Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan
Dark Matter is a hypothetical particle proposed to explain the missing matter discovered from the cosmological observation. The motivation of Dark Matter is overwhelming, however those studies mainly deduced from gravitational interaction which does little to understand the underlying structure o...
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| Format: | Thesis |
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2017
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| Online Access: | http://studentsrepo.um.edu.my/9135/ http://studentsrepo.um.edu.my/9135/2/Hoh_Siew_Yan.pdf http://studentsrepo.um.edu.my/9135/6/siew_yan.pdf |
| _version_ | 1848773844546879488 |
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| author | Hoh , Siew Yan |
| author_facet | Hoh , Siew Yan |
| author_sort | Hoh , Siew Yan |
| building | UM Research Repository |
| collection | Online Access |
| description | Dark Matter is a hypothetical particle proposed to explain the missing matter discovered
from the cosmological observation. The motivation of Dark Matter is overwhelming,
however those studies mainly deduced from gravitational interaction which does little to
understand the underlying structure of the particle. On the other hand, the WIMP Miracle
motivating dark matter production at weak scale, implying the possibility of detecting
dark matter in LHC. Assuming Dark Matter is the only new particle accessible in LHC,
it is expected to be pair produced in association with a Standard Model particles which
can be inferred from the Transverse Missing Energy. Search for dark matter in monojet
final state is a dominant channel in placing model-independent constrains on a set of effective
operators coupling Dark Matter to Standard Model particle. However in the case
of effective operators generated by the exchange of heavy scalar mediator, the inclusive
Monojet channel is weakened due to the light quark suppression. An exclusive search
on heavy quark final state such as bottom quark can improve the coupling strength of the
Dark Matter process and reduce significantly the Standard Model backgrounds. A preliminary
study on the search for Dark Matter produced in association with a bottom-quark
is carried out as an extension to the Monojet search by requiring a b-tagged jet using the
data collected by Compact Muon Solenoid detector in proton-proton collisions at center
of mass energy of 8 TeV. The study shows that the data is consistent with Standard
Model prediction and a limit is derived on the interaction scale and nucleon-dark matter
scattering cross section. |
| first_indexed | 2025-11-14T13:48:52Z |
| format | Thesis |
| id | um-9135 |
| institution | University Malaya |
| institution_category | Local University |
| last_indexed | 2025-11-14T13:48:52Z |
| publishDate | 2017 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | um-91352020-06-08T20:53:59Z Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan Hoh , Siew Yan Q Science (General) Dark Matter is a hypothetical particle proposed to explain the missing matter discovered from the cosmological observation. The motivation of Dark Matter is overwhelming, however those studies mainly deduced from gravitational interaction which does little to understand the underlying structure of the particle. On the other hand, the WIMP Miracle motivating dark matter production at weak scale, implying the possibility of detecting dark matter in LHC. Assuming Dark Matter is the only new particle accessible in LHC, it is expected to be pair produced in association with a Standard Model particles which can be inferred from the Transverse Missing Energy. Search for dark matter in monojet final state is a dominant channel in placing model-independent constrains on a set of effective operators coupling Dark Matter to Standard Model particle. However in the case of effective operators generated by the exchange of heavy scalar mediator, the inclusive Monojet channel is weakened due to the light quark suppression. An exclusive search on heavy quark final state such as bottom quark can improve the coupling strength of the Dark Matter process and reduce significantly the Standard Model backgrounds. A preliminary study on the search for Dark Matter produced in association with a bottom-quark is carried out as an extension to the Monojet search by requiring a b-tagged jet using the data collected by Compact Muon Solenoid detector in proton-proton collisions at center of mass energy of 8 TeV. The study shows that the data is consistent with Standard Model prediction and a limit is derived on the interaction scale and nucleon-dark matter scattering cross section. 2017-01 Thesis NonPeerReviewed application/pdf http://studentsrepo.um.edu.my/9135/2/Hoh_Siew_Yan.pdf application/pdf http://studentsrepo.um.edu.my/9135/6/siew_yan.pdf Hoh , Siew Yan (2017) Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan. Masters thesis, University of Malaya. http://studentsrepo.um.edu.my/9135/ |
| spellingShingle | Q Science (General) Hoh , Siew Yan Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title | Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title_full | Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title_fullStr | Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title_full_unstemmed | Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title_short | Search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 TeV with the CMS experiment / Hoh Siew Yan |
| title_sort | search for dark matter produced in association with a bottom-quark in proton-proton collisions at /s=8 tev with the cms experiment / hoh siew yan |
| topic | Q Science (General) |
| url | http://studentsrepo.um.edu.my/9135/ http://studentsrepo.um.edu.my/9135/2/Hoh_Siew_Yan.pdf http://studentsrepo.um.edu.my/9135/6/siew_yan.pdf |