8,146 research outputs found
ILC Operating Scenarios
The ILC Technical Design Report documents the design for the construction of
a linear collider which can be operated at energies up to 500 GeV. This report
summarizes the outcome of a study of possible running scenarios, including a
realistic estimate of the real time accumulation of integrated luminosity based
on ramp-up and upgrade processes. The evolution of the physics outcomes is
emphasized, including running initially at 500 GeV, then at 350 GeV and 250
GeV. The running scenarios have been chosen to optimize the Higgs precision
measurements and top physics while searching for evidence for signals beyond
the standard model, including dark matter. In addition to the certain precision
physics on the Higgs and top that is the main focus of this study, there are
scientific motivations that indicate the possibility for discoveries of new
particles in the upcoming operations of the LHC or the early operation of the
ILC. Follow-up studies of such discoveries could alter the plan for the
centre-of-mass collision energy of the ILC and expand the scientific impact of
the ILC physics program. It is envisioned that a decision on a possible energy
upgrade would be taken near the end of the twenty year period considered in
this report
Comment on "Quantum mechanics of smeared particles"
In a recent article, Sastry has proposed a quantum mechanics of smeared
particles. We show that the effects induced by the modification of the
Heisenberg algebra, proposed to take into account the delocalization of a
particle defined via its Compton wavelength, are important enough to be
excluded experimentally.Comment: 2 page
Upper and lower bounds on the mean square radius and criteria for occurrence of quantum halo states
In the context of non-relativistic quantum mechanics, we obtain several upper
and lower limits on the mean square radius applicable to systems composed by
two-body bound by a central potential. A lower limit on the mean square radius
is used to obtain a simple criteria for the occurrence of S-wave quantum halo
sates.Comment: 12 pages, 2 figure
Center Domains and their Phenomenological Consequences
We argue that the domain structure of deconfined QCD matter, which can be
inferred from the properties of the Polyakov loop, can simultaneously explain
the two most prominent experimentally verified features of the quark-gluon
plasma, namely its large opacity as well as its near ideal fluid properties
Sufficient conditions for the existence of bound states in a central potential
We show how a large class of sufficient conditions for the existence of bound
states, in non-positive central potentials, can be constructed. These
sufficient conditions yield upper limits on the critical value,
, of the coupling constant (strength), , of the
potential, , for which a first -wave bound state appears.
These upper limits are significantly more stringent than hitherto known
results.Comment: 7 page
Radiative diagnostics for sub-Larmor scale magnetic turbulence
Radiative diagnostics of high-energy density plasmas is addressed in this
paper. We propose that the radiation produced by energetic particles in
small-scale magnetic field turbulence, which can occur in laser-plasma
experiments, collisionless shocks, and during magnetic reconnection, can be
used to deduce some properties of the turbulent magnetic field. Particles
propagating through such turbulence encounter locally strong magnetic fields,
but over lengths much shorter than a particle gyroradius. Consequently, the
particle is accelerated but not deviated substantially from a straight line
path. We develop the general jitter radiation solutions for this case and show
that the resulting radiation is directly dependent upon the spectral
distribution of the magnetic field through which the particle propagates. We
demonstrate the power of this approach in considering the radiation produced by
particles moving through a region in which a (Weibel-like) filamentation
instability grows magnetic fields randomly oriented in a plane transverse to
counterstreaming particle populations. We calculate the spectrum as would be
seen from the original particle population and as could be seen by using a
quasi-monoenergetic electron beam to probe the turbulent region at various
angles to the filamentation axis.Comment: 17 pages, 4 figures, submitted to Phys. Plasma
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