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CMS-HIG-17-034 ; CERN-EP-2019-029

Constraints on anomalous HVV couplings from the production of Higgs bosons decaying to $\tau$ lepton pairs

CMS Collaboration

16 March 2019

Phys. Rev. D 100 (2019) 112002

Abstract: A study is presented of anomalous HVV interactions of the Higgs boson, including its CP properties. The study uses Higgs boson candidates produced mainly in vector boson fusion and gluon fusion that subsequently decay to a pair of $\tau$ leptons. The data were recorded by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 35.9 fb$^{-1}$. A matrix element technique is employed for the analysis of anomalous interactions. The results are combined with those from the $\mathrm{H}\to 4\ell$ decay channel presented earlier, yielding the most stringent constraints on anomalous Higgs boson couplings to electroweak vector bosons expressed as effective cross-section fractions and phases: the CP-violating parameter $f_{a3}\cos(\phi_{a3})=(0.00 \pm 0.27 )\times10^{-3}$ and the CP-conserving parameters $f_{a2}\cos(\phi_{a2})=(0.08^{+1.04}_{-0.21})\times10^{-3}$, $f_{\Lambda1}\cos(\phi_{\Lambda1})=(0.00^{+0.53}_{-0.09})\times10^{-3}$, and $f_{\Lambda1}^{\mathrm{Z}\gamma}\cos(\phi_{\Lambda1}^{\mathrm{Z}\gamma})=(0.0^{+1.1}_{-1.3})\times10^{-3}$. The current data set does not allow for precise constraints on CP properties in the gluon fusion process. The results are consistent with standard model expectations.

Links: e-print arXiv:1903.06973 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ;

Figures
png pdf	Figure 1: Examples of leading-order Feynman diagrams for H boson production via the gluon fusion (left), vector boson fusion (middle), and associated production with a vector boson (right). The HWW and HZZ couplings may appear at tree level, as the SM predicts. Additionally, HWW, HZZ, HZ$\gamma$, H$\gamma \gamma$, and Hgg couplings may be generated by loops of SM or unknown particles, as indicated in the left diagram but not shown explicitly in the middle and right diagrams.
png pdf	Figure 1-a: Example of leading-order Feynman diagram for H boson production via the gluon fusion. The HWW, HZZ, HZ$\gamma$, H$\gamma \gamma$, and Hgg couplings may be generated by loops of SM or unknown particles, as indicated in the diagram.
png pdf	Figure 1-b: Example of leading-order Feynman diagram for H boson production via vector boson fusion. The HWW and HZZ couplings may appear at tree level, as the SM predicts.
png pdf	Figure 1-c: Example of leading-order Feynman diagram for H boson production via associated production with a vector boson. The HWW and HZZ couplings may appear at tree level, as the SM predicts.
png pdf	Figure 2: Illustrations of H boson production in ${\mathrm {q}}{{\mathrm {q}}^\prime}\to {\mathrm {g}} {\mathrm {g}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\mathrm {H}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\tau} {\tau}({\mathrm {q}}{{\mathrm {q}}^\prime})$ or VBF ${\mathrm {q}}{{\mathrm {q}}^\prime}\to \mathrm {V}^*\mathrm {V}^*({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\mathrm {H}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\tau} {\tau}({\mathrm {q}}{{\mathrm {q}}^\prime})$ (left) and in associated production ${\mathrm {q}}\bar{{\mathrm {q}}}^\prime \to \mathrm {V}^*\to \mathrm {V} {\mathrm {H}} \to {\mathrm {q}}\bar{{\mathrm {q}}}^\prime {\tau} {\tau}$ (right). The ${\mathrm {H}} \to {\tau} {\tau}$ decay is shown without further illustrating the ${\tau}$ decay chain. Angles and invariant masses fully characterize the orientation of the production and two-body decay chain and are defined in suitable rest frames of the V and H bosons, except in the VBF case, where only the H boson rest frame is used [26,28].
png pdf	Figure 2-a: Illustration of H boson production in ${\mathrm {q}}{{\mathrm {q}}^\prime}\to {\mathrm {g}} {\mathrm {g}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\mathrm {H}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\tau} {\tau}({\mathrm {q}}{{\mathrm {q}}^\prime})$ or VBF ${\mathrm {q}}{{\mathrm {q}}^\prime}\to \mathrm {V}^*\mathrm {V}^*({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\mathrm {H}} ({\mathrm {q}}{{\mathrm {q}}^\prime})\to {\tau} {\tau}({\mathrm {q}}{{\mathrm {q}}^\prime})$. The ${\mathrm {H}} \to {\tau} {\tau}$ decay is shown without further illustrating the ${\tau}$ decay chain. Angles and invariant masses fully characterize the orientation of the production and two-body decay chain and are defined in suitable rest frames of the V and H bosons, except in the VBF case, where only the H boson rest frame is used.
png pdf	Figure 2-b: Illustration of H boson production in associated production ${\mathrm {q}}\bar{{\mathrm {q}}}^\prime \to \mathrm {V}^*\to \mathrm {V} {\mathrm {H}} \to {\mathrm {q}}\bar{{\mathrm {q}}}^\prime {\tau} {\tau}$.
png pdf	Figure 3: The distributions of ${m_\text {vis}}$ and ${m_{{\tau} {\tau}}}$ in the 0-jet category of the ${\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ (left) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (right) decay channels. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 3-a: The distribution of ${m_\text {vis}}$ and ${m_{{\tau} {\tau}}}$ in the 0-jet category of the ${\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ decay channel. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 3-b: The distribution of ${m_\text {vis}}$ and ${m_{{\tau} {\tau}}}$ in the 0-jet category of the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 4: The distributions of transverse momentum of the H boson in the boosted category of the ${\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}} + {\mathrm {e}} {{\mu}}$ (left) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (right) decay channels. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 4-a: The distribution of transverse momentum of the H boson in the boosted category of the ${\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}} + {\mathrm {e}} {{\mu}}$ decay channel. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 4-b: The distribution of transverse momentum of the H boson in the boosted category of the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel. The BSM hypothesis corresponds to $f_{a3}=$ 1.
png pdf	Figure 5: The distributions of $\mathcal {D}_\mathrm {0-}$, $\mathcal {D}_{CP}$, $\mathcal {D}_\mathrm {0h+}$, $\mathcal {D}_{\Lambda 1}$, and $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis depends on the variable shown: it corresponds to $f_{a3}=$ 1 for the $\mathcal {D}_\mathrm {0-}$ (upper left) distributions, the maximal mixing ("BSM mix") in VBF production for the $\mathcal {D}_{CP}$ distribution (upper right), $f_{a2}=$ 1 for the $\mathcal {D}_\mathrm {0h+}$ distribution (middle left), $f_{\Lambda 1}=$ 1 for the $\mathcal {D}_{\Lambda 1}$ distribution (middle right), and $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}=$ 1 for the $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ distribution (lower).
png pdf	Figure 5-a: The distribution of $\mathcal {D}_\mathrm {0-}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis shown corresponds to $f_{a3}=$ 1.
png pdf	Figure 5-b: The distribution of $\mathcal {D}_{CP}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis shown corresponds to the maximal mixing ("BSM mix") in VBF production.
png pdf	Figure 5-c: The distribution of $\mathcal {D}_\mathrm {0h+}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis shown corresponds to $f_{a2}=$ 1.
png pdf	Figure 5-d: The distribution of $\mathcal {D}_{\Lambda 1}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis shown corresponds to $f_{\Lambda 1}=$ 1.
png pdf	Figure 5-e: The distribution of $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the VBF category. All four decay channels, ${\mathrm {e}} {{\mu}}$, ${\mathrm {e}} {{\tau} _\mathrm {h}}$, ${{\mu}} {{\tau} _\mathrm {h}}$, and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$, are summed. The BSM hypothesis shown corresponds to $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}=$ 1.
png pdf	Figure 6: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0-}$ in the $f_{a3}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ (upper) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (middle and lower) decay channels.
png pdf	Figure 6-a: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0-}$ in the $f_{a3}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 6-b: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0-}$ in the $f_{a3}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 6-c: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0-}$ in the $f_{a3}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 7: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0h+}$ in the $f_{a2}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ (upper) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (middle and lower) decay channels.
png pdf	Figure 7-a: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0h+}$ in the $f_{a2}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 7-b: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0h+}$ in the $f_{a2}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 7-c: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_\mathrm {0h+}$ in the $f_{a2}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 8: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}$ in the $f_{\Lambda 1}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\mu}}$ (upper) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (middle and lower) decay channels.
png pdf	Figure 8-a: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}$ in the $f_{\Lambda 1}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\mu}} {{\mu}}$ decay channel.
png pdf	Figure 8-b: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}$ in the $f_{\Lambda 1}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 8-c: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}$ in the $f_{\Lambda 1}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 9: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (upper) and ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ (middle and lower) decay channels.
png pdf	Figure 9-a: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ analysis for the ${\mathrm {e}} {{\mu}}+ {\mathrm {e}} {{\tau} _\mathrm {h}} + {{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 9-b: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 9-c: Observed and expected distributions in the VBF category in bins of ${m_{{\tau} {\tau}}}$, ${m_{JJ}}$, and $\mathcal {D}_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ in the $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}$ analysis for the ${{\tau} _\mathrm {h}} {{\tau} _\mathrm {h}}$ decay channel.
png pdf	Figure 10: Observed (solid) and expected (dashed) likelihood scans of $f_{a3}\cos(\phi _{a3})$ (top left), $f_{a2}\cos(\phi _{a2})$ (top right), $f_{\Lambda 1}\cos(\phi _{\Lambda 1})$ (bottom left), and $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}\cos(\phi _{\Lambda 1}^{{\mathrm {Z}} \gamma})$ (bottom right).
png pdf	Figure 10-a: Observed (solid) and expected (dashed) likelihood scans of $f_{a3}\cos(\phi _{a3})$.
png pdf	Figure 10-b: Observed (solid) and expected (dashed) likelihood scans of $f_{a2}\cos(\phi _{a2})$.
png pdf	Figure 10-c: Observed (solid) and expected (dashed) likelihood scans of $f_{\Lambda 1}\cos(\phi _{\Lambda 1})$.
png pdf	Figure 10-d: Observed (solid) and expected (dashed) likelihood scans of $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}\cos(\phi _{\Lambda 1}^{{\mathrm {Z}} \gamma})$.
png pdf	Figure 11: Combination of results using the ${\mathrm {H}} \to {\tau} {\tau}$ decay (presented in this paper) and the ${\mathrm {H}} \to 4\ell$ decay [17]. The observed (solid) and expected (dashed) likelihood scans of $f_{a3}\cos(\phi _{a3})$ (top left), $f_{a2}\cos(\phi _{a2})$ (top right), $f_{\Lambda 1}\cos(\phi _{\Lambda 1})$ (bottom left), and $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}\cos(\phi _{\Lambda 1}^{{\mathrm {Z}} \gamma})$ (bottom right) are shown. For better visibility of all features, the $x$- and $y$-axes are presented with variable scales. On the linear-scale $x$-axis, a zoom is applied in the range $-$0.03 to $+$0.03. The $y$-axis is shown in linear (logarithmic) scale for values of $-2 \Delta \ln{\mathcal L}$ below (above) 11.
png pdf	Figure 11-a: Combination of results using the ${\mathrm {H}} \to {\tau} {\tau}$ decay (presented in this paper) and the ${\mathrm {H}} \to 4\ell$ decay [17]. Shown is the observed (solid) and expected (dashed) likelihood scan of $f_{a3}\cos(\phi _{a3})$. For better visibility of all features, the $x$- and $y$-axes are presented with variable scales. On the linear-scale $x$-axis, a zoom is applied in the range $-$0.03 to $+$0.03. The $y$-axis is shown in linear (logarithmic) scale for values of $-2 \Delta \ln{\mathcal L}$ below (above) 11.
png pdf	Figure 11-b: Combination of results using the ${\mathrm {H}} \to {\tau} {\tau}$ decay (presented in this paper) and the ${\mathrm {H}} \to 4\ell$ decay [17]. Shown is the observed (solid) and expected (dashed) likelihood scan of $f_{a2}\cos(\phi _{a2})$. For better visibility of all features, the $x$- and $y$-axes are presented with variable scales. On the linear-scale $x$-axis, a zoom is applied in the range $-$0.03 to $+$0.03. The $y$-axis is shown in linear (logarithmic) scale for values of $-2 \Delta \ln{\mathcal L}$ below (above) 11.
png pdf	Figure 11-c: Combination of results using the ${\mathrm {H}} \to {\tau} {\tau}$ decay (presented in this paper) and the ${\mathrm {H}} \to 4\ell$ decay [17]. Shown is the observed (solid) and expected (dashed) likelihood scan of $f_{\Lambda 1}\cos(\phi _{\Lambda 1})$. For better visibility of all features, the $x$- and $y$-axes are presented with variable scales. On the linear-scale $x$-axis, a zoom is applied in the range $-$0.03 to $+$0.03. The $y$-axis is shown in linear (logarithmic) scale for values of $-2 \Delta \ln{\mathcal L}$ below (above) 11.
png pdf	Figure 11-d: Combination of results using the ${\mathrm {H}} \to {\tau} {\tau}$ decay (presented in this paper) and the ${\mathrm {H}} \to 4\ell$ decay [17]. Shown is the observed (solid) and expected (dashed) likelihood scan of $f_{\Lambda 1}^{{\mathrm {Z}} \gamma}\cos(\phi _{\Lambda 1}^{{\mathrm {Z}} \gamma})$. For better visibility of all features, the $x$- and $y$-axes are presented with variable scales. On the linear-scale $x$-axis, a zoom is applied in the range $-$0.03 to $+$0.03. The $y$-axis is shown in linear (logarithmic) scale for values of $-2 \Delta \ln{\mathcal L}$ below (above) 11.

Tables
png pdf	Table 1: Kinematic selection criteria for the four decay channels. For the trigger threshold requirements, the numbers indicate the trigger thresholds in GeV. The lepton selection criteria include the transverse momentum threshold, pseudorapidity range, as well as isolation criteria.
png pdf	Table 2: Allowed 68% CL (central values with uncertainties) and 95% CL (in square brackets) intervals on anomalous coupling parameters using the ${\mathrm {H}} \to {\tau} {\tau}$ decay. The observed 95% CL constraints on $f_{a3}\cos(\phi _{a3})$ and $f_{a2}\cos(\phi _{a2})$ allow the full physics range $[-1,1]$.
png pdf	Table 3: Allowed 68% CL (central values with uncertainties) and 95% CL (in square brackets) intervals on anomalous coupling parameters using a combination of the ${\mathrm {H}} \to {\tau} {\tau}$ and ${\mathrm {H}} \to 4\ell$ [17] decay channels.
png pdf	Table 4: Summary of the allowed 95% CL intervals for the anomalous HVV couplings using the results in Table 3. The coupling ratios are assumed to be real and include the factor $\cos(\phi _{\Lambda 1})$ or $\cos(\phi _{\Lambda 1}^{{\mathrm {Z}} \gamma})= \pm$1.

Summary

A study is presented of anomalous HVV interactions of the H boson with vector bosons V, including CP violation, using its associated production with two hadronic jets in vector boson fusion, in the VH process, and in gluon fusion, and subsequently decaying to a pair of $\tau$ leptons. Constraints on the CP-violating parameter $f_{a3}$ and on the CP-conserving parameters $f_{a2}$, $f_{\Lambda1}$, and $f_{\Lambda1}^{\mathrm{Z}\gamma}$, defined in Eqs. (2) and (3), are set using matrix element techniques. The observed and expected limits on the parameters are summarized in Table 2. The 68% confidence level constraints are generally tighter than those from previous measurements using either production or decay information. Further constraints are obtained in the combination of the $\mathrm{H}\to\tau\tau$ and $\mathrm{H}\to 4\ell$ decay [17] channels and are summarized in Table 3. This combination places the most stringent constraints on anomalous H boson couplings: $f_{a3}\cos(\phi_{a3})=(0.00 \pm 0.27 )\times10^{-3}$, $f_{a2}\cos(\phi_{a2})=(0.08^{+1.04}_{-0.21})\times10^{-3}$, $f_{\Lambda1}\cos(\phi_{\Lambda1})=(0.00^{+0.53}_{-0.09})\times10^{-3}$, and $f_{\Lambda1}^{\mathrm{Z}\gamma}\cos(\phi_{\Lambda1}^{\mathrm{Z}\gamma})=(0.0^{+1.1}_{-1.3})\times10^{-3}$. A simultaneous measurement of $f_{a3}$ and $f_{a3}^{\mathrm{g}\mathrm{g}\mathrm{H}}$ parameters is performed, where the latter parameter, defined in Eqs. (2) and (4), is sensitive to CP violation effects in the gluon fusion process. The current data set does not allow for precise constraints on CP properties in the gluon fusion process. The results are consistent with expectations for the standard model H boson .

Additional Figures

png pdf

Additional Figure 1: Summary of confidence level intervals of anomalous coupling parameters in HVV interactions under the assumption that all the coupling ratios are real ($\phi _{ai}^{\mathrm {V} \mathrm {V}}=$ 0 or $\pi$). The HZZ+HWW coupling limits assume that $a_{i}^{{\mathrm {Z}} {\mathrm {Z}}}=a_{i}^{{\mathrm {W}} {\mathrm {W}}}$. The expected 68% and 95% CL regions are shown as green and yellow bands. The observed intervals for 68% CL are shown as points with error bars, and the hatched areas indicate the excluded regions at 95% CL. The limits on $f_{a2,3}^{{\mathrm {Z}} \gamma,\gamma \gamma}$ are from Ref. [13], and the limits on $f_{\Lambda Q}$ are from Ref. [14].

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