The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ulfg Meisner - One of the best experts on this subject based on the ideXlab platform.
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towards a precise determination of the scattering amplitudes of the charmed and light flavor Pseudoscalar mesons
European Physical Journal C, 2019Co-Authors: Zhihui Guo, J A Oller, Liuming Liu, Ulfg Meisner, Akaki RusetskyAbstract:We study the scattering of the light-flavor Pseudoscalar mesons ( $$\pi , K, \eta $$ ) off the ground-state charmed mesons ( $$D,D_s$$ ) within chiral effective field theory. The recent lattice simulation results on various scattering lengths and the finite-volume spectra both in the moving and center-of-mass frames, most of which are obtained at unphysical meson masses, are used to constrain the free parameters in our theory. Explicit formulas to include the S- and P-wave mixing to determine the finite-volume energy levels are provided. After a successful reproduction of the lattice data, we perform a chiral extrapolation to predict the quantities with physical meson masses, including phase shifts, inelasticities, resonance pole positions and the corresponding residues from the scattering of the light Pseudoscalar and charmed mesons.
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strangeness s 2 baryon baryon interaction at next to leading order in chiral effective field theory
Nuclear Physics, 2016Co-Authors: J Haidenbauer, Ulfg Meisner, Stefan PetschauerAbstract:Abstract The strangeness S = − 2 baryon–baryon interaction is studied in chiral effective field theory up to next-to-leading order. The potential at this order consists of contributions from one- and two-Pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the interaction in the S = − 2 sector. Specifically, the couplings of the Pseudoscalar mesons to the baryons are fixed by SU(3) symmetry and, in general, also the contact terms are related via SU(3) symmetry to those determined in a previous study of the S = − 1 hyperon–nucleon interaction. The explicit SU(3) symmetry breaking due to the physical masses of the Pseudoscalar mesons (π, K, η) is taken into account. It is argued that the ΞN interaction has to be relatively weak to be in accordance with available experimental constraints. In particular, the published values and upper bounds for the Ξ − p elastic and inelastic cross sections apparently rule out a somewhat stronger attractive ΞN force and, specifically, disfavor any near-threshold deuteron-like bound states in that system.
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hyperon nucleon interaction at next to leading order in chiral effective field theory
Nuclear Physics, 2013Co-Authors: J Haidenbauer, Ulfg Meisner, Stefan Petschauer, N Kaiser, A Nogga, W WeiseAbstract:Abstract Results for the ΛN and ΣN interactions obtained at next-to-leading order in chiral effective field theory are reported. At the order considered there are contributions from one- and two-Pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the hyperon–nucleon interaction, however, the explicit SU(3) symmetry breaking by the physical masses of the Pseudoscalar mesons (π, K, η) and of the involved baryons is taken into account. An excellent description of the hyperon–nucleon system can be achieved at next-to-leading order. It is on the same level of quality as the one obtained by the most advanced phenomenological hyperon–nucleon interaction models.
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predictions for the strangeness s 3 and 4 baryon baryon interactions in chiral effective field theory
Physics Letters B, 2010Co-Authors: J Haidenbauer, Ulfg MeisnerAbstract:Abstract The leading order strangeness S = − 3 and −4 baryon–baryon interactions are analyzed within chiral effective field theory. The chiral potentials consist of contact terms without derivatives and of one-Pseudoscalar-meson exchanges. Assuming SU ( 3 ) flavor symmetry those contact terms and the couplings of the Pseudoscalar mesons to the baryons are related to the corresponding quantities of the S = − 1 hyperon–nucleon channels. Specifically, the values of the pertinent five low-energy constants related to the contact terms are already fixed from our preceding study of the ΛN and ΣN systems and thus genuine predictions for the ΞΛ, ΞΣ, and ΞΞ interactions can be made. Strong attraction is found in some of the S = − 3 and −4 channels, suggesting the possible existence of bound states.
J Haidenbauer - One of the best experts on this subject based on the ideXlab platform.
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strangeness s 2 baryon baryon interaction at next to leading order in chiral effective field theory
Nuclear Physics, 2016Co-Authors: J Haidenbauer, Ulfg Meisner, Stefan PetschauerAbstract:Abstract The strangeness S = − 2 baryon–baryon interaction is studied in chiral effective field theory up to next-to-leading order. The potential at this order consists of contributions from one- and two-Pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the interaction in the S = − 2 sector. Specifically, the couplings of the Pseudoscalar mesons to the baryons are fixed by SU(3) symmetry and, in general, also the contact terms are related via SU(3) symmetry to those determined in a previous study of the S = − 1 hyperon–nucleon interaction. The explicit SU(3) symmetry breaking due to the physical masses of the Pseudoscalar mesons (π, K, η) is taken into account. It is argued that the ΞN interaction has to be relatively weak to be in accordance with available experimental constraints. In particular, the published values and upper bounds for the Ξ − p elastic and inelastic cross sections apparently rule out a somewhat stronger attractive ΞN force and, specifically, disfavor any near-threshold deuteron-like bound states in that system.
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hyperon nucleon interaction at next to leading order in chiral effective field theory
Nuclear Physics, 2013Co-Authors: J Haidenbauer, Ulfg Meisner, Stefan Petschauer, N Kaiser, A Nogga, W WeiseAbstract:Abstract Results for the ΛN and ΣN interactions obtained at next-to-leading order in chiral effective field theory are reported. At the order considered there are contributions from one- and two-Pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the hyperon–nucleon interaction, however, the explicit SU(3) symmetry breaking by the physical masses of the Pseudoscalar mesons (π, K, η) and of the involved baryons is taken into account. An excellent description of the hyperon–nucleon system can be achieved at next-to-leading order. It is on the same level of quality as the one obtained by the most advanced phenomenological hyperon–nucleon interaction models.
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predictions for the strangeness s 3 and 4 baryon baryon interactions in chiral effective field theory
Physics Letters B, 2010Co-Authors: J Haidenbauer, Ulfg MeisnerAbstract:Abstract The leading order strangeness S = − 3 and −4 baryon–baryon interactions are analyzed within chiral effective field theory. The chiral potentials consist of contact terms without derivatives and of one-Pseudoscalar-meson exchanges. Assuming SU ( 3 ) flavor symmetry those contact terms and the couplings of the Pseudoscalar mesons to the baryons are related to the corresponding quantities of the S = − 1 hyperon–nucleon channels. Specifically, the values of the pertinent five low-energy constants related to the contact terms are already fixed from our preceding study of the ΛN and ΣN systems and thus genuine predictions for the ΞΛ, ΞΣ, and ΞΞ interactions can be made. Strong attraction is found in some of the S = − 3 and −4 channels, suggesting the possible existence of bound states.
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strangeness s 2 baryon baryon interactions using chiral effective field theory
Physics Letters B, 2007Co-Authors: H Polinder, J Haidenbauer, Ulfg MeissnerAbstract:We derive the leading order strangeness S =−2 baryon–baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-Pseudoscalar-meson exchanges. The contact terms and the couplings of the Pseudoscalar mesons to the baryons are related via SU(3)f symmetry to the S =−1 hyperon–nucleon channels.We show that the chiral effective field theory predictions with natural values for the low-energy constants agree with the experimental information in the S =−2 sector
Ulfg Meissner - One of the best experts on this subject based on the ideXlab platform.
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strangeness s 2 baryon baryon interactions using chiral effective field theory
Physics Letters B, 2007Co-Authors: H Polinder, J Haidenbauer, Ulfg MeissnerAbstract:We derive the leading order strangeness S =−2 baryon–baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-Pseudoscalar-meson exchanges. The contact terms and the couplings of the Pseudoscalar mesons to the baryons are related via SU(3)f symmetry to the S =−1 hyperon–nucleon channels.We show that the chiral effective field theory predictions with natural values for the low-energy constants agree with the experimental information in the S =−2 sector
Albert M Sirunyan - One of the best experts on this subject based on the ideXlab platform.
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search for an exotic decay of the higgs boson to a pair of light Pseudoscalars in the final state with two muons and two b quarks in pp collisions at 13 tev
Physics Letters B, 2019Co-Authors: Albert M Sirunyan, Robin Erbacher, C Carrillo A Montoya, Wagner Carvalho, Maciej Gorski, Danek Kotlinski, B Ujvari, S Ozturk, Samila Muthumuni, Shaaban KhalilAbstract:Abstract A search for exotic decays of the Higgs boson to a pair of light Pseudoscalar particles a 1 is performed under the hypothesis that one of the Pseudoscalars decays to a pair of opposite sign muons and the other decays to b b ‾ . Such signatures are predicted in a number of extensions of the standard model (SM), including next-to-minimal supersymmetry and two-Higgs-doublet models with an additional scalar singlet. The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb − 1 , accumulated with the CMS experiment at the CERN LHC in 2016 at a centre-of-mass energy of 13 TeV. No statistically significant excess is observed with respect to the SM backgrounds in the search region for Pseudoscalar masses from 20 GeV to half of the Higgs boson mass. Upper limits at 95% confidence level are set on the product of the production cross section and branching fraction, σ h B ( h → a 1 a 1 → μ + μ − b b ‾ ) , ranging from 5 to 33 fb, depending on the Pseudoscalar mass. Corresponding limits on the branching fraction, assuming the SM prediction for σ h , are ( 1 – 7 ) × 10 − 4 .
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search for an exotic decay of the higgs boson to a pair of light Pseudoscalars in the final state with two b quarks and two τ leptons in proton proton collisions at s 13tev
Physics Letters B, 2018Co-Authors: Albert M Sirunyan, A Tumasyan, W Adam, E Asilar, T Bergauer, J Brandstetter, E Brondolin, M Dragicevic, F Ambrogi, J EroAbstract:Abstract A search for an exotic decay of the Higgs boson to a pair of light Pseudoscalar bosons is performed for the first time in the final state with two b quarks and two τ leptons. The search is motivated in the context of models of physics beyond the standard model (SM), such as two Higgs doublet models extended with a complex scalar singlet (2HDM + S), which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on a data set of proton–proton collisions corresponding to an integrated luminosity of 35.9 fb − 1 , accumulated by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV . Masses of the Pseudoscalar boson between 15 and 60 GeV are probed, and no excess of events above the SM expectation is observed. Upper limits between 3 and 12% are set on the branching fraction B ( h → a a → 2 τ 2 b ) assuming the SM production of the Higgs boson. Upper limits are also set on the branching fraction of the Higgs boson to two light Pseudoscalar bosons in different 2HDM + S scenarios. Assuming the SM production cross section for the Higgs boson, the upper limit on this quantity is as low as 20% for a mass of the Pseudoscalar of 40 GeV in the NMSSM.
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search for an exotic decay of the higgs boson to a pair of light Pseudoscalars in the final state of two muons and two tau leptons in proton proton collisions at sqrt s 13 tev
Journal of High Energy Physics, 2018Co-Authors: Albert M Sirunyan, Robin Erbacher, C Carrillo A Montoya, Wagner Carvalho, Maciej Gorski, Danek Kotlinski, B Ujvari, S Ozturk, Samila MuthumuniAbstract:A search for exotic Higgs boson decays to light Pseudoscalars in the final state of two muons and two τ leptons is performed using proton-proton collision data recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb−1. Masses of the Pseudoscalar boson between 15.0 and 62.5 GeV are probed, and no significant excess of data is observed above the prediction of the standard model. Upper limits are set on the branching fraction of the Higgs boson to two light Pseudoscalar bosons in different types of two-Higgs-doublet models extended with a complex scalar singlet.
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combined search for anomalous Pseudoscalar hvv couplings in vh h bb production and h vv decay
Physics Letters B, 2016Co-Authors: V. Khachatryan, Albert M Sirunyan, A Tumasyan, W Adam, E Asilar, T Bergauer, J Brandstetter, E Brondolin, M Dragicevic, J EroAbstract:A search for anomalous Pseudoscalar couplings of the Higgs boson H to electroweak vector bosons V (=W or Z) in a sample of proton–proton collision events corresponding to an integrated luminosity of 18.9 fb^(−1) at a center-of-mass energy of 8 TeV is presented. Events consistent with the topology of associated VH production, where the Higgs boson decays to a pair of bottom quarks and the vector boson decays leptonically, are analyzed. The consistency of data with a potential Pseudoscalar contribution to the HVV interaction, expressed by the effective Pseudoscalar cross section fractions f_a_3, is assessed by means of profile likelihood scans. Results are given for the VH channels alone and for a combined analysis of the VH and previously published H→VV channels. Under certain assumptions, f_(a3)^(ZZ)>0.0034 is excluded at 95% confidence level in the combination. Scenarios in which these assumptions are relaxed are also considered.
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search for a low mass Pseudoscalar higgs boson produced in association with a bb pair in pp collisions at s 8 tev
Physics Letters B, 2016Co-Authors: V. Khachatryan, Albert M Sirunyan, A Tumasyan, W Adam, E Asilar, T Bergauer, J Brandstetter, E Brondolin, M Dragicevic, J EroAbstract:A search is reported for a light Pseudoscalar Higgs boson decaying to a pair of tau leptons, produced in association with a b-bbar pair, in the context of two-Higgs-doublet models. The results are based on pp collision data at a centre-of-mass energy of 8 TeV collected by the CMS experiment at the LHC and corresponding to an integrated luminosity of 19.7 inverse-femtobarns. Pseudoscalar boson masses between 25 and 80 GeV are probed. No evidence for a Pseudoscalar boson is found and upper limits are set on the production cross section times branching fraction to tau pairs between 7 and 39 pb at the 95% confidence level. This search excludes a Pseudoscalar Higgs boson with mass below 80 GeV, in Type II two-Higgs-doublet models with a negative coupling of standard model-like Higgs boson to down-type fermions.
E. Oset - One of the best experts on this subject based on the ideXlab platform.
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Effects of Pseudoscalar-baryon channels in the dynamically generated vector-baryon resonances
The European Physical Journal A, 2012Co-Authors: E. J. Garzon, E. OsetAbstract:We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled channels unitary approach, including also the Pseudoscalar-baryon channels which couple to the same quantum numbers. We examine the scattering amplitudes and their poles, which can be associated to known $J^P=1/2^-,3/2^-$ baryon resonances, and determine the role of the Pseudoscalar-baryon channels, changing the width and eventually the mass of the resonances generated with only the basis of vector-baryon states.
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effects of Pseudoscalar baryon channels in the dynamically generated vector baryon resonances
European Physical Journal A, 2012Co-Authors: E. J. Garzon, E. OsetAbstract:We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled-channels unitary approach, including also the Pseudoscalar-baryon channels which couple to the same quantum numbers. We examine the scattering amplitudes and their poles, which can be associated to the known J P = 1/2−, 3/2− baryon resonances, and determine the role of the Pseudoscalar-baryon channels, changing the width and eventually the mass of the resonances generated with only the basis of vector-baryon states.
