Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμ b b and ττ b b final states
A search for exotic decays of the Higgs boson ( $$\text {H}$$ H ) with a mass of 125...
| Main Authors: | , , , , , , , , , , , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Science and Business Media LLC
2024
|
| Online Access: | https://hdl.handle.net/1721.1/154999 |
| Summary: | A search for exotic decays of the Higgs boson (
$$\text {H}$$
H
) with a mass of 125
$$\,\text {Ge}\hspace{-.08em}\text {V}$$
Ge
V
to a pair of light pseudoscalars
$$\text {a}_{1} $$
a
1
is performed in final states where one pseudoscalar decays to two
$${\textrm{b}}$$
b
quarks and the other to a pair of muons or
$$\tau $$
τ
leptons. A data sample of proton–proton collisions at
$$\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V} $$
s
=
13
Te
V
corresponding to an integrated luminosity of 138
$$\,\text {fb}^{-1}$$
fb
-
1
recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (
$$\text {CL}$$
CL
) on the Higgs boson branching fraction to
$$\upmu \upmu \text{ b } \text{ b } $$
μ
μ
b
b
and to
$$\uptau \uptau \text{ b } \text{ b },$$
τ
τ
b
b
,
via a pair of
$$\text {a}_{1} $$
a
1
s. The limits depend on the pseudoscalar mass
$$m_{\text {a}_{1}}$$
m
a
1
and are observed to be in the range (0.17–3.3)
$$\times 10^{-4}$$
×
10
-
4
and (1.7–7.7)
$$\times 10^{-2}$$
×
10
-
2
in the
$$\upmu \upmu \text{ b } \text{ b } $$
μ
μ
b
b
and
$$\uptau \uptau \text{ b } \text{ b } $$
τ
τ
b
b
final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction
$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} \rightarrow \ell \ell \text{ b } \text{ b})$$
B
(
H
→
a
1
a
1
→
ℓ
ℓ
b
b
)
at 95%
$$\text {CL}$$
CL
, with
$$\ell $$
ℓ
being a muon or a
$$\uptau $$
τ
lepton. For different types of 2HDM+S, upper bounds on the branching fraction
$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$
B
(
H
→
a
1
a
1
)
are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space,
$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$
B
(
H
→
a
1
a
1
)
values above 0.23 are excluded at 95%
$$\text {CL}$$
CL
for
$$m_{\text {a}_{1}}$$
m
a
1
values between 15 and 60
$$\,\text {Ge}\hspace{-.08em}\text {V}$$
Ge
V
. |
|---|