1,212 research outputs found
Operational experience with crab cavities at KEKB
KEKB was in operation from December 1988 to June 2010. The crab cavities were
installed at KEKB in February 2007 and worked very stably until the end of KEKB
operation. Operational experience of the crab cavities with beams is described.Comment: 10 pages, contribution to the ICFA Mini-Workshop on Beam-Beam Effects
in Hadron Colliders, CERN, Geneva, Switzerland, 18-22 Mar 201
Clean Prediction of \CP violating processes , and decay to KsKs and KLKL
The ratio of () and production rates is
calculated by considering oscillation in
decay. The theoretical uncertainty due to strong interaction in decay
is completely canceled in the ratio, therefore, the absolute branching
fractions of the \CP violating processes of and
can be cleanly and model-independently determined in case that decay is precisely measured. In the future -Charm factory, the
expected \CP violating process of should be reached. It
is important to measure to and K_S K_L decays
simultaneously, so that many systematic errors will be canceled. More precise
measurements are suggested to examine the predicted isospin relation in decays. All results can be extended to decays of other vector
quarkonia, , and and so on.Comment: Version 2 is the same as published one at PR
Finite element analysis of magnetic circuits composed of axisymmetric and rectangular regions
A new approximate method is developed for calculating three-dimensional magnetic fields in magnetic circuits composed of connected axisymmetric and rectangular regions. Using this new method, fairly accurate solutions can be obtained when the leakage flux from the magnetic circuit is small. In this paper, the new method is explained and then the usefulness of the technique is clarified by comparing calculated and measured flux densities.</p
Beam-size effect and particle losses at Super factory (Italy)
In the colliders, the macroscopically large impact parameters give a
substantial contribution to the standard cross section of the process. These impact parameters may be much larger than the
transverse sizes of the colliding bunches. It means that the standard cross
section of this process has to be substantially modified. In the present paper
such a beam-size effect is calculated for bremsstrahlung at Super factory
developed in Italy. We find out that this effect reduces beam losses due to
bremsstrahlung by about 40%.Comment: 11 pages, 4 figure
Beam-beam effects in crab crossing and crab waist schemes
To boost up the luminosity performance in B factories, crab crossing and crab waist schemes are proposed. The crab crossing scheme compensates crossing angle, while the crab waist scheme compensates nonlinear terms induced by crossing angle with sextupole magnets. We discuss which nonlinear terms in the beam-beam map are enhanced by the crossing angle and which terms are compensated by the crab waist sextupole
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