$ rays can be detected with high efficiency also at very low pion momentum. In our experiments using |1|2C~ions of 60, 74 and 84~MeV/u and |1|80 of 84~MeV/u we were able to clearly sep from background from different sources. The large efficiency of the annular lead gl...

  17. Sketching the pion's valence-quark generalised parton distribution

    CERN Document Server

    Mezrag, C; Moutarde, H; Roberts, C D; Rodriguez-Quintero, J; Sabatie, F; Schmidt, S M

    2014-01-01

    In order to learn effectively from measurements of generalised parton distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's valence dressed-quark GPD, $H_\\pi^{\\rm v}(x,\\xi,t)$. Our analysis focuses primarily on $\\xi=0$, although we also capitalise on the symmetry-preserving nature of the RL truncation by connecting $H_\\pi^{\\rm v}(x,\\xi=\\pm 1,t)$ with the pion's valence-quark parton distribution amplitude. We explain that the impulse-approximation used hitherto to define the pion's valence dressed-quark GPD is generally invalid owing to omission of contributions from the gluons which bind dressed-quarks into the pion. A simple correction enables us to identify a practicable improvement to the approximation for $H_\\pi^{\\rm v}(x,0,t)$, expressed as th...

  18. Homemade-device-induced negative pressure promotes wound healing more efficiently than VSD-induced positive pressure by regulating inflammation, proliferation and remodeling.

    Science.gov (United States)

    Liu, Jinyan; Hu, Feng; Tang, Jintian; Tang, Shijie; Xia, Kun; Wu, Song; Yin, Chaoqi; Wang, Shaohua; He, Quanyong; Xie, Huiqing; Zhou, Jianda

    2017-04-01

    Vacuum sealing drainage (VSD) is an effective technique used to promote wound healing. However, recent studies have shown that it exerts positive pressure (PP) rather than negative pressure (NP) on skin. In this study, we created a homemade device that could maintain NP on the wound, and compared the therapeutic effects of VSD-induced PP to those of our homemade device which induced NP on wound healing. The NP induced by our device required less time for wound healing and decreased the wound area more efficiently than the PP induced by VSD. NP and PP both promoted the inflammatory response by upregulating neutrophil infiltration and interleukin (IL)‑1β expression, and downregulating IL‑10 expression. Higher levels of epidermal growth factor (EGF), transforming growth factor (TGF)‑β and platelet-derived growth factor (PDGF), and lower levels of basic fibroblast growth factor (bFGF) were observed in the wound tissue treated with NP compared to the wound tissue exposed to PP. Proliferation in the wound tissue exposed to NP on day 10 was significantly higher than that in wound tissue exposed to PP. NP generated more fibroblasts, keratinized stratified epithelium, and less epithelia with stemness than PP. The levels of ccollagen Ⅰ and Ⅲ were both decreased in both the NP and PP groups. NP induced a statistically significant increase in the expression of fibronectin (FN) on days 3 and 10 compared to PP. Furthermore, the level of matrix metalloproteinase (MMP)‑13 increased in the NP group, but decreased in the PP group on day 3. NP also induced a decrease in the levels of tissue inhibitor of metalloproteinase (TIMP)‑1 and TIMP‑2 during the early stages of wound healing, which was significantly different from the increasing effect of PP on TIMP‑1 and TIMP‑2 levels at the corresponding time points. On the whole, our data indicate that our homemade device which induced NP, was more efficient than VSD‑induced PP on wound healing by

  19. Homemade-device-induced negative pressure promotes wound healing more efficiently than VSD-induced positive pressure by regulating inflammation, proliferation and remodeling

    Science.gov (United States)

    Liu, Jinyan; Hu, Feng; Tang, Jintian; Tang, Shijie; Xia, Kun; Wu, Song; Yin, Chaoqi; Wang, Shaohua; He, Quanyong; Xie, Huiqing; Zhou, Jianda

    2017-01-01

    Vacuum sealing drainage (VSD) is an effective technique used to promote wound healing. However, recent studies have shown that it exerts positive pressure (PP) rather than negative pressure (NP) on skin. In this study, we created a homemade device that could maintain NP on the wound, and compared the therapeutic effects of VSD-induced PP to those of our home-made device which induced NP on wound healing. The NP induced by our device required less time for wound healing and decreased the wound area more efficiently than the PP induced by VSD. NP and PP both promoted the inflammatory response by upregulating neutrophil infiltration and interleukin (IL)-1β expression, and downregulating IL-10 expression. Higher levels of epidermal growth factor (EGF), transforming growth factor (TGF)-β and platelet-derived growth factor (PDGF), and lower levels of basic fibroblast growth factor (bFGF) were observed in the wound tissue treated with NP compared to the wound tissue exposed to PP. Proliferation in the wound tissue exposed to NP on day 10 was significantly higher than that in wound tissue exposed to PP. NP generated more fibroblasts, keratinized stratified epithelium, and less epithelia with stemness than PP. The levels of ccollagen I and III were both decreased in both the NP and PP groups. NP induced a statistically significant increase in the expression of fibronectin (FN) on days 3 and 10 compared to PP. Furthermore, the level of matrix metalloproteinase (MMP)-13 increased in the NP group, but decreased in the PP group on day 3. NP also induced a decrease in the levels of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 during the early stages of wound healing, which was significantly different from the increasing effect of PP on TIMP-1 and TIMP-2 levels at the corresponding time points. On the whole, our data indicate that our homemade device which induced NP, was more efficient than VSD-induced PP on wound healing by regulating inflammation, secretion

  20. Doxycycline inhibits proliferation and induces apoptosis of both human papillomavirus positive and negative cervical cancer cell lines.

    Science.gov (United States)

    Zhao, Yan; Wang, Xinyu; Li, Lei; Li, Changzhong

    2016-05-01

    The clinical management of cervical cancer remains a challenge and the development of new treatment strategies merits attention. However, the discovery and development of novel compounds can be a long and labourious process. Drug repositioning may circumvent this process and facilitate the rapid translation of hypothesis-driven science into the clinics. In this work, we show that a FDA-approved antibiotic, doxycycline, effectively targets human papillomavirus (HPV) positive and negative cervical cancer cells in vitro and in vivo. Doxycycline significantly inhibits proliferation of a panel of cervical cancer cell lines. It also induces apoptosis of cervical cancer cells in a time- and dose-dependent manner. In addition, the apoptosis induced by doxycycline is through caspase-dependent pathway. Mechanism studies demonstrate that doxycycline affects oxygen consumption rate, glycolysis, and reduces ATP levels in cervical cancer cells. In HeLa xenograft mouse model, doxycycline significantly inhibits growth of tumour. Our in vitro and in vivo data clearly demonstrate the inhibitory effects of doxycycline on the growth and survival of cervical cancer cells. Our work provides the evidence that doxycycline can be repurposed for the treatment of cervical cancer and targeting energy metabolism may represent a potential therapeutic strategy for cervical cancer.

  1. Virtual photons in the pion form factors and the energy-momentum tensor

    CERN Document Server

    Kubis, B; Kubis, Bastian; Mei{\\ss}ner, Ulf-G.

    2000-01-01

    We evaluate the vector and scalar form factor of the pion in the presence of virtual photons at next-to-leading order in two-flavor chiral perturbation theory. We also consider the scalar and tensor pion form factors of the energy-momentum tensor. We find that the intrinsic electromagnetic corrections are very small for the vector and charged pion scalar form factor. The scalar radius of the neutral pion is reduced by two percent. We perform infrared regularization by considering electron-positron annihilation into pions and the decay of a light Higgs boson into a pion pair. We discuss the detector resolution dependent contributions to the various form factors and pion radii.

  2. KIR/HLA interactions negatively affect rituximab- but not GA101 (obinutuzumab)-induced antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Terszowski, Grzegorz; Klein, Christian; Stern, Martin

    2014-06-15

    Ab-dependent cellular cytotoxicity (ADCC) mediated by NK cells is regulated by inhibitory killer cell Ig-like receptors (KIRs), which interact with target cell HLA class I. We analyzed how KIR/HLA interactions influence ADCC induced by rituximab and by GA101, a novel type II CD20 Ab glycoengineered for increased FcgRIII binding and ADCC capacity. We found that KIR/HLA interactions strongly and selectively inhibit rituximab-induced in vitro ADCC toward target cells expressing cognate HLA KIR ligands. NK cells of donors carrying all three ligands to inhibitory KIR showed weak activation and target cell depletion capacity when incubated with rituximab and KIR-ligand matched target B cells. In contrast, NK cells from individuals missing one or more KIR ligands activated more strongly and depleted KIR ligand-matched target B cells more efficiently in the presence of rituximab. NK cells expressing a KIR for which the ligand was absent were the main effectors of ADCC in these donors. Notably, the influence of KIR/HLA interactions on NK cell activation was synergistic with the effect of the V158F FCGR3A single nucleotide polymorphism. In contrast, GA101 induced activation of NK cells irrespective of inhibitory KIR expression, and efficiency of target cell depletion was not negatively affected by KIR/HLA interactions. These data show that modification of the Fc fragment to enhance ADCC can be an effective strategy to augment the efficacy of therapeutic mAbs by recruiting NK cells irrespective of their inhibitory KIR expression.

  3. Pterostilbene inhibits triple-negative breast cancer metastasis via inducing microRNA-205 expression and negatively modulates epithelial-to-mesenchymal transition.

    Science.gov (United States)

    Su, Chih-Ming; Lee, Wei-Hwa; Wu, Alexander T H; Lin, Yen-Kuang; Wang, Liang-Shun; Wu, Chih-Hsiung; Yeh, Chi-Tai

    2015-06-01

    Breast cancer is the leading cause of cancer-related deaths among females in economically developing countries. Greater than 95% of breast malignancies are of epithelial origin; the induction of epithelial-to-mesenchymal transition (EMT) has been shown to initiate the metastatic process in breast carcinoma and remains the key target for drug development. Here, we examine the anti-metastatic potential of pterostilbene in modulating EMT process in breast cancer cells both in vitro and in vivo. The differential invasive ability among MCF7, Hs578t and MDA-MB-231 breast cancer cell lines were closely correlated with the expression of EMT markers, determined by Western blots and Matrigel-coated transwells assay. Pterostilbene inhibited the migratory and invasive potential of triple-negative MDA-MB-231 and Hs578t cells, accompanied by the up-regulation of E-cadherin and down-regulation of Snail, Slug, vimentin and ZEB1. Mechanistic investigations revealed a significant up-regulation of miR-205, which resulted in the reduction of Src expression in pterostilbene-treated breast cancer cells. Importantly, pterostilbene suppressed tumor growth and metastasis in MDA-MB-231-bearing NOD/SCID mice by reducing Src/Fak signaling; this observation was consistent with the negative correlations between miR-205 and Src expression in both normal and malignant breast tissues. Our findings provide supports for the usage of pterostilbene as an inhibitor of EMT process and potential candidate for adjuvant therapy.

  4. Large-angle production of charged pions with incident pion beams on nuclear targets

    CERN Document Server

    Apollonio, M.; Bagulya, A.; Barr, G.; Blondel, A.; Bobisut, F.; Bogomilov, M.; Bonesini, M.; Booth, C.; Borghi, S.; Bunyatov, S.; Burguet-Castell, J.; Catanesi, M.G.; Cervera-Villanueva, A.; Chimenti, P.; Coney, L.; Di Capua, E.; Dore, U.; Dumarchez, J.; Edgecock, R.; Ellis, M.; Ferri, F.; Gastaldi, U.; Giani, S.; Giannini, G.; Gibin, D.; Gilardoni, S.; Gorbunov, P.; Gossling, C.; Gomez-Cadenas, J.J.; Grant, A.; Graulich, J.S.; Gregoire, G.; Grichine, V.; Grossheim, A.; Guglielmi, A.; Howlett, L.; Ivanchenko, A.; Ivanchenko, V.; Kayis-Topaksu, A.; Kirsanov, M.; Kolev, D.; Krasnoperov, A.; Martin-Albo, J.; Meurer, C.; Mezzetto, M.; Mills, G.B.; Morone, M.C.; Novella, P.; Orestano, D.; Palladino, V.; Panman, J.; Papadopoulos, I.; Pastore, F.; Piperov, S.; Polukhina, N.; Popov, B.; Prior, G.; Radicioni, E.; Schmitz, D.; Schroeter, R.; Skoro, G.; Sorel, M.; Tcherniaev, E.; Temnikov, P.; Tereschenko, V.; Tonazzo, A.; Tortora, L.; Tsenov, R.; Tsukerman, I.; Vidal-Sitjes, G.; Wiebusch, C.; Zucchelli, P.

    2009-01-01

    Measurements of the double-differential pi+/- production cross-section in the range of momentum 100 MeV/c <= p <= 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad using pi+/- beams incident on beryllium, aluminium, carbon, copper, tin, tantalum and lead targets are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. The secondary pions were produced by beams in a momentum range from 3 GeV/c to 12.9 GeV/c hitting a solid target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross-sections d2sigma/dpdtheta at six incident beam momenta. Data at 3 GeV/c, 5 GeV/c, 8 GeV/c, and 12 GeV/c are available for all targets while additional data at 8.9 GeV/...

  5. Large-angle production of charged pions with incident pion beams on nuclear targets

    CERN Document Server

    Apollonio, M; Bagulya, A; Barr, G; Blondel, A; Bobisut, F; Bogomilov, M; Bonesini, M; Booth, C; Borghi, S; Bunyatov, S; Burguet-Castell, J; Catanesi, M G; Cervera-Villanueva, A; Chimenti, P; Coney, L; Di Capua, E; Dore, U; Dumarchez, J; Edgecock, R; Ellis, M; Ferri, F; Gastaldi, U; Giani, S; Giannini, G; Gibin, D; Gilardoni, S; Gorbunov, P; Gößling, C; Gómez-Cadenas, J J; Grant, A; Graulich, J S; Grégoire, G; Grichine, V; Grossheim, A; Guglielmi, A; Howlett, L; Ivanchenko, A; Ivanchenko, V; Kayis-Topaksu, A; Kirsanov, M; Kolev, D; Krasnoperov, A; MartíinAlbo, J; Meurer, C; Mezzetto, M; B Mills, G; Morone, M C; Novella, P; Orestano, D; Palladino, V; Panman, J; Papadopoulos, I; Pastore, F; Piperov, S; Polukhina, N; Popov, B; Prior, G; Radicioni, E; Schmitz, D; Schroeter, R; Skoro, G; Sorel, M; Tcherniaev, E; Temnikov, P; Tereschenko, V; Tonazzo, A; Tortora, L; Tsenov, R; Tsukerman, I; Vidal-Sitjes, G; Wiebusch, C; Zucchelli, P

    2009-01-01

    Measurements of the double-differential pi+/- production cross-section in the range of momentum 100 MeV/c <= p <= 800 MeV/c and angle 0.35 rad <= theta <= 2.15 rad using pi+/- beams incident on beryllium, aluminium, carbon, copper, tin, tantalum and lead targets are presented. The data were taken with the large acceptance HARP detector in the T9 beam line of the CERN PS. The secondary pions were produced by beams in a momentum range from 3 GeV/c to 12.9 GeV/c hitting a solid target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber (TPC) placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross-sections d2sigma/dpdtheta at six incident beam momenta. Data at 3 GeV/c, 5 GeV/c, 8 GeV/c, and 12 GeV/c are available for all targets while additional data at 8.9 GeV/...

  6. Double radiative pion capture on hydrogen and deuterium and the nucleon's pion cloud

    CERN Document Server

    Tripathi, S; Christy, M E; Clark, J H D; Gorringe, T P; Hasinoff, M D; Kovash, M A; Wright, D H; Zolnierczuk, P A

    2007-01-01

    We report measurements of double radiative capture in pionic hydrogen and pionic deuterium. The measurements were performed with the RMC spectrometer at the TRIUMF cyclotron by recording photon pairs from pion stops in liquid hydrogen and deuterium targets. We obtained absolute branching ratios of $(3.02 \\pm 0.27 (stat.) \\pm 0.31 (syst.)) \\times 10^{-5}$ for hydrogen and $(1.42 \\pm ^{0.09}_{0.12} (stat.) \\pm 0.11 (syst.)) \\times 10^{-5}$ for deuterium, and relative branching ratios of double radiative capture to single radiative capture of $(7.68 \\pm 0.69(stat.) \\pm 0.79(syst.)) \\times 10^{-5}$ for hydrogen and $(5.44 \\pm^{0.34}_{0.46}(stat.) \\pm 0.42(syst.)) \\times 10^{-5}$ for deuterium. For hydrogen, the measured branching ratio and photon energy-angle distributions are in fair agreement with a reaction mechanism involving the annihilation of the incident $\\pi^-$ on the $\\pi^+$ cloud of the target proton. For deuterium, the measured branching ratio and energy-angle distributions are qualitatively consisten...

  7. Negative Ion CID Fragmentation of O-linked Oligosaccharide Aldoses—Charge Induced and Charge Remote Fragmentation

    Science.gov (United States)

    Doohan, Roisin A.; Hayes, Catherine A.; Harhen, Brendan; Karlsson, Niclas Göran

    2011-06-01

    Collision induced dissociation (CID) fragmentation was compared between reducing and reduced sulfated, sialylated, and neutral O-linked oligosaccharides. It was found that fragmentation of the [M - H]- ions of aldoses with acidic residues gave unique Z-fragmentation of the reducing end GalNAc containing the acidic C-6 branch, where the entire C-3 branch was lost. This fragmentation pathway, which is not seen in the alditols, showed that the process involved charge remote fragmentation catalyzed by a reducing end acidic anomeric proton. With structures containing sialic acid on both the C-3 and C-6 branch, the [M - H]- ions were dominated by the loss of sialic acid. This fragmentation pathway was also pronounced in the [M - 2H]2- ions revealing both the C-6 Z-fragment plus its complementary C-3 C-fragment in addition to glycosidic and cross ring fragmentation. This generation of the Z/C-fragment pairs from GalNAc showed that the charges were not participating in their generation. Fragmentation of neutral aldoses showed pronounced Z-fragmentation believed to be generated by proton migration from the C-6 branch to the negatively charged GalNAc residue followed by charge remote fragmentation similar to the acidic oligosaccharides. In addition, A-type fragments generated by charge induced fragmentation of neutral oligosaccharides were observed when the charge migrated from C-1 of the GalNAc to the GlcNAc residue followed by rearrangement to accommodate the 0,2A-fragmentation. LC-MS also showed that O-linked aldoses existed as interchangeable α/β pyranose anomers, in addition to a third isomer (25% of the total free aldose) believed to be the furanose form.

  8. Orphan nuclear receptor NR4A1 is a negative regulator of DHT-induced rat preantral follicular growth.

    Science.gov (United States)

    Xue, Kai; Liu, Jia-yin; Murphy, Bruce D; Tsang, Benjamin K

    2012-12-01

    Nuclear receptor subfamily 4 group A member1 (NR4A1), an orphan nuclear receptor, is involved in the transcriptional regulation of thecal cell androgen biosynthesis and paracrine factor insulin-like 3 (INSL3) expression. Androgens are known to play an important regulatory role in ovarian follicle growth. Using a chronically androgenized rat model, a preantral follicle culture model and virus-mediated gene delivery, we examined the role and regulation of NR4A1 in the androgenic control of preantral follicular growth. In the present study, Ki67 staining was increased in preantral follicles on ovarian sections from 5α-dihydrotestosterone (DHT)-treated rats. Preantral follicles from DHT-treated rats cultured for 4 d exhibited increased growth and up-regulation of mRNA abundance of G(1)/S-specific cyclin-D2 (Ccnd2) and FSH receptor (Fshr). Similarly, DHT (1 μm) increased preantral follicular growth and Ccnd2 and Fshr mRNA abundance in vitro. The NR4A1 expression was high in theca cells and was down-regulated by DHT in vivo and in vitro. Forced expression of NR4A1 augmented preantral follicular growth, androstenedione production, and Insl3 expression in vitro. Inhibiting the action of androgen (with androgen receptor antagonist flutamide) or INSL3 (with INSL3 receptor antagonist INSL3 B-chain) reduced NR4A1-induced preantral follicular growth. Furthermore, NR4A1 overexpression enhanced DHT-induced preantral follicular growth, a response attenuated by inhibiting INSL3. In conclusion, DHT promotes preantral follicular growth and attenuates thecal NR4A1 expression in vivo and in vitro. Our findings are consistent with the notion that NR4A1 serves as an important point of negative feedback to minimize the excessive preantral follicle growth in hyperandrogenism.

  9. Impact of lower body negative pressure induced hypovolemia on peripheral venous pressure waveform parameters in healthy volunteers.

    Science.gov (United States)

    Alian, Aymen A; Galante, Nicholas J; Stachenfeld, Nina S; Silverman, David G; Shelley, Kirk H

    2014-07-01

    Lower body negative pressure (LBNP) creates a reversible hypovolemia by sequestrating blood volume in the lower extremities. This study sought to examine the impact of central hypovolemia on peripheral venous pressure (PVP) waveforms in spontaneously breathing subjects. With IRB approval, 11 healthy subjects underwent progressive LBNP (baseline, -30, -75, and -90 mmHg or until the subject became symptomatic). Each was monitored for heart rate (HR), finger arterial blood pressure (BP), a chest respiratory band and PVP waveforms which are generated from a transduced upper extremity intravenous site. The first subject was excluded from PVP analysis because of technical errors in collecting the venous pressure waveform. PVP waveforms were analyzed to determine venous pulse pressure, mean venous pressure, pulse width, maximum and minimum slope (time domain analysis) together with cardiac and respiratory modulations (frequency domain analysis). No changes of significance were found in the arterial BP values at -30 mmHg LBNP, while there were significant reductions in the PVP waveforms time domain parameters (except for 50% width of the respiration induced modulations) together with modulation of the PVP waveform at the cardiac frequency but not at the respiratory frequency. As the LBNP progressed, arterial systolic BP, mean BP and pulse pressure, PVP parameters and PVP cardiac modulation decreased significantly, while diastolic BP and HR increased significantly. Changes in hemodynamic and PVP waveform parameters reached a maximum during the symptomatic phase. During the recovery phase, there was a significant reduction in HR together with a significant increase in HR variability, mean PVP and PVP cardiac modulation. Thus, in response to mild hypovolemia induced by LBNP, changes in cardiac modulation and other PVP waveform parameters identified hypovolemia before detectable hemodynamic changes.

  10. Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). 2. Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Akopov, N. [Yerevan Physics Institute (Argentina); Akopov, Z. [DESY Hamburg (Germany)] [and others; Collaboration: HERMES Collaboration

    2013-10-15

    Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle {psi} about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum P{sub T} relative to the direction of the incident beam, and the Feynman variable x{sub F}. The sin {psi} amplitudes are positive for {pi}{sup +} and K{sup +}, slightly negative for {pi}{sup -} consistent with zero for K{sup -}, with particular P{sub T} but weak x{sub F} dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer.

  11. A study of transverse charge density of pions in relativistic quantum mechanics%A study of transverse charge density of pions in relativistic quantum mechanics

    Institute of Scientific and Technical Information of China (English)

    董宇兵; 王翼展

    2011-01-01

    The transverse charge density of pions is calculated based on relativistic quantum mechanics, where the pion is regarded as a quark-antiquark bound state. Corrections from the two spin-1/2 constituents and from the wave function of a quark and antiquark i

  12. Fragmentation study of iridoid glucosides through positive and negative electrospray ionization, collision-induced dissociation and tandem mass spectrometry.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Kerhoas, Lucien; Ducrot, Paul-Henri

    2007-01-01

    Mass spectrometric methodology based on the combined use of positive and negative electrospray ionization, collision-induced dissociation (CID) and tandem mass spectrometry (MS/MS) has been applied to the mass spectral study of a series of six naturally occurring iridoids through in-source fragmentation of the protonated [M+H]+, deprotonated [M--H]- and sodiated [M+Na]+ ions. This led to the unambiguous determination of the molecular masses of the studied compounds and allowed CID spectra of the molecular ions to be obtained. Valuable structural information regarding the nature of both the glycoside and the aglycone moiety was thus obtained. Glycosidic cleavage and ring cleavages of both aglycone and sugar moieties were the major fragmentation pathways observed during CID, where the losses of small molecules, the cinnamoyl and the cinnamate parts were also observed. The formation of the ionized aglycones, sugars and their product ions was thus obtained giving information on their basic skeleton. The protonated, i.e. [M+H]+ and deprotonated [M--H]-, ions were found to fragment mainly by glycosidic cleavages. MS/MS spectra of the [M+Na]+ ions gave complementary information for the structural characterization of the studied compounds. Unlike the dissociation of protonated molecular ions, that of sodiated molecules also provided sodiated sugar fragments where the C0+ fragment corresponding to the glucose ion was obtained as base peak for all the studied compounds.

  13. Identification of a novel human MD-2 splice variant that negatively regulates Lipopolysaccharide-induced TLR4 signaling.

    Science.gov (United States)

    Gray, Pearl; Michelsen, Kathrin S; Sirois, Cherilyn M; Lowe, Emily; Shimada, Kenichi; Crother, Timothy R; Chen, Shuang; Brikos, Constantinos; Bulut, Yonca; Latz, Eicke; Underhill, David; Arditi, Moshe

    2010-06-01

    Myeloid differentiation factor 2 (MD-2) is a secreted gp that assembles with TLR4 to form a functional signaling receptor for bacterial LPS. In this study, we have identified a novel alternatively spliced isoform of human MD-2, termed MD-2 short (MD-2s), which lacks the region encoded by exon 2 of the MD-2 gene. Similar to MD-2, MD-2s is glycosylated and secreted. MD-2s also interacted with LPS and TLR4, but failed to mediate LPS-induced NF-kappaB activation and IL-8 production. We show that MD-2s is upregulated upon IFN-gamma, IL-6, and TLR4 stimulation and negatively regulates LPS-mediated TLR4 signaling. Furthermore, MD-2s competitively inhibited binding of MD-2 to TLR4. Our study pinpoints a mechanism that may be used to regulate TLR4 activation at the onset of signaling and identifies MD-2s as a potential therapeutic candidate to treat human diseases characterized by an overly exuberant or chronic immune response to LPS.

  14. Down-regulation of hypoxia-inducible factor-1 suppresses malignant biological behavior of triple-negative breast cancer cells.

    Science.gov (United States)

    Wang, Fang; Chang, Miaomiao; Shi, Yonghong; Jiang, Lili; Zhao, Jing; Hai, Ling; Sharen, Gaowa; Du, Hua

    2014-01-01

    This study is to investigate the effect and mechanism of reduced hypoxia-inducible factor (HIF)-1a expression on malignant behavior of MDA-MB-231 cells. HIF-1α expression was interfered by siRNA. Western blot was used to detect protein expression of HIF-1α, active fragments of caspase 3 and vimentin. Cell count, flow cytometry and Hoechst staining were used to evaluate cell growth and apoptosis. Matrigel invasion and wound scratch assay were performed to measure the ability of cell invasion and migration. After MDA-MB-231 cells were transfected with HIF-1α-targeted siRNA, HIF-1α protein expression was successfully interrupted and cell growth was retarded. Compared with random siRNA group, reduced HIF-1α protein expression in HIF-1α-targeted siRNA group facilitated cell apoptosis but had no effect on cell cycle. In addition, cells treated with HIF-1α-targeted siRNA expressed active fragments of caspase 3 (17 and 12 kD) after serum starvation for 0 to 60 h. Caspase 3 activity assay further confirmed the above finding. Reduced HIF-1α expression impaired the migration and invasiveness with a reduction in the expression of vimentin and CK18 protein. Inhibition of HIF-1α protein synthesis or enhancement of its degradation reversed its malignant phenotypes and could probably be a potential means for the treatment of triple-negative breast cancer.

  15. A precise method for the detection of the two photons from the neutral pion decay in hypernuclear spectroscopy

    CERN Document Server

    Petkovic, T

    2003-01-01

    An experimental technique for the light lambda-hypernuclei structure studies by using (negative kaon, neutral pion) reaction and Neutral Meson Spectrometer (NMS) developed at the BNL has been described. Position dependence calibration of the BGO conversion planes of the NMS was invented as the solution to the crucial constraint of the high resolution in single-lambda spectroscopy. Position parameters of the BGO crystal rods were fitted out from the out-of-kaon beam measured data as obtained by the original small highly collimated Co-60 source method, based on the coincidences between top and bottom signals of each BGO rod.

  16. Adipose tissue remodeling in late-lactation dairy cows during feed-restriction-induced negative energy balance.

    Science.gov (United States)

    Contreras, G Andres; Thelen, Kyan; Schmidt, Sarah E; Strieder-Barboza, Clarissa; Preseault, Courtney L; Raphael, William; Kiupel, Matti; Caron, John; Lock, Adam L

    2016-12-01

    Excessive rates of demand lipolysis in the adipose tissue (AT) during periods of negative energy balance (NEB) are associated with increased susceptibility to disease and limited lactation performance. Lipolysis induces a remodeling process within AT that is characterized by an inflammatory response, cellular proliferation, and changes in the extracellular matrix (ECMT). The adipose tissue macrophage (ATM) is a key component of the inflammatory response. Infiltration of ATM-forming cellular aggregates was demonstrated in transition cows, suggesting that ATM trafficking and phenotype changes may be associated with disease. However, it is currently unknown if ATM infiltration occurs in dairy cows only during NEB states related to the transition period or also during NEB-induced lipolysis at other stages of lactation. The objective of this study was to evaluate changes in ATM trafficking and inflammatory phenotypes, and the expression of genetic markers of AT remodeling in healthy late-lactation cows during feed restriction-induced NEB. After a 14-d (d -14 to d -1) preliminary period, Holstein cows were randomly assigned to 1 of 2 feeding protocols, ad libitum (AL) or feed restriction (FR), for 4 d (d 1-4). Caloric intake was reduced in FR to achieve a targeted energy balance of -15 Mcal/d of net energy for lactation. Omental and subcutaneous AT samples were collected laparoscopically to harvest stromal vascular fraction (SVF) cells on d -3 and 4. The FR induced a NEB of -14.1±0.62 Mcal/d of net energy for lactation, whereas AL cows remained in positive energy balance (3.2±0.66 Mcal/d of NEL). The FR triggered a lipolytic response reflected in increased plasma nonesterified fatty acids (0.65±0.05 mEq/L on d 4), enhanced phosphorylation of hormone sensitive lipase, and reduced adipocyte diameter. Flow cytometry and immunohistochemistry analysis revealed that on d 4, FR cows had increased numbers of CD172a(+), an ATM (M1 and M2) surface marker, cells in SVF that were

  17. Charged pion anisotropy in relativistic nucleus-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Poitou, J.; L' Hote, D.; Cavata, C.; Babinet, R.; Demoulins, M.; Fanet, H.; Gosset, J.; Lemaire, M.C.; Le Merdy, A.; Lucas, B.; Terrien, Y.; Valette, O. (CEN Saclay, 91 - Gif-sur-Yvette (France)); Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Dupieux, P.; Fraysse, L.; Marroncle, J.; Montarou, G.; Parizet, M.J.; Rahmani, A. (LPC Clermont-Ferrand, 63 - Aubiere (France)); Brochard, F.; Gorodetzky, P.; Racca, C. (CRN, 67 - Strasbourg (France))

    1992-01-27

    The momentum distributions with respect to the reaction plane for charged pions emitted in Ne-nucleus and Ar-nucleus collisions have been measured with the 4{pi} detector Diogene at the Saturne synchrotron. The reaction plane is estimated from the baryon momenta, using a standard technique for flow analysis. The pions exhibit a non-zero flow. For asymmetric systems, there is a preferential emission in the direction of the lighter (projectile) nucleus. Such a behaviour contradicts the predictions of INC calculations and is underestimated by QMD calculations which include mean field effects. It can be interpreted with a simple geometrical model in terms of absorption by the spectator nuclear matter. (orig.).

  18. Charm Physics with Domain Wall Fermions and Physical Pion Masses

    CERN Document Server

    Boyle, Peter; Jüttner, Andreas; Khamseh, Ava; Sanfilippo, Francesco; Tsang, Justus Tobias; Witzel, Oliver

    2016-01-01

    We present RBC/UKQCD's charm project using $N_f=2+1$ flavour ensembles with inverse lattice spacings in the range $1.73-2.77\\,\\mathrm{GeV}$ and two physical pion mass ensembles. Domain wall fermions are used for the light as well as the charm quarks. We discuss our strategy for the extraction of the decay constants $f_D$ and $f_{D_s}$ and their extrapolation to the continuum limit, physical pion masses and the physical heavy quark mass. Our preliminary results are $f_D=208.7(2.8)\\,\\mathrm{MeV}$ and $f_{D_s}=246.4(1.9)\\,\\mathrm{MeV}$ where the quoted error is statistical only. We outline our current approach to extend the reach in the heavy quark mass and present preliminary results.

  19. Pion Form Factor in QCD at Intermediate Momentum Transfers

    CERN Document Server

    Braun, V M; Maul, M

    1999-01-01

    We present a quantitative analysis of the electromagnetic pion form factor in the light-cone sum rule approach, including radiative corrections and higher-twist effects. The comparison to the existing data favors the asymptotic profile of the pion distribution amplitude and allows to estimate the deviation: $(\\int du/u \\phi_\\pi(u))/ (\\int du/u \\phi^{\\rm as}_\\pi(u))=$ 1.1$\\pm$ 0.1 at the scale 1 GeV. Special attention is payed to the precise definition and interplay of soft and hard contributions at intermediate momentum transfer, and to matching of the sum rule to the perturbative QCD prediction. We observe a strong numerical cancellation between the soft (end point) contribution and power suppressed hard contributions of higher twist, so that the total nonperturbative correction to the usual pQCD result turns out to be of order 30% for $Q^2\\sim 1$ GeV$^2$.

  20. Pion Electroproduction form Helium 3, Deuterium, and Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    S. Avery

    2002-05-01

    A series of measurements for pion electroproduction from helium-3, deuterium, and hydrogen were completed at the Thomas Jefferson National Accelerator Facility by the NucPi Collaboration. E91003 began taking data in February 1998 and was completed in April 1998. The longitudinal and transverse parts of the differential cross section were extracted, by means of a Rosenbluth type separation, in the direction parallel to the virtual photon, at Q 2 = 0.4 GeV 2 , for W = 1.15 and W = 1.6 GeV. The mass dependence of the longitudinal cross section should provide insight into the surprising apparent absence of any significant cross section enhancement due to excess pions in the nuclear medium.