77,197 research outputs found
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Prompt charm production in pp collisions at √<span style="text-decoration:overline">s</span>=7 TeV
No full textCharm production at the LHC in pp collisions at s√=7 TeV is studied with the LHCb detector. The decays D0→K−π+, D+→K−π+π+, D⁎+→D0(K−π+)π+, D+s→ϕ(K−K+)π+, Λ+c→pK−π+, and their charge conjugates are analysed in a data set corresponding to an integrated luminosity of 15 nb−1. Differential cross-sections dσ/dpT are measured for prompt production of the five charmed hadron species in bins of transverse momentum and rapidity in the region 0<pT<8 GeV/c and 2.0<y<4.5. Theoretical predictions are compared to the measured differential cross-sections. The integrated cross-sections of the charm hadrons are computed in the above pT-y range, and their ratios are reported. A combination of the five integrated cross-section measurements gives
σ(cc¯)pT<8 GeV/c,2.0<y<4.5=1419±12(stat)±116(syst)±65(frag) μb,
where the uncertainties are statistical, systematic, and due to the fragmentation functions
Seed source and region effects on growth rate and survival of blue spruce (Picea pungens) Christmas trees in New Jersey
No full textSeedlings from five different seed sources of blue spruce Christmas trees were planted at five sites throughout New Jersey. Two sites in northern New Jersey and one in central New Jersey had significantly higher survival rates than the two in southern New Jersey. Additionally, the two sites in northern New Jersey had significantly faster growth rates than those in southern and central New Jersey. There were no significant differences in survival rates between seed sources. In terms of growth rates, however, seedlings from seeds obtained in Santa Fe National Forest, New Mexico grew significantly faster than seedlings from the other seed sources tested. This forther growth rate is predicted to shorten the time needed to reach marketability size by one to five years
Measurement of the inclusive φ cross-section in pp collisions at √s=7 TeV
No full textThe cross-section for inclusive φ meson production in pp collisions at a centre-of-mass energy of √s = 7 TeV has been measured with the LHCb detector at the Large Hadron Collider. The differential cross-section is measured as a function of the φ transverse momentum pT and rapidity y in the region 0.6< pT <5.0 GeV/c and 2.44< y <4.06. The cross-section for inclusive φ production in this kinematic range is σ(pp→φX)=1758±19(stat) +43−14(syst)±182(scale) μb, where the first systematic uncertainty depends on the pT and y region and the second is related to the overall scale. Predictions based on the Pythia 6.4 generator underestimate the cross-section
Elliptic Problems With L1-data In The Half-space
No full textIn this paper, we study the div-curl-grad operators and some el- liptic problems in the half-space Rn +, with n 2. We consider data in weighted Sobolev spaces and in L1.53369397Adams, R.A., Fournier, J.J., (2003) Sobolev Spaces," Second Edition, Pure and Applied Math- Ematics (Amsterdam), p. 140. , Elsevier/Academic Press, AmsterdamAmrouche, C., The Neumann problem in the half-space (2002) Comptes Rendus Mathematique, 335 (2), pp. 151-156. , DOI 10.1016/S1631-073X(02)02428-7, PII S1631073X02024287Amrouche, C., Girault, V., Giroire, J., Weighted Sobolev spaces for Laplace's equation in Rn (1994) Journal de Mathematiques Pures et Appliquees (9), 73, pp. 579-606Amrouche, C., Girault, V., Giroire, J., Dirichlet and Neumann exterior problems for the n-dimensional Laplace operator an approach in weighted Sobolev spaces (1997) Journal des Mathematiques Pures et Appliquees, 76 (1), pp. 55-81Amrouche, C., Necasova, S., Laplace equation in the half-space with a nonhomogeneous Dirichlet boundary condition (2001) Proceedings of Partial Differential Equations and Applications (Olomouc, 1999), Mathematica Bohemica, 126, pp. 265-274Amrouche, C., Necasova, S., Raudin, Y., Very weak, generalized and strong solutions to the Stokes system in the half-space (2008) Journal of Differential Equations, 244, pp. 887-915Amrouche, C., Necasova, S., Raudin, Y., From strong to very weak solutions to the Stokes system with Navier boundary conditions in the half-space (2009) SIAM J. Math. Anal., 41, pp. 1792-1815Bourgain, J., Brezis, H., On the equation div Y = f and application to control of phases (2003) Journal of the American Mathematical Society, 16 (2), pp. 393-426. , DOI 10.1090/S0894-0347-02-00411-3Bourgain, J., Brezis, H., New estimates for elliptic equations and Hodge type systems (2007) Journal of the European Mathematical Society, 9, pp. 277-315Bourgain, J., Brezis, H., Sur l'equation div u = f (2002) Comptes Rendus de l'Academie des Sciences de Paris, 334, pp. 973-976Bourgain, J., Brezis, H., New estimates for the Laplacian, the div-curl, and related Hodge systems (2004) Comptes Rendus Mathematique, 338 (7), pp. 539-543. , DOI 10.1016/j.crma.2003.12.031, PII S1631073X04000329Brezis, H., Van Schaftingen, J., Boundary extimates for elliptic systems with L1-data (2007) Calculus of Variations and Partial Differential Equations, 30, pp. 369-388Deny, J., Lions, J.L., Les espaces du type de Beppo Levi (1953) Annales de l'Institut Fourier, Grenoble, 5, pp. 305-370Girault, V., The gradient, divergence, curl and Stokes operators in weighted Sobolev spaces of R3 (1992) Journal of the Faculty of Science, 39, pp. 279-307. , The University of Tokyo, Sect. IA MathHanouzet, B., Espaces de Sobolev avec poids application au probleme de Dirichlet dans un demi espace (1971) Rendiconti Del Seminario Matematico della Universite di Padova, 46, pp. 227-272Van Schaftingen, J., Estimates for L1-vector elds (2004) Comptes Rendus de l'Academie des Sci- Ences de Paris, 339, pp. 181-18
Review of “St. Clive:” An Eastern Orthodox Author Looks Back at C. S. Lewis
No full textReview of C. J. S. Hayward, “St. Clive:” An Eastern Orthodox Author Looks Back at C. S. Lewis (Wheaton, Illinois: C. J. S. Hayward Publications, 2000-19). 381 pages. $49.99. ISBN 9781794669956
New Estimates For The Div-curl-grad Operators And Elliptic Problems With L1-data In The Whole Space And In The Half-space
No full textIn this paper, we study the div-curl-grad operators and some elliptic problems in the whole space Rn and in the half-space R+n, with n≥2. We consider data in weighted Sobolev spaces and in L1. © 2011 Elsevier Inc.250731503195Adams, R.A., (2003) Sobolev Spaces, , Academic Press, New YorkAlliot, F., Amrouche, C., The Stokes problem in Rn: an approach in weighted Sobolev spaces (1999) Math. Models Methods Appl. Sci., 9, pp. 723-754Amrouche, C., The Neumann problem in the half-space (2002) C. R. Acad. Sci. Paris, I 335, pp. 151-156Amrouche, C., Girault, V., Giroire, J., Weighted Sobolev spaces for the Laplace equation in Rn (1994) J. Math. Pures Appl., 73 (6), pp. 579-606Amrouche, C., Girault, V., Giroire, J., Dirichlet and Neumann exterior problems for the n-dimensional Laplace operator: an approach in weighted Sobolev spaces (1997) J. Math. Pures Appl., 76 (1), pp. 55-81Amrouche, C., Neasová, S., Laplace equation in the half-space with a nonhomogeneous Dirichlet boundary condition (2001) Math. Bohem., 126 (2), pp. 265-274Amrouche, C., Neasová, S., Raudin, Y., Very weak, generalized and strong solutions to the Stokes system in the half-space (2008) J. Differential Equations, 244, pp. 887-915Amrouche, C., Raudin, Y., From strong to very weak solutions to the Stokes system with Navier boundary conditions in the half-space (2009) SIAM J. Math. Anal., 41 (5), pp. 1792-1815Amrouche, C., Razafison, U., The stationary Oseen equations in R3. An approach in weighted Sobolev spaces (2007) J. Math. Fluids Mech., 9 (2), pp. 211-225Bourgain, J., Brézis, H., On the equation divY=f and application to control of phases (2002) J. Amer. Math. Soc., 16 (2), pp. 393-426Bourgain, J., Brézis, H., New estimates for elliptic equations and Hodge type systems (2007) J. Eur. Math. Soc. (JEMS), 9 (2), pp. 277-315Bourgain, J., Brézis, H., Sur l'équation divu=f (2002) C. R. Acad. Sci. Paris, I 334, pp. 973-976Bourgain, J., Brézis, H., New estimates for the Laplacian, the div-curl, and related Hodge systems (2003) C. R. Acad. Sci. Paris, I 338, pp. 539-543Brézis, H., (1999) Analyse fonctionnelle: Théorie et applications, , Dunod, ParisBrézis, H., Van Schaftingen, J., Boundary estimates for elliptic systems with L1-data (2007) Calc. Var. Partial Differential Equations, 30 (3), pp. 369-388Deny, J., Lions, J.L., Les espaces du type de Beppo Levi (1954) Ann. Inst. Fourier (Grenoble), 5, pp. 305-370Girault, V., The gradient, divergence, curl and Stokes operators in weighted Sobolev spaces of R3 (1992) J. Math. Sci. Univ. Tokyo (Sec. IA), 39 (2), pp. 279-307Hanouzet, B., Espaces de Sobolev avec poids application au problème de Dirichlet dans un demi espace (1971) Rend. Semin. Mat. Univ. Padova, 46, pp. 227-272Miyakawa, T., Hardy spaces of solenoidal vector fields, with applications to the Navier-Stokes equations (1996) Kyushu J. Math., 50, pp. 1-64Miyakawa, T., On L1-stability of stationary Navier-Stokes flows in Rn (1997) J. Math. Sci. Univ. Tokyo, 4, pp. 67-119Payne, L.E., Weinberger, H.F., Note on a lemma of Finn and Gilbarg (1957) Acta Math., 98, pp. 297-299Van Schaftingen, J., Estimates for L1-vector fields (2004) C. R. Acad. Sci. Paris, I 339, pp. 181-18
Observations of Bºs→ψ(2S)η and Bº(s)→ψ(2S)π+π- decays
No full textFirst observations of the B0s
→ψ(2S)η, B0 →ψ(2S)π
+
π
− and B0s
→ψ(2S)π
+
π
− decays are made
using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in
proton–proton collisions at a centre-of-mass energy of
√
s = 7 TeV. The ratios of the branching fractions
of each of the ψ(2S) modes with respect to the corresponding J/ψ decays are
B(B0s
→ψ(2S)η)
÷
B(B0s
→J/ψη)
= 0.83± 0.14 (stat)±0.12 (syst) ±0.02 (B),
;
B(B0→ψ(2S)π
+
π
−
)
÷
B(B0→J/ψπ
+
π
−
)
= 0.56± 0.07 (stat)±0.05 (syst)± 0.01 (B),
;
B(B0s
→ψ(2S)π
+
π
−
)
÷
B(B0s
→J/ψπ
+
π
−
)
= 0.34± 0.04 (stat)±0.03 (syst)± 0.01 (B),
where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the J/ψ
and ψ(2S) meson decays
APC/C and SCFcyclin F Constitute a Reciprocal Feedback Circuit Controlling S-Phase Entry
No full textSummaryThe anaphase promoting complex/cyclosome (APC/C) is an ubiquitin ligase and core component of the cell-cycle oscillator. During G1 phase, APC/C binds to its substrate receptor Cdh1 and APC/CCdh1 plays an important role in restricting S-phase entry and maintaining genome integrity. We describe a reciprocal feedback circuit between APC/C and a second ubiquitin ligase, the SCF (Skp1-Cul1-F box). We show that cyclin F, a cell-cycle-regulated substrate receptor (F-box protein) for the SCF, is targeted for degradation by APC/C. Furthermore, we establish that Cdh1 is itself a substrate of SCFcyclin F. Cyclin F loss impairs Cdh1 degradation and delays S-phase entry, and this delay is reversed by simultaneous removal of Cdh1. These data indicate that the coordinated, temporal ordering of cyclin F and Cdh1 degradation, organized in a double-negative feedback loop, represents a fundamental aspect of cell-cycle control. This mutual antagonism could be a feature of other oscillating systems
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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