Inclusive double-quarkonium production at the Large Hadron Collider

Based on the nonrelativistic QCD (NRQCD) factorization formalism, we investigate inclusive productions of two spin-triplet S-wave quarkonia pp->2J/psi+X, 2Upsilon+X, and J/psi+Upsilon+X at the CERN Large Hadron Collider. The total production rates integrated over the rapidity (y) and transverse-momentum (p_T) ranges |y|<2.4 and p_T<50 GGeV are predicted to be sigma[pp->2J/psi+X] = 22 (35) nb, sigma[pp->2Upsilon+X] = 24 (49) pb, and sigma[pp->J/psi+Upsilon+X] = 7 (13) pb at the center-of-momentum energy sqrt{s} = 7 (14) TeV. In order to provide predictions that can be useful in both small- and large-p_T regions, we do not employ the fragmentation approximation and we include the spin-triplet S-wave color-singlet and color-octet channels for each quarkonium final state at leading order in the strong coupling. The p_T distributions of pp->2J/psi+X and 2Upsilon+X in the low-p_T region are dominated by the color-singlet contributions. At leading order in the strong coupling, the color-singlet channel is absent for pp->J/psi+Upsilon+X. Therefore, the process pp->J/psi+Upsilon+X may provide a useful probe to the color-octet mechanism of NRQCD.Comment: 26 pages, 7 figures, 3 tables, version published in JHE

On Glauber modes in Soft-Collinear Effective Theory

Gluon interactions involving spectator partons in collisions at hadronic machines are investigated. We find a class of examples in which a mode, called Glauber gluons, must be introduced to the effective theory for consistency.Comment: 19 pages, three figures. Uses JHEP3.cl

Fully-Unintegrated Parton Distribution and Fragmentation Functions at Perturbative k_T

We define and study the properties of generalized beam functions (BFs) and fragmenting jet functions (FJFs), which are fully-unintegrated parton distribution functions (PDFs) and fragmentation functions (FFs) for perturbative k_T. We calculate at one loop the coefficients for matching them onto standard PDFs and FFs, correcting previous results for the BFs in the literature. Technical subtleties when measuring transverse momentum in dimensional regularization are clarified, and this enables us to renormalize in momentum space. Generalized BFs describe the distribution in the full four-momentum k_mu of a colliding parton taken out of an initial-state hadron, and therefore characterize the collinear initial-state radiation. We illustrate their importance through a factorization theorem for pp -> l^+ l^- + 0 jets, where the transverse momentum of the lepton pair is measured. Generalized FJFs are relevant for the analysis of semi-inclusive processes where the full momentum of a hadron, fragmenting from a jet with constrained invariant mass, is measured. Their significance is shown for the example of e^+ e^- -> dijet+h, where the perpendicular momentum of the fragmenting hadron with respect to the thrust axis is measured.Comment: Journal versio

Diarrhea is a Major killer of Children with Severe Acute Malnutrition Admitted to Inpatient Set-up in Lusaka, Zambia

<p>Abstract</p> <p>Introduction</p> <p>Mortality of children with Severe Acute Malnutrition (SAM) in inpatient set-ups in sub-Saharan Africa still remains unacceptably high. We investigated the prevalence and effect of diarrhea and HIV infection on inpatient treatment outcome of children with complicated SAM receiving treatment in inpatient units.</p> <p>Method</p> <p>A cohort of 430 children aged 6-59 months old with complicated SAM admitted to Zambia University Teaching Hospital's stabilization centre from August to December 2009 were followed. Data on nutritional status, socio-demographic factors, and admission medical conditions were collected up on enrollment. T-test and chi-square tests were used to compare difference in mean or percentage values. Logistic regression was used to assess risk of mortality by admission characteristics.</p> <p>Results</p> <p>Majority, 55.3% (238/430) were boys. The median age of the cohort was 17 months (inter-quartile range, IQR 12-22). Among the children, 68.9% (295/428) had edema at admission. The majority of the children, 67.3% (261/388), presented with diarrhea; 38.9% (162/420) tested HIV positive; and 40.5% (174/430) of the children died. The median Length of stay of the cohort was 9 days (IQR, 5-14 days); 30.6% (53/173) of the death occurred within 48 hours of admission. Children with diarrhea on admission had two and half times higher odds of mortality than those without diarrhea; Adjusted OR = 2.5 (95% CI 1.50-4.09, P < 0.001). The odds of mortality for children with HIV infection was higher than children without HIV infection; Adjusted OR = 1.6 (95% CI 0.99-2.48 P = 0.5).</p> <p>Conclusion</p> <p>Diarrhea is a major cause of complication in children with severe acute malnutrition. Under the current standard management approach, diarrhea in children with SAM was found to increase their odds of death substantially irrespective of other factors.</p

A spatially-structured PCG method for content diversity in a Physics-based simulation game

This paper presents a spatially-structured evolutionary algorithm (EA) to procedurally generate game maps of di ferent levels of di ficulty to be solved, in Gravityvolve!, a physics-based simulation videogame that we have implemented and which is inspired by the n- body problem, a classical problem in the fi eld of physics and mathematics. The proposal consists of a steady-state EA whose population is partitioned into three groups according to the di ficulty of the generated content (hard, medium or easy) which can be easily adapted to handle the automatic creation of content of diverse nature in other games. In addition, we present three fitness functions, based on multiple criteria (i.e:, intersections, gravitational acceleration and simulations), that were used experimentally to conduct the search process for creating a database of maps with di ferent di ficulty in Gravityvolve!.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Central Exclusive Production in QCD

We investigate the theoretical description of the central exclusive production process, h1+h2 -> h1+X+h2. Taking Higgs production as an example, we sum logarithmically enhanced corrections appearing in the perturbation series to all orders in the strong coupling. Our results agree with those originally presented by Khoze, Martin and Ryskin except that the scale appearing in the Sudakov factor, mu=0.62 \sqrt{\hat{s}}, should be replaced with mu=\sqrt{\hat{s}}, where \sqrt{\hat{s}} is the invariant mass of the centrally produced system. We confirm this result using a fixed-order calculation and show that the replacement leads to approximately a factor 2 suppression in the cross-section for central system masses in the range 100-500 GeV.Comment: 41 pages, 19 figures; minor typos fixed; version published in JHE

Defining goal terms in development and health

YesMost academic literature uses ‘goal’, ‘aim’, ‘objective’ and ‘target’ as synonymous terms, but development and healthcare sectors define them as distinct etymological entities with varied and confusing interpretations. This review sought to constructively harmonise and differentiate each definition using a thematic framework. An inductive synthesis of definitions of the goal terms collected from 22 literature sources selected through a systematic internet search. Thirty-three specific definitions were reduced through serial category-building to single general definitions, and a set of theoretical themes generated as characteristic framework of each goal. Seven conceptual themes evolved from the synthesis, including the object, scope, hierarchy, timeframe, measurability, significance and expression of each goal term. Two terms, ‘goal’ and ‘aim’ are thematically similar as broad objects of immeasurable terminal impact, with a long-term timeframe. They signify organisational success, expressed as general purpose statements. ‘Objective’ is differentiated as a specific object of measurable intermediate outcome, with short-term timeframe. It signifies intervention effectiveness, expressed as a SMART statement. ‘Target’ is simply a specific quantifiable level of an indicator. Goal, aim, objective and target are conceptually different. New frameworks for writing complete goal statements are proposed, including impact and timeframe; and outcome, indicator and timeframe frameworks for aim and objective respectivel

An effective theory for jet propagation in dense QCD matter: jet broadening and medium-induced bremsstrahlung

Two effects, jet broadening and gluon bremsstrahlung induced by the propagation of a highly energetic quark in dense QCD matter, are reconsidered from effective theory point of view. We modify the standard Soft Collinear Effective Theory (SCET) Lagrangian to include Glauber modes, which are needed to implement the interactions between the medium and the collinear fields. We derive the Feynman rules for this Lagrangian and show that it is invariant under soft and collinear gauge transformations. We find that the newly constructed theory SCET$_{\rm G}$ recovers exactly the general result for the transverse momentum broadening of jets. In the limit where the radiated gluons are significantly less energetic than the parent quark, we obtain a jet energy-loss kernel identical to the one discussed in the reaction operator approach to parton propagation in matter. In the framework of SCET$_{\rm G}$ we present results for the fully-differential bremsstrahlung spectrum for both the incoherent and the Landau-Pomeranchunk-Migdal suppressed regimes beyond the soft-gluon approximation. Gauge invariance of the physics results is demonstrated explicitly by performing the calculations in both the light-cone and covariant $R_{\xi}$ gauges. We also show how the process-dependent medium-induced radiative corrections factorize from the jet production cross section on the example of the quark jets considered here.Comment: 52 pages, 15 pdf figures, as published in JHE

Two real parton contributions to non-singlet kernels for exclusive QCD DGLAP evolution

Results for the two real parton differential distributions needed for implementing a next-to-leading order (NLO) parton shower Monte Carlo are presented. They are also integrated over the phase space in order to provide solid numerical control of the MC codes and for the discussion of the differences between the standard $\bar{MS}$ factorization and Monte Carlo implementation at the level of inclusive NLO evolution kernels. Presented results cover the class of non-singlet diagrams entering into NLO kernels. The classic work of Curci-Furmanski-Pertonzio was used as a guide in the calculations.Comment: 34 pages, 3 figure

Soft-Gluon-Pole Contribution in Single Transverse-Spin Asymmetries of Drell-Yan Processes

We use multi-parton states to examine the leading order collinear factorization of single transverse-spin asymmetries in Drell-Yan processes. Twist-3 operators are involved in the factorization. We find that the so-called soft-gluon-pole contribution in the factorization must exist in order to make the factorization correct. This contribution comes from the corresponding cross-section at one-loop, while the hard-pole contribution in the factorization comes from the cross-section at tree-level. Although the two contributions come from results at different orders, their perturbative coefficient functions in the factorization are at the same order. This is in contrast to factorizations only involving twist-2 operators. The soft-gluon-pole contribution found in this work is in agreement with that derived in a different way. For the hard-pole contributions we find an extra contribution from an extra parton process contributing to the asymmetries. We also solve a part of discrepancy in evolutions of the twist-3 operator. The method presented here for analyzing the factorization can be generalized to other processes and can be easily used for studying factorizations at higher orders, because the involved calculations are of standard scattering amplitudes.Comment: typos eliminated. Published in JHEP 1104:062,201