TY  - JOUR
AU  - Sirunyan, A.
AU  - Tumasyan, A.
AU  - Adam, W.
AU  - Ambrogi, F.
AU  - Bergauer, T.
AU  - Adžić, Petar
AU  - Ćirković, Predrag
AU  - Đorđević, Miloš
AU  - Milenović, Predrag
AU  - Milošević, Jovan
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9988
AB  - Results of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13 $$\,\text {TeV}$$     TeV    , corresponding to an integrated luminosity of 35.9 $$\,\text {fb}^{-1}$$      fb  - 1      , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.
T2  - European Physical Journal C. Particles and Fields
T1  - MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV
VL  - 81
IS  - 7
SP  - 629
DO  - 10.1140/epjc/s10052-021-09236-z
ER  - 

@article{
author = "Sirunyan, A. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Bergauer, T. and Adžić, Petar and Ćirković, Predrag and Đorđević, Miloš and Milenović, Predrag and Milošević, Jovan",
year = "2021",
abstract = "Results of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13 $$\,\text {TeV}$$     TeV    , corresponding to an integrated luminosity of 35.9 $$\,\text {fb}^{-1}$$      fb  - 1      , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.",
journal = "European Physical Journal C. Particles and Fields",
title = "MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV",
volume = "81",
number = "7",
pages = "629",
doi = "10.1140/epjc/s10052-021-09236-z"
}

Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, P., Ćirković, P., Đorđević, M., Milenović, P.,& Milošević, J.. (2021). MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV. in European Physical Journal C. Particles and Fields, 81(7), 629.
https://doi.org/10.1140/epjc/s10052-021-09236-z

Sirunyan A, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Adžić P, Ćirković P, Đorđević M, Milenović P, Milošević J. MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV. in European Physical Journal C. Particles and Fields. 2021;81(7):629.
doi:10.1140/epjc/s10052-021-09236-z .

Sirunyan, A., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, Petar, Ćirković, Predrag, Đorđević, Miloš, Milenović, Predrag, Milošević, Jovan, "MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV" in European Physical Journal C. Particles and Fields, 81, no. 7 (2021):629,
https://doi.org/10.1140/epjc/s10052-021-09236-z . .

TY  - JOUR
AU  - Sirunyan, A. M.
AU  - Tumasyan, A.
AU  - Adam, W.
AU  - Ambrogi, F.
AU  - Bergauer, T.
AU  - Adžić, Petar
AU  - Ćirković, Predrag
AU  - Đorđević, Miloš
AU  - Milenović, Predrag
AU  - Milošević, Jovan
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9550
AB  - Results are reported from a search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at     s    $$ \sqrt{\mathrm{s}} $$  = 13 TeV. The data sample corresponds to an integrated luminosity of 33.2 fb −1 recorded by the CMS experiment at the LHC in 2016. The search exploits τ leptons produced in both W boson and heavy-flavor hadron decays. No significant excess above the expected background is observed. An upper limit on the branching fraction ℬ(τ → 3μ) of 8.0 × 10 −8 at 90% confidence level is obtained, with an expected upper limit of 6.9 × 10 −8.
T2  - Journal of High Energy Physics
T1  - Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at √s = 13 TeV
VL  - 2021
IS  - 1
SP  - 163
DO  - 10.1007/JHEP01(2021)163
ER  - 

@article{
author = "Sirunyan, A. M. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Bergauer, T. and Adžić, Petar and Ćirković, Predrag and Đorđević, Miloš and Milenović, Predrag and Milošević, Jovan",
year = "2021",
abstract = "Results are reported from a search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at     s    $$ \sqrt{\mathrm{s}} $$  = 13 TeV. The data sample corresponds to an integrated luminosity of 33.2 fb −1 recorded by the CMS experiment at the LHC in 2016. The search exploits τ leptons produced in both W boson and heavy-flavor hadron decays. No significant excess above the expected background is observed. An upper limit on the branching fraction ℬ(τ → 3μ) of 8.0 × 10 −8 at 90% confidence level is obtained, with an expected upper limit of 6.9 × 10 −8.",
journal = "Journal of High Energy Physics",
title = "Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at √s = 13 TeV",
volume = "2021",
number = "1",
pages = "163",
doi = "10.1007/JHEP01(2021)163"
}

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, P., Ćirković, P., Đorđević, M., Milenović, P.,& Milošević, J.. (2021). Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at √s = 13 TeV. in Journal of High Energy Physics, 2021(1), 163.
https://doi.org/10.1007/JHEP01(2021)163

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Adžić P, Ćirković P, Đorđević M, Milenović P, Milošević J. Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at √s = 13 TeV. in Journal of High Energy Physics. 2021;2021(1):163.
doi:10.1007/JHEP01(2021)163 .

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, Petar, Ćirković, Predrag, Đorđević, Miloš, Milenović, Predrag, Milošević, Jovan, "Search for the lepton flavor violating decay τ → 3μ in proton-proton collisions at √s = 13 TeV" in Journal of High Energy Physics, 2021, no. 1 (2021):163,
https://doi.org/10.1007/JHEP01(2021)163 . .

TY  - JOUR
AU  - Sirunyan, A. M.
AU  - Tumasyan, A.
AU  - Adam, W.
AU  - Ambrogi, F.
AU  - Bergauer, T.
AU  - Adžić, Petar
AU  - Ćirković, Predrag
AU  - Đorđević, Miloš
AU  - Milenović, Predrag
AU  - Milošević, Jovan
AU  - Stojanović, Milan
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9784
AB  - Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10−6  sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production (σtt¯) via the selection of charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, σtt¯=2.54−0.74+0.84 and 2.03−0.64+0.71  μb, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.
T2  - Physical Review Letters
T1  - Evidence for Top Quark Production in Nucleus-Nucleus Collisions
VL  - 125
SP  - 222001
DO  - 10.1103/PhysRevLett.125.222001
ER  - 

@article{
author = "Sirunyan, A. M. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Bergauer, T. and Adžić, Petar and Ćirković, Predrag and Đorđević, Miloš and Milenović, Predrag and Milošević, Jovan and Stojanović, Milan",
year = "2020",
abstract = "Ultrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10−6  sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, we report the first evidence for the production of top quarks in nucleus-nucleus collisions, using lead-lead collision data at a nucleon-nucleon center-of-mass energy of 5.02 TeV recorded by the CMS experiment. Two methods are used to measure the cross section for top quark pair production (σtt¯) via the selection of charged leptons (electrons or muons) and bottom quarks. One method relies on the leptonic information alone, and the second one exploits, in addition, the presence of bottom quarks. The measured cross sections, σtt¯=2.54−0.74+0.84 and 2.03−0.64+0.71  μb, respectively, are compatible with expectations from scaled proton-proton data and QCD predictions.",
journal = "Physical Review Letters",
title = "Evidence for Top Quark Production in Nucleus-Nucleus Collisions",
volume = "125",
pages = "222001",
doi = "10.1103/PhysRevLett.125.222001"
}

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, P., Ćirković, P., Đorđević, M., Milenović, P., Milošević, J.,& Stojanović, M.. (2020). Evidence for Top Quark Production in Nucleus-Nucleus Collisions. in Physical Review Letters, 125, 222001.
https://doi.org/10.1103/PhysRevLett.125.222001

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Adžić P, Ćirković P, Đorđević M, Milenović P, Milošević J, Stojanović M. Evidence for Top Quark Production in Nucleus-Nucleus Collisions. in Physical Review Letters. 2020;125:222001.
doi:10.1103/PhysRevLett.125.222001 .

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, Petar, Ćirković, Predrag, Đorđević, Miloš, Milenović, Predrag, Milošević, Jovan, Stojanović, Milan, "Evidence for Top Quark Production in Nucleus-Nucleus Collisions" in Physical Review Letters, 125 (2020):222001,
https://doi.org/10.1103/PhysRevLett.125.222001 . .

TY  - JOUR
AU  - Sirunyan, A. M.
AU  - Tumasyan, A.
AU  - Adam, W.
AU  - Ambrogi, F.
AU  - Bergauer, T.
AU  - Adžić, Petar
AU  - Ćirković, Predrag
AU  - Đorđević, Miloš
AU  - Milenović, Predrag
AU  - Milošević, Jovan
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9777
AB  - The ratios of the Bc(2S)+ to Bc+, Bc*(2S)+ to Bc+, and Bc*(2S)+ to Bc(2S)+ production cross sections are measured in proton-proton collisions at s=13  TeV, using a data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 143  fb−1. The three measurements are made in the Bc+ meson phase space region defined by the transverse momentum pT>15  GeV and absolute rapidity |y|<2.4, with the excited Bc(*)(2S)+ states reconstructed through the Bc(*)+π+π−, followed by the Bc+→J/ψπ+ and J/ψ→μ+μ− decays. The Bc(2S)+ to Bc+, Bc*(2S)+ to Bc+, and Bc*(2S)+ to Bc(2S)+ cross section ratios, including the unknown Bc(*)(2S)+→Bc(*)+π+π− branching fractions, are (3.47±0.63(stat)±0.33(syst))%, (4.69±0.71(stat)±0.56(syst))%, and 1.35±0.32(stat)±0.09(syst), respectively. None of these ratios shows a significant dependence on the pT or |y| of the Bc+ meson. The normalized dipion invariant mass distributions from the decays Bc(*)(2S)+→Bc(*)+π+π− are also reported.
T2  - Physical Review D
T1  - Measurement of Bc(2S)+ and Bc*(2S)+ cross section ratios in proton-proton collisions at s=13 TeV
VL  - 102
SP  - 092007
DO  - 10.1103/PhysRevD.102.092007
ER  - 

@article{
author = "Sirunyan, A. M. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Bergauer, T. and Adžić, Petar and Ćirković, Predrag and Đorđević, Miloš and Milenović, Predrag and Milošević, Jovan",
year = "2020",
abstract = "The ratios of the Bc(2S)+ to Bc+, Bc*(2S)+ to Bc+, and Bc*(2S)+ to Bc(2S)+ production cross sections are measured in proton-proton collisions at s=13  TeV, using a data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 143  fb−1. The three measurements are made in the Bc+ meson phase space region defined by the transverse momentum pT>15  GeV and absolute rapidity |y|<2.4, with the excited Bc(*)(2S)+ states reconstructed through the Bc(*)+π+π−, followed by the Bc+→J/ψπ+ and J/ψ→μ+μ− decays. The Bc(2S)+ to Bc+, Bc*(2S)+ to Bc+, and Bc*(2S)+ to Bc(2S)+ cross section ratios, including the unknown Bc(*)(2S)+→Bc(*)+π+π− branching fractions, are (3.47±0.63(stat)±0.33(syst))%, (4.69±0.71(stat)±0.56(syst))%, and 1.35±0.32(stat)±0.09(syst), respectively. None of these ratios shows a significant dependence on the pT or |y| of the Bc+ meson. The normalized dipion invariant mass distributions from the decays Bc(*)(2S)+→Bc(*)+π+π− are also reported.",
journal = "Physical Review D",
title = "Measurement of Bc(2S)+ and Bc*(2S)+ cross section ratios in proton-proton collisions at s=13 TeV",
volume = "102",
pages = "092007",
doi = "10.1103/PhysRevD.102.092007"
}

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, P., Ćirković, P., Đorđević, M., Milenović, P.,& Milošević, J.. (2020). Measurement of Bc(2S)+ and Bc*(2S)+ cross section ratios in proton-proton collisions at s=13 TeV. in Physical Review D, 102, 092007.
https://doi.org/10.1103/PhysRevD.102.092007

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Adžić P, Ćirković P, Đorđević M, Milenović P, Milošević J. Measurement of Bc(2S)+ and Bc*(2S)+ cross section ratios in proton-proton collisions at s=13 TeV. in Physical Review D. 2020;102:092007.
doi:10.1103/PhysRevD.102.092007 .

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, Petar, Ćirković, Predrag, Đorđević, Miloš, Milenović, Predrag, Milošević, Jovan, "Measurement of Bc(2S)+ and Bc*(2S)+ cross section ratios in proton-proton collisions at s=13 TeV" in Physical Review D, 102 (2020):092007,
https://doi.org/10.1103/PhysRevD.102.092007 . .

TY  - JOUR
AU  - Sirunyan, A. M.
AU  - Tumasyan, A.
AU  - Adam, W.
AU  - Ambrogi, F.
AU  - Bergauer, T.
AU  - Adžić, Petar
AU  - Ćirković, Predrag
AU  - Đorđević, Miloš
AU  - Milenović, Predrag
AU  - Milošević, Jovan
AU  - Stojanović, Milan
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9738
AB  - Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at     s    $$ \sqrt{s} $$  = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb −1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04–1.31% and 0.31–0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740–940 and 730–950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.
T2  - Journal of High Energy Physics
T1  - Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson
VL  - 2020
IS  - 11
SP  - 1
EP  - 42
DO  - 10.1007/JHEP11(2020)039
ER  - 

@article{
author = "Sirunyan, A. M. and Tumasyan, A. and Adam, W. and Ambrogi, F. and Bergauer, T. and Adžić, Petar and Ćirković, Predrag and Đorđević, Miloš and Milenović, Predrag and Milošević, Jovan and Stojanović, Milan",
year = "2020",
abstract = "Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at     s    $$ \sqrt{s} $$  = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb −1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04–1.31% and 0.31–0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740–940 and 730–950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.",
journal = "Journal of High Energy Physics",
title = "Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson",
volume = "2020",
number = "11",
pages = "1-42",
doi = "10.1007/JHEP11(2020)039"
}

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, P., Ćirković, P., Đorđević, M., Milenović, P., Milošević, J.,& Stojanović, M.. (2020). Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson. in Journal of High Energy Physics, 2020(11), 1-42.
https://doi.org/10.1007/JHEP11(2020)039

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Adžić P, Ćirković P, Đorđević M, Milenović P, Milošević J, Stojanović M. Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson. in Journal of High Energy Physics. 2020;2020(11):1-42.
doi:10.1007/JHEP11(2020)039 .

Sirunyan, A. M., Tumasyan, A., Adam, W., Ambrogi, F., Bergauer, T., Adžić, Petar, Ćirković, Predrag, Đorđević, Miloš, Milenović, Predrag, Milošević, Jovan, Stojanović, Milan, "Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson" in Journal of High Energy Physics, 2020, no. 11 (2020):1-42,
https://doi.org/10.1007/JHEP11(2020)039 . .