79 research outputs found
Study of the lineshape of the chi(c1) (3872) state
A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations
Measurement of the CKM angle in and decays with
A measurement of -violating observables is performed using the decays
and , where the meson is
reconstructed in one of the self-conjugate three-body final states and (commonly denoted ). The decays are analysed in bins of the -decay phase space, leading
to a measurement that is independent of the modelling of the -decay
amplitude. The observables are interpreted in terms of the CKM angle .
Using a data sample corresponding to an integrated luminosity of
collected in proton-proton collisions at centre-of-mass
energies of , , and with the LHCb experiment,
is measured to be . The hadronic
parameters , , , and ,
which are the ratios and strong-phase differences of the suppressed and
favoured decays, are also reported
Study of the doubly charmed tetraquark T+cc
Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed
Cultivation systems for straw incorporation on clay soils, 1985-1986
SIGLEAvailable from British Library Document Supply Centre- DSC:3604.9221(AFRC-IER-DN--1450) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Genotypic and environmental variation in barley limit dextrinase activity and its relation to malt quality
Variation in the limit dextrinase activity of barley malt, and the relationships between limit dextrinase activity and malt quality parameters were investigated using eight cultivars grown at seven diverse locations in China for two successive years. Limit dextrinase activity varied with genotype and location, with the levels ranging from 0.245 U/g to 0.980 U/g. The results showed that the variation in limit dextrinase activity was more attributable to the environment (location and year) than to the genotype. The response of limit dextrinase activity to the environment differed markedly among cultivars, and was reflected by large difference in coefficient of variation of cultivars across diverse locations. Regression analysis showed that limit dextrinase activity was negatively correlated with malt viscosity (r=−0.52, P<0.01), positively correlated with Kolbach index (r=0.38, P<0.01) and malt extract (r=0.30, P<0.05), but had no significant correlation with malt protein content and diastatic power
Gamma expansion of the Heston stochastic volatility model
Stochastic volatility model, Monte Carlo methods, 60H35, 65C05, 91B70, C63, G12, G13,
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