Luca Fedeli

Quality assurance multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging

To propose a magnetic resonance imaging (MRI) quality assurance procedure that can be used for multicenter comparison of different MR scanners for quantitative diffusion‐weighted imaging (DWI).

Interference effects in heavy W'-boson searches at the LHC

Interference effects are widely neglected in searches for new physics. This is the case in recent publications on searches for W?-bosons using leptonic final states. We examine the effects of interference on distributions frequently used to determine mass limits for possible W?-bosons and show that there are important qualitative effects on the behaviour of the new physics signal. There are two main consequences. The first is that current exclusion limits, where interferences effects have not been considered, are likely to have been overestimated. The second is that the way observed limits on the cross-section are presented, in terms of the contribution of new physics to the total cross-section, is not meaningful.

Drell-Yan production at the LHC in a four site Higgsless model

We consider a four site Higgsless model based on the SU(2){sub L}xSU(2){sub 1}xSU(2){sub 2}xU(1){sub Y} gauge symmetry, which predicts two neutral and four charged extra gauge bosons, Z{sub 1,2} and W{sub 1,2}{sup {+-}}. We compute the properties of the new particles, and derive indirect and direct limits on their masses and couplings from the CERN LEP and Tevatron data. In contrast to other Higgsless models, characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. The prospects of detecting the new predicted particles in the favored Drell-Yan channel at the CERN LHC are thus investigated. The outcome is that all six extra gauge bosons could be discovered in the early stage of the LHC low-luminosity run.

The Four site Higgsless model at the LHC

We consider the four-site Higgsless model, which predicts the existence of four charged and two neutral extra gauge bosons,

Z' production at the LHC in the four-site Higgsless model

W_{1,2}^\pm

W' production at the LHC in the 4-site Higgsless model

and

Improved analysis of the bounds from the electroweak precision tests on the 4-site model

Z_{1,2}

Dependence of apparent diffusion coefficient measurement on diffusion gradient direction and spatial position – A quality assurance intercomparison study of forty-four scanners for quantitative diffusion-weighted imaging

. In contrast to other Higgsless models, characterized by fermiophobic extra gauge bosons, here sizeable fermion-boson couplings are allowed by the electroweak precision data. We thus analyse the prospects of detecting the new predicted particles in the mostly favored Drell-Yan channel at the LHC.

A straightforward multiparametric quality control protocol for proton magnetic resonance spectroscopy: Validation and comparison of various 1.5 T and 3 T clinical scanner systems

We study the phenomenology of the neutral gauge sector of the four-site Higgsless model, based on the SU(2){sub L}xSU(2){sub 1}xSU(2){sub 2}xU(1){sub Y} gauge symmetry, at present colliders. The model predicts the existence of two neutral and four charged extra gauge bosons, Z{sub 1,2} and W{sub 1,2}{sup {+-}}. We expand and update a previous study, by concentrating on the neutral sector. We derive new limits on Z{sub 1,2}-boson masses and couplings from recent direct searches at the Tevatron. We moreover estimate the discovery potential at the Tevatron with a project luminosity L=10 fb{sup -1}, and at the 7 TeV LHC with L=1 fb{sup -1}. In contrast to other Higgsless theories characterized by almost fermiophobic extra gauge bosons, the four-site model allows sizable Z{sub 1,2}-boson couplings to standard model fermions. Owing to this feature, we find that in the next 2 years the extra Z{sub 1,2} bosons could be discovered in the favored Drell-Yan channel at the 7 TeV LHC for Z{sub 1,2} masses in the TeV region, depending on model parameters.

OC-0458: Delivery errors detectability with IQM, a system for real-time monitoring of radiotherapy treatments

We study the phenomenology of the 4-site Higgsless model, based on the SU(2)_L × SU(2)_1 × SU(2)_2 × U(1)_Y gauge symmetry, at present colliders. The model predicts the existence of two neutral and four charged extra gauge bosons, Z_(1,2) and W±. In this paper, we focus on the charged gauge sector. We first derive limits on W1,2-boson masses and couplings to SM fermions from direct searches at the Tevatron. We then estimate at the 7 TeV LHC the exclusion limits with the actual L=1 fb?1 and the discovery potential with the expected L=10 fb?1. In contrast to the minimal (or 3-site) Higgsless model which predicts almost fermiophobic extra gauge bosons, the next-to-minimal (or 4-site) Higgsless model recovers sizeable W_(1,2)-boson couplings to ordinary matter, expressing the non-fermiophobic multiresonance inner nature of extra-dimensional theories. Owing to this feature, we find that in one year from now the new heavy gauge bosons, W± , could be discovered in the final state with an electron and large missing transverse energy at the 7 TeV LHC for W1,2-boson masses in the TeV region, depending on model parameters