The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
R Aaij - One of the best experts on this subject based on the ideXlab platform.
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measurement of the ratio of branching fractions b b over 0 d τ ν over _ τ b b over 0 d μ ν over _ μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D^{*})≡B(B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]^{0}→D^{*+}μ^{-}ν[over ¯]_{μ}) is measured using a sample of proton-proton collision data corresponding to 3.0 fb^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B[over ¯]^{0} decays gives R(D^{*})=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions b b 0 d τ ν τ b b 0 d μ ν μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio RðDÞ ≡ BðB¯ 0 → Dþτ−ν¯ τÞ=BðB¯ 0 → Dþμ−ν¯μÞ is measured using a sample of proton-proton collision data corresponding to 3.0 fb−1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ− → μ−ν¯μντ. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯ 0 decays gives RðDÞ ¼ 0.336 0.027ðstatÞ 0.030ðsystÞ. This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model. DOI:
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measurement of the ratio of branching fractions b b over bar 0 d tau nu over bar tau b b over bar 0 d mu nu over bar mu
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions b b 0 d τ ν τ b b 0 d μ ν μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions mathcal b bar b 0 to d tau bar nu _ tau mathcal b bar b 0 to d mu bar nu _ mu
Physical Review Letters, 2015Co-Authors: R Aaij, G Ciezarek, J Rouvinet, Paula Collins, G Collazuol, S Roiser, W Qian, Achim Vollhardt, B Storaci, Oscar De Aguiar FranciscoAbstract:The branching fraction ratio R(D*)≡B(B¯0→D*+τ-ν¯τ)/B(B¯0→D*+μ-ν¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb-1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ-→μ-ν¯μντ. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯0 decays gives R(D*)=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
C Fabjan - One of the best experts on this subject based on the ideXlab platform.
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search for a non standard Model higgs boson decaying to a pair of new light bosons in four muon final states
Physics Letters B, 2013Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, E Aguilo, T Bergauer, M Dragicevic, J Ero, C FabjanAbstract:Results are reported from a search for Non-Standard-Model Higgs boson decays to pairs of new light bosons, each of which decays into the μ+μ− final state. The new bosons may be produced either promptly or via a decay chain. The data set corresponds to an integrated luminosity of 5.3 fb−1 of proton–proton collisions at View the MathML source, recorded by the CMS experiment at the LHC in 2011. Such Higgs boson decays are predicted in several scenarios of new physics, including supersymmetric Models with extended Higgs sectors or hidden valleys. Thus, the results of the search are relevant for establishing whether the new particle observed in Higgs boson searches at the LHC has the properties expected for a standard Model Higgs boson. No excess of events is observed with respect to the yields expected from standard Model processes. A Model-independent upper limit of 0.86±0.06 fb on the product of the cross section times branching fraction times acceptance is obtained. The results, which are applicable to a broad spectrum of new physics scenarios, are compared with the predictions of two benchmark Models as functions of a Higgs boson mass larger than 86 GeV/c2 and of a new light boson mass within the range 0.25–3.55 GeV/c2.
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search for new physics in events with same sign dileptons and b jets in pp collisions at s 8 tev
Journal of High Energy Physics, 2013Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C FabjanAbstract:A search for new physics is performed using isolated same-sign dileptons with at least two b-quark jets in the final state. Results are based on a 4.98 inverse femtobarn sample of proton-proton collisions at a centre-of-mass energy of 7 TeV collected by the CMS detector. No excess above the standard Model background is observed. Upper limits at 95% confidence level are set on the number of events from Non-Standard-Model sources. These limits are used to set constraints on a number of new physics Models. Information on acceptance and efficiencies are also provided so that the results can be used to confront additional Models in an approximate way.
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search for physics beyond the standard Model in events with a z boson jets and missing transverse energy in pp collisions at s 7 tev
Physics Letters B, 2012Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C Fabjan, M FriedlAbstract:A search is presented for physics beyond the standard Model (BSM) in events with a Z boson, jets, and missing transverse energy (MET). This signature is motivated by BSM physics scenarios, including supersymmetry. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.98 inverse femtobarns. The contributions from the dominant standard Model backgrounds are estimated from data using two complementary strategies, the jet-Z balance technique and a method based on Modeling MET with data control samples. In the absence of evidence for BSM physics, we set limits on the Non-Standard-Model contributions to event yields in the signal regions and interpret the results in the context of simplified Model spectra. Additional information is provided to facilitate tests of other BSM physics Models.
S Ali - One of the best experts on this subject based on the ideXlab platform.
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measurement of the ratio of branching fractions b b over 0 d τ ν over _ τ b b over 0 d μ ν over _ μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D^{*})≡B(B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]^{0}→D^{*+}μ^{-}ν[over ¯]_{μ}) is measured using a sample of proton-proton collision data corresponding to 3.0 fb^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B[over ¯]^{0} decays gives R(D^{*})=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions b b 0 d τ ν τ b b 0 d μ ν μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio RðDÞ ≡ BðB¯ 0 → Dþτ−ν¯ τÞ=BðB¯ 0 → Dþμ−ν¯μÞ is measured using a sample of proton-proton collision data corresponding to 3.0 fb−1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ− → μ−ν¯μντ. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯ 0 decays gives RðDÞ ¼ 0.336 0.027ðstatÞ 0.030ðsystÞ. This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model. DOI:
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measurement of the ratio of branching fractions b b over bar 0 d tau nu over bar tau b b over bar 0 d mu nu over bar mu
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions b b 0 d τ ν τ b b 0 d μ ν μ
Physical Review Letters, 2015Co-Authors: R Aaij, B Adeva, M Adinolfi, A Affolder, Z Ajaltouni, S Akar, J Albrecht, F Alessio, M Alexander, S AliAbstract:The branching fraction ratio R(D-*) = B((B) over bar (0) -> D-*(+)tau(-)(nu) over bar (tau))/B((B) over bar (0) -> D-*(+)mu(-)(nu) over bar (mu)) is measured using a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode tau(-) -> mu(-)(nu) over bar (mu)nu(tau). The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate (B) over bar (0) decays gives R(D-*) = 0.336 +/- 0.027(stat) +/- 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
Oscar De Aguiar Francisco - One of the best experts on this subject based on the ideXlab platform.
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measurement of the ratio of branching fractions mathcal b bar b 0 to d tau bar nu _ tau mathcal b bar b 0 to d mu bar nu _ mu
Physical Review Letters, 2015Co-Authors: R Aaij, G Ciezarek, J Rouvinet, Paula Collins, G Collazuol, S Roiser, W Qian, Achim Vollhardt, B Storaci, Oscar De Aguiar FranciscoAbstract:The branching fraction ratio R(D*)≡B(B¯0→D*+τ-ν¯τ)/B(B¯0→D*+μ-ν¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb-1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ-→μ-ν¯μντ. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯0 decays gives R(D*)=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard Model.
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measurement of the ratio of branching fractions mathcal b overline b 0 to d tau overline nu _ tau mathcal b overline b 0 to d mu overline nu _ mu
Physical Review Letters, 2015Co-Authors: R Aaij, G Ciezarek, J Rouvinet, Paula Collins, G Collazuol, S Roiser, W Qian, Achim Vollhardt, B Storaci, Oscar De Aguiar FranciscoAbstract:The branching fraction ratio $\mathcal{R}(D^{*}) \equiv \mathcal{B}(\overline{B}^0 \to D^{*+}\tau^{-}\overline{\nu}_{\tau})/\mathcal{B}(\overline{B}^0 \to D^{*+}\mu^{-}\overline{\nu}_{\mu})$ is measured using a sample of proton-proton collision data corresponding to 3.0\invfb of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-} \to \mu^{-}\overline{\nu}_{\mu}\nu_{\tau}$. The semitauonic decay is sensitive to contributions from Non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate $\overline{B}^0$ decays gives $\mathcal{R}(D^{*}) = 0.336 \pm 0.027(stat) \pm 0.030 (syst)$. This result, which is the first measurement of this quantity at a hadron collider, is $2.1$ standard deviations larger than the value expected from lepton universality in the Standard Model.
A M Sirunyan - One of the best experts on this subject based on the ideXlab platform.
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search for mssm higgs bosons decaying to μ μ in proton proton collisions at s 13tev
Physics Letters B, 2019Co-Authors: A M Sirunyan, R Erbacher, C Carrillo A Montoya, Wagner Carvalho, M Gorski, D Kotlinski, B Ujvari, Sertac Ozturk, S Muthumuni, Vinicius Massami MikuniAbstract:Abstract A search is performed for neutral Non-Standard-Model Higgs bosons decaying to two muons in the context of the minimal supersymmetric standard Model (MSSM). Proton-proton collision data recorded by the CMS experiment at the CERN Large Hadron Collider at a center-of-mass energy of 13 TeV were used, corresponding to an integrated luminosity of 35.9 fb − 1 . The search is sensitive to neutral Higgs bosons produced via the gluon fusion process or in association with a b b ‾ quark pair. No significant deviations from the standard Model expectation are observed. Upper limits at 95% confidence level are set in the context of the m h mod+ and phenomenological MSSM scenarios on the parameter tan β as a function of the mass of the pseudoscalar A boson, in the range from 130 to 600 GeV. The results are also used to set a Model-independent limit on the product of the branching fraction for the decay into a muon pair and the cross section for the production of a scalar neutral boson, either via gluon fusion, or in association with b quarks, in the mass range from 130 to 1000 GeV.
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search for a non standard Model higgs boson decaying to a pair of new light bosons in four muon final states
Physics Letters B, 2013Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, E Aguilo, T Bergauer, M Dragicevic, J Ero, C FabjanAbstract:Results are reported from a search for Non-Standard-Model Higgs boson decays to pairs of new light bosons, each of which decays into the μ+μ− final state. The new bosons may be produced either promptly or via a decay chain. The data set corresponds to an integrated luminosity of 5.3 fb−1 of proton–proton collisions at View the MathML source, recorded by the CMS experiment at the LHC in 2011. Such Higgs boson decays are predicted in several scenarios of new physics, including supersymmetric Models with extended Higgs sectors or hidden valleys. Thus, the results of the search are relevant for establishing whether the new particle observed in Higgs boson searches at the LHC has the properties expected for a standard Model Higgs boson. No excess of events is observed with respect to the yields expected from standard Model processes. A Model-independent upper limit of 0.86±0.06 fb on the product of the cross section times branching fraction times acceptance is obtained. The results, which are applicable to a broad spectrum of new physics scenarios, are compared with the predictions of two benchmark Models as functions of a Higgs boson mass larger than 86 GeV/c2 and of a new light boson mass within the range 0.25–3.55 GeV/c2.
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search for new physics in events with same sign dileptons and b jets in pp collisions at s 8 tev
Journal of High Energy Physics, 2013Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C FabjanAbstract:A search for new physics is performed using isolated same-sign dileptons with at least two b-quark jets in the final state. Results are based on a 4.98 inverse femtobarn sample of proton-proton collisions at a centre-of-mass energy of 7 TeV collected by the CMS detector. No excess above the standard Model background is observed. Upper limits at 95% confidence level are set on the number of events from Non-Standard-Model sources. These limits are used to set constraints on a number of new physics Models. Information on acceptance and efficiencies are also provided so that the results can be used to confront additional Models in an approximate way.
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search for physics beyond the standard Model in events with a z boson jets and missing transverse energy in pp collisions at s 7 tev
Physics Letters B, 2012Co-Authors: S Chatrchyan, A M Sirunyan, V Khachatryan, A Tumasyan, W Adam, T Bergauer, M Dragicevic, J Ero, C Fabjan, M FriedlAbstract:A search is presented for physics beyond the standard Model (BSM) in events with a Z boson, jets, and missing transverse energy (MET). This signature is motivated by BSM physics scenarios, including supersymmetry. The study is performed using a sample of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.98 inverse femtobarns. The contributions from the dominant standard Model backgrounds are estimated from data using two complementary strategies, the jet-Z balance technique and a method based on Modeling MET with data control samples. In the absence of evidence for BSM physics, we set limits on the Non-Standard-Model contributions to event yields in the signal regions and interpret the results in the context of simplified Model spectra. Additional information is provided to facilitate tests of other BSM physics Models.