Search results for "Lhc"
showing 10 items of 342 documents
"Expected exclusion contours on HVT $\{g_q,g_l\}$ at 5 TeV" of "Search for high-mass dilepton resonances using 139 fb$^{-1}$ of $pp$ collision data c…
2019
Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 5 TeV for the dilepton channel. The area outside the curves is excluded.
"Expected exclusion contours on HVT $\{g_q,g_l\}$ at 4 TeV" of "Search for high-mass dilepton resonances using 139 fb$^{-1}$ of $pp$ collision data c…
2019
Expected 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance masses of 4 TeV for the dilepton channel. The area outside the curves is excluded.
"Observed exclusion contours on HVT $\{g_q,g_l\}$ at 5 TeV" of "Search for high-mass dilepton resonances using 139 fb$^{-1}$ of $pp$ collision data c…
2019
Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 5 TeV for the dilepton channel. The area outside the curves is excluded.
"Observed exclusion contours on HVT $\{g_q,g_l\}$ at 4 TeV" of "Search for high-mass dilepton resonances using 139 fb$^{-1}$ of $pp$ collision data c…
2019
Observed 95% exclusion contours in the HVT parameter space $\{g_q,g_l\}$ with $g_h$ set to zero for a resonance mass of 4 TeV for the dilepton channel. The area outside the curves is excluded.
Measurement of Upsilon production in collisions at root s=2.76 TeV
2014
The production of Υ(1S) , Υ(2S) and Υ(3S) mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3pb-1 collected in proton–proton collisions at a centre-of-mass energy of s=2.76 TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the Υ transverse momentum and rapidity, over the ranges pT<15 GeV/ c and 2.0<y<4.5 . The total cross-sections in this kinematic region, assuming unpolarised production, are measured to be σpp→Υ(1S)X×BΥ(1S)→μ+μ-=1.111±0.043±0.044nb,σpp→Υ(2S)X×BΥ(2S)→μ+μ-=0.264±0.023±0.011nb,σpp→Υ(3S)X×BΥ(3S)→μ+μ-=0.159±0.020±0.…
Measurement of Wγ and Zγ production in proton-proton collisions at √s =7 TeV with the ATLAS detector
2011
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
Determination of the $X(3872)$ meson quantum numbers
2013
The quantum numbers of the X(3872) meson are determined to be J(PC) = 1(++) based on angular correlations in B+ -> X(3872)K+ decays, where X(3872) -> pi(+) pi(-) j/psi and J/psi -> pi(+) mu(-). The data correspond to 1.0 fb(-1) of pp collisions collected by the LHCb detector. The only alternative assignment allowed by previous measurements J(PC) = 2(-+) is rejected with a confidence level equivalent to more than 8 Gaussian standard deviations using a likelihood-ratio test in the full angular phase space. This result favors exotic explanations of the X(3872) state.
Nuclear structure functions at a future electron-ion collider
2017
The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction $x$---robust experimental constraints below $x\ensuremath{\sim}{10}^{\ensuremath{-}2}$ at low resolution scale ${Q}^{2}$ are particularly scarce. This is in sharp contrast to the free proton's structure which has been probed in Deep Inelastic Scattering (DIS) measurements down to $x\ensuremath{\sim}{10}^{\ensuremath{-}5}$ at perturbative resolution scales. The construction of an electron-ion collider (EIC) with a possibility to operate with a wide variety of nuclei, will allow one to explore the low-$x$ region in much greater detail. In the present paper we simula…
Initial conditions in AA and pA collisions
2016
A full understanding of the spacetime evolution of the QCD matter created in a heavy ion collision requires understanding the properties of the initial stages. In the weak coupling picture these are dominated by classical gluon fields, whose properties can also be studied via the scattering of dilute probes off a high energy hadron or nucleus. A particular challenge is understanding small systems, where LHC data is also showing signs of collective behavior. We discuss some recent results of on the initial matter production and thermalization in heavy ion collisions, in particular in the gluon saturation framework.
Search for a heavy neutral particle decaying into an electron and a muon using 1 fb−1 of ATLAS data
2011
A search is presented for a high mass neutral particle that decays directly to the e±μ∓ final state. The data sample was recorded by the ATLAS detector in s√=7~TeVpp collisions at the LHC from March to June 2011 and corresponds to an integrated luminosity of 1.07 fb−1. The data are found to be consistent with the Standard Model background. The high e±μ∓ mass region is used to set 95% confidence level upper limits on the production of two possible new physics processes: tau sneutrinos in an R-parity violating supersymmetric model and Z′-like vector bosons in a lepton flavor violating model.