624 research outputs found
Rare Top-quark Decays to Higgs boson in MSSM
In full one-loop generality and in next-to-leading order in QCD, we study
rare top to Higgs boson flavour changing decay processes with
quarks, in the general MSSM with R-parity conservation. Our primary
goal is to search for enhanced effects on that could be visible
at current and high luminosity LHC running. To this end, we perform an
analytical expansion of the amplitude in terms of flavour changing squark mass
insertions that treats both cases of hierarchical and degenerate squark masses
in a unified way. We identify two enhanced effects allowed by various
constraints: one from holomorphic trilinear soft SUSY breaking terms and/or
right handed up squark mass insertions and another from non-holomorphic
trilinear soft SUSY breaking terms and light Higgs boson masses. Interestingly,
even with flavour violating effects in the, presently
unconstrained, up-squark sector, SUSY effects on come out to be
unobservable at LHC mainly due to leading order cancellations between penguin
and self energy diagrams and the constraints from charge- and colour-breaking
minima (CCB) of the MSSM vacuum. An exception to this conclusion may be effects
arising from non-holomorphic soft SUSY breaking terms in the region where the
CP-odd Higgs mass is smaller than the top-quark mass but this scenario is
disfavoured by recent LHC searches. Our calculations for decay are
made available in SUSY_FLAVOR numerical library.Comment: 32 pages, 6 figures; version accepted for publication in JHEP:
additional comparison with literature added, minor misprints correcte
Mass Insertions vs. Mass Eigenstates calculations in Flavour Physics
We present and prove a theorem of matrix analysis, the Flavour Expansion
Theorem (or FET), according to which, an analytic function of a Hermitian
matrix can be expanded polynomially in terms of its off-diagonal elements with
coefficients being the divided differences of the analytic function and
arguments the diagonal elements of the Hermitian matrix. The theorem is
applicable in case of flavour changing amplitudes. At one-loop level this
procedure is particularly natural due to the observation that every loop
function in the Passarino-Veltman basis can be recursively expressed in terms
of divided differences. FET helps to algebraically translate an amplitude
written in mass eigenbasis into flavour mass insertions, without performing
diagrammatic calculations in flavour basis. As a non-trivial application of FET
up to a third order, we demonstrate its use in calculating strong bounds on the
real parts of flavour changing mass insertions in the up- squark sector of the
MSSM from neutron Electric Dipole Moment (nEDM) measurements, assuming that
CP-violation arises only from the CKM matrix.Comment: 23 page
Topcolor assisted technicolor models and muon anomalous magnetic moment
We discuss and estimate the contributions of the new particles predicted by
topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment
. Our results show that the contributions of Pseudo Goldstone bosons
are very small which can be safely ignored. The main contributions come from
the ETC gauge boson and topcolor gauge boson . If we
demand that the mass of is consistent with other experimental
constrains, its contributions are smaller than that of . With
reasonable values of the parameters in TC2 models, the observed BNL results for
could be explained.Comment: latex file, 11 pages, several figures and references adde
SmeftFR v3 -- Feynman rules generator for the Standard Model Effective Field Theory
We present version 3 of SmeftFR, a Mathematica package designed to generate
the Feynman rules for the Standard Model Effective Field Theory (SMEFT)
including the complete set of gauge invariant operators up to dimension-6 and
the complete set of bosonic operators of dimension-8. Feynman rules are
generated with the use of FeynRules package, directly in the physical (mass
eigenstates) basis for all fields. The complete set of interaction vertices can
be derived, including all or any chosen subset of SMEFT operators. As an
option, the user can also choose preferred gauge fixing, generating Feynman
rules in unitary or -gauges. The novel feature in version-3 of SmeftFR
is its ability to calculate SMEFT interactions consistently up to dimension-8
in EFT expansion (including quadratic dimension-6 terms) and express the
vertices directly in terms of user-defined set of input-parameters. The derived
Lagrangian in the mass basis can be exported in various formats supported by
FeynRules, such as UFO, FeynArts etc. Initialisation of numerical values of
Wilson coefficients of higher dimension operators is interfaced to WCxf format.
The package also includes a dedicated Latex generator allowing to print the
result in clear human-readable form. The SmeftFR v3 is publicly available at
www.fuw.edu.pl/smeft.Comment: 51 pages, version accepted for publication in Computer Physics
Communications. arXiv admin note: substantial text overlap with
arXiv:1904.0320
Cost-effectiveness of trastuzumab in the adjuvant treatment of early breast cancer: a model-based analysis of the HERA and FinHer trial
BACKGROUND: Routine adjuvant administration of trastuzumab (T) has been implemented in most centers, but its economic impact has not yet been well examined. METHODS: A Markov model was constructed based on clinical data of the Herceptin Adjuvant (HERA) and the Finland Herceptin (FinHer) trials. Costs from the perspective of a Swiss health care provider were calculated based on resource use. RESULTS: On the basis of HERA data, our model yielded an overall survival rate of 71.8% for the T group versus 62.8% for the control group [risk ratio (RR) = 0.87) after 10 years and 62.9% versus 52.7% (RR = 0.84) after 15 years. Cost-effectiveness resulted in 40505 Euros (EUR) per life years gained (LYG) after 10 years and 19673 EUR per LYG after 15 years. For the FinHer regimen, overall survival after 10 and 15 years resulted in 81.8% versus 66.1% (RR = 0.81) and 73.6% versus 57.0% (RR = 0.77). Costs of 8497 EUR per patient could be saved after 10 years and 9256 EUR after 15 years compared with the control group. CONCLUSION: In a long-term perspective, adjuvant T based on the HERA regimen can be considered cost-effective. The regimen used in the FinHer trial is even cost saving, but estimations are based on a single small tria
b-tau Unification and neutrino masses in SU(5) extensions of the MSSM with radiative electroweak symmetry breaking
We make a complete analysis of the Yukawa coupling unification in SU(5)
extensions of the MSSM in the framework of the radiative symmetry breaking
scenario. Both logarithmic and finite threshold corrections of sparticles have
been included in the determination of the gauge and Yukawa couplings at M_Z.
The effect of the heavy masses of each model in the renormalization group
equations is also included. We find that in the minimal SU(5) model b-tau
Yukawa unification can be achieved for too large a value of alpha_s. On the
other hand the Peccei-Quinn version of the Missing Doublet model, with the
effect of the right handed neutrino also included, exhibits b-tau unification
in excellent agreement with all low energy experimental data. Unification of
all Yukawa couplings is also discussed.Comment: 20 pages, LaTeX2e,uses psfig,5 figures,full postscript file available
at http://artemis.cc.uoi.gr/~adedes/new97.ps.g
- …