7,249 research outputs found
polarizations in collisions at 7 and 8 TeV by the LHCb collaboration
A polarization measurement carried out for the ,
and mesons produced in pp collisions at 7 and 8 TeV
is presented. Data samples used for the polarization measurement were collected
by the LHCb experiment during the 2011 and 2012 data taking runs with
integrated luminosities of 1 and 2 fb, respectively. The measurement has
been performed in three polarization frames, using an angular distribution
analysis of the decays in the kinematic region of
the transverse momentum GeV/c and rapidity
. No large polarization is observed.Comment: Proceedings of XVII International Workshop on High Energy Spin
Physics (DSPIN-17), Dubna, Russia, September 11 - 15, 2017; All figures and
tables, along with any supplementary material and additional information, are
available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-028.htm
The Schlesinger system and isomonodromic deformations of bundles with connections on Riemann surfaces
We introduce a way of presentation of pairs , where is a
bundle on a Riemann surface and is a logarithmic connection in ,
which is based on a presentation of the surface as a factor of the exterior of
the unit disc. In this presentation we write the local equation of
isomonodormic deformation of pairs . These conditions are written
as a modified Schlesinger system on a Riemann sphere (and in the typical case
just as an ordinary Schlesinger system) plus some linear system.Comment: 19 pages, final version accepted to publicatio
Kaon experiments at CERN: NA48 and NA62
Searches for violation of lepton flavour universality and lepton number
conservation in kaon decays by the NA62 and NA48/2 experiments at CERN, status
and future plans of the CERN kaon programme are presented. A precision
measurement of the helicity-suppressed ratio of the
and decay rates has been performed using the full data set
collected by the NA62 experiment in 2007--2008. The result is
, in agreement with the Standard Model
expectation. An improved upper limit on the rate of the lepton number violating
decay from the NA48/2 experiment (2003--2004
data set) is presented. Finally, the NA62 project aiming at a measurement of
the branching ratio of the ultra-rare decay at 10%
precision is discussed.Comment: Talk given at PhiPsi 2011 conference (Novosibirsk, Russia, September
2011). To be published in Nucl.Phys.B Proc.Sup
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