1,258 research outputs found
3-Loop Heavy Flavor Corrections in Deep-Inelastic Scattering with Two Heavy Quark Lines
We consider gluonic contributions to the heavy flavor Wilson coefficients at
3-loop order in QCD with two heavy quark lines in the asymptotic region . Here we report on the complete result in the case of two equal
masses for the massive operator matrix element ,
which contributes to the corresponding heavy flavor transition matrix element
in the variable flavor number scheme. Nested finite binomial sums and iterated
integrals over square-root valued alphabets emerge in the result for this
quantity in and -space, respectively. We also present results for the
case of two unequal masses for the flavor non-singlet OMEs and on the scalar
integrals ic case of , which were calculated without a further
approximation. The graphs can be expressed by finite nested binomial sums over
generalized harmonic sums, the alphabet of which contains rational letters in
the ratio .Comment: 10 pages LATEX, 1 Figure, Proceedings of Loops and Legs in Quantum
Field Theory, Weimar April 201
The 3-Loop Non-Singlet Heavy Flavor Contributions and Anomalous Dimensions for the Structure Function and Transversity
We calculate the massive flavor non-singlet Wilson coefficient for the heavy
flavor contributions to the structure function in the asymptotic
region and the associated operator matrix element to 3-loop order in Quantum Chromodynamics at general values of the
Mellin variable . This matrix element is associated to the vector current
and axial vector current for the even and the odd moments , respectively. We
also calculate the corresponding operator matrix elements for transversity,
compute the contributions to the 3-loop anomalous dimensions to and
compare to results in the literature. The 3-loop matching of the flavor
non-singlet distribution in the variable flavor number scheme is derived. All
results can be expressed in terms of nested harmonic sums in space and
harmonic polylogarithms in -space. Numerical results are presented for the
non-singlet charm quark contribution to .Comment: 82 pages, 3 style files, 33 Figure
New Results on Massive 3-Loop Wilson Coefficients in Deep-Inelastic Scattering
We present recent results on newly calculated 2- and 3-loop contributions to
the heavy quark parts of the structure functions in deep-inelastic scattering
due to charm and bottom.Comment: Contribution to the Proc. of Loops and Legs 2016, PoS, in prin
3-loop heavy flavor Wilson coefficients in deep-inelastic scattering
We present our most recent results on the calculation of the heavy flavor
contributions to deep-inelastic scattering at 3-loop order in the large
limit, where the heavy flavor Wilson coefficients are known to factorize into
light flavor Wilson coefficients and massive operator matrix elements. We
describe the different techniques employed for the calculation and show the
results in the case of the heavy flavor non-singlet and pure singlet
contributions to the structure function .Comment: 4 pages Latex, 2 style files, 4 Figures, Contribution to the
Proceedings of QCD '14, Montpellier, Jult 201
Patient choice at the point of GP referral: Department of Health
1 The Department of Health has a Public Service
Agreement target to ensure that by the end of 2005 every
hospital appointment in the National Health Service in
England (the NHS) will be booked for the convenience of
the patient, making it easier for patients and their General
Practitioners (GPs) to choose the hospital and consultant
that best meets their need. The Department aims to
provide patients with the opportunity to choose between
four to five healthcare providers for elective hospital
treatment by December 2005. In consultation with their
GP, patients should be able to choose, from a menu of
NHS and independent sector healthcare providers, their
preferred location for treatment. Patients should also be
able to book the time and date of their initial outpatient
appointment within 24 hours of the decision to refer the
patient for treatment. This target will apply to around
9.4 million patients referred for hospital treatment by their
GP each year, around four per cent of the total estimated
241 million GP consultations.
2 Choice at referral can contribute to a more patientfocused health service, bringing benefits to both patients
and the NHS. But providing such a choice will not happen
by accident. There are a number of dependencies and
interactions with other policies that need to be managed.
Information Technology (IT) systems need to be developed
and modified and significant cultural, organisational and
behavioural changes will need to be made by patients,
NHS organisations and staff.
3 This report examines whether the Department is on
track to deliver choice at the point of referral successfully
by the target date of December 2005. Our work has
found that:
a Progress has been made towards delivering choice
at referral through establishing the required
organisational infrastructure, commissioning new
IT systems and modifications to existing ones, and
providing support for the NHS organisations that will
deliver it.
b The engagement of GPs is currently low and is a key
risk which the Department must address to deliver
choice successfully. The Department plans to
address this risk through a campaign to inform and
engage GPs during 2005 and it will need to monitor
carefully the progress of this campaign.
c Choice at referral will be delivered most efficiently
and effectively through electronic booking (e-booking,
also known as Choose and Book), in which the
Electronic Booking Service, commissioned by the
Department’s National Programme for IT (NPfIT),
is linked to upgraded or new computer systems in
hospitals and GPs’ surgeries. However, e-booking
will not be universally available by December 2005.
Until e-booking is fully adopted choice will have to be
provided in other, less efficient, ways.
d Parts of the NHS still have much to do if they
are to deliver choice. A significant minority of
Primary Care Trusts do not yet have adequate plans
in place to manage the introduction of choice and
some may struggle to manage the required new
commissioning arrangements.
4 Our more detailed findings are as follows.
Progress has been made towards
delivering choice at referral
5 The Department believes that choice is affordable.
Additional annual infrastructure and transaction costs
are estimated to be £122 million – or 1.4 per cent of the
current total expenditure on elective care. The main aim
of introducing choice is to improve services for patients,
but it should lead to increased efficiencies in primary and
secondary care services worth an estimated £71 million,
off-setting some of these costs.
6 It is essential that choice is supported by other
elements of system reform including e-booking, payment
by results, commissioning and appropriate capacity.
Modelling exercises have shown that the system reforms
should work in harmony with one another. Payment by
results should enable the transfer of funding to follow the
patient and there should be sufficient capacity across the
system to enable choice to be effective.
7 Much of the organisational infrastructure that
is required for choice is in place and there is clear
accountability for the delivery of the programme. To
strengthen detailed national programme management
arrangements the Department created, on 22 December
2004, a new post of National Implementation Director
for Choose and Book, with effect from 10 January 2005.
The new Director will be responsible for overseeing the
implementation of choice within the NHS whilst the
National Programme for IT Group Programme Director for
Choose and Book will continue to be responsible for Choose
and Book technology development and deployment, patient
access and Choose and Book contract management.
8 The Department has provided different types of
support to the NHS – for example, ten pilot schemes
have been run to test the policy in practice. It has set up a
system for periodically measuring progress and used this to
establish the position at the end of October 2004, creating
a baseline against which to monitor future progress.
9 Research has identified what information patients
will want to base their choices on, and the Department
is seeking to provide this. While it is unlikely that full
information will be available for December 2005, the
majority of those aspects identified by patients as being
the most important, such as waiting times and basic
access information, will be in place. The Department
plans to increase the information available over time.
The key risk to the delivery of choice
is the engagement of GPs
10 Choice cannot be delivered without support from
GPs but our survey of GPs found that around half of
GPs know very little about it and 61 per cent feel either
very negative or a little negative. GPs’ concerns include
practice capacity, workload, consultation length and fears
that existing health inequalities will be exacerbated. The
Department has deliberately held back its main effort to
inform and engage GPs about choice until it has had a
working e-booking system to show GPs, but it intends to
mount a campaign to inform and engage GPs during 2005.
Until e-booking is fully adopted
choice will be supported by
other mechanisms
11 The Department has commissioned Atos Origin to
develop a national system for e-booking, which will be
linked to upgraded or new Patient Administration Systems
in hospitals and IT systems in GPs’ surgeries to provide
an overall service known as e-booking. The National
Programme for IT has planned the roll out of e-booking on
an incremental basis to minimise risk, and to link it by the
end of 2005 to some 60 to 70 per cent of hospital systems
and GP practices.
12 E-booking is the most effective and efficient way
of delivering the Department’s plans for choice, and
alternative booking mechanisms offer poorer value for
money. Atos Origin has delivered a functioning system
and the first booking using e-booking was made in
July 2004. However the roll-out of e-booking has been
slower than planned and at the end of December 2004
only 63 bookings had been made. Problems have
included the reluctance of users to work with an
unreliable end-to-end system, limited progress in linking
to GP and hospital systems, and the limited number of
GPs willing to use the system.
13 The Department believes that new releases of
software have addressed the reliability of the whole
end-to-end system and that having a fully operational
system will encourage GPs to engage with e-booking. The
roll-out of changes to hospital systems to allow them to
link to e-booking is gathering pace and four types of GP
systems can now link to e-booking, although the largest
supplier has not yet agreed an implementation plan. A
combined team of Departmental and NHS personnel
are working with the three main existing GP system
suppliers to agree a national deployment schedule. This
work should be completed by February 2005, along with
a nationally negotiated commercial arrangement. The
Department is also developing and trialling contingency
plans against further delays, as well as alternatives to the
fully integrated Choose and Book solution.
Parts of the NHS still have much to do
14 Programme management arrangements in the NHS
are incomplete. While most Primary Care Trusts expect to
be able to deliver the choice target, there is variability in
their overall performance. As many as a quarter of Primary
Care Trusts currently forecast that they will not deliver the
choice targets. In addition, some Primary Care Trusts may
struggle to manage the new commissioning arrangements
and two-thirds have yet to commission the required number
of providers. The department is developing a framework of
support to assist trusts to overcome these obstacles.
15 The Department needs urgently to address the low
level of GP support for their plans for implementing
choice at referral, and should:
I Press on urgently with its plans for informing GPs
about the implementation of choice at referral and
its impact on GPs and patients.
II Monitor the views of GPs, for example by a regular
survey, repeating key questions from our own survey,
to assess the rate of progress being achieved towards
the level of support needed to meet its target of full
implementation by December 2005.
III Consider whether further action is needed to secure
the required level of GP support, once GPs are fully
informed on what choice at referral involves.
16 The Department should also:
IV Complete its planned benefits realisation plan for
choice at referral by the summer of 2005, along with
a monitoring mechanism and quantified targets.
V Keep under regular and close review the progress
of its planned implementation of choice through
implementing e-booking and consider the scope
for accelerating the roll-out of e-booking to make it
available everywhere by December 2005.
VI If it becomes clear that it is not possible to deliver
e-booking everywhere by December 2005, the
Department should:
a monitor closely the development of the interim
solutions to ensure that they meet their delivery
dates; and
b ensure that the implementation of interim
solutions does not detract from the priority of
bringing in fully integrated e-booking systems
as soon as possible.
VII Establish an evaluation framework for Primary
Care Trust commissioning to assist Strategic Health
Authorities in assessing the capacity and skills
of Primary Care Trusts in this area and securing
improvements in capacity and skills where necessary
3-Loop Corrections to the Heavy Flavor Wilson Coefficients in Deep-Inelastic Scattering
A survey is given on the status of 3-loop heavy flavor corrections to
deep-inelastic structure functions at large enough virtualities .Comment: 13 pages Latex, 8 Figures, Contribution to the Proceedings of EPS
2015 Wie
Recent progress on the calculation of three-loop heavy flavor Wilson coefficients in deep-inelastic scattering
We report on our latest results in the calculation of the three-loop heavy
flavor contributions to the Wilson coefficients in deep-inelastic scattering in
the asymptotic region . We discuss the different methods used to
compute the required operator matrix elements and the corresponding Feynman
integrals. These methods very recently allowed us to obtain a series of new
operator matrix elements and Wilson coefficients like the flavor non-singlet
and pure singlet Wilson coefficients.Comment: 11 pages Latex, 2 Figures, Proc. of Loops and Legs in Quantum Field
Theory, April 2014, Weimar, German
Variations of Heavy Ion Abundances Relative to Proton Abundances in Large Solar Energetic (E \u3e 10 MeV) Particle Events
The elemental composition of heavy ions (with atomic number Z \u3e 2) (hi-Z) in large gradual E \u3e 10 MeV nuc-1 SEP events has been extensively studied in the 2-15 MeV nuc-1 range to determine the acceleration processes and transport properties of SEPs. These studies invariably are based on abundances relative to those of a single element such as C or O and often neglect H and He, the elements of primary interest for space weather. The total radiation of an SEP event is determined not only by the H and He properties but also by those of hi-Z ions whose abundances and variations relative to H from one event to another are unknown. We report a study to determine those variations in a group of 15 large SEP events over the period 2000 to 2015. Five hi-Z ions (He, C, O, Mg, & Fe) were selected to determine variations of their fluences relative to those of H in the 13.5-50.7 MeV nuc-1 energy range for each SEP event. Our average hi-Z abundance ratios slightly exceed those reported by [1] at lower energies, with the Fe event abundances showing the largest standard deviation of an order of magnitude. The event abundances were weakly correlated with H fluences and strongly correlated with speeds Vcme of associated coronal mass ejections (CMEs). These correlations may be evidence of streaming limits in the shock regions of H in the largest events
Electroluminescence from single nanowires by tunnel injection: an experimental study
We present a hybrid light-emitting diode structure composed of an n-type
gallium nitride nanowire on a p-type silicon substrate in which current is
injected along the length of the nanowire. The device emits ultraviolet light
under both bias polarities. Tunnel-injection of holes from the p-type substrate
(under forward bias) and from the metal (under reverse bias) through thin
native oxide barriers consistently explains the observed electroluminescence
behaviour. This work shows that the standard p-n junction model is generally
not applicable to this kind of device structure.Comment: 6 pages, 6 figure
Measuring the activity of European and African Countries using Social Accounting Matrices
Economic models at the micro, meso and macro levels presuppose the existence of consistent
databases that make it possible to quantify the activity of enterprises, sectors, regions, countries or
continents. Such models can also be important aids in the policy decision process, since they permit
the construction of scenarios resulting from the adoption of policy measures and the consequent
changes that they introduce.
When consistent with the United Nations System of National Accounts (SNA), the Social
Accounting Matrix (SAM) can include all the nominal flows of the measured part of the economy,
at the level of both production and the institutions, and therefore satisfies these requirements. Thus,
in its numerical version, a SAM constitutes a database and provides a snapshot of the measured
reality at a certain moment, whereas its possible algebraic versions, i.e. models that are based upon
it, permit the construction of the above-mentioned scenarios.
The possibility and usefulness of constructing SAMs for African countries consistent with the SNA
will be examined and experimented. The SAM’s basic structure and consistency within the whole
system will be studied, as well as any possible disaggregations, extensions, aggregates, indicators
and balances that can be calculated. Other aspects beyond that basic structure will also be examined
in order to show to what extent the SAM is capable of covering parts of the economy that are not
covered by the SNA.info:eu-repo/semantics/publishedVersio
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