The inclusive double-spin asymmetry, MathML equation, has been measured at COMPASS in deep-inelastic polarised muon scattering off a large polarised NH sub(3) target. The data, collected in the year ...2007, cover the range MathML equation, 0.004<x<0.7 and improve the statistical precision of MathML equation by a factor of two in the region x<0.02. The new proton asymmetries are combined with those previously published for the deuteron to extract the non-singlet spin-dependent structure function MathML equation. The isovector quark density, Delta q sub(3)(x,Q super(2)), is evaluated from a NLO QCD fit of MathML equation. The first moment of Delta q sub(3) is in good agreement with the value predicted by the Bjorken sum rule and corresponds to a ratio of the axial and vector coupling constants MathML equation.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A model-dependent amplitude analysis of the decay B 0arrow rightD(K S 0 pi + pi -)K 0 is performed using ...proton-proton collision data corresponding to an integrated luminosity of 3.0 fb-1, recorded at ... and 8 TeV by the LHCb experiment. The CP violation observables x ± and y ±, sensitive to the CKM angle γ, are measured to be ... where the first uncertainties are statistical, the second systematic and the third arise from the uncertainty on the Darrow rightK S 0 pi + pi - amplitude model. These are the most precise measurements of these observables. They correspond to γ=(80 -22 +21 )° and ..., where ... is the magnitude of the ratio of the suppressed and favoured B 0 arrow right DK + pi - decay amplitudes, in a Kpi mass region of ±50 MeV around the K *(892)0 mass and for an absolute value of the cosine of the K *0 decay angle larger than 0.4. Figure not available: see fulltext.
Reconstruction of the image in Positron Emission Tomographs (PET) requires the knowledge of the system response kernel which describes the contribution of each pixel (voxel) to each tube of response ...(TOR). This is especially important in list-mode reconstruction systems, where an efficient analytical approximation of such function is required. In this contribution, we present a derivation of the system response kernel for a novel 2D strip PET.
Compressive Sensing theory says that it is possible to reconstruct a measured signal if an enough sparse representation of this signal exists in comparison to the number of random measurements. This ...theory was applied to reconstruct signals from measurements of plastic scintillators. Sparse representation of obtained signals was found using SVD transform.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A binned Dalitz plot analysis of the decays B 0 arrow right DK 0, with Darrow rightK S 0 pi + pi - and Darrow ...rightK S 0 K + K -, is performed to measure the observables x ± and y ±, which are related to the CKM angle γ and the hadronic parameters of the decays. The D decay strong phase variation over the Dalitz plot is taken from measurements performed at the CLEO-c experiment, making the analysis independent of the D decay model. With a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb -1, collected by the LHCb experiment, the values of the CP violation parameters are found to be x + = 0.05 ± 0.35 ± 0.02, x - = -0.31 ± 0.20 ± 0.04, y + = -0.81 ± 0.28 ± 0.06 and y - = 0.31 ± 0.21 ± 0.05, where the first uncertainties are statistical and the second systematic. These observables correspond to values γ = (71 ± 20)°, ... and ... The parameters ... and ... are the magnitude ratio and strong phase difference between the suppressed and favoured B 0 decay amplitudes, and have been measured in a region of ±50 MeV/c 2 around the K (892)0 mass and with the magnitude of the cosine of the K (892)0 helicity angle larger than 0.4. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract We perform a search for near-threshold Xi b 0 resonances decaying to Xi b - pi + in a sample of proton-proton ...collision data corresponding to an integrated luminosity of 3 fb-1 collected by the LHCb experiment. We observe one resonant state, with the following properties: ... This confirms the previous observation by the CMS collaboration. The state is consistent with the J P=3/2+ Xi b 0 resonance expected in the quark model. This is the most precise determination of the mass and the first measurement of the natural width of this state. We have also measured the ratio ...Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract The decays Lambda b 0 arrow rightpsi(2S)pK- and Lambda b 0 arrow rightJ/ψπ + pi -pK- are observed in a data sample ...corresponding to an integrated luminosity of 3 fb-1, collected in proton-proton collisions at 7 and 8 TeV centre-of-mass energies by the LHCb detector. The psi(2S) mesons are reconstructed through the decay modes psi(2S) arrow right mu+mu- and psi(2S) arrow right J/psipi + pi -. The branching fractions relative to that of Lambda b 0 arrow rightJ/psipK- are measured to be ... where the first uncertainties are statistical, the second are systematic and the third is related to the knowledge of J/psi and psi(2S) branching fractions. The mass of the Lambda b 0 baryon is measured to be ... where the uncertainties are statistical and systematic. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract The production of psi(2S) mesons is studied in dimuon final states using proton-lead (pPb) collision data ...collected by the LHCb detector. The data sample corresponds to an integrated luminosity of 1.6 nb-1. The nucleon-nucleon centre-of-mass energy of the pPb collisions is ... TeV. The measurement is performed using psi(2S) mesons with transverse momentum less than 14 GeV/c and rapidity y in the ranges 1.5 < y < 4.0 and -5.0 < y < -2.5 in the nucleon-nucleon centre-of-mass system. The forward-backward production ratio and the nuclear modification factor are determined for psi(2S) mesons. Using the production cross-section results of psi(2S) and J/psi mesons from b-hadron decays, the ... cross-section in pPb collisions at ... TeV is obtained. Figure not available: see fulltext.
The decay asymmetries of the weak radiative hyperon decays
Ξ
0
→
Λ
γ
and
Ξ
0
→
Σ
0
γ
have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52 000
Ξ
0
→
Λ
γ
...and 15 000
Ξ
0
→
Σ
0
γ
decays, we obtain for the decay asymmetries
α
Ξ
0
→
Λ
γ
=
−
0.704
±
0.019
stat
±
0.064
syst
and
α
Ξ
0
→
Σ
0
γ
=
−
0.729
±
0.030
stat
±
0.076
syst
, respectively. These results are in good agreement with previous experiments, but more precise.
Abstract A search is performed for D ^sub sJ^^sup (*)+^ mesons in the reactions pparrow rightD ^sup +^ K ^sub S^^sup 0^ X and pp arrow right D ^sup *0^ K ^sup +^ X using data collected at ...centre-of-mass energies of 7 and 8 TeV with the LHCb detector. For the D ^sup +^ K ^sub S^^sup 0^ final state, the decays D ^sup *+^ arrow right D ^sup 0^ pi ^sup +^ with D ^sup 0^ arrow right K ^sup -^ pi ^sup +^ and D ^sup 0^ arrow right K ^sup -^ pi ^sup +^ pi ^sup +^ pi ^sup -^ are used. For D ^sup *0^ K ^sup +^, the decay D ^sup *0^ arrow right D ^sup 0^ pi ^sup 0^ with D ^sup 0^ arrow right K ^sup -^ pi ^sup +^ is used. A prominent D ^sub s1^(2536)^sup +^ signal is observed in both D ^sup +^ K ^sub S^^sup 0^ and D ^sup *0^ K ^sup +^ final states. The resonances D ^sub s1^^sup *^(2700)^sup +^ and D ^sub s3^^sup *^(2860)^sup +^ are also observed, yielding information on their properties, including spin-parity assignments. The decay D ^sub s2^^sup *^(2573)^sup +^arrow rightD ^sup +^ K ^sub S^^sup 0^ is observed for the first time, at a significance of 6.9 sigma, and its branching fraction relative to the D ^sub s2^^sup *^(2573)^sup +^arrow rightD ^sup +^ K ^sub S^^sup 0^ decay mode is measured. Figure not available: see fulltext.
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