| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 4. |
- Crivellin, Andreas, et al.
(författare)
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Searching for lepton flavor universality violation and collider signals from a singly charged scalar singlet
- 2021
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:7
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, evidence for lepton flavor universality violation beyond the Standard Model has been accumulated. In this context, a singly charged SU(2)(L) singlet scalar (phi(+/-)) is very interesting, as it can only have flavor off-diagonal couplings to neutrinos and charged leptons therefore necessarily violating lepton flavor (universality). In fact, it gives a (necessarily constructive) tree-level effect in l -> l'nu nu processes, while contributing to charged lepton flavor violating only at the loop level. Therefore, it can provide a common explanation of the hints for new physics in tau -> mu nu nu/tau(mu) -> e nu nu and of the Cabibbo Angle Anomaly. Such an explanation predicts Br[tau -> e gamma] to be of the order of a few times 10(-11), while Br[tau -> e mu mu] can be of the order of 10(-9) for order one couplings and therefore in the reach of forthcoming experiments. Furthermore, we derive a novel coupling-independent lower limit on the scalar mass of approximate to 200 GeV by recasting LHC slepton searches. In the scenario preferred by low energy precision data, the lower limit is even strengthened to approximate to 300 GeV, showing the complementary between LHC searches and flavor observables. Furthermore, we point out that this model can be tested by reinterpreting dark matter monophoton searches at future e(+)e(-) colliders.
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| 5. |
- dell'Isola, Francesco, et al.
(författare)
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Advances in pantographic structures : design, manufacturing, models, experiments and image analyses
- 2019
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Ingår i: Continuum Mechanics and Thermodynamics. - : Springer. - 0935-1175 .- 1432-0959. ; 31:4, s. 1231-1282
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Tidskriftsartikel (refereegranskat)abstract
- In the last decade, the exotic properties of pantographic metamaterials have been investigated and different mathematical models (both discrete or continuous) have been introduced. In a previous publication, a large part of the already existing literature about pantographic metamaterials has been presented. In this paper, we give some details about the next generation of research in this field. We present an organic scheme of the whole process of design, fabrication, experiments, models and image analyses.
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| 6. |
- Laudato, M., et al.
(författare)
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Dynamics of pantographic sheet around the clamping region : experimental and numerical analysis
- 2021
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Ingår i: Mathematics and mechanics of solids. - : SAGE Publications. - 1081-2865 .- 1741-3028. ; 26:10, s. 1515-1537
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Tidskriftsartikel (refereegranskat)abstract
- The experimental and numerical analyses of the linear time-invariant dynamical behavior of the clamping region of a 2D pantographic material are presented. The experimental observations of the clamping area, obtained by means of a specialized stereo microscope, are compared with the results of a second gradient linear model enforcing the same symmetries as the system microstructure.
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| 7. |
- Laudato, Marco, et al.
(författare)
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Experimental analysis on metamaterials boundary layers by means of a pantographic structure under large deformations
- 2022
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Ingår i: Mechanics research communications. - : Elsevier BV. - 0093-6413 .- 1873-3972. ; 125, s. 103990-
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the dynamical behavior of a pantographic structure undergoing large deformations is analyzed. A harmonic force is applied on the structure, while its motion in time is recorded by means of a high-speed camera system. The resulting displacement field is obtained via the digital image correlation (DIC) method for the whole domain. A parametric study with respect to the amplitude of the imposed force exhibits the appearance of non-linear effects in the system response as well as the presence of a so-called boundary layer region. Such geometric nonlinearities are of paramount interest for studying the accuracy of a potential computational model. Boundary layers are known to be effected by the microstructure, but their roles in the system response are yet to be comprehended. The experimental results obtained in this work may be used as a benchmark case in modeling metamaterials.
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| 8. |
- Laudato, Marco, et al.
(författare)
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First experimental observation of the dynamical behavior of a pantographic metamaterial
- 2018
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Ingår i: Mechanics research communications. - : Elsevier. - 0093-6413 .- 1873-3972. ; 94, s. 125-127
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Tidskriftsartikel (refereegranskat)abstract
- The first experimental observation of the dynamical behavior of a pantographic sheet is presented. The experimental setup and the measurement procedures are accurately described. Finally, a qualitative description of the displacement vector field in time for a set of relevant frequencies is presented.
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| 9. |
- Laudato, Marco, 1990-, et al.
(författare)
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Linear dynamics of 2D pantographic metamaterial: numerical and experimental study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, the results of numerical and experimental studies on the linear time-invariant dynamics of a 2D pantographic material are presented. The outcomes of a linear second gradient model enforcing the same symmetry of the microstructure is compared to experimental observations obtained via Digital Image Correlation.
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| 10. |
- Laudato, M, et al.
(författare)
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Linear Dynamics of 2D Pantographic Metamaterials: Numerical and Experimental Study
- 2020
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Ingår i: Advanced Structured Materials. - Cham : Springer Nature. ; , s. 353-375
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, the results of numerical and experimental studies on the linear time-invariant dynamics of a 2D pantographic material are presented. The outcomes of a linear second gradient model enforcing the same symmetry of the microstructure is compared to experimental observations obtained via Digital Image Correlation (DIC).
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