Limit on the production of a new vector boson in e(+)e(-) -%26gt; U gamma, U -%26gt; pi(+)pi(-) with the KLOE experiment

作者：Anastasi A; Babusci D; Bencivenni G; Berlowski M; Bloise C; Bossi F; Branchini P; Budano A; Balkestahl L Caldeira; Cao B; Ceradini F; Ciambrone P; Curciarello F; Czerwinski E; D' Agostini G; Dane E; De Leo V; De Lucia E; De Santis A; De Simone P; Di Cicco A; Di Domenico A; Di Salvo R; Domenici D; D' Uffizi A; Fantini A; Felici G; Fiore S; Gajos A; Gauzzi P; Giardina G; Giovannella S; Grazianir E; Happacher F

来源：Physics Letters B, 2016, 757: 356-361.

DOI：10.1016/j.physletb.2016.04.019

• Dark matter
• Dark forces
• Dark photon
• U boson

The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e(+)e(-) -> U gamma, U -> pi(+)pi(-) based on 28 million e(+)e(-) -> pi(+)pi(-) gamma events collected at DA Phi NE by the KLOE experiment. The pi(+) pi(-) production by initial-state radiation compensates for a loss of sensitivity of previous KLOE U -> e(+) e(-), mu(+) mu(-) searches due to the small branching ratios in the rho-omega resonance region. We found no evidence for a signal and set a limit at 90% CL on the mixing strength between the photon and the dark photon, epsilon(2), in the U mass range between 527 and 987 MeV. Above 700 MeV this new limit is more stringent than previous ones.

• 出版日期2016-6-10