132 research outputs found
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
Louse-borne relapsing fever (Borrelia recurrentis) diagnosed in 15 refugees from northeast Africa: epidemiology and preventive control measures, Bavaria, Germany, July to October 2015
We report 15 imported louse-borne relapsing fever (LBRF) cases in refugees in Bavaria, Germany. One patient died. Epidemiological findings confirmed that all were young males from the Horn of Africa (12 from Somalia), who had similar migration routes converging in Sudan continuing through Libya and Italy. The majority likely acquired their infection during migration. Healthcare workers should be aware of LBRF in refugees passing through north Africa to ensure correct treatment and preventive measures.</jats:p
Yukawa potentials in systems with partial periodic boundary conditions I : Ewald sums for quasi-two dimensional systems
Yukawa potentials are often used as effective potentials for systems as
colloids, plasmas, etc. When the Debye screening length is large, the Yukawa
potential tends to the non-screened Coulomb potential ; in this small screening
limit, or Coulomb limit, the potential is long ranged. As it is well known in
computer simulation, a simple truncation of the long ranged potential and the
minimum image convention are insufficient to obtain accurate numerical data on
systems. The Ewald method for bulk systems, i.e. with periodic boundary
conditions in all three directions of the space, has already been derived for
Yukawa potential [cf. Y., Rosenfeld, {\it Mol. Phys.}, \bm{88}, 1357, (1996)
and G., Salin and J.-M., Caillol, {\it J. Chem. Phys.}, \bm{113}, 10459,
(2000)], but for systems with partial periodic boundary conditions, the Ewald
sums have only recently been obtained [M., Mazars, {\it J. Chem. Phys.}, {\bf
126}, 056101 (2007)]. In this paper, we provide a closed derivation of the
Ewald sums for Yukawa potentials in systems with periodic boundary conditions
in only two directions and for any value of the Debye length. A special
attention is paid to the Coulomb limit and its relation with the
electroneutrality of systems.Comment: 40 pages, 5 figures and 4 table
F18-FDG PET/CT imaging early predicts pathologic complete response to induction chemoimmunotherapy of locally advanced head and neck cancer: preliminary single-center analysis of the checkrad-cd8 trial
Aim
In the CheckRad-CD8 trial patients with locally advanced head and neck squamous cell cancer are treated with a single cycle of induction chemo-immunotherapy (ICIT). Patients with pathological complete response (pCR) in the re-biopsy enter radioimmunotherapy. Our goal was to study the value of F-18-FDG PET/CT in the prediction of pCR after induction therapy.
Methods
Patients treated within the CheckRad-CD8 trial that additionally received FDG- PET/CT imaging at the following two time points were included: 3â14 days before (pre-ICIT) and 21â28 days after (post-ICIT) receiving ICIT. Tracer uptake in primary tumors (PT) and suspicious cervical lymph nodes (LNâ+) was measured using different quantitative parameters on EANM Research Ltd (EARL) accredited PET reconstructions. In addition, mean FDG uptake levels in lymphatic and hematopoietic organs were examined. Percent decrease (Î) in FDG uptake was calculated for all parameters. Biopsy of the PT post-ICIT acquired after FDG-PET/CT served as reference. The cohort was divided in patients with pCR and residual tumor (ReTu).
Results
Thirty-one patients were included. In ROC analysis, ÎSUVmax PT performed best (AUCâ=â0.89) in predicting pCR (nâ=â17), with a decline of at least 60% (sensitivity, 0.77; specificity, 0.93). Residual SUVmax PT post-ICIT performed best in predicting ReTu (nâ=â14), at a cutpoint of 6.0 (AUCâ=â0.91; sensitivity, 0.86; specificity, 0.88). Combining two quantitative parameters (ÎSUVmaxââ„â50% and SUVmax PT post-ICITââ€â6.0) conferred a sensitivity of 0.81 and a specificity of 0.93 for determining pCR. Background activity in lymphatic organs or uptake in suspected cervical lymph node metastases lacked significant predictive value.
Conclusion
FDG-PET/CT can identify patients with pCR after ICIT via residual FDG uptake levels in primary tumors and the related changes compared to baseline. FDG-uptake in LNâ+âhad no predictive value.
Trial registry
ClinicalTrials.gov identifier: NCT03426657
Restoration of factorization for low hadron hadroproduction
We discuss the applicability of the factorization theorem to low-
hadron production in hadron-hadron collision in a simple toy model, which
involves only scalar particles and gluons. It has been shown that the
factorization for high- hadron hadroproduction is broken by soft gluons in
the Glauber region, which are exchanged among a transverse-momentum-dependent
(TMD) parton density and other subprocesses of the collision. We explain that
the contour of a loop momentum can be deformed away from the Glauber region at
low , so the above residual infrared divergence is factorized by means of
the standard eikonal approximation. The factorization is then restored in
the sense that a TMD parton density maintains its universality. Because the
resultant Glauber factor is independent of hadron flavors, experimental
constraints on its behavior are possible. The factorization can also be
restored for the transverse single-spin asymmetry in hadron-hadron collision at
low in a similar way, with the residual infrared divergence being
factorized into the same Glauber factor.Comment: 12 pages, 2 figures, version to appear in EPJ
F18-FDG PET/CT imaging early predicts pathologic complete response to induction chemoimmunotherapy of locally advanced head and neck cancer: preliminary single-center analysis of the checkrad-cd8 trial
Aim In the CheckRad-CD8 trial patients with locally advanced head and neck squamous cell cancer are treated with a single cycle of induction chemo-immunotherapy (ICIT). Patients with pathological complete response (pCR) in the re-biopsy enter radioimmunotherapy. Our goal was to study the value of F-18-FDG PET/CT in the prediction of pCR after induction therapy. Methods Patients treated within the CheckRad-CD8 trial that additionally received FDG- PET/CT imaging at the following two time points were included: 3â14 days before (pre-ICIT) and 21â28 days after (post-ICIT) receiving ICIT. Tracer uptake in primary tumors (PT) and suspicious cervical lymph nodes (LNâ+) was measured using different quantitative parameters on EANM Research Ltd (EARL) accredited PET reconstructions. In addition, mean FDG uptake levels in lymphatic and hematopoietic organs were examined. Percent decrease (Î) in FDG uptake was calculated for all parameters. Biopsy of the PT post-ICIT acquired after FDG-PET/CT served as reference. The cohort was divided in patients with pCR and residual tumor (ReTu). Results Thirty-one patients were included. In ROC analysis, ÎSUVmax PT performed best (AUCâ=â0.89) in predicting pCR ( n â=â17), with a decline of at least 60% (sensitivity, 0.77; specificity, 0.93). Residual SUVmax PT post-ICIT performed best in predicting ReTu ( n â=â14), at a cutpoint of 6.0 (AUCâ=â0.91; sensitivity, 0.86; specificity, 0.88). Combining two quantitative parameters (ÎSUVmaxââ„â50% and SUVmax PT post-ICITââ€â6.0) conferred a sensitivity of 0.81 and a specificity of 0.93 for determining pCR. Background activity in lymphatic organs or uptake in suspected cervical lymph node metastases lacked significant predictive value. Conclusion FDG-PET/CT can identify patients with pCR after ICIT via residual FDG uptake levels in primary tumors and the related changes compared to baseline. FDG-uptake in LNâ+âhad no predictive value. Trial registry ClinicalTrials.gov identifier: NCT03426657.Open Access funding enabled and organized by Projekt DEAL.AstraZeneca http://dx.doi.org/10.13039/100004325Friedrich-Alexander-UniversitĂ€t Erlangen-NĂŒrnberg (1041
Bessel-Weighted Asymmetries in Semi Inclusive Deep Inelastic Scattering
The concept of weighted asymmetries is revisited for semi-inclusive deep
inelastic scattering. We consider the cross section in Fourier space, conjugate
to the outgoing hadron's transverse momentum, where convolutions of transverse
momentum dependent parton distribution functions and fragmentation functions
become simple products. Individual asymmetric terms in the cross section can be
projected out by means of a generalized set of weights involving Bessel
functions. Advantages of employing these Bessel weights are that they suppress
(divergent) contributions from high transverse momentum and that soft factors
cancel in (Bessel-) weighted asymmetries. Also, the resulting compact
expressions immediately connect to previous work on evolution equations for
transverse momentum dependent parton distribution and fragmentation functions
and to quantities accessible in lattice QCD. Bessel weighted asymmetries are
thus model independent observables that augment the description and our
understanding of correlations of spin and momentum in nucleon structure.Comment: Matches published version, JHEP style, 36 pages and 2 figures, minor
correction
Proceedings of the 38th International Symposium on Multiparticle Dynamics (ISMD08)
Proceedings of ISMD08Comment: Edited by: J. Bartels, K. Borras, G. Gustafson, H. Jung, K. Kutak, S.
Levonian, and J. Mnic
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