4,851 research outputs found
Electromagnetic Form Factors and the Hypercentral CQM
New results about the electromagnetic form factors of the nucleon are
obtained with a semirelativistic version of the hypercentral constituent quark
model (hCQM) and a relativistic current. The complex structure of the
constituent quarks is taken into account implicitly by means of
phenomenological constituent quark form factors. We obtain a detailed
reproduction of the experimental data up to , moreover our findings
about constituent quark root mean square radii are of the same order than the
recent ones obtained analyzing the proton structure functions.Comment: 11 pages, 4 figure
Why Tau First?
Electron neutrino has been the first neutral lepton to be foreseen and
discovered last century. The un-ordered muon and its neutrino arose later by
cosmic rays. The tau discover, the heaviest, the most unstable charged lepton,
was found surprisingly on 1975. Its neutrino was hardly revealed just on 2000.
So why High Energy Neutrino Astronomy should rise first via tau neutrino, the
last, the most rare one? The reasons are based on a chain of three favorable
coincidences found last decade: the neutrino masses and their flavor mixing,
the UHECR opacity on Cosmic Black Body (GZK cut off on BBR), the amplified tau
air-shower decaying in flight. Indeed guaranteed UHE GZK tau neutrinos, feed by
muon mixing, while skimming the Earth might lead to boosted UHE tau, mostly
horizontal ones. These UHE lepton decay in flight are spread, amplified, noise
free Air-Shower: a huge event for an unique particle. To be observed soon:
within Auger sky, in present decade. Its discover may sign of the first tau
appearance.Comment: 8 pages, 4 figure
Ultra High Energy Neutrino-Relic Neutrino Interactions In Dark Halos to Solve Infrared-Tev And GZK Cut-Off
Ultra High Energy Neutrino scattering on Relic Light Neutrinos in Dark
Galactic or Local Group lead to Z and WW,ZZ showering: the nucleon component of
the shower may overcome the GZK cut-off while the electro-magnetic tail at TeVs
up to EeVs energy may solve the Infrared-TeV cut-off in a natural way.
Different Gamma TeV puzzles may find a solution within this scenario: new
predictions on UHECR spectra in future data are derived.Comment: 4 pages, 3 figures, 2 tables ICRC 2001 HE 3.6 Dark Matter - German
Single Spin Asymmetries in Semi-Inclusive Electroproduction: Access to Transversity
We discuss the quark transversity distribution function and a possible way to
access it through the measurement of single spin azimuthal asymmetry in
semi-inclusive single pion electroproduction on a transversely polarized
target.Comment: 5 pages, Latex using aipproc.sty (included), to appear in proceedings
of "Second Workshop on Physics with an Electron Polarized Light Ion
Collider", Sept. 14-16, 2000, MIT, Cambridge, US
UHECR narrow clustering correlating IceCube through-going muons
The recent UHECR events by AUGER and the Telescope Array (TA) suggested that
wide clusterings as the North and South, named Hot Spot, are related to near
AGNs such as the one in M82 and Cen A. In the same frame since 2008 we assumed
that the UHECR are made by light and lightest nuclei to explain the otherwise
embarrassing absence of the huge nearby Virgo cluster, absence due to the
fragility and the opacity of lightest nuclei by photo-dissociation from Virgo
distances. Moreover UHECR map exhibits a few narrow clustering, some near the
galactic plane, as toward SS 433 and on the opposite side of the plane at
celestial horizons: we tagged them in 2014 suggesting possible near source
active also as a UHE neutrino. Indeed since last year, 2015, highest IceCube
trough-going muons, UHE up-going neutrino events at hundreds TeV energy, did
show (by two cases over three tagged in North sky) the expected overlapping of
UHE neutrinos signals with narrow crowding UHECR. New data with higher energy
threshold somehow re-confirmed our preliminary proposal; new possible sources
appear by a additional correlated UHE-neutrino versus UHE-neutrino and-or with
narrow UHECR clustering events. A possible role of relic neutrino mass
scattering by ZeV neutrino arised.Comment: 6 pages, 5 figure
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