213 research outputs found
Non-relativistic pair annihilation of nearly mass degenerate neutralinos and charginos II. P-wave and next-to-next-to-leading order S-wave coefficients
This paper is a continuation of an earlier work (arXiv:1210.7928) which
computed analytically the tree-level annihilation rates of a collection of
non-relativistic neutralino and chargino two-particle states in the general
MSSM. Here we extend the results by providing the next-to-next-to-leading order
corrections to the rates in the non-relativistic expansion in momenta and mass
differences, which include leading P-wave effects, in analytic form. The
results are a necessary input for the calculation of the Sommerfeld-enhanced
dark matter annihilation rates including short-distance corrections at
next-to-next-to-leading order in the non-relativistic expansion in the general
MSSM with neutralino LSP.Comment: LaTeX, 16 pages (+ 36 pages Appendix), 4 figures; v2 - new appendix
with analytic results for the P-wave and rest of v^2 corrections to
annihilation rates in the wino limit added, matches published versio
On the minimality of the order p^6 chiral Lagrangian
A method to find relations between the operators in the mesonic Lagrangian of
Chiral Perturbation Theory at order p^6 is presented. The procedure can be used
to establish if the basis of operators in the Lagrangian is minimal. As an
example, we apply the method to the two-flavour case in the absence of scalar
and pseudo-scalar sources (s=p=0), and conclude that the minimal Lagrangian
contains 27 independent operators.Comment: 14 pages, 2 figure
New contributions to heavy quark sum rules
We analyse new contributions to the theoretical input in heavy quark sum
rules and we show that the general theory of singularities of perturbation
theory amplitudes yields the method to handle these specific features. In
particular we study the inclusion of heavy quark radiation by light quarks at
O(alpha_s^2) and non-symmetric correlators at O(alpha_s^3). Closely related, we
also propose a solution to the construction of moments of the spectral
densities at O(alpha_s^3) where the presence of massless contributions
invalidates the standard approach. We circumvent this problem through a new
definition of the moments, providing an infrared safe and consistent procedure.Comment: 15 pages, 3 figures. Version accepted for publication in The European
Journal of Physics C; several new comments and references added, conclusions
unchange
Renormalization Group Analysis in NRQCD for Colored Scalars
The vNRQCD Lagrangian for colored heavy scalar fields in the fundamental
representation of QCD and the renormalization group analysis of the
corresponding operators are presented. The results are an important ingredient
for renormalization group improved computations of scalar-antiscalar bound
state energies and production rates at next-to-next-to-leading-logarithmic
(NNLL) order.Comment: 19 pages, 8 figures; revtex4. References added; version to appear in
Phys. Rev.
Heavy neutralino relic abundance with Sommerfeld enhancements - a study of pMSSM scenarios
We present a detailed discussion of Sommerfeld enhancements in neutralino
dark matter relic abundance calculations for several popular benchmark
scenarios in the general MSSM. Our analysis is focused on models with heavy
wino- and higgsino-like neutralino LSP and models interpolating between these
two scenarios. This work is the first phenomenological application of effective
field theory methods that we have developed in earlier work and that allow for
the consistent study of Sommerfeld enhancements in non-relativistic neutralino
and chargino co-annihilation reactions within the general MSSM, away from the
pure-wino and pure-higgsino limits.Comment: 38 pages, 14 figures, 3 table
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