Forward Jets and Energy Flow in Hadronic Collisions

We observe that at the Large Hadron Collider, using forward + central detectors, it becomes possible for the first time to carry out calorimetric measurements of the transverse energy flow due to "minijets" accompanying production of two jets separated by a large rapidity interval. We present parton-shower calculations of energy flow observables in a high-energy factorized Monte Carlo framework, designed to take into account QCD logarithmic corrections both in the large rapidity interval and in the hard transverse momentum. Considering events with a forward and a central jet, we examine the energy flow in the interjet region and in the region away from the jets. We discuss the role of these observables to analyze multiple parton collision effects.Comment: 9 pages, 5 figures. Version2: added results on azimuthal distributions and more discussion of energy flow definition using jet clusterin

Structure functions and perturbative hysteresis

We discuss hysteresis effects in the perturbative solution of renormalization group equations for the strong coupling and parton distribution functions, and study their impact on precision determinations of proton's deep-inelastic structure functions F2 and FL

Clostridium difficile-associated diarrhea in radiooncology: an underestimated problem for the feasibility of the radiooncological treatment?

Background and Purpose Over the last years an increasing incidence of Clostridium difficile-associated diarrhea (CDAD) has been reported. Especially haematology-oncology patients are at risk of developing CDAD. The aim of this analysis is to determine the incidence of CDAD in radiooncological patients and to find out what relevance CDAD has for the feasibility of the radiooncological treatment, as well as to detect and describe risk factors. Patients and Methods In a retrospective analysis from 2006 to 2010 34 hospitalized radiooncological patients could be identified having CDAD. The risk factors of these patients were registered, the incidence was calculated and the influence on the feasibility of the radiooncological therapy was evaluated. Induced arrangements for prophylaxis of CDAD were identified and have been correlated with the incidence. Results The incidence of CDAD in our collective is 1,6%. Most of the patients suffering from a CDAD were treated for carcinoma in the head and neck area. Common risk factors were antibiotics, proton pump inhibitors, cytostatic agents and tube feeding. Beside a high rate of electrolyte imbalance and hypoproteinemia a decrease of general condition was frequent. 12/34 patients had a prolonged hospitalization, in 14/34 patients radiotherapy had to be interrupted due to CDAD. In 21 of 34 patients a concomitant chemotherapy was planned. 4/21 patients could receive all of the planned cycles and only 2/21 patients could receive all of the planned cycles in time. 4/34 patients died due to CDAD. In 4/34 patients an initially curative treatment concept has to be changed to a palliative concept. With intensified arrangements for prophylaxis the incidence of CDAD decreased from 4,0% in 2007 to 0,4% in 2010. Conclusion The effect of CDAD on the feasibility of the radiotherapy and a concomitant chemotherapy is remarkable. The morbidity of patients is severe with a high lethality. Reducing of risk factors, an intense screening and the use of probiotics as prophylaxis can reduce the incidence of CDAD

The CCFM Monte Carlo generator CASCADE 2.2.0

CASCADE is a full hadron level Monte Carlo event generator for ep, \gamma p and p\bar{p} and pp processes, which uses the CCFM evolution equation for the initial state cascade in a backward evolution approach supplemented with off - shell matrix elements for the hard scattering. A detailed program description is given, with emphasis on parameters the user wants to change and variables which completely specify the generated events

NLO prescription for unintegrated parton distributions

We show how parton distributions unintegrated over the parton transverse momentum, k_t, may be generated, at NLO accuracy, from the known integrated (DGLAP-evolved) parton densities determined from global data analyses. A few numerical examples are given, which demonstrate that sufficient accuracy is obtained by keeping only the LO splitting functions together with the NLO integrated parton densities. However, it is important to keep the precise kinematics of the process, by taking the scale to be the virtuality rather than the transverse momentum, in order to be consistent with the calculation of the NLO splitting functions.Comment: 20 pages, 8 figures. v2: version to appear in Eur. Phys. J.

QCD

We discuss QCD studies that will be possible at LEP2. We examine both experimental and theoretical aspects of jets, fragmentation functions, multiplicities and particle spectra.Comment: 44 pages, Latex, epsfig, 18 figures, to appear on the Report of the Workshop on Physics at LEP2, CERN 96-01, vol. 1, 199

ArthroRad trial: multicentric prospective and randomized single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis depending on the dose-results after 3 months' follow-up

Purpose Randomized comparison of the effect of radiotherapy on painful osteoarthritis (OA) applying a standard-dose vs. a very-low-dose regime Patients and methods Patients with OA of the hand and knee joints were included. Further inclusion criteria: symptoms for more than 3 months, favorable general health status, age above 40 years. Patients with prior local radiotherapy, trauma, rheumatoid arthritis, or vascular diseases were excluded. After randomization (every joint was randomized separately), the following protocols were applied: standard arm: total dose 3.0 Gy, single fractions of 0.5 Gy twice weekly; experimental arm: total dose 0.3 Gy, single fractions of 0.05 Gy twice weekly. The dosage was not known to the patients. The patients were examined 3 and 12 months after radiotherapy. Scores like VAS (visual analogue scale), KOOS-SF (the knee injugy and osteoarthritis outcome score), SF-SACRAH (short form score for the assessment and quantification of chronic rheumatic affections of the hands), and SF-12 (short form 12) were used. Results A total of 64 knees and 172 hands were randomized. 3.0 Gy was applied to 87 hands and 34 knees, 0.3 Gy was given to 85 hands and 30 knees. After 3 months, we observed good pain relief after 3 Gy and after 0.3 Gy, there was no statistically significant difference. Side effects were not recorded. The trial was closed prematurely due to slow recruitment. Conclusion We found favorable pain relief and a limited response in the functional and quality of life scores in both arms. The effect of low doses such as 0.3 Gy on pain is widely unknown. Further trials are necessary to compare a conventional dose to placebo and to further explore the effect of low doses on inflammatory disorders

Gamma(*)Gamma(*) reaction at high energies

The energy available for gamma(*)gamma(*) physics at LEP2 is opening a new window on the study of diffractive phenomena, both non-perturbative and perturbative. We discuss some of the uncertainties and problems connected with the experimental measurements and their interpretation.Comment: 6 pages, 6 figures, submitted to proceedings of the Durham Collider Workshop, 22-26 September 199

Higgs production in gluon fusion at next-to-next-to-leading order QCD for finite top mass

The inclusive Higgs production cross section from gluon fusion is calculated through NNLO QCD, including its top quark mass dependence. This is achieved through a matching of the 1/mtop expansion of the partonic cross sections to the exact large s-hat limits which are derived from k_T-factorization. The accuracy of this procedure is estimated to be better than 1% for the hadronic cross section. The final result is shown to be within 1% of the commonly used effective theory approach, thus confirming earlier findings.Comment: 28 pages, 14 figure

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