22,607 research outputs found

### A model of gravitation with global U(1)-symmetry

It is shown that an embedding of the general relativity $4-$space into a flat
$12-$space gives a model of gravitation with the global $U(1)-$symmetry and the
discrete $D_{1}-$one. The last one may be transformed into the $SU(2)-$symmetry
of the unified model, and the demand of independence of $U(1)-$ and
$SU(2)-$transformations leads to the estimate $\sin^{2}\theta_{min}=0,20$ where
$\theta_{min}$ is an analog of the Weinberg angle of the standard model.Comment: 7 page

### On the polarization properties of the charmed baryon Lambda^+_c in the Lambda^+_c -> p + K^- + pi^+ + pi^0 decay

The polarization properties of the charmed Lambda^+_c baryon are investigated
in weak non-leptonic four-body Lambda^+_c -> p + K^- + pi^+ + pi^0 decay. The
probability of this decay and the angular distribution of the probability are
calculated in the effective quark model with chiral U(3)XU(3) symmetry
incorporating Heavy Quark Effective theory (HQET) and the extended
Nambu-Jona-Lasinio model with a linear realization of chiral U(3)XU(3)
symmetry. The theoretical value of the probability of the decay Lambda^+_c -> p
+ K^- + pi^+ + pi^0 relative to the probability of the decay Lambda^+_c -> p +
K^- + pi^+ does not contain free parameters and fits well experimental data.
The application of the obtained results to the analysis of the polarization of
the Lambda^+_c produced in the processes of photo and hadroproduction is
discussed.Comment: 10 pages, no figures, Late

### Data compression using correlations and stochastic processes in the ALICE Time Projection chamber

In this paper lossless and a quasi lossless algorithms for the online
compression of the data generated by the Time Projection Chamber (TPC) detector
of the ALICE experiment at CERN are described. The first algorithm is based on
a lossless source code modelling technique, i.e. the original TPC signal
information can be reconstructed without errors at the decompression stage. The
source model exploits the temporal correlation that is present in the TPC data
to reduce the entropy of the source. The second algorithm is based on a lossy
source code modelling technique. In order to evaluate the consequences of the
error introduced by the lossy compression, the results of the trajectory
tracking algorithms that process data offline are analyzed, in particular, with
respect to the noise introduced by the compression. The offline analysis has
two steps: cluster finder and track finder. The results on how these algorithms
are affected by the lossy compression are reported. In both compression
technique entropy coding is applied to the set of events defined by the source
model to reduce the bit rate to the corresponding source entropy. Using TPC
simulated data, the lossless and the lossy compression achieve a data reduction
to 49.2% of the original data rate and respectively in the range of 35% down to
30% depending on the desired precision.In this study we have focused on methods
which are easy to implement in the frontend TPC electronics.Comment: 8 pages, 3 figures, Talk from the 2003 Computing in High Energy and
Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, PSN THLT00

### Standard Electroweak Interactions in Gravitational Theory with Chameleon Field and Torsion

We propose a version of a gravitational theory with the torsion field,
induced by the chameleon field. Following Hojman et al. Phys. Rev. D17, 3141
(1976) the results, obtained in Phys. Rev. D90, 045040 (2014), are generalised
by extending the Einstein gravity to the Einstein-Cartan gravity with the
torsion field as a gradient of the chameleon field through a modification of
local gauge invariance of minimal coupling in the Weinberg-Salam electroweak
model. The contributions of the chameleon (torsion) field to the observables of
electromagnetic and weak processes are calculated. Since in our approach the
chameleon-photon coupling constant beta_(gamma) is equal to the
chameleon-matter coupling constant beta, i.e. beta_(gamma) = beta, the
experimental constraints on beta, obtained in terrestrial laboratories by T.
Jenke et al. (Phys. Rev. Lett. 112, 115105 (2014)) and by H. Lemmel et al.
(Phys. Lett. B743, 310 (2015)), can be used for the analysis of astrophysical
sources of chameleons, proposed by C. Burrage et al. (Phys. Rev. D79, 044028
(2009)), A.-Ch. Davis et al. (Phys. Rev. D80, 064016 (2009), and in references
therein, where chameleons induce photons because of direct chameleon-photon
transitions in the magnetic fields.Comment: 26 pages, 8 figure

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