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Sullivan, Matthew

Publications and source records attributed to Sullivan, Matthew.

2 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Resonant multiscalar production in the generic complex singlet model in the multi-TeV region

We develop benchmarks for resonant discalar production in the generic complex singlet scalar extension of the Standard Model (SM) with no additional symmetries, which contains two new scalars. These benchmarks maximize discalar resonant production modes at future ๐‘โข๐‘ colliders: ๐‘โข๐‘ โ†’ โ„Ž 2 โ†’ โ„Ž 1โก โ„Ž 1 , ๐‘โข๐‘ โ†’ โ„Ž 2 โ†’ โ„Ž 1 โกโ„Ž 3 , and ๐‘โข๐‘ โ†’ โ„Ž 2 โ†’ โ„Ž 3 โกโ„Ž 3 , where โ„Ž 1 is the observed SM-like Higgs boson and โ„Ž 2,3 are new scalars. The decays โ„Ž 2 โ†’ โ„Ž 1 โกโ„Ž 3 and โ„Ž 2 โ†’ โ„Ž 3 โกโ„Ž 3 may be the only way to discover โ„Ž 3 , leading to a discovery of two new scalars at once. Current LHC and projected future collider (HL-LHC, FCC-ee+HL-LHC, ILโขCโข500+HL-LHC) constraints on this model are used to produce benchmarks at the HL-LHC for โ„Ž 2 masses between 250 GeV and 1 TeV and a future ๐‘โข๐‘ collider (FCC-hh) for โ„Ž 2 masses between 250 GeV and 12 TeV. We update the current LHC bounds on the singlet-Higgs boson mixing angle for these benchmarks. As the mass of โ„Ž 2 approaches the multi-TeV region, certain limiting behaviors of the maximum rates are uncovered due to theoretical constraints on the parameters. These limits, which can be derived analytically, are BRโก(โ„Ž 2 โ†’ โ„Ž 1โก โ„Ž 1 ) โ†’ 0.25, BRโก(โ„Ž 2 โ†’ โ„Ž 3 โกโ„Ž 3 ) โ†’ 0.5, and BRโก(โ„Ž 2 โ†’ โ„Ž 1โก โ„Ž 3 ) โ†’ 0. It can also be shown that the maximum rates of ๐‘โข๐‘ โ†’ โ„Ž 2 โ†’ โ„Ž 1 โกโ„Ž 1 and ๐‘โข๐‘ โ†’ โ„Ž 2 โ†’ โ„Ž 3โก โ„Ž 3 approach the same value. Hence, all three โ„Ž 2 โ†’ โ„Ž ๐‘– โกโ„Ž ๐‘— decays are promising discovery modes for โ„Ž 2 masses at and below ๐’ชโก(1 TeV), while above ๐’ชโก(1 TeV) the decays โ„Ž 2 โ†’ โ„Ž 1 โกโ„Ž 1 and โ„Ž 2 โ†’ โ„Ž 3 โกโ„Ž 3 are more encouraging. We choose benchmark masses for โ„Ž 3 to produce a large range of decay signatures including multi-๐‘, multivector boson, and multi-SM-like Higgs production. As we will show, the behavior of the maximum rates leads to the surprising conclusion that in the multi-TeV region this model may be discovered in the Higgs quartet production mode via โ„Ž 2 โ†’ โ„Ž 3 โกโ„Ž 3 โ†’ 4โขโ„Ž 1 decays before Higgs triple production is observed. The maximum di- and four Higgs production rates are similar in the multi-TeV range.

Extensions of Higgs sectorโ†—
DOE OSTI2024

Code conversion with the quantum Golay code for a universal transversal gate set

The [[7,1,3]] Steane code and [[23,1,7]] quantum Golay code have been identified as good candidates for fault-tolerant quantum computing via code concatenation. These two codes have transversal implementations of all Clifford gates but require some other scheme for fault-tolerant T gates. Using magic states, Clifford operations, and measurements is one common scheme, but magic-state distillation can have a large overhead. Code conversion is one avenue for implementing a universal gate set fault tolerantly without the use of magic-state distillation. Analogously to how the [[7,1,3]] Steane code can be fault tolerantly converted to and from the [[15,1,3]] Reed-Muller code which has a transversal T gate, the [[23,1,7]] Golay code can be converted to a [[95,1,7]] triorthogonal code with a transversal T gate. Further, a crucial ingredient of this procedure is the [[49,1,5]] triorthogonal code, which can itself be seen as being related to the self-dual [[17,1,5]] two-dimensional color code. Additionally, a method for code conversion based on a transversal CNOT between the codes, rather than stabilizer measurements, is described.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDSโ†—