2,501 research outputs found
Heavy quarkonium production in the Regge limit of QCD: from Tevatron to LHC
Heavy quarkonium production in the framework of the non-relativistic quantum
chromodynamics and leading order of the parton Reggeization approach at the
Tevatron and LHC is discussed. In this note, we compare our predictions for the
bottomonium production at the LHC due to the color-singlet approximation of the
non-relativistic quantum chromodynamics with CMS and LHCb data. It is found,
that in the production of Upsilon(1S) states, the color-singlet mechanism is
dominating, whereas to describe the data for the inclusive Upsilon(2S) and
Upsilon(3S) production, the color- octet contributions should be taken into
account.Comment: 4 pages, 1 figure, Xth Quark Confinement and the Hadron Spectrum 8-12
October 2012 TUM Campus Garching, Munich, German
and hadroproduction in the parton Reggeization approach: Yield, polarization, and the role of fragmentation
The hadroproduction of the radially excited heavy-quarkonium states
and at high energies is studied in the parton
reggeization approach and the factorization formalism of nonrelativistic QCD at
lowest order in the strong-coupling constant and the relative
heavy-quark velocity . A satisfactory description of the
transverse-momentum () distributions measured by ATLAS, CMS, and LHCb at
center-of-mass energy TeV is obtained using the color-octet
long-distance matrix elements (LDMEs) extracted from CDF data at
TeV. The importance of the fragmentation mechanism and the
scale evolution of the fragmentation functions in the upper range, beyond
30 GeV, is demonstrated. The distributions measured by CDF
at TeV and by LHCb at TeV and forward rapidities
are well described using LDMEs fitted to ATLAS data at TeV.
Comparisons of polarization measurements by CDF and CMS at large values
with our predictions consolidate the familiar problem in the case,
but yield reasonable agreement in the case.Comment: 28 pages, 12 figures, minor text additions, references added, matches
journal versio
Interaction of water with oligo(ethylene glycol) terminated monolayers: Wetting: versus hydration
Solving the difference initial-boundary value problems by the operator exponential method
We suggest a modification of the operator exponential method for the
numerical solving the difference linear initial boundary value problems. The
scheme is based on the representation of the difference operator for given
boundary conditions as the perturbation of the same operator for periodic ones.
We analyze the error, stability and efficiency of the scheme for a model
example of the one-dimensional operator of second difference
Magnetization reversal of ferromagnetic nanodisc placed above a superconductor
Using numerical simulation we have studied a magnetization distribution and a
process of magnetization reversal in nanoscale magnets placed above a
superconductor plane. In order to consider an influence of superconductor on
magnetization distribution in the nanomagnet we have used London approximation.
We have found that for usual values of London penetration depth the ground
state magnetization is mostly unchanged. But at the same time the fields of
vortex nucleation and annihilation change significantly: the interval where
vortex is stable enlarges on 100-200 Oe for the particle above the
superconductor. Such fields are experimentally observable so there is a
possibility of some practical applications of this effect.Comment: 8 pages, 9 figure
On TPC cluster reconstruction
For a bias-free momentum measurement of TPC tracks, the correct determination of cluster positions is mandatory. We argue in particular that (i) the reconstruction of the entire longitudinal signal shape in view of longitudinal diffusion, electronic pulse shaping, and track inclination is important both for the polar angle reconstruction and for optimum r phi resolution; and that (ii) self-crosstalk of pad signals calls for special measures for the reconstruction of the z coordinate. The problem of 'shadow clusters' is resolved. Algorithms are presented for accepting clusters as 'good' clusters, and for the reconstruction of the r phi and z cluster coordinates, including provisions for 'bad' pads and pads next to sector boundaries, respectively
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