3,707 research outputs found
A Consistent Prescription for Combining Perturbative Calculations and Parton Showers in Case of Associated Z b anti-b Hadroproduction
This paper presents the method of combining parton shower formalism with
perturbative calculations (matrix elements) in form of a Monte-Carlo algorithm
for the process g g -> Z b anti-b,consistenlty including the heavy quark masses
and overlap removal.Comment: accepted by JHEP, revised according to suggestions from JHEP refere
On Time-Space Noncommutativity for Transition Processes and Noncommutative Symmetries
We explore the consequences of time-space noncommutativity in the quantum
mechanics of atoms and molecules, focusing on the Moyal plane with just
time-space noncommutativity (,
\theta_{0i}\neqq 0, ). Space rotations and parity are not
automorphisms of this algebra and are not symmetries of quantum physics. Still,
when there are spectral degeneracies of a time-independent Hamiltonian on a
commutative space-time which are due to symmetries, they persist when
\theta_{0i}\neqq 0; they do not depend at all on . They give no
clue about rotation and parity violation when \theta_{0i}\neqq 0. The
persistence of degeneracies for \theta_{0i}\neqq 0 can be understood in terms
of invariance under deformed noncommutative ``rotations'' and ``parity''. They
are not spatial rotations and reflection. We explain such deformed symmetries.
We emphasize the significance of time-dependent perturbations (for example, due
to time-dependent electromagnetic fields) to observe noncommutativity. The
formalism for treating transition processes is illustrated by the example of
nonrelativistic hydrogen atom interacting with quantized electromagnetic field.
In the tree approximation, the transition for hydrogen is
zero in the commutative case. As an example, we show that it is zero in the
same approximation for . The importance of the deformed
rotational symmetry is commented upon further using the decay
as an example.Comment: 13 pages, revised version, references adde
GnRH agonist is not required for frozen embryo transfers conducted under artificial hormone therapy
Lepton Flavor Violation at the LHC
Recent results from Super Kamiokande suggest mixing and
hence lepton flavor violation. In supersymmetric models, this flavor violation
may have implications for the pattern of slepton masses and mixings. Possible
signals for this mixing in the decays of sleptons produced at the LHC are
discussed. The sensitivity expected is compared to that of rare decays such as
.Comment: 14 pages, 9 figure
Measurements in SUGRA Models with Large tan beta at LHC
We present an example of a scenario of particle production and decay in
supersymmetry models in which the supersymmetry breaking is transmitted to the
observable world via gravitational interactions. The case is chosen so that
there is a large production of tau leptons in the final state. It is
characteristic of large tan beta in that decays into muons and electrons may be
suppressed. It is shown that hadronic tau decays can be used to reconstruct
final states.Comment: 15 pages, 12 figure
Non-Commutative GUTs, Standard Model and C,P,T
Noncommutative Yang-Mills theories are sensitive to the choice of the
representation that enters in the gauge kinetic term. We constrain this
ambiguity by considering grand unified theories. We find that at first order in
the noncommutativity parameter \theta, SU(5) is not truly a unified theory,
while SO(10) has a unique noncommutative generalization. In view of these
results we discuss the noncommutative SM theory that is compatible with SO(10)
GUT and find that there are no modifications to the SM gauge kinetic term at
lowest order in \theta.
We study in detail the reality, hermiticity and C,P,T properties of the
Seiberg-Witten map and of the resulting effective actions expanded in ordinary
fields. We find that in models of GUTs (or compatible with GUTs) right-handed
fermions and left-handed ones appear with opposite Seiberg-Witten map.Comment: 28 pages. Added references and comments in the introductio
Relaxation paths for single modes of vibrations in isolated molecules
A numerical simulation of vibrational excitation of molecules was devised,
and used to excite computational models of common molecules into a prescribed,
pure, normal vibration mode in the ground electronic state, with varying,
controlable energy content. The redistribution of this energy (either
non-chaotic or irreversible IVR) within the isolated, free molecule is then
followed in time with a view to determining the coupling strength between
modes. This work was triggered by the need to predict the general characters of
the infrared spectra to be expected from molecules in interstellar space, after
being excited by photon absorption or reaction with a radical. It is found that
IVR from a pure normal mode is very "restricted" indeed at energy contents of
one mode quantum or so. However, as this is increased, or when the excitation
is localized, our approach allows us to isolate, describe and quantify a number
of interesting phenomena, known to chemists and in non-linear mechanics, but
difficult to demonstrate experimentally: frequency dragging, mode locking or
quenching or, still, instability near a potential surface crossing, the first
step to generalized chaos as the energy content per mode is increased.Comment: 25 pages, 15 figures; accepted by J. Atom. Phys.
PIVET rFSH dosing algorithms for individualized controlled ovarian stimulation enables optimized pregnancy productivity rates and avoidance of ovarian hyperstimulation syndrome
© 2016 Yovich et al.The first PIVET algorithm for individualized recombinant follicle stimulating hormone (rFSH) dosing in in vitro fertilization, reported in 2012, was based on age and antral follicle count grading with adjustments for anti-Müllerian hormone level, body mass index, day-2 FSH, and smoking history. In 2007, it was enabled by the introduction of a metered rFSH pen allowing small dosage increments of ~8.3 IU per click. In 2011, a second rFSH pen was introduced allowing more precise dosages of 12.5 IU per click, and both pens with their individual algorithms have been applied continuously at our clinic. The objective of this observational study was to validate the PIVET algorithms pertaining to the two rFSH pens with the aim of collecting =15 oocytes and minimizing the risk of ovarian hyperstimulation syndrome. The data set included 2, 822 in vitro fertilization stimulations over a 6-year period until April 2014 applying either of the two individualized dosing algorithms and corresponding pens. The main outcome measures were mean oocytes retrieved and resultant embryos designated for transfer or cryopreservation permitted calculation of oocyte and embryo utilization rates. Ensuing pregnancies were tracked until live births, and live birth productivity rates embracing fresh and frozen transfers were calculated. Overall, the results showed that mean oocyte numbers were 10.0 for all women <40 years with 24% requiring rFSH dosages <150 IU. Applying both specific algorithms in our clinic meant that the starting dose was not altered for 79.1% of patients and for 30.1% of those receiving the very lowest rFSH dosages (=75 IU). Only 0.3% patients were diagnosed with severe ovarian hyperstimulation syndrome, all deemed avoidable due to definable breaches from the protocols. The live birth productivity rates exceeded 50% for women <35 years and was 33.2% for the group aged 35–39 years. Routine use of both algorithms led to only 11.6% of women generating.15 oocytes, significantly lower than recently published data applying conventional dosages (38.2%; P<0.0001). When comparing both specific algorithms to each other, the outcomes were mainly comparable for pregnancy, live birth, and miscarriage rate. However, there were significant differences in relation to number of oocytes retrieved, but the mean for both the algorithms remained well below 15 oocytes. Consequently, application of both these algorithms in our in vitro fertilization clinic allows the use of both the rFSH products, with very similar results, and they can be considered validated on the basis of effectiveness and safety, clearly avoiding ovarian hyperstimulation syndrome
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