Browsing by Author "Almeida, Nuno"
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- A New Boson with a Mass of 125 GeV Observed with the CMS Experiment at the Large Hadron ColliderPublication . CMS collaboration (2898 authors); Hollar, Jonathan; Nayak, Aruna; Calpas, Betty; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Ribeiro, Pedro Quinaz; Seixas, Joao; Rasteiro Da Silva, Jose; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Musella, Pasquale; Rodrigues Antunes, Joao; Silva, Pedro; Pela, Joao; Leonardo, Nuno
- A search for a doubly-charged Higgs boson in $pp$ collisions at $\sqrt{s}=7$ TeVPublication . CMS collaboration (2192 authors); Hollar, Jonathan; Nayak, Aruna; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Fernandes, Miguel; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Musella, Pasquale; Rodrigues Antunes, Joao; Silva, Pedro; Pela, Joao; Leonardo, NunoA search for a doubly-charged Higgs boson in pp collisions at sqrt(s) = 7 TeV is presented. The data correspond to an integrated luminosity of 4.9 inverse femtobarns, collected by the CMS experiment at the LHC. The search is performed using events with three or more isolated charged leptons of any flavor, giving sensitivity to the decays of pair-produced triplet components Phi[++]Phi[--], and Phi[++]Phi[-] from associated production. No excess is observed compared to the background prediction, and upper limits at the 95% confidence level are set on the Phi[++] production cross section, under specific assumptions on its branching fractions. Lower bounds on the Phi[++] mass are reported, providing significantly more stringent constraints than previously published limits.
- Uma Análise da Função de Combate Apoio de Serviços na Campanha Militar no Teatro de Operações de Angola (1961-1974)Publication . Silva, Elisabete; Silva, Josias; Sousa, Emanuel; Costa, Tiago; Almeida, NunoA campanha militar no teatro de operações de Angola entre 1961 e 1974, foi marcada pelo aparecimento do conceito de guerra subversiva em Portugal, que originou uma mudança no paradigma doutrinário até aí existente, que estava essencialmente focado numa tipologia de guerra convencional. Consequentemente, o apoio de serviços e as funções logísticas em análise nomeadamente, transportes, evacuação e hospitalização e serviço de construções, também sofreram alterações ao nível da doutrina, materializadas em normas de execução permanente e relatórios logísticos do Quartel-general da Região Militar de Angola. Os meios e organização do apoio de serviços foram sendo adaptados consoante o aumento da conflitualidade, emprego das forças de manobra e as zonas do teatro onde os conflitos se desenvolveram. As operações militares, o desenrolar do conflito e as caraterísticas geográficas do teatro de operações, produziram efeitos e consequências no desenvolvimento do conceito e organização do apoio de serviços, nomeadamente nas funções logísticas transportes, hospitalização e evacuação e serviço de construções. Abstract: Between 1961 and 1974, one of the highlights of the military campaigns in Angola, was the appearing of a subversive war that led to the change of the existing doctrinal paradigm, which was primarily focused on conventional war. Also on the services support component and logistics functions, transports, evacuations and hospitalization, and in construction service, the paradigm was being updated trough standard operational procedures implementation and logistics reports from Angola regional headquarter. For this campaign, as the maneuver assets and therefore their support services were being adapted to the conflict increasing and to the areas in which the conflicts took place, as well the organization of those assents for the missions. The Military operations, the development of the conflict and the geographic of the theater of operations, caused effects and consequences on the development of the service support organization concept, particularly in the logistics functions, transports, evacuation and hospitalization and construction service.
- Angular analysis and branching fraction measurement of the decay $B^0 \to K^{*0} \mu^+\mu^-$Publication . CMS collaboration (2217 authors); Hollar, Jonathan; Nayak, Aruna; Calpas, Betty; Almeida, Nuno; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; David Tinoco Mendes, Andre; Musella, Pasquale; Silva, Pedro; Pela, Joao; Leonardo, NunoThe angular distributions and the differential branching fraction of the decay $B^0 \to K^*(892)^0 \mu^+ \mu^-$ are studied using a data sample corresponding to an integrated luminosity of 5.2 inverse femtobarns collected with the CMS detector at the LHC in pp collisions at $\sqrt{s}$ = 7 TeV. From more than 400 signal decays, the forward-backward asymmetry of the muons, the $K^*(892)^0$ longitudinal polarization fraction, and the differential branching fraction are determined as a function of the square of the dimuon invariant mass. The measurements are in good agreement with standard model predictions.
- Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at $\sqrt{s_{NN}}=2.76$ TeVPublication . CMS collaboration (2206 authors); Hollar, Jonathan; Nayak, Aruna; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Silva, Pedro; Pela, Joao; Leonardo, NunoThe azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.
- Centrality dependence of dihadron correlations and azimuthal anisotropy harmonics in PbPb collisions at $\sqrt{s_{NN}}=2.76$ TeVPublication . CMS collaboration (2279 authors); Hollar, Jonathan; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Nayak, Aruna; Pela, Joao; Ribeiro, Pedro Quinaz; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Silva, Pedro; Leonardo, NunoMeasurements from the CMS experiment at the LHC of dihadron correlations for charged particles produced in PbPb collisions at a nucleon-nucleon centre-of-mass energy of 2.76 TeV are presented. The results are reported as a function of the particle transverse momenta (pt) and collision centrality over a broad range in relative pseudorapidity [Delta(eta)] and the full range of relative azimuthal angle [Delta(phi)]. The observed two-dimensional correlation structure in Delta(eta) and Delta(phi) is characterised by a narrow peak at (Delta(eta), Delta(phi)) approximately (0, 0) from jet-like correlations and a long-range structure that persists up to at least |Delta(eta)| = 4. An enhancement of the magnitude of the short-range jet peak is observed with increasing centrality, especially for particles of pt around 1-2 GeV/c. The long-range azimuthal dihadron correlations are extensively studied using a Fourier decomposition analysis. The extracted Fourier coefficients are found to factorise into a product of single-particle azimuthal anisotropies up to pt approximately 3-3.5 GeV/c for at least one particle from each pair, except for the second-order harmonics in the most central PbPb events. Various orders of the single-particle azimuthal anisotropy harmonics are extracted for associated particle pt of 1-3 GeV/c, as a function of the trigger particle pt up to 20 GeV/c and over the full centrality range.
- Combined results of searches for the standard model Higgs boson in $pp$ collisions at $\sqrt{s}=7$ TeVPublication . CMS collaboration (2271 authors); Hollar, Jonathan; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Musella, Pasquale; Nayak, Aruna; Pela, Joao; Ribeiro, Pedro Quinaz; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Silva, Pedro; Leonardo, NunoCombined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.
- Combined search for the quarks of a sequential fourth generationPublication . CMS collaboration (2202 authors); Hollar, Jonathan; Nayak, Aruna; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; Musella, Pasquale; Rodrigues Antunes, Joao; Silva, Pedro; Pela, Joao; Leonardo, NunoResults are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.
- Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at $\sqrt{s}$ = 7 TeVPublication . CMS collaboration (2211 authors); Hollar, Jonathan; Nayak, Aruna; Calpas, Betty; Almeida, Nuno; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Lloret Iglesias, Lara; David Tinoco Mendes, Andre; Musella, Pasquale; Silva, Pedro; Pela, Joao; Leonardo, NunoThe inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, $m_t^{pole}$, or the strong coupling constant, $\alpha_S$. With the parton distribution function set NNPDF2.3, a pole mass of 176.7$^{+3.0}_{-2.8}$ GeV is obtained when constraining $\alpha_S$ at the scale of the Z boson mass, $m_Z$, to the current world average. Alternatively, by constraining $m_t^{pole}$ to the latest average from direct mass measurements, a value of $\alpha_S(m_Z)$ = 0.1151$^{+0.0028}_{-0.0027}$ is extracted. This is the first determination of $\alpha_S$ using events from top-quark production.
- Developing a Wine Experience Scale: A New Strategy to Measure Holistic Behaviour of Wine TouristsPublication . Santos, Vasco; Ramos, Paulo; Almeida, Nuno; Santos-Pavón, EnriqueThis study develops a scale to measure wine tourism experiences and was tested in Portugal, in two of the main wine tourism centres: Porto and Madeira. The wine experience scale combines experience traits with the traditional approach to scales related to wine tourism. The development of the scale follows the most recognised validated procedures. Data were collected from a total of 647 international wine tourists in the wine cellars of the two main fortified wine tourism regions visiting areas: Porto and Madeira. Structural equation modelling (SEM-AMOS) was used as the main analysis and validation tool. The resulting 18-item wine experience scale comprises four major dimensions: (1) Wine storytelling, (2) wine tasting excitement, (3) wine involvement, and (4) winescape. All these showed reliable and validated indicators. This new scale presents a valid new tool to better measure and evaluate experiences in a wine tourism setting. This study o ers a broad range of use for academics, managers, planners, and practitioners. It shows how a new measurement tool focused on the wine tourism experience in terms of several outcomes and applications, addressing important practical managerial implications, can have an impact on academic research. Most previous tourism scales still fail to measure the specifics of wine settings. This is the first scale that comprises the dimensions of experience with wine senses, applied in a relevant wine destination where research is still limited. The results are relevant in boosting the increasingly recognized awareness of Portugal as wine tourism, as well as bringing experience scales to the body of knowledge.