### Abstract

In this paper we study the gauge mediation signal with the ATLAS detector at the CERN Large Hadron Collider. We focus on the case where next lightest supersymmetric particle is the long-lived lightest neutralino [Formula Presented] which decays predominantly into a photon [Formula Presented] and a gravitino [Formula Presented] A nonpointing photon from the neutralino decay can be detected with good position and time resolution by the electromagnetic calorimeter (ECAL), while the photon momentum could be precisely measured if the photon were converted inside the inner tracking detector before reaching the ECAL. A new technique is developed to determine the masses of the slepton [Formula Presented] and the neutralino from events with a lepton and a converted nonpointing photon arising from the cascade decay [Formula Presented] A Monte Carlo simulation at a sample point shows that the masses could be measured with an error of 3% for [Formula Presented] selected [Formula Presented] pairs. Once the sparticle masses are determined by this method, the decay time and momentum of the neutralino are solved using the ECAL data and the lepton momentum only, for all [Formula Presented] pairs without the photon conversion. We estimate the sensitivity to the neutralino lifetime for [Formula Presented] to [Formula Presented].

Original language | English |
---|---|

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 69 |

Issue number | 3 |

DOIs | |

Publication status | Published - Feb 23 2004 |

Externally published | Yes |

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### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)

### Cite this

*Physical Review D - Particles, Fields, Gravitation and Cosmology*,

*69*(3). https://doi.org/10.1103/PhysRevD.69.035003

**Study of the gauge mediation signal with nonpointing photons at the CERN LHC.** / Kawagoe, Kiyotomo; Kobayashi, Tomio; Nojiri, Mihoko M.; Ochi, Atsuhiko.

Research output: Contribution to journal › Article

*Physical Review D - Particles, Fields, Gravitation and Cosmology*, vol. 69, no. 3. https://doi.org/10.1103/PhysRevD.69.035003

}

TY - JOUR

T1 - Study of the gauge mediation signal with nonpointing photons at the CERN LHC

AU - Kawagoe, Kiyotomo

AU - Kobayashi, Tomio

AU - Nojiri, Mihoko M.

AU - Ochi, Atsuhiko

PY - 2004/2/23

Y1 - 2004/2/23

N2 - In this paper we study the gauge mediation signal with the ATLAS detector at the CERN Large Hadron Collider. We focus on the case where next lightest supersymmetric particle is the long-lived lightest neutralino [Formula Presented] which decays predominantly into a photon [Formula Presented] and a gravitino [Formula Presented] A nonpointing photon from the neutralino decay can be detected with good position and time resolution by the electromagnetic calorimeter (ECAL), while the photon momentum could be precisely measured if the photon were converted inside the inner tracking detector before reaching the ECAL. A new technique is developed to determine the masses of the slepton [Formula Presented] and the neutralino from events with a lepton and a converted nonpointing photon arising from the cascade decay [Formula Presented] A Monte Carlo simulation at a sample point shows that the masses could be measured with an error of 3% for [Formula Presented] selected [Formula Presented] pairs. Once the sparticle masses are determined by this method, the decay time and momentum of the neutralino are solved using the ECAL data and the lepton momentum only, for all [Formula Presented] pairs without the photon conversion. We estimate the sensitivity to the neutralino lifetime for [Formula Presented] to [Formula Presented].

AB - In this paper we study the gauge mediation signal with the ATLAS detector at the CERN Large Hadron Collider. We focus on the case where next lightest supersymmetric particle is the long-lived lightest neutralino [Formula Presented] which decays predominantly into a photon [Formula Presented] and a gravitino [Formula Presented] A nonpointing photon from the neutralino decay can be detected with good position and time resolution by the electromagnetic calorimeter (ECAL), while the photon momentum could be precisely measured if the photon were converted inside the inner tracking detector before reaching the ECAL. A new technique is developed to determine the masses of the slepton [Formula Presented] and the neutralino from events with a lepton and a converted nonpointing photon arising from the cascade decay [Formula Presented] A Monte Carlo simulation at a sample point shows that the masses could be measured with an error of 3% for [Formula Presented] selected [Formula Presented] pairs. Once the sparticle masses are determined by this method, the decay time and momentum of the neutralino are solved using the ECAL data and the lepton momentum only, for all [Formula Presented] pairs without the photon conversion. We estimate the sensitivity to the neutralino lifetime for [Formula Presented] to [Formula Presented].

UR - http://www.scopus.com/inward/record.url?scp=1642387800&partnerID=8YFLogxK

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U2 - 10.1103/PhysRevD.69.035003

DO - 10.1103/PhysRevD.69.035003

M3 - Article

AN - SCOPUS:1642387800

VL - 69

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 3

ER -