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- Successful pain relief in chronic low back pain undergoing multimodal physiotherapy are associated with early response to treatmentPublication . Cruz, Eduardo; Fernandes, Rita; Pires, Diogo; Ribeiro, Ana; Caldeira, Carolina; Costa, Daniela; Duarte, Susana; Domingues, Lúcia
- Clinical course of physiotherapy treatment response in patients with chronic low back pain: a prospective cohort study with survival analysisPublication . Ribeiro, Ana Margarida; Caldeira, Carolina; Semedo, Ana; Pires, Diogo; Cruz, Eduardo
- How to define the success of physiotherapy in chronic low back pain patients?Publication . Pires, Diogo; Cruz, Eduardo; Costa, Daniela; Ribeiro, Ana Margarida; Vieira, Ana Cristina; Moniz, Sara; Nunes, Carla
- Coherent $J/\psi$ photoproduction in ultra-peripheral PbPb collisions at $\sqrt {s_{NN}} =$ 2.76 TeV with the CMS experimentPublication . CMS collaboration (2289 authors); Calpas, Betty; Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoThe cross section for coherent J/ψ photoproduction accompanied by at least one neutron on one side of the interaction point and no neutron activity on the other side, Xn0n , is measured with the CMS experiment in ultra-peripheral PbPb collisions at sNN=2.76 TeV . The analysis is based on a data sample corresponding to an integrated luminosity of 159 μb−1 , collected during the 2011 PbPb run. The J/ψ mesons are reconstructed in the dimuon decay channel, while neutrons are detected using zero degree calorimeters. The measured cross section is dσXn0ncoh/dy(J/ψ)=0.36±0.04(stat)±0.04(syst) mb in the rapidity interval 1.8<|y|<2.3 . Using a model for the relative rate of coherent photoproduction processes, this Xn0n measurement gives a total coherent photoproduction cross section of dσcoh/dy(J/ψ)=1.82±0.22(stat)±0.20(syst)±0.19(theo) mb . The data strongly disfavor the impulse approximation model prediction, indicating that nuclear effects are needed to describe coherent J/ψ photoproduction in γ+Pb interactions. The data are found to be consistent with the leading twist approximation, which includes nuclear gluon shadowing.
- Search for high-mass $\mathrm{ Z }\gamma$ resonances in proton-proton collisions at $\sqrt{s}=$ 8 and 13 TeV using jet substructure techniquesPublication . CMS collaboration (2229 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoA search for massive resonances decaying to a Z boson and a photon is performed in events with a hadronically decaying Z boson candidate, separately in light-quark and b quark decay modes, identified using jet substructure and advanced b tagging techniques. Results are based on samples of proton–proton collisions collected with the CMS detector at the LHC at center-of-mass energies of 8 and 13TeV , corresponding to integrated luminosities of 19.7 and 2.7 fb −1 , respectively. The results of the search are combined with those of a similar search in the leptonic decay modes of the Z boson, based on the same data sets. Spin-0 resonances with various widths and with masses in a range between 0.2 and 3.0TeV are considered. No significant excess is observed either in the individual analyses or the combination. The results are presented in terms of upper limits on the production cross section of such resonances and constitute the most stringent limits to date for a wide range of masses.
- Search for standard model production of four top quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeVPublication . CMS collaboration (2235 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoA search for events containing four top quarks ( tt¯tt¯ ) is reported from proton–proton collisions recorded by the CMS experiment at s=13 TeV and corresponding to an integrated luminosity of 2.6 fb −1 . The analysis considers the single-lepton (e or μ )+jets and the opposite-sign dilepton ( μ+μ− , μ±e∓ , or e+e− )+jets channels. It uses boosted decision trees to combine information on the global event and jet properties to distinguish between tt¯tt¯ and tt¯ production. The number of events observed after all selection requirements is consistent with expectations from background and standard model signal predictions, and an upper limit is set on the cross section for tt¯tt¯ production in the standard model of 94 fb at 95% confidence level ( 10.2 × the prediction), with an expected limit of 118 fb. This is combined with the results from the published CMS search in the same-sign dilepton channel, resulting in an improved limit of 69 fb at 95% confidence level ( 7.4 × the prediction), with an expected limit of 71 fb. These are the strongest constraints on the rate of tt¯tt¯ production to date.
- Search for anomalous couplings in boosted $\mathrm{ WW/WZ }\to\ell\nu\mathrm{ q \bar{q} }$ production in proton-proton collisions at $\sqrt{s} =$ 8 TeVPublication . CMS collaboration (2235 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoThis Letter presents a search for new physics manifested as anomalous triple gauge boson couplings in WW and WZ diboson production in proton–proton collisions. The search is performed using events containing a W boson that decays leptonically and a W or Z boson whose decay products are merged into a single reconstructed jet. The data, collected at s=8 TeV with the CMS detector at the LHC, correspond to an integrated luminosity of 19 fb−1 . No evidence for anomalous triple gauge couplings is found and the following 95% confidence level limits are set on their values: λ ( [−0.011,0.011] ), Δκγ ( [−0.044,0.063] ), and Δg1Z ( [−0.0087,0.024] ). These limits are also translated into their effective field theory equivalents: cWWW/Λ2 ( [−2.7,2.7] TeV−2 ), cB/Λ2 ( [−14,17] TeV−2 ), and cW/Λ2 ( [−2.0,5.7] TeV−2 ).
- Cross section measurement of $t$-channel single top quark production in pp collisions at $\sqrt s =$ 13 TeVPublication . CMS collaboration (2269 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoThe cross section for the production of single top quarks in the t channel is measured in proton–proton collisions at 13 TeV with the CMS detector at the LHC. The analyzed data correspond to an integrated luminosity of 2.2 fb−1 . The event selection requires one muon and two jets where one of the jets is identified as originating from a bottom quark. Several kinematic variables are then combined into a multivariate discriminator to distinguish signal from background events. A fit to the distribution of the discriminating variable yields a total cross section of 238±13(stat)±29(syst) pb and a ratio of top quark and top antiquark production of Rt-ch.=1.81±0.18(stat)±0.15(syst) . From the total cross section the absolute value of the CKM matrix element Vtb is calculated to be 1.05±0.07(exp)±0.02(theo) . All results are in agreement with the standard model predictions.
- First measurement of the Sivers asymmetry for gluons using SIDIS dataPublication . COMPASS collaboration (228 authors); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M.The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. For quarks, it was studied in previous measurements of the azimuthal asymmetry of hadrons produced in semi-inclusive deep inelastic scattering of leptons off transversely polarised nucleon targets, and it was found to be non-zero. In this letter the evaluation of the Sivers asymmetry for gluons is presented. The contribution of the photon–gluon fusion subprocess is enhanced by requiring two high transverse-momentum hadrons. The analysis method is based on a Monte Carlo simulation that includes three hard processes: photon–gluon fusion, QCD Compton scattering and the leading-order virtual-photon absorption process. The Sivers asymmetries of the three processes are simultaneously extracted using the LEPTO event generator and a neural network approach. The method is applied to samples of events containing at least two hadrons with large transverse momentum from the COMPASS data taken with a 160 GeV/ c muon beam scattered off transversely polarised deuterons and protons. With a significance of about two standard deviations, a negative value is obtained for the gluon Sivers asymmetry. The result of a similar analysis for a Collins-like asymmetry for gluons is consistent with zero.
- Measurements of the charm jet cross section and nuclear modification factor in pPb collisions at $\sqrt{{s}_{NN}}$ = 5.02 TeVPublication . CMS collaboration (2270 authors); Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoThe CMS Collaboration presents the first measurement of the differential cross section of jets from charm quarks produced in proton–lead (pPb) collisions at a nucleon–nucleon center-of-mass energy of sNN=5.02TeV , as well as results from charm quark jets in proton–proton (pp) collisions at s=2.76 and 5.02 TeV . By comparing the yields of the pPb and pp collision systems at the same energy, a nuclear modification factor for charm jets from 55 to 400 GeV/c in pPb collisions at sNN=5.02TeV of RpA=0.92±0.07(stat)±0.11(syst) is obtained. This is consistent with an absence of final-state energy loss for charm quarks in pPb collisions. In addition, the fraction of jets coming from charm quarks is found to be consistent with that predicted by pythia 6 for pp collisions at s=2.76 and 5.02 TeV , and is independent of the jet transverse momentum from 55 to 400 GeV/c .