Publicação

Search for Higgs boson pair production in the $b\bar{b}b\bar{b}$ final state from pp collisions at $\sqrt{s} = 8$ TeVwith the ATLAS detector

Detalhes bibliográficos
Resumo:	A search for Higgs boson pair production $pp \rightarrow hh$ is performed with 19.5 fb$^{-1}$ of proton–proton collision data at $\sqrt{s}=8$ TeV, which were recorded by the ATLAS detector at the Large Hadron Collider in 2012. The decay products of each Higgs boson are reconstructed as a high-momentum $b\bar{b}$ system with either a pair of small-radius jets or a single large-radius jet, the latter exploiting jet substructure techniques and associated b-tagged track-jets. No evidence for resonant or non-resonant Higgs boson pair production is observed. The data are interpreted in the context of the Randall–Sundrum model with a warped extra dimension as well as the two-Higgs-doublet model. An upper limit on the cross-section for $pp\rightarrow G^{\mathrm {KK}} \rightarrow hh \rightarrow b\bar{b}b\bar{b} $ of 3.2 (2.3) fb is set for a Kaluza–Klein graviton $G^{\mathrm {KK}}$ mass of 1.0 (1.5) TeV, at the 95 % confidence level. The search for non-resonant Standard Model hh production sets an observed 95 % confidence level upper limit on the production cross-section $\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b})$ of 202 fb, compared to a Standard Model prediction of $\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b}) = 3.6 \pm 0.5$ fb.
Autores principais:	ATLAS collaboration (2838 authors)
Outros Autores:	Aguilar-Saavedra, Juan Antonio; Amor Dos Santos, Susana Patricia; Anjos, Nuno; Araque, Juan Pedro; Cantrill, Robert; Carvalho, João; Castro, Nuno Filipe; Conde Muiño, Patricia; Da Cunha Sargedas De Sousa, Mario Jose; Fiolhais, Miguel; Galhardo, Bruno; Gomes, Agostinho; Gonçalo, Ricardo; Jorge, Pedro; Lopes, Lourenco; Machado Miguens, Joana; Maio, Amélia; Maneira, José; Onofre, António; Palma, Alberto; Pedro, Rute; Pina, João Antonio; Pinto, Belmiro; Santos, Helena; Saraiva, João; Silva, José; Tavares Delgado, Ademar; Veloso, Filipe; Wolters, Helmut
Ano:	2015
País:	Portugal
Tipo de documento:	artigo
Tipo de acesso:	acesso aberto
Instituição associada:	Laboratório de Instrumentação e Física Experimental de Partículas
Idioma:	inglês
Origem:	Laboratório de Instrumentação e Física Experimental de Partículas

Descrição
Resumo:	A search for Higgs boson pair production $pp \rightarrow hh$ is performed with 19.5 fb$^{-1}$ of proton–proton collision data at $\sqrt{s}=8$ TeV, which were recorded by the ATLAS detector at the Large Hadron Collider in 2012. The decay products of each Higgs boson are reconstructed as a high-momentum $b\bar{b}$ system with either a pair of small-radius jets or a single large-radius jet, the latter exploiting jet substructure techniques and associated b-tagged track-jets. No evidence for resonant or non-resonant Higgs boson pair production is observed. The data are interpreted in the context of the Randall–Sundrum model with a warped extra dimension as well as the two-Higgs-doublet model. An upper limit on the cross-section for $pp\rightarrow G^{\mathrm {KK}} \rightarrow hh \rightarrow b\bar{b}b\bar{b} $ of 3.2 (2.3) fb is set for a Kaluza–Klein graviton $G^{\mathrm {KK}}$ mass of 1.0 (1.5) TeV, at the 95 % confidence level. The search for non-resonant Standard Model hh production sets an observed 95 % confidence level upper limit on the production cross-section $\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b})$ of 202 fb, compared to a Standard Model prediction of $\sigma (pp \rightarrow hh \rightarrow b\bar{b}b\bar{b}) = 3.6 \pm 0.5$ fb.