1. Precise measurement on effective gluon Yukawa coupling via jet energy profile
In collaboration with
Gexing Li, Zhao Li, Yandong Liu, Xiaoran Zhao
Yan Wang
Institute of High Energy Physics

2. A Busy Hadronic Environment LHC
Underlying event, the remnants of the scattering protons
Multiple interactions, additional collisions of partons arising from the same p-p collision as the hard interaction
Pile-up, additional p-p collisions from other protons in the colliding bunches
Z, W, T and H are produced with enough of a boost. The simple picturethat one parton corresponds to one jet breaks down badly.

3. Jet shape
A function f( 𝑝 𝑗 ) without the explicit use of jet algorithm
Affected by unassociated radiation (pileup)
Need to be infrared-safe and collinear-safe,
If f( 𝑝 𝑗 ) is linear, automatically safe.
Sensitive to color charge, initial gluons will radiate more with a large angles than initial quarks ( 𝐶 𝐹 < 𝐶 𝐴 )

4. Jet shape Probing the characteristic shower structure of QCD Jet mass.
Jet broadening:
the momentum –weighted transverse spread of the particle.
𝐵 𝐻 = 1 ∑| 𝑝 𝑖 | ∑ 𝑝 𝑖 × 𝑛
Differential 𝜌(𝑟) and integrated jet shape 𝜓(𝑟):
the radial distribution of radiation inside a jet.
Ψ 𝑟 = 1 𝑁 𝐽 𝑖 𝑝 𝑇 0< 𝑟 𝑖 <𝑟 𝑝 𝑇,𝐽
𝜌 𝑟 = 1 𝛿r 1 𝑁 𝐽 𝑖 𝑝 𝑇 0< 𝑟 𝑖 <𝑟+𝛿r 𝑝 𝑇,𝐽
Girth: the linear radial moment of the jet
𝑔 𝐽 = 𝑖 𝑝 𝑇,𝑖 𝑟 𝑖 𝑝 𝑇,𝐽
Angularities
𝜏 𝑎 = 1 2 𝐸 𝐽 ∑ 𝑝 𝑇,𝑖 𝑒 (𝑎−1 )𝜂 𝑖

5. Energy Profile at LHC Gluon fusion
ψ 𝑟 = 1 𝑁 𝐽 𝑟 ′ <𝑟 𝑝 𝑇 𝑟′ 𝑟 ′ <𝑅 𝑝 𝑇 𝑟′ 𝑝 𝑝→𝐻+𝑗+𝑗
VBF
gluon initiated jets radiate more, produce a slowly raising JEP
quark initiated jets radiate less, produce a quickly raising JEP.
so JEP has been applied to identify higgs production mechanism.
and applied in searching DM.
The OPAL Collaboration, R. Akers et al., Z. Phys. C (1994)
The ATLAS Collaboration, Phys.Rev.D83:052003,(2011)
C. Rentala, N. Vignaroli, H.N. Li, Z. Li, and C. P. Yuan, PRD88, (2013)
P. Agrawal and V. Rentala, JHEP05, 098 (2014)
R. S. Chivukula, E. H. Simmons, and N. Vignaroli, Arxiv:

6. JEP on CEPC measure higgs coupling
𝑒 + 𝑒 − →𝑍ℎ→ 𝑙 + 𝑙 − 𝑏𝑏 , 𝑒 + 𝑒 − →𝑍ℎ→ 𝑙 + 𝑙 − 𝑔𝑔,
𝑒 + 𝑒 − →𝑍ℎ→𝑏𝑏𝑏𝑏, 𝑒 + 𝑒 − →𝑍ℎ→𝑗𝑗𝑏𝑏,
𝑒 + 𝑒 − →𝑍ℎ→𝑏𝑏𝑔𝑔, 𝑒 + 𝑒 − →𝑍ℎ→𝑗𝑗𝑔𝑔,
𝑒 + 𝑒 − →𝑍ℎ→𝜈𝜈𝑏𝑏, 𝑒 + 𝑒 − →𝑍ℎ→𝜈𝜈𝑔𝑔,
huge higgs production rate
clear background
dijet final state
𝑘 𝑔 ℎ 𝐺 𝜇𝜈 𝑎 𝐺 𝑎𝜇𝜈

7. observable
First, normal cut for dijet final state from higgs decay (mass window and recoil mass cut and …)
Then, jet substructure:
define 𝜓(𝑟) 𝑝 𝑇 𝑖 = 𝜓 𝑟 𝑗1 𝑝 𝑇 𝑖 + 𝜓 𝑟 𝑗2 𝑝 𝑇 𝑖 2
The average value of JEP
The observable

8. Relation between 𝜅 𝑔 and Λ 𝑁 (𝑟)

9. b&c tagging veto
Pt 30
Delphes 0
2e2b 4b 2

10. JEP on LEP

11. How about the background?
We are working for that….
But..

12. Another observable

13. Conclusion Using JEP to study effective gluon Yukawa coupling .
New Observables : Λ 𝑁 𝑟 , 𝑋 𝑁 (𝑟)

14. Thanks