8,062 research outputs found
Solar cell cover glass development Final report
High vacuum ion beam sputtering of integral coverslips for solar cell utilizatio
Silicon solar cell development for low temperature and low illumination intensity operation, volume 1 Analysis report, 30 Jun. 1969 - 30 Apr. 1970
Operational performance of solar cell at low temperatures and under low illumination intensit
Enhanced Molecular Orientation Induced by Molecular Anti-Alignment
We explore the role of laser induced anti-alignment in enhancing molecular
orientation. A field-free enhanced orientation via anti-alignment scheme is
presented, which combines a linearly polarized femtosecond laser pulse with a
half-cycle pulse. The laser pulse induces transient anti-alignment in the plane
orthogonal to the field polarization, while the half-cycle pulse leads to the
orientation. We identify two qualitatively different enhancement mechanisms
depending on the pulse order, and optimize their effects using classical and
quantum models both at zero and non-zero temperature
The Small-x Behaviour of the Singlet Polarized Structure Function g_2 in the Double Logarithmic Approximation
The small-x behavior of the singlet contributions to the polarized structure
function g_2(x,Q^2) is calculated in the double-logarithmic approximation of
perturbative QCD. The dominant contribution is due to the gluons which, in
contrast to the unpolarized case, mix with the fermions also in the small-x
domain. We find a power-like growth in 1/x in the odd-signature parts of the
amplitude with the same power as in the singlet function g_1(x,Q^2) at x<< 1.Comment: 20 pages, latex, 3 ps figure
Three Jet Events and New Strong Couplings at LEP and NLC
We study the effects of new dimension--6 operators, resulting from a general
invariant effective Lagrangian, on
three jet production at LEP and at the Next Linear Collider. Contributions to
the total event rate and to some event shape variables are analysed in order to
establish bounds on these operators.Comment: 5 pages, LaTeX, 1 Figur
High Energy Quark-Antiquark Elastic scattering with Mesonic Exchange
We studies the high energy elastic scattering of quark anti-quark with an
exchange of a mesonic state in the channel with .
Both the normalization factor and the Regge trajectory can be calculated in
PQCD in cases of fixed (non-running) and running coupling constant. The
dependence of the Regge trajectory on the coupling constant is highly
non-linear and the trajectory is of order of in the interesting physical
range.Comment: 29 page
Spin constraints on Regge predictions and perturbative evolution in high energy collisions
Two key issues in the application of perturbative QCD and Regge predictions
to high energy processes are whether the hard and soft pomerons should be
considered as two separate distinct exchanges and whether the Regge intercepts
are Q^2 independent or not. Models involving a distinct hard pomeron exchange
predict much larger values for the LHC total cross-section. Here we argue that
there is a polarized analogue of this issue in the isovector part of the spin
structure function g_1 and that the spin data appear to favour a distinct hard
exchange.Comment: 8 page
Inclusive production of a pair of hadrons separated by a large interval of rapidity in proton collisions
We consider within QCD collinear factorization the inclusive process , where the pair of identified hadrons, , having large
transverse momenta is produced in high-energy proton-proton collisions. In
particular, we concentrate on the kinematics where the two identified hadrons
in the final state are separated by a large interval of rapidity . In
this case the (calculable) hard part of the reaction receives large higher
order corrections . We provide a theoretical input
for the resummation of such contributions with next-to-leading logarithmic
accuracy (NLA) in the BFKL approach. Specifically, we calculate in NLA the
vertex (impact-factor) for the inclusive production of the identified hadron.
This process has much in common with the widely discussed Mueller-Navelet jets
production and can be also used to access the BFKL dynamics at proton
colliders. Another application of the obtained identified-hadron vertex could
be the NLA BFKL description of inclusive forward hadron production in DIS.Comment: 29 pages, 9 figures; corrected few typos and added an acknowledgment;
version to be published on JHEP. arXiv admin note: substantial text overlap
with arXiv:1202.108
Saturation Effects in Deep Inelastic Scattering at low and its Implications on Diffraction
We present a model based on the concept of saturation for small and
small . With only three parameters we achieve a good description of all Deep
Inelastic Scattering data below . This includes a consistent treatment
of charm and a successful extrapolation into the photoproduction regime. The
same model leads to a roughly constant ratio of diffractive and inclusive cross
section.Comment: 24 pages, 12 figures, Latex-fil
Orienting coupled quantum rotors by ultrashort laser pulses
We point out that the non-adiabatic orientation of quantum rotors, produced
by ultrashort laser pulses, is remarkably enhanced by introducing dipolar
interaction between the rotors. This enhanced orientation of quantum rotors is
in contrast with the behavior of classical paired rotors, in which dipolar
interactions prevent the orientation of the rotors. We demonstrate also that a
specially designed sequence of pulses can most efficiently enhances the
orientation of quantum paired rotors.Comment: 7 pages, 5 figures, to appear in Phys. Rev.
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