1,273 research outputs found
Electroweak corrections to squark-antisquark production at the LHC
We present the calculation of the electroweak corrections for
squark-antisquark pair production at the LHC within the Minimal Supersymmetric
Standard Model. Taking into account all possible chirality and light-flavor
configurations, we evaluate the NLO EW corrections, which are of O(a_s^2 a), as
well as the subleading tree-level contributions of O(a_s a) and O(a^2).
Numerical results are presented for several scans in the SUSY parameter space
and relevant differential distributions are investigated. The impact of the
electroweak corrections is nonnegligible and strongly depends on the chirality
configuration of the produced squarks. Our analysis includes a discussion of
photon-gluon initiated processes with a focus on the impact of the
corresponding large PDF uncertainties.Comment: 33 pages, 12 figures; V2: Original results unchanged. Various minor
modifications. Matches version published in JHE
Top-squark pair production at the LHC: a complete analysis at next-to-leading order
We present a complete next-to-leading order study of top-squark pair
production at the LHC, including QCD and EW corrections. The calculation is
performed within the Minimal Supersymmetric Standard Model and numerical
results are presented for parameter regions compatible with the observed Higgs
boson. We employ the most recent parton distribution functions including QED
corrections and we find NLO EW corrections to the inclusive stop-pair
production cross section up to compared to the leading-order
prediction. Besides corrections to inclusive cross sections also important
kinematic distributions are investigated.Comment: 27 pages, 10 figures. Version published in JHEP. The numerical
discussion in Section 3 has been extended. References have been adde
On the test of single via related defects in digital VLSI designs
Vias are critical for digital circuit manufacturing, as they represent a common defect location, and a general DfM rule suggests replicating every instance for redundancy. When this is not achievable, a mandatory requirement is that the remaining single vias must be tested. We propose an automated method for generating tests and accurately evaluating test coverage of such defects, ready for use in any digital implementation flow and for integration within EDA tools, and also providing a useful quality metric. A prototype tool implementation and experimental results for an industrial case study are presented
Semi-inclusive bottom-Higgs production at LHC: The complete one-loop electroweak effect in the MSSM
We present the first complete calculation of the one-loop electroweak effect
in the process of semi-inclusive bottom-Higgs production at LHC in the MSSM.
The size of the electroweak contribution depends on the choice of the final
produced neutral Higgs boson, and can be relevant, in some range of the input
parameters. A comparison of the one-loop results obtained in two different
renormalization schemes is also performed, showing a very good NLO scheme
independence. We further comment on two possible, simpler, approximations of
the full NLO result, and on their reliabilty
Deterministic Algorithms for Four-Dimensional Imaging in Colocated MIMO OFDM-Based Radar Systems
In this manuscript, the problem of detecting multiple targets and jointly estimating their spatial coordinates (namely, the range, the Doppler and the direction of arrival of their electromagnetic echoes) in a colocated multiple-input multiple-output radar system employing orthogonal frequency division multiplexing is investigated. It is well known its optimal solution, namely the joint maximum likelihood estimator of an unknown number of targets, is unfeasible because of its huge computational complexity. Moreover, until now, sub-optimal solutions have not been proposed in the technical literature. In this manuscript a novel approach to the development of reduced complexity solutions is illustrated. It is based on the idea of separating angle estimation from range-Doppler estimation, and of exploiting known algorithms for solving these two sub-problems. A detailed analysis of the accuracy and complexity of various detection and estimation methods based on this approach is provided. Our numerical results evidence that one of these methods is able to approach optimal performance in the maximum likelihood sense with a limited computational effort in different scenarios
On the Use of a Two-Dimensional Cyclic Prefix in OTFS Modulation and Its Implications
In this manuscript we investigate the implications of adopting a double cyclic prefix in the orthogonal time-frequency space modulation. Our study first focuses on the analysis of the modulated signal and on the development of a useful model for the received signal in the presence of a doubly selective fading channel. On the one hand, our mathematical results allow us to accurately assess the impact of pulse shaping on the structure of the transmitted waveform and on its power spectral density, and to develop some simple rules for allocating multiple pilot symbols within each orthogonal time-frequency space symbol. On the other hand, they are exploited to develop a novel algorithm for pilot-aided channel estimation, whose output provides a detailed representation of the communication channel; for this reason, it can be used for sensing at the transmit side in integrated sensing and communication applications, or for channel equalization at the receive side in digital communications. Our numerical results evidence that our channel estimation & equalization algorithm outperforms the other related techniques available in the technical literature at the price of a limited increase in computational complexity
A complete one-loop calculation of electroweak supersymmetric effects in -channel single top production at LHC
We have computed the complete one-loop electroweak effects in the MSSM for
single top (and single antitop) production in the -channel at hadron
colliders, generalizing a previous analysis performed for the dominant
final state and fully including QED effects. The results are quite similar for
all processes. The overall Standard Model one-loop effect is small, of the few
percent size. This is due to a compensation of weak and QED contributions that
are of opposite sign. The genuine SUSY contribution is generally quite modest
in the mSUGRA scenario. The experimental observables would therefore only
practically depend, in this framework, on the CKM coupling.Comment: 25 pages, several eps figures. Update corresponding to published
versio
Seismic reflection data in the Umbria Marche Region: limits and capabilities to unravel the subsurface structure in a seismically active area
Before seismic data were made available, the subsurface setting of the Umbria-Marche area was mainly derived
from the extrapolation of surface data and from models resulting from analogies with other mountain chains
around the world. During the ‘90s industrial seismic data availability considerably increased, allowing the definition
of new, previously unknown features. Beside the industrial seismic data availability, a deep crustal, near
vertical seismic section trending E-W was acquired (CROP-03) across the Italian peninsula from the Tyrrhenian
to the Adriatic coast. The subsurface data defined the compressional deformation style (thin- Vs thick- skinned)
and the extensional deformation style. A set of east-dipping low-angle-normal faults, which dissect the previous
compressional structures and which are the dominant features controlling the extension of the Apennines were
recognised. The subsequent application of the seismic data interpretation to seismotectonic issues, defined in
more detail the subsurface geometries of the active faults and the relationships between upper crust structure and
seismicity
Inflammatory Abdominal Aortic Aneurysm (IAAA)
Purpose: The aim of this study is to report our experience about the inflammatory abdominal aortic aneurysm (IAAA).
Methods: Between January 1999 and January 2008 we treated 8 cases of IAAA. Two patients underwent surgery in emergency. The preoperative diagnostic procedures were ultrasound (US), computed tomography (CT) and intravenous urography (IVU). In 6 elective patients the diagnosis of IAAA was obtained preoperatively. In one case a left hydroureteronephrosis was demonstrated by intravenous urography (IVU). All patients underwent open surgery with midline incision and transperitoneal access.
Results: No 30-days mortality occurred. A case of pancreatitis was treated with conservative therapy. All patients had 60-days corticosteroid therapy.
Conclusions: Our data suggest that because IAAA have the same rate of rupture of AAA, they need the same preventive treatment as non inflammatory abdominal aortic aneurysm (AAA) The kind of approach OPEN-EVAR should be chosen with the same criteria as AAA, even if EVAR teatment doesn't allow us to obtain the biopsy. Furthermore there are no sufficient evidences about regression of retroperitoneal fibrosis after EVAR treatment. Also the premature onset should be considered in the choice of treatment
An Approximate Maximum Likelihood Method for the Joint Estimation of Range and Doppler of Multiple Targets in OFDM-Based Radar Systems
In this manuscript, an innovative method for the detection and the estimation of multiple targets in a radar system employing orthogonal frequency division multiplexing is illustrated. The core of this method is represented by a novel algorithm for detecting multiple superimposed two-dimensional complex tones in the presence of noise and estimating their parameters. This algorithm is based on a maximum likelihood approach and combines a single tone estimator with a serial cancellation procedure. Our numerical results lead to the conclusion that the developed method can achieve a substantially better accuracy-complexity trade-off than various related techniques in the presence of closely spaced targets
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