Search for lepton-flavor violating decays of heavy resonances and quantum black holes to eμ final states in proton-proton collisions at $ \sqrt{s}=13 $ TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1804 (2018) 073, 2018.
Inspire Record 1653123 DOI 10.17182/hepdata.86568

A search is reported for heavy resonances decaying into e$\mu$ final states in proton-proton collisions recorded by the CMS experiment at the CERN LHC at $\sqrt{s}=$ 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The search focuses on resonance masses above 200 GeV. With no evidence found for physics beyond the standard model in the e$\mu$ mass spectrum, upper limits are set at 95% confidence level on the product of the cross section and branching fraction for this lepton-flavor violating signal. Based on these results, resonant $\tau$ sneutrino production in R-parity violating supersymmetric models is excluded for masses below 1.7 TeV, for couplings $\lambda_{132} = \lambda_{231} = \lambda'_{311} = 0.01$. Heavy Z$'$ gauge bosons with lepton-flavor violating transitions are excluded for masses up to 4.4 TeV. The e$\mu$ mass spectrum is also interpreted in terms of non-resonant contributions from quantum black-hole production in models with one to six extra spatial dimensions, and lower mass limits are found between 3.6 and 5.6 TeV. In all interpretations used in this analysis, the results of this search improve previous limits by about 1 TeV. These limits correspond to the most sensitive values obtained at colliders.

7 data tables

Cross section of QBH as a function of mass. The cross section includes the branching ratio of QBH decaying to $e\mu$.

Cross section of RPV tau-sneutrino as a function of mass. Cross section includes the branching ratio of tau-sneutrino decaying to $e\mu$.

Cross section of Z' as a function of mass. The cross sections include branching ratio $BR(Z' -> e \mu) = 10\%$

More…

Search for new particles decaying to a jet and an emerging jet

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP, 2018.
Inspire Record 1700173 DOI 10.17182/hepdata.88380

A search is performed for events consistent with the pair production of a new heavy particle that acts as a mediator between a dark sector and normal matter, and that decays to a light quark and a new fermion called a dark quark. The search is based on data corresponding to an integrated luminosity of 16.1 fb$^{-1}$ from proton-proton collisions at $\sqrt{s}=$ 13 TeV collected by the CMS experiment at the LHC in 2016. The dark quark is charged only under a new quantum-chromodynamics-like force, and forms an `emerging jet' via a parton shower, containing long-lived dark hadrons that give rise to displaced vertices when decaying to standard model hadrons. The data are consistent with the expectation from standard model processes. Limits are set at 95% confidence level excluding dark mediators with masses between 400 and 1250 GeV that have dark pion decay lengths between 5 and 225 mm, with a wider mass-dependent range excluded at lower masses. The dependence of the limit on the dark pion mass is weak for masses between 1 and 10 GeV. This analysis is the first dedicated search for the pair production of a new particle that decays to a jet and an emerging jet.

10 data tables

Distributions of $\langle IP_{\mathrm{2D}}\rangle$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion proper decay length of 25 mm, for various dark pion masses.

Distributions of $\alpha_\mathrm{3D}$ for background (black) and for signals with a mediator mass of 1 TeV and a dark pion mass of 5 GeV for dark pion proper decay lengths ranging from 1 to 300 mm.

The signal acceptance A, defined as the fraction of simulated signal events passing the selection criteria, for models with a dark pion mass $m_{\pi_\mathrm{DK}}$ of 5 GeV as a function of the mediator mass $m_{\mathrm{X_{DK}}}$ and the dark pion proper decay length $c\tau_{\pi_\mathrm{DK}}$. The corresponding selection set number for each model is indicated as text on the plot.

More…

Measurements of the $\mathrm {p}\mathrm {p}\rightarrow \mathrm{Z}\mathrm{Z}$ production cross section and the $\mathrm{Z}\rightarrow 4\ell $ branching fraction, and constraints on anomalous triple gauge couplings at $\sqrt{s} = 13\,\text {TeV} $

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J. C78 (2018) 165, 2018.
Inspire Record 1625296 DOI 10.17182/hepdata.80152

Four-lepton production in proton-proton collisions, $\mathrm {p}\mathrm {p}\rightarrow (\mathrm{Z}/ \gamma ^*)(\mathrm{Z}/\gamma ^*) \rightarrow 4\ell $ , where $\ell = \mathrm {e}$ or $\mu $ , is studied at a center-of-mass energy of 13 $\,\text {TeV}$ with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 $\,\text {fb}^{-1}$ . The ZZ production cross section, $\sigma (\mathrm {p}\mathrm {p}\rightarrow \mathrm{Z}\mathrm{Z}) = 17.2 \pm 0.5\,\text {(stat)} \pm 0.7\,\text {(syst)} \pm 0.4\,\text {(theo)} \pm 0.4\,\text {(lumi)} \text { pb} $ , measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region $60< m_{\ell ^+\ell ^-} < 120\,\text {GeV} $ , is consistent with standard model predictions. Differential cross sections are measured and are well described by the theoretical predictions. The Z boson branching fraction to four leptons is measured to be $\mathcal {B}(\mathrm{Z}\rightarrow 4\ell ) = 4.8 \pm 0.2\,\text {(stat)} \pm 0.2\,\text {(syst)} \pm 0.1\,\text {(theo)} \pm 0.1\,\text {(lumi)} \times 10^{-6}$ for events with a four-lepton invariant mass in the range $80< m_{4\ell } < 100\,\text {GeV} $ and a dilepton mass $m_{\ell \ell } > 4\,\text {GeV} $ for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ $\gamma $ couplings at 95% confidence level: $-0.0012<f_4^\mathrm{Z}<0.0010$ , $-0.0010<f_5^\mathrm{Z}<0.0013$ , $-0.0012<f_4^{\gamma }<0.0013$ , $-0.0012<f_5^{\gamma }< 0.0013$ .

14 data tables

The measured total ZZ cross section using 2016 data. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity and theortical sources, the second is theoretical uncertianty on the extrapolation from the selected region to the total phase space, the third is the luminosity uncertianty

The measured total ZZ cross section using 2015 and 2016. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity and theortical sources, the second is theoretical uncertianty on the extrapolation from the selected region to the total phase space, the third is the luminosity uncertianty

The measured fiducial ZZ cross sections. The first systematic uncertainty is the combined systematic uncertainty excluding luminosity, the second is the luminosity uncertianty

More…

Jet shapes of isolated photon-tagged jets in PbPb and pp collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett., 2018.
Inspire Record 1695278 DOI 10.17182/hepdata.85627

We report the first measurement of jet shapes for jets tagged with an isolated photon in pp and heavy-ion collisions. Jet shapes give crucial information on the evolution of parton shower in the plane transverse to parton's propagation. Photons constrain the associated parton's flavor and, not interacting with the QCD matter, provide precise information about the parton's momentum before traversing the medium. With this experimental control, available only with samples delivered by the LHC, jet shapes are observed to be strongly modified in the hot QCD medium, the results impose unprecedented constraints on theories for parton-medium interactions.

9 data tables

The differential jet shape, $\rho(r)$, for jets associated with an isolated photon in pp collisions.

The differential jet shape, $\rho(r)$, for jets associated with an isolated photon in 50-100% centrality PbPb collisions.

The differential jet shape, $\rho(r)$, for jets associated with an isolated photon in 30-50% centrality PbPb collisions.

More…

Version 2
Measurement of nuclear modification factors of $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons in PbPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
No Journal Information, 2018.
Inspire Record 1674529 DOI 10.17182/hepdata.83200

The cross sections for $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, R$_\mathrm{AA}$, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, R$_\mathrm{AA}$($\Upsilon$(1S)) $>$ R$_\mathrm{AA}$($\Upsilon$(2S)) $>$ R$_\mathrm{AA}$($\Upsilon$(3S)) . The suppression of $\Upsilon$(1S) is larger than that seen at $\sqrt{s_{_\mathrm{NN}}} =$ 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the R$_\mathrm{AA}$ of $\Upsilon$(3S) integrated over $p_\mathrm{T}$ and rapidity is 0.094 at 95% confidence level, which is the strongest suppression observed for any hadron species in heavy ion collisions to date.

23 data tables

Differential cross sections of the Y(1S) meson as a function of pT for pp collisions. The global uncertainty arises from the integrated luminosity uncertainty in pp collisions.

Differential cross sections of the Y(2S) meson as a function of pT for pp collisions. The global uncertainty arises from the integrated luminosity uncertainty in pp collisions.

Differential cross sections of the Y(3S) meson as a function of pT for pp collisions. The global uncertainty arises from the integrated luminosity uncertainty in pp collisions.

More…

Search for the Higgs boson decaying to two muons in proton-proton collisions at $\sqrt{s} =$ 13 TeV

The CMS collaboration Sirunyan, Albert M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 122 (2019) 021801, 2019.
Inspire Record 1682776 DOI 10.17182/hepdata.88058

A search for the Higgs boson decaying to two oppositely charged muons is presented using data recorded by the CMS experiment at the CERN LHC in 2016 at a center-of-mass energy s=13  TeV, corresponding to an integrated luminosity of 35.9  fb-1. Data are found to be compatible with the predicted background. For a Higgs boson with a mass of 125.09 GeV, the 95% confidence level observed (background-only expected) upper limit on the production cross section times the branching fraction to a pair of muons is found to be 3.0 (2.5) times the standard model expectation. In combination with data recorded at center-of-mass energies s=7 and 8 TeV, the background-only expected upper limit improves to 2.2 times the standard model value with a standard model expected significance of 1.0 standard deviation. The corresponding observed upper limit is 2.9 with an observed significance of 0.9 standard deviation. This corresponds to an observed upper limit on the standard model Higgs boson branching fraction to muons of 6.4×10-4 and to an observed signal strength of 1.0±1.0(stat)±0.1(syst).

6 data tables

The 95% CL upper limit on the signal strength modifier in the region around the Higgs boson mass using the 13 TeV data sets together with the expected limit obtained in the background-only hypothesis.

The 95% CL upper limit on the signal strength modifier in the region around the Higgs boson mass for the combination of the 7, 8, and 13 TeV data sets together with the expected limit obtained in the background-only hypothesis and in the signal-plus-background hypothesis for the SM Higgs boson with m_H=125 GeV.

The significance of the incompatibility with the background-only hypothesis using the 13 TeV data sets.

More…

Charged-particle nuclear modification factors in XeXe collisions at $ \sqrt{s_{\mathrm{NN}}} = 5.44 $ TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1810 (2018) 138, 2018.
Inspire Record 1692558 DOI 10.17182/hepdata.85626

The differential yields of charged particles having pseudorapidity within |η| < 1 are measured using xenon-xenon (XeXe) collisions at $ \sqrt{s_{\mathrm{NN}}} = 5.44 $ TeV. The data, corresponding to an integrated luminosity of 3.42 μb$^{−1}$, were collected in 2017 by the CMS experiment at the LHC. The yields are reported as functions of collision centrality and transverse momentum, p$_{T}$, from 0.5 to 100 GeV. A previously reported p$_{T}$ spectrum from proton-proton collisions at $ \sqrt{s}=5.02 $ TeV is used for comparison after correcting for the difference in center-of-mass energy. The nuclear modification factors using this reference, R$_{AA}^{*}$ , are constructed and compared to previous measurements and theoretical predictions. In head-on collisions, the R$_{AA}^{*}$ has a value of 0.17 in the p$_{T}$ range of 6–8 GeV, but increases to approximately 0.7 at 100 GeV. Above ≈6 GeV, the XeXe data show a notably smaller suppression than previous results for lead-lead (PbPb) collisions at $ \sqrt{s_{\mathrm{NN}}}=5.02 $ TeV when compared at the same centrality (i.e., the same fraction of total cross section). However, the XeXe suppression is slightly greater than that for PbPb in events having a similar number of participating nucleons.

10 data tables

The per-event differential invariant yield of charged particles having |eta|<1 in XeXe collisions at sqrt(s_NN)=5.44 TeV. The first systematic uncertainty describes uncertainties that are not fully correlated across points, while the second systematic uncertainty is a normalization uncertainty that is fully correlated across all points. Bins where no data point has been reported are denoted as 'empty'.

The per-event differential invariant yield of charged particles having |eta|<1 in pp collisions at sqrt(s)=5.44 TeV, after extrpolation from 5.02 TeV data. The first systematic uncertainty describes uncertainties that are not fully correlated across points, while the second systematic uncertainty is a normalization uncertainty that is fully correlated across all points. The data is measured and extrapolated as a differential cross section, and transformed into a differential yield using an inelastic cross-section of 70 mb.

The nuclear modification factor of charged particles having |eta|<1 in XeXe collisions at sqrt(s_NN)=5.44 TeV. The first systematic uncertainty describes uncertainties that are not fully correlated across points, while the second systematic uncertainty is a normalization uncertainty that is fully correlated across all points. Bins where no data point has been reported are denoted as 'empty'.

More…

Search for long-lived particles with displaced vertices in multijet events in proton-proton collisions at $\sqrt{s}= $13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev. D98 (2018) 092011, 2018.
Inspire Record 1685992 DOI 10.17182/hepdata.85138

Results are reported from a search for long-lived particles in proton-proton collisions at s=13  TeV delivered by the CERN LHC and collected by the CMS experiment. The data sample, which was recorded during 2015 and 2016, corresponds to an integrated luminosity of 38.5  fb-1. This search uses benchmark signal models in which long-lived particles are pair-produced and each decays into two or more quarks, leading to a signal with multiple jets and two displaced vertices composed of many tracks. No events with two well-separated high-track-multiplicity vertices are observed. Upper limits are placed on models of R-parity violating supersymmetry in which the long-lived particles are neutralinos or gluinos decaying solely into multijet final states or top squarks decaying solely into dijet final states. For neutralino, gluino, or top squark masses between 800 and 2600 GeV and mean proper decay lengths between 1 and 40 mm, the analysis excludes cross sections above 0.3 fb at 95% confidence level. Gluino and top squark masses are excluded below 2200 and 1400 GeV, respectively, for mean proper decay lengths between 0.6 and 80 mm. A method is provided for extending the results to other models with pair-produced long-lived particles.

24 data tables

Distribution of the distance between vertices in the $x$-$y$ plane, $d_{VV}$, for simulated multijet signals with $m$ = 800 GeV, production cross section 1 fb, and $c\tau$ = 0.3, 1.0, and 10 mm, with the background template overlaid. All vertex and event selection criteria have been applied. The last bin includes the overflow events.

Distribution of $d_{BV}$ in $\geq$5-track one-vertex events for data and simulated multijet signals with $m$ = 800 GeV, production cross section 1 fb, and $c\tau$ = 0.3, 1.0, and 10 mm. Event preselection and vertex selection criteria have been applied. The last bin includes the overflow events.

Signal efficiency as a function of signal mass and lifetime for the multijet signal samples. All vertex and event selection criteria have been applied, as well as the requirement $d_{VV}$ > 0.4 mm.

More…

Search for heavy resonances decaying into two Higgs bosons or into a Higgs boson and a W or Z boson in proton-proton collisions at 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1901 (2019) 051, 2019.
Inspire Record 1685235 DOI 10.17182/hepdata.88169

A search is presented for massive narrow resonances decaying either into two Higgs bosons, or into a Higgs boson and a W or Z boson. The decay channels considered are HH$\to \mathrm{b\overline{b}}\tau^{+}\tau^{-}$ and VH$ \to \mathrm{q\overline{q}}\tau^{+}\tau^{-}$, where H denotes the Higgs boson, and V denotes the W or Z boson. This analysis is based on a data sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV by the CMS Collaboration, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. For the TeV-scale mass resonances considered, substructure techniques provide ways to differentiate among the hadronization products from vector boson decays to quarks, Higgs boson decays to bottom quarks, and quark- or gluon-induced jets. Reconstruction techniques are used that have been specifically optimized to select events in which the tau lepton pair is highly boosted. The observed data are consistent with standard model expectations and upper limits are set at 95% confidence level on the product of cross section and branching fraction for resonance masses between 0.9 and 4.0 TeV. Exclusion limits are set in the context of bulk radion and graviton models: spin-0 radion resonances are excluded below a mass of 2.7 TeV at 95% confidence level. In the spin-1 heavy vector triplet framework, mass-degenerate W' and Z' resonances with dominant couplings to the standard model gauge bosons are excluded below a mass of 2.8 TeV at 95% confidence level. There are the first limits for these decay channels at $\sqrt{s}=$ 13 TeV.

5 data tables

Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-0 resonance decaying to HH, as a function of the resonance mass hypothesis.

Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-2 resonance decaying to HH, as a function of the resonance mass hypothesis.

Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-1 W prime resonance decaying to WH, as a function of the resonance mass hypothesis.

More…

Observation of the $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) and measurement of their masses

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 092002, 2018.
Inspire Record 1675256 DOI 10.17182/hepdata.85742

The $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) states are observed through their $\Upsilon$(3S) $\gamma$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$^{-1}$. The $\Upsilon$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $\chi_\mathrm{b}$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$\,$513.42 $\pm$ 0.41 (stat) $\pm$ 0.18 (syst) MeV and 10$\,$524.02 $\pm$ 0.57 (stat) $\pm$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $\Upsilon$(3S) mass, which has an uncertainty of 0.5 MeV. The mass splitting is measured to be 10.60 $\pm$ 0.64 (stat) $\pm$ 0.17 (syst) MeV.

2 data tables

Observation of the $\chi_{b1}(3P)$ and $\chi_{b2}(3P)$ and measurement of their masses.

Observation of the $\chi_{b1}(3P)$ and $\chi_{b2}(3P)$ and mass splitting measurement.


Measurement of the groomed jet mass in PbPb and pp collisions at $ \sqrt{s_{\mathrm{NN}}}=5.02 $ TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1810 (2018) 161, 2018.
Inspire Record 1672962 DOI 10.17182/hepdata.83199

A measurement of the groomed jet mass in PbPb and pp collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV with the CMS detector at the LHC is presented. Jet grooming is a recursive procedure which sequentially removes soft constituents of a jet until a pair of hard subjets is found. The resulting groomed jets can be used to study modifications to the parton shower evolution in the presence of the hot and dense medium created in heavy ion collisions. Predictions of groomed jet properties from the pythia and herwig++ event generators agree with the measurements in pp collisions. When comparing the results from the most central PbPb collisions to pp data, a hint of an increase of jets with large jet mass is observed, which could originate from additional medium-induced radiation at a large angle from the jet axis. However, no modification of the groomed mass of the core of the jet is observed for all PbPb centrality classes. The PbPb results are also compared to predictions from the jewel and q-pythia event generators, which predict a large modification of the groomed mass not observed in the data.

12 data tables

Groomed jet energy fraction in pp collision for jets with PTJET 160-180 GeV

Groomed jet energy fraction in PbPb collision for jets with PTJET 160-180 GeV

MG/PTJET for SD (0.1,0.0) in PP collision

More…

Version 2
Observation of the Higgs boson decay to a pair of $\tau$ leptons with the CMS detector

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett. B779 (2018) 283-316, 2018.
Inspire Record 1613900 DOI 10.17182/hepdata.83008

A measurement of the H→ττ signal strength is performed using events recorded in proton–proton collisions by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13TeV . The data set corresponds to an integrated luminosity of 35.9fb−1 . The H→ττ signal is established with a significance of 4.9 standard deviations, to be compared to an expected significance of 4.7 standard deviations. The best fit of the product of the observed H→ττ signal production cross section and branching fraction is 1.09−0.26+0.27 times the standard model expectation. The combination with the corresponding measurement performed with data collected by the CMS experiment at center-of-mass energies of 7 and 8TeV leads to an observed significance of 5.9 standard deviations, equal to the expected significance. This is the first observation of Higgs boson decays to τ leptons by a single experiment.

3 data tables

Best fit signal strength per category (left) and channel (right), for mH = 125.09 GeV. The constraints from the global fit are used to extract each of the individual best fit signal strengths. The combined best fit signal strength is μ = 1.09+0.27

Best fit signal strength per channel, for mH = 125.09 GeV. The constraints from the global fit are used to extract each of the individual best fit signal strengths. The combined best fit signal strength is μ = 1.09+0.27

Local p-value and significance as a function of the SM Higgs boson mass hypothesis. The observation (red, solid) is compared to the expectation (blue, dashed) for a Higgs boson with a mass mH = 125.09 GeV. The background includes Higgs boson decays to pairs of W bosons, with mH = 125.09 GeV.


Observation of Higgs boson decay to bottom quarks

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 121801, 2018.
Inspire Record 1691854 DOI 10.17182/hepdata.86132

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3  fb-1 of proton-proton collisions at s=13  TeV, are described. When combined with previous VH measurements using data collected at s=7, 8, and 13 TeV, an excess of events is observed at mH=125  GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01±0.22. The combination of this result with searches by the CMS experiment for H→bb¯ in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04±0.20.

2 data tables

Expected and observed significances, in number of standard deviations, and observed signal strengths for the VH production process with H-->b bbar. Results are shown separately for 2017 data, combined Run 2 (2016 and 2017 data), and for the combination of the Run 1 and Run 2 data. For the 2017 analysis, results are shown separately for the individual mu value for each channel from a combined simultaneous fit to all channels. All results are obtained for mH=125.09 GeV. Data are from Table 2 and 2016 added from Figure 1b.

Best-fit value of the H-->b bbar signal strength with its 1 sigma systematic (red) and total (blue) uncertainties for the five individual production modes considered, as well as the overall combined result. The vertical dashed line indicates the standard model expectation. All results are extracted from a single fit combining all input analyses, with mH = 125.09 GeV. Data from Figure 3.


Version 2
Measurement of jet substructure observables in $\mathrm{t\overline{t}}$ events from proton-proton collisions at $\sqrt{s}=$ 13TeV

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev. D98 (2018) 092014, 2018.
Inspire Record 1690148 DOI 10.17182/hepdata.84716

A measurement of jet substructure observables is presented using tt¯ events in the lepton+jets channel from proton-proton collisions at s=13  TeV recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9  fb-1. Multiple jet substructure observables are measured for jets identified as bottom, light-quark, and gluon jets, as well as for inclusive jets (no flavor information). The results are unfolded to the particle level and compared to next-to-leading-order predictions from powheg interfaced with the parton shower generators pythia 8 and herwig 7, as well as from sherpa 2 and Dire 2. A value of the strong coupling at the Z boson mass, αS(mZ)=0.115-0.013+0.015, is extracted from the substructure data at leading-order plus leading-log accuracy.

132 data tables

Distribution of $C_{1}^{(0.0)}$ reconstructed from all particles with pt > 1 GeV, unfolded to the particle level.

Distribution of $C_{1}^{(0.0)}$ reconstructed from charged particles with pt > 1 GeV, unfolded to the particle level.

Distribution of $C_{1}^{(0.2)}$ reconstructed from all particles with pt > 1 GeV, unfolded to the particle level.

More…

Search for leptoquarks coupled to third-generation quarks in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 241802, 2018.
Inspire Record 1694381 DOI 10.17182/hepdata.85765

Three of the most significant measured deviations from standard model predictions, the enhanced decay rate for B→D(*)τν, hints of lepton universality violation in B→K(*)ℓℓ decays, and the anomalous magnetic moment of the muon, can be explained by the existence of leptoquarks (LQs) with large couplings to third-generation quarks and masses at the TeV scale. The existence of these states can be probed at the LHC in high energy proton-proton collisions. A novel search is presented for pair production of LQs coupled to a top quark and a muon using data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9  fb-1, recorded by the CMS experiment. No deviation from the standard model prediction has been observed and scalar LQs decaying exclusively into tμ are excluded up to masses of 1420 GeV. The results of this search are combined with those from previous searches for LQ decays into tτ and bν, which excluded scalar LQs below masses of 900 and 1080 GeV. Vector LQs are excluded up to masses of 1190 GeV for all possible combinations of branching fractions to tμ, tτ and bν. With this analysis, all relevant couplings of LQs with an electric charge of -1/3 to third-generation quarks are probed for the first time.

6 data tables

Distributions for $M_{LQ}^{rec}$ (category A) after applying the full selection. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Distributions for $S_{T}$ (category B) after applying the full selection and estimating the $t\overline{t}$ and DY+jets background contributions from data in category B. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.

Observed upper limits on the production cross section for pair production of LQs decaying into a top quark and a muon or a $\tau$ lepton at 95% CL in the $M_{LQ} - B(LQ \rightarrow t\mu)$ plane.

More…

Search for resonant pair production of Higgs bosons decaying to bottom quark-antiquark pairs in proton-proton collisions at 13 TeV

The CMS collaboration Sirunyan, Albert M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1808 (2018) 152, 2018.
Inspire Record 1677276 DOI 10.17182/hepdata.86134

A search for a narrow-width resonance decaying into two Higgs bosons, each decaying into a bottom quark-antiquark pair, is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 35.9 fb$^{-1}$ at $\sqrt{s}=$ 13 TeV recorded by the CMS detector at the LHC. No evidence for such a signal is observed. Upper limits are set on the product of the production cross section for the resonance and the branching fraction for the selected decay mode in the resonance mass range from 260 to 1200 GeV.

2 data tables

The observed and expected upper limits on the cross section for a spin-2 resonance X $\rightarrow$ H(bb) H(bb) at 95% CL, using the asymptotic CLs method

The observed and expected upper limits on the cross section for a spin-0 resonance X $\rightarrow$ H(bb) H(bb) at 95% CL, using the asymptotic CLs method


Studies of ${\mathrm {B}} ^{*{\mathrm {s}}2}(5840)^0 $ and ${\mathrm {B}} _{{\mathrm {s}}1}(5830)^0 $ mesons including the observation of the ${\mathrm {B}} ^{*{\mathrm {s}}2}(5840)^0 \rightarrow {\mathrm {B}} ^0 \mathrm {K} ^0_{\mathrm {S}} $ decay in proton-proton collisions at $\sqrt{s}=8\,\text {TeV} $

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Eur.Phys.J. C78 (2018) 939, 2018.
Inspire Record 1693614 DOI 10.17182/hepdata.85740

Measurements of $\mathrm{B}^*_\mathrm{s2}(5840)^0$ and $\mathrm{B}_\mathrm{s1}(5830)^0$ mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.6 fb$^{-1}$, collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV. The analysis studies $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson decays into $\mathrm{B}^{(*)+}\mathrm{K}^-$ and $\mathrm{B}^{(*)0}\mathrm{K}^0_\mathrm{S}$, where the $\mathrm{B}^+$ and $\mathrm{B}^0$ mesons are identified using the decays $\mathrm{B}^+\to\mathrm{J}/\psi\,\mathrm{K}^+$ and $\mathrm{B}^0\to\mathrm{J}/\psi\,\mathrm{K}^*(892)^0$. The masses of the $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson states are measured and the natural width of the $\mathrm{B}^*_\mathrm{s2}(5840)^0$ state is determined. The first measurement of the mass difference between the charged and neutral $\mathrm{B}^*$ mesons is also presented. The $\mathrm{B}^*_\mathrm{s2}(5840)^0$ decay to $\mathrm{B}^0\mathrm{K}^0_\mathrm{S}$ is observed, together with a measurement of its branching fraction relative to the $\mathrm{B}^*_\mathrm{s2}(5840)^0\to\mathrm{B}^+\mathrm{K}^-$ decay.

12 data tables

The $\mathrm{J}/\psi\mathrm{K}^+$ invariant mass distribution in data

The $\mathrm{J}/\psi\mathrm{K}^{*0}$ invariant mass distribution in data

The $\mathrm{B}^+\pi^-$ invariant mass distribution of the selected candidates in data

More…

Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at $ \sqrt{s}=7 $ and 8 TeV

The ATLAS & CMS collaborations Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 1608 (2016) 045, 2016.
Inspire Record 1468068 DOI 10.17182/hepdata.78403

Combined ATLAS and CMS measurements of the Higgs boson production and decay rates, as well as constraints on its couplings to vector bosons and fermions, are presented. The combination is based on the analysis of five production processes, namely gluon fusion, vector boson fusion, and associated production with a W or a Z boson or a pair of top quarks, and of the six decay modes H → ZZ, W W , γγ, ττ, bb, and μμ. All results are reported assuming a value of 125.09 GeV for the Higgs boson mass, the result of the combined measurement by the ATLAS and CMS experiments. The analysis uses the CERN LHC proton-proton collision data recorded by the ATLAS and CMS experiments in 2011 and 2012, corresponding to integrated luminosities per experiment of approximately 5 fb$^{−1}$ at $ \sqrt{s}=7 $ TeV and 20 fb$^{−1}$ at $ \sqrt{s}=8 $ TeV. The Higgs boson production and decay rates measured by the two experiments are combined within the context of three generic parameterisations: two based on cross sections and branching fractions, and one on ratios of coupling modifiers. Several interpretations of the measurements with more model-dependent parameterisations are also given. The combined signal yield relative to the Standard Model prediction is measured to be 1.09 ± 0.11. The combined measurements lead to observed significances for the vector boson fusion production process and for the H → ττ decay of 5.4 and 5.5 standard deviations, respectively. The data are consistent with the Standard Model predictions for all parameterisations considered.

44 data tables

Best fit values of $\sigma_i \cdot \mathrm{B}^f$ for each specific channel $i \to H\to f$, as obtained from the generic parameterisation with 23 parameters for the combination of the ATLAS and CMS measurements, using the $\sqrt{s}$=7 and 8 TeV data. The cross sections are given for $\sqrt{s}$=8 TeV, assuming the SM values for $\sigma_i(7 \mathrm{TeV})/\sigma_i(8 \mathrm{TeV})$. The results are shown together with their total uncertainties and their breakdown into statistical and systematic components. The missing values are either not measured with a meaningful precision and therefore not quoted, in the case of the $H\to ZZ$ decay channel for the $WH$, $ZH$, and $ttH$ production processes, or not measured at all and therefore fixed to their corresponding SM predictions, in the case of the $H\to bb$ decay mode for the $gg\mathrm{F}$ and VBF production processes.

Best fit values of $\sigma_i \cdot \mathrm{B}^f$ relative to their SM prediction for each specific channel $i \to H\to f$, as obtained from the generic parameterisation with 23 parameters for the combination of the ATLAS and CMS measurements, using the $\sqrt{s}$=7 and 8 TeV data. The results are shown together with their total uncertainties and their breakdown into statistical and systematic components. The missing values are either not measured with a meaningful precision and therefore not quoted, in the case of the $H\to ZZ$ decay channel for the $WH$, $ZH$, and $ttH$ production processes, or not measured at all and therefore fixed to their corresponding SM predictions, in the case of the $H\to bb$ decay mode for the $gg\mathrm{F}$ and VBF production processes.

Best fit values of $\sigma(gg\to H\to ZZ)$, $\sigma_i/\sigma_{gg\mathrm{F}}$, and $\mathrm{B}^f/\mathrm{B}^{ZZ}$ from the combined analysis of the $\sqrt{s}$=7 and 8 TeV data. The values involving cross sections are given for $\sqrt{s}$=8 TeV, assuming the SM values for $\sigma_i(7 \mathrm{TeV})/\sigma_i(8 \mathrm{TeV})$. The results are shown for the combination of ATLAS and CMS, and also separately for each experiment, together with their total uncertainties and their breakdown into the four components described in the text. The expected uncertainties in the measurements are also shown.

More…

Non-Gaussian elliptic-flow fluctuations in PbPb collisions at $\sqrt{\smash[b]{s_{_\text{NN}}}} = 5.02$ TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
No Journal Information, 2017.
Inspire Record 1636197 DOI 10.17182/hepdata.80151

Event-by-event fluctuations in the elliptic-flow coefficient $v_2$ are studied in PbPb collisions at $\sqrt{s_{_\text{NN}}} = 5.02$ TeV using the CMS detector at the CERN LHC. Elliptic-flow probability distributions ${p}(v_2)$ for charged particles with transverse momentum 0.3$< p_\mathrm{T} <$3.0 GeV and pseudorapidity $| \eta | <$ 1.0 are determined for different collision centrality classes. The moments of the ${p}(v_2)$ distributions are used to calculate the $v_{2}$ coefficients based on cumulant orders 2, 4, 6, and 8. A rank ordering of the higher-order cumulant results and nonzero standardized skewness values obtained for the ${p}(v_2)$ distributions indicate non-Gaussian initial-state fluctuation behavior. Bessel-Gaussian and elliptic power fits to the flow distributions are studied to characterize the initial-state spatial anisotropy.

14 data tables

Unfolded elliptic flow probability density (p(v_2)) for 15-20\% collision centralities

Unfolded elliptic flow probability density (p(v_2)) for 30-35\% collision centralities

Unfolded elliptic flow probability density (p(v_2)) for 55-60\% collision centralities

More…

Elliptic flow of charm and strange hadrons in high-multiplicity pPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 8.16 TeV

The CMS collaboration Sirunyan, A. M. ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Rev.Lett. 121 (2018) 082301, 2018.
Inspire Record 1670168 DOI 10.17182/hepdata.83911

The elliptic azimuthal anisotropy coefficient (v2) is measured for charm (D0) and strange (KS0, Λ, Ξ-, and Ω-) hadrons, using a data sample of p+Pb collisions collected by the CMS experiment, at a nucleon-nucleon center-of-mass energy of sNN=8.16  TeV. A significant positive v2 signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity p+Pb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest that charm quarks have a smaller v2 than the lighter quarks, probably reflecting a weaker collective behavior. This effect is not seen in the larger PbPb collision system at sNN=5.02  TeV, also presented.

24 data tables

The elliptic flow, $v_{2}$, for $K^{0}_{S}$ as a function of $p_{T}$ in pPb collision at 8.16 TeV.

The elliptic flow, $v_{2}$, for $\Lambda$ as a function of $p_{T}$ in pPb collision at 8.16 TeV.

The elliptic flow, $v_{2}$, for $\Xi^{-}$ as a function of $p_{T}$ in pPb collision at 8.16 TeV.

More…

Search for pair-produced resonances decaying to quark pairs in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
No Journal Information, 2018.
Inspire Record 1685989 DOI 10.17182/hepdata.85857

A search for the pair production of resonances, each decaying to two quarks, is reported. The search is conducted separately for heavier resonances (masses above 400 GeV), where each of the four final-state quarks generates a hadronic jet resulting in a four-jet signature, and for lighter resonances (masses between 80 and 400 GeV), where the pair of quarks from each resonance is collimated and reconstructed as a single jet resulting in a two-jet signature. In addition, a b-tagged selection is applied to target resonances with a bottom quark in the final state. The analysis uses data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 35.9 fb$^{-1}$, from proton-proton collisions at a center-of-mass energy of 13 TeV. The mass spectra are analyzed for the presence of new resonances, and are found to be consistent with standard model expectations. The results are interpreted in the framework of $R$-parity-violating supersymmetry assuming the pair production of scalar top quarks decaying via the hadronic coupling $\lambda_{312}"$ or $\lambda_{323}"$, and upper limits on the cross section as a function of the top squark mass are set. These results probe lower masses than previously explored at the LHC, and extend the top squark mass limits in the $\widetilde{\mathrm{t}}$$\to$qq$'$ scenario.

8 data tables

Resolved search distribution of average dijet mass for the data, along with the resulting fit to the functional form for the b-tagged selection

Resolved search distribution of average dijet mass for the data, along with the resulting fit to the functional form for the inclusive selection

Boosted search average pruned mass distribution for data and for the total background prediction for the b-tagged selection.

More…

Measurements of the associated production of a Z boson and b jets in pp collisions at ${\sqrt{s}} = 8\,\text {TeV} $

The CMS collaboration Khachatryan, V. ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Eur.Phys.J. C77 (2017) 751, 2017.
Inspire Record 1499471 DOI 10.17182/hepdata.77544

Measurements of the associated production of a Z boson with at least one jet originating from a b quark in proton-proton collisions at $\sqrt{s} =$ 8 TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8 inverse femtobarns. Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the b jet and the Z boson. Ratios of differential cross sections for the associated production with at least one b jet to the associated production with any jet are also presented. The production of a Z boson with two b jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.

20 data tables

Differential fiducial cross section for Z(1b) production as a function of the leading b jet pT

Cross section ratio for Z(1b) and Z+jets production as a function of the leading b/inclusive (j) jet pT

Differential fiducial cross section for Z(1b) production as a function of the leading b jet |eta|

More…

Constraints on anomalous Higgs boson couplings using production and decay information in the four-lepton final state

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett. B775 (2017) 1-24, 2017.
Inspire Record 1608386 DOI 10.17182/hepdata.80811

A search is performed for anomalous interactions of the recently discovered Higgs boson using matrix element techniques with the information from its decay to four leptons and from associated Higgs boson production with two quark jets in either vector boson fusion or associated production with a vector boson. The data were recorded by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 38.6 inverse femtobarns. These data are combined with the data collected at center-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 inverse femtobarns, respectively. All observations are consistent with the expectations for the standard model Higgs boson.

4 data tables

Observed and expected likelihood scans $f_{\Lambda1}\cos\phi_{\Lambda1}$. See Section 2 of the paper for more details.

Observed and expected likelihood scans $f_{\Lambda1}^{Z\gamma}\cos\phi_{\Lambda1}^{Z\gamma}$. See Section 2 of the paper for more details.

Observed and expected likelihood scans $f_{a2}\cos\phi_{a2}$. See Section 2 of the paper for more details.

More…

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 $\tau$ leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
Phys.Lett. B785 (2018) 462, 2018.
Inspire Record 1674926 DOI 10.17182/hepdata.86228

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 $\tau$ 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 $\mathcal{B}$(h $\to$ aa $\to$ 2$\tau$2b) 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.

1 data table

Expected and observed 95% CL upper limits on (sigma(pp->h)/sigma(pp->hSM)) * B(h -> aa -> bbtautau) as a function of m(a), where h(SM) is the Higgs boson of the standard model, h is the observed particle with mass of 125 GeV, and a denotes a light Higgs-like state, as obtained from the 13 TeV data.


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

The CMS collaboration Sirunyan, Albert M ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 1811 (2018) 018, 2018.
Inspire Record 1673011 DOI 10.17182/hepdata.85886

A search for exotic Higgs boson decays to light pseudoscalars in the final state of two muons and two $\tau$ 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.

1 data table

Expected and observed 95% CL upper limits on (sigma(pp->h)/sigma(pp->hSM)) * B(h -> aa -> mumutautau) as a function of m(a), where h(SM) is the Higgs boson of the standard model, h is the observed particle with mass of 125 GeV, and a denotes a light Higgs-like state, as obtained from the 13 TeV data.