7,740 research outputs found
Collinear Factorization for Single Transverse-Spin Asymmetry in Drell-Yan Processes
We study the scattering of a single parton state with a multi-parton state to
derive the complete results of perturbative coefficient functions at leading
order, which appear in the collinear factorization for Single transverse-Spin
Asymmetry(SSA) in Drell-Yan processes with a transversely polarized hadron in
the initial state. We find that the factorization formula of SSA contains
hard-pole-, soft-quark-pole- and soft-gluon-pole contributions. It is
interesting to note that the leading order perturbative coefficient functions
of soft-quark-pole- and soft-gluon-pole contributions are extracted from parton
scattering amplitudes at one-loop, while the functions of hard-pole
contributions are extracted from the tree level amplitudes at tree-level. Our
method to derive the factorization of SSA is different than the existing one in
literature. A comparison of our results with those obtained by other method is
made.Comment: 27 pages, 14 figures, text improved, to appear in Phys. Rev.
Influence of Selected Econonic Factors on Girl child Participation in Secondary School Education in Bureti Sub county, Kenya
This study, carried out in Bureti Sub County, sought to investigate selected economic factors that affect girl child’s participation in secondary school education in Bureti Sub county. The sub county had 62 secondary schools of which 15 were girls’ schools while 30 were mixed secondary schools and 17 were boys’ schools. The entire sub county had a total population of 12250 students and 406 teachers. The target populations were 5541 Female students and 62 secondary school teacher counselors in thesub countyt. Descriptive Survey research design was used in this study. A saniple of 360 female students and 16 teacher counselors were drawn from 15 girls’ schools and mixed secondary schools in thesub county using stratified sampling technique. Students and teachers’ questionnaires were used to collect therequired data from therespondents. Research Instruments were validated through pilot study and reliability of 0.75 was determined using theCronbach’s alpha procedure. Descriptive statistics; mean, frequencies and percentages were used to analyze thedata while Statistical Packages for Social Sciences (SPSS) program was used for analysis. From thestudy, it was established that themost common factors that affected girl child participation in secondary school education were parents’ level of income. These have led to a number of girls dropping out of school. As a recommendation, the govemment should aid education of the girl child through provision of bursaries as effort to ensure equal participation by all students irrespective of their gender.. Key words: Girl Child, Participation, Economic factors,Secondary school educatio
Berry phases for composite fermions: effective magnetic field and fractional statistics
The quantum Hall superfluid is presently the only viable candidate for a
realization of quasiparticles with fractional Berry phase statistics. For a
simple vortex excitation, relevant for a subset of fractional Hall states
considered by Laughlin, non-trivial Berry phase statistics were demonstrated
many years ago by Arovas, Schrieffer, and Wilczek. The quasiparticles are in
general more complicated, described accurately in terms of excited composite
fermions. We use the method developed by Kjonsberg, Myrheim and Leinaas to
compute the Berry phase for a single composite-fermion quasiparticle, and find
that it agrees with the effective magnetic field concept for composite
fermions. We then evaluate the "fractional statistics", related to the change
in the Berry phase for a closed loop caused by the insertion of another
composite-fermion quasiparticle in the interior. Our results support the
general validity of fractional statistics in the quantum Hall superfluid, while
also giving a quantitative account of corrections to it when the quasiparticle
wave functions overlap. Many caveats, both practical and conceptual, are
mentioned that will be relevant to an experimental measurement of the
fractional statistics. A short report on some parts of this article has
appeared previously.Comment: 14 pages, 9 figure
Toda systems in closed string tachyon condensation
We consider equations appearing in the study of localized tachyon
condensations. They are described by various Toda system when we consider the
condensation by the lowest tachyon corresponding to the monomial . The
tachyon potential is calculated as a solution to these equations. The Toda
system appearing in the deformation of \C^2/\Z_n by is identical to that
of singularity deformed by . For \C^3/\Z_n with deformation,
we find only generic non-simple form, similar to the case appearing in
\C/\Z_5\to \C/\Z_3 and we discuss the difficulties in these cases.Comment: 20 pages, no figur
Josephson effect in a weak link between borocarbides
A stationary Josephson effect is analyzed theoretically for a weak link
between borocarbide superconductors. It is shown that different models of the
order parameter result in qualitatively different current-phase relations
Localized tachyon condensation and G-parity conservation
We study the condensation of localized tachyon in non-supersymmetric orbifold
{\C^2/\Z_n}. We first show that the G-parities of chiral primaries are
preserved under the condensation of localized tachyon(CLT) given by the chiral
primaries. Using this, we finalize the proof of the conjecture that the
lowest-tachyon-mass-squared increases under CLT at the level of type II string
with full consideration of GSO projection. We also show the equivalence between
the -parity given by coming from partition function
and that given by coming from the monomial
construction for the chiral primaires in the dual mirror picture.Comment: 12 pages, 2 figures, final form to appear in JHE
LHC Signature of Mirage Mediation
We study LHC phenomenology of mirage mediation scenario in which anomaly and
modulus contributions to soft SUSY breaking terms are comparable to each other.
A Monte Carlo study of mirage mediation, with model parameters , GeV, , and , is presented. It is
shown that masses of supersymmetric particles can be measured in a model
independent way, providing information on SUSY breaking sector. In particular,
the mass ratio of gluino to the lightest neutralino for the benchmark scenario
is determined to be 1.9 \lesssim m_{\tildeg}/m_{\tilde\chi_1^0} \lesssim 3.1,
well reproducing theoretical input value of which is quite distinctive from the predictions of other SUSY scenarios in which gaugino
masses are unified at the GUT scale. The model parameters of mirage mediation
can be also determined from various kinematic distributions
- …