55 research outputs found

    Deep exclusive π+\pi^+ electroproduction off the proton at CLAS

    Get PDF
    The exclusive electroproduction of π+\pi^+ above the resonance region was studied using the CEBAF\rm{CEBAF} Large Acceptance Spectrometer (CLAS\rm{CLAS}) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of CLAS\rm{CLAS}, together with the high luminosity, allowed us to measure the cross section for the γ∗p→nπ+\gamma^* p \to n \pi^+ process in 140 (Q2Q^2, xBx_B, tt) bins: 0.16<xB<0.580.16<x_B<0.58, 1.6 GeV2<^2<Q2Q^2<4.5<4.5 GeV2^2 and 0.1 GeV2<^2<−t-t<5.3<5.3 GeV2^2. For most bins, the statistical accuracy is on the order of a few percent. Differential cross sections are compared to two theoretical models, based either on hadronic (Regge phenomenology) or on partonic (handbag diagram) degrees of freedom. Both can describe the gross features of the data reasonably well, but differ strongly in their ingredients. If the handbag approach can be validated in this kinematical region, our data contain the interesting potential to experimentally access transversity Generalized Parton Distributions.Comment: 18pages, 21figures,2table

    Use of boost radiotherapy in oncoplastic breast-conserving surgery – a systematic review

    No full text
    Background: The use of local boost radiotherapy to the tumour bed has been demonstrated in randomised-controlled trials to reduce local recurrence rates following breast-conserving surgery (BCS) and is the standard of care. Oncoplastic BCS techniques with parenchymal rearrangement present new challenges to the localisation of the tumour bed and therefore delivery of local boost radiotherapy. The aim of this review was to evaluate the reporting of boost radiotherapy in the oncoplastic BCS literature.&lt;p&gt;&lt;/p&gt; Methods: Pubmed, Ovid MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched for studies reporting oncoplastic BCS using volume displacement techniques.&lt;p&gt;&lt;/p&gt; Results: 24 studies met the inclusion criteria (n = 1933 patients). Use of boost radiotherapy was reported in 11 studies, in 2 of which it was for the treatment of incomplete or close margins, and marking of the tumour bed was only reported in 8 studies. None of the studies reported the number of patients where the tumour bed could not be localised.&lt;p&gt;&lt;/p&gt; Conclusions: The use of local boost radiotherapy and tumour bed marking was not reported in the majority of studies of oncoplastic BCS. Future studies need to provide detailed information regarding the use of boost radiotherapy and difficulties determining the target volume so that current radiotherapy approaches can be reviewed and improved for these advanced techniques.&lt;p&gt;&lt;/p&gt
    • 

    corecore