1,320 research outputs found
Elastic and scattering in the models of unitarized pomeron
Elastic scattering amplitudes dominated by the Pomeron singularity which obey
the principal unitarity bounds at high energies are constructed and analyzed.
Confronting the models of double and triple (at ) Pomeron pole
(supplemented by some terms responsible for the low energy behaviour) with
existing experimental data on and total and differential cross
sections at GeV and GeV we are able to tune
the form of the Pomeron singularity. Actually the good agreement with those
data is received for both models though the behaviour given by the dipole model
is more preferable in some aspects. The predictions made for the LHC energy
values display, however, the quite noticeable difference between the
predictions of models at GeV. Apparently the future
results of TOTEM will be more conclusive to make a true choice.Comment: Revtex4, 8 pages, 5 figures. Text is improved, no changes in figures
and conclusions. Version to be published in Phys. Rev.
The soft and the hard pomerons in hadron elastic scattering at small t
We consider simple-pole descriptions of soft elastic scattering for pp, pbar
p, pi+ p, pi- p, K+ p and K- p. We work at t and s small enough for
rescatterings to be neglected, and allow for the presence of a hard pomeron.
After building and discussing an exhaustive dataset, we show that simple poles
provide an excellent description of the data in the region - 0.5 GeV^2 < t <
-0.1 GeV^2, 6 GeV<sqrt(s)< 63 GeV. We show that new form factors have to be
used, and get information on the trajectories of the soft and hard pomerons.Comment: 27 pages, 9 figures, LaTeX. A few typos fixed, and references
correcte
Phase diagram of superfluid 3He in "nematically ordered" aerogel
Results of experiments with liquid 3He immersed in a new type of aerogel are
described. This aerogel consists of Al2O3 strands which are nearly parallel to
each other, so we call it as a "nematically ordered" aerogel. At all used
pressures a superfluid transition was observed and a superfluid phase diagram
was measured. Possible structures of the observed superfluid phases are
discussed.Comment: 6 pages, 8 figures. Submitted to Pis'ma v ZhETF (JETP Letters
LHC Predictions from a Tevatron Anomaly in the Top Quark Forward-Backward Asymmetry
We examine the implications of the recent CDF measurement of the top-quark
forward-backward asymmetry, focusing on a scenario with a new color octet
vector boson at 1-3 TeV. We study several models, as well as a general
effective field theory, and determine the parameter space which provides the
best simultaneous fit to the CDF asymmetry, the Tevatron top pair production
cross section, and the exclusion regions from LHC dijet resonance and contact
interaction searches. Flavor constraints on these models are more subtle and
less severe than the literature indicates. We find a large region of allowed
parameter space at high axigluon mass and a smaller region at low mass; we
match the latter to an SU(3)xSU(3)/SU(3) coset model with a heavy vector-like
fermion. Our scenario produces discoverable effects at the LHC with only 1-2
inverse femtobarns of luminosity at 7-8 TeV. Lastly, we point out that a
Tevatron measurement of the b-quark forward-backward asymmetry would be very
helpful in characterizing the physics underlying the top-quark asymmetry.Comment: 35 pages, 10 figures, 4 table
Rare B decays and Tevatron top-pair asymmetry
The recent Tevatron result on the top quark forward-backward asymmetry, which
deviates from its standard model prediction by 3.4, has prompted many
authors to build new models to account for this anomaly. Among the various
proposals, we find that those mechanisms which produce via - or
-channel can have a strong correlation to the rare B decays. We demonstrate
this link by studying a model with a new charged gauge boson, . In terms of
the current measurements on decays, we conclude that the branching
ratio for is affected most by the new effects.
Furthermore, using the world average branching ratio for the exclusive B decays
at level, we discuss the allowed values for the new parameters.
Finally, we point out that the influence of the new physics effects on the
direct CP asymmetry in B decays is insignificant.Comment: 15 page, 6 figures, typos corrected and references added, final
version to appear journa
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