14,708 research outputs found
Meat: A Novel
An English-language translation of a Russian novel that appeared in the Soviet thick journal Novyi Mir in three installments during February, March, and April of 1936
Boundary Terms in Supergravity and Supersymmetry
We begin with the simplest possible introduction to supergravity. Then we
discuss its spin 3/2 stress tensor; these results are new. Next, we discuss
boundary conditions on fields and boundary actions for N=1 supergravity.
Finally, we discuss new boundary contributions to the mass and central charge
of monopoles in N=4 super Yang-Mills theory. All models are in 3+1 dimensions.Comment: 15 pages. Talk given by P. van Nieuwenhuizen at the
Einstein-celebration gravitational conference at Puri (India) in December
200
Gauge invariant effective action for the Polyakov line in the SU(N) Yang--Mills theory at high temperatures
We integrate out fast varying quantum fluctuations around static A_4 and A_i
fields for the SU(N) gauge group. By assuming that the gluon fields are slowly
varying but allowing for an arbitrary amplitude of A_4 we obtain two variants
of the effective high-temperature theory for the Polyakov line. One is the
effective action for the gauge-invariant eigenvalues of the Polyakov line, and
it is explicitly Z(N) symmetric. The other is the effective action for the
Polyakov line itself as an element of the SU(N). In this case the theory
necessarily includes the spatial components A_i to ensure its gauge invariance
under spatial gauge transformations. We derive the 1-loop effective action in
the `electric' and `magnetic' sectors, summing up all powers of A_4.Comment: RevTex4, 2 figure
Natural SUSY: LHC and Dark Matter direct detection experiments interplay
Natural SUSY scenarios with a low value of the parameter, are
characterised by a higgsino-like dark matter candidate, and a compressed
spectrum for the lightest higgsinos. We explore the prospects for probing this
scenario at the 13 TeV stage of the LHC via monojet searches, with various
integrated luminosity options, and demonstrate how these results are affect by
different assumptions on the achievable level of control on the experimental
systematic uncertainties. The complementarity between collider and direct
detection experiments (present and future) is also highlighted.Comment: Proceeding for the 18th International Conference From the Planck
Scale to the Electroweak Scale (Ioannina, Greece, 25-29 May 2015
Perturbation of a lattice spectral band by a nearby resonance
A soluble model of weakly coupled "molecular" and "nuclear" Hamiltonians is
studied in order to exhibit explicitly the mechanism leading to the enhancement
of fusion probability in case of a narrow near-threshold nuclear resonance. We,
further, consider molecular cells of this type being arranged in lattice
structures. It is shown that if the real part of the narrow nuclear resonance
lies within the molecular band generated by the intercellular interaction, an
enhancement, proportional to the inverse width of the nuclear resonance, is to
be expected.Comment: RevTeX, 2 figures within the file. In May 2000 the title changed and
some minor corrections have been don
Positive and negative-parity flavor-octet baryons in coupled QCD sum rules
We apply the method of the QCD sum rule, in which positive- and
negative-parity baryons couple with each other, to the flavor-octet hyperons
and investigate the parity splittings. We also reexamine the nucleon in the
method, which was studied in our previous paper, by carefully choosing the
Borel weight. Both in the nucleon and hyperon channels the obtained sum rules
turn out to have a very good Borel stability and also have a Borel window, an
energy region in which the OPE converges and the pole contribution dominates
over the continuum contribution. The predicted masses of the positive- and
negative-parity baryons reproduce the experimental ones fairly well in the
and channels, if we assign the and the
to the parity partners of the and the ,
respectively. This implies that the is not the party partner of
the and may be a flavor-singlet or exotic state. In the
channel, the sum rule predicts the mass of the negative-parity state to be
about 1.8 GeV, which leads to two possibilities; one is that the observed state
with the closest mass, , is the parity partner and the other is that
the parity partner is not yet found but exists around 1.8 GeV.Comment: 15 pages, 4 figure
Yukawa Coupling Unification in Supersymmetric Models
We present an updated assessment of the viability of t-b-tau Yukawa coupling
unification in supersymmetric models. For the superpotential Higgs mass
parameter mu>0, we find unification to less than 1% is possible, but only for
GUT scale scalar mass parameter m_{16}~8-20 TeV, and small values of gaugino
mass m_{1/2}<400 GeV. Such models require that a GUT scale mass splitting
exists amongst Higgs scalars with m_{H_u}^2<m_{H_d}^2. Viable solutions lead to
a radiatively generated inverted scalar mass hierarchy, with third generation
and Higgs scalars being lighter than other sfermions. These models have very
heavy sfermions, so that unwanted flavor changing and CP violating SUSY
processes are suppressed, but may suffer from some fine-tuning requirements.
While the generated spectra satisfy b->s gamma and (g-2)_mu constraints, there
exists tension with the dark matter relic density unless m_{16}<3 TeV. These
models offer prospects for a SUSY discovery at the Fermilab Tevatron collider
via the search for chargino_1 neutralino_2 -> 3 leptons events, or via gluino
pair production. If mu<0, Yukawa coupling unification to less than 5% can occur
for m_{16} and m_{1/2}>1-2 TeV. Consistency of negative mu Yukawa unified
models with b->s gamma, (g-2)_mu, and relic density all imply very large values
of m_{1/2} typically greater than about 2.5 TeV, in which case direct detection
of sparticles may be a challenge even at the LHC.Comment: 38 pages, 15 figures. Fig.15 changed, some references were added. A
copy of the paper with better resolution figures can be found at
http://www.hep.fsu.edu/~balazs/Physics/Papers/2003
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