Measuring the Lifetime of Trapped Sleptons Using the General Purpose LHC Detectors

In supergravity where the gravitino is the lightest supersymmetric particle (LSP), the next-to-lightest supersymmetric particle (NLSP) decays to the gravitino with a naturally long lifetime (10^4 - 10^8). However, cosmological constraints favour charged sleptons with lifetimes below a year as the natural NLSP candidate. For this scenario we report a method to accurately determine the slepton lifetime and SUSY cross-section from observation of the decays of sleptons trapped in the material comprising the main detector (ATLAS, CMS). A measurement of the lifetime to 5% is possible after 3 years at nominal luminosity and running conditions. This method is sensitive to the cosmologically preferred stau lifetime of ~37 days and does not require the use of ancillary trapping volumes

A Precise Determination of tan⁡β\tan\beta from Heavy Charged Higgs Decay

We compute the energy spectrum of charged leptons in the decay $H^+\to \bar b+(t\to bl\nu_l)$. The shape of the lepton spectrum obtained, and also the mean lepton energy, are sensitive to the handedness of the intermediate top quark. This sensitivity can be used to precisely determine $\tan\beta$, a fundamental parameter of two Higgs doublet models.Comment: 5 pages plus 2 figures available upon request, latex, MZ-TH/94-0

The impact of mental health recovery narratives on recipients experiencing mental health problems: Qualitative analysis and change model.

BACKGROUND: Mental health recovery narratives are stories of recovery from mental health problems. Narratives may impact in helpful and harmful ways on those who receive them. The objective of this paper is to develop a change model identifying the range of possible impacts and how they occur. METHOD: Semi-structured interviews were conducted with adults with experience of mental health problems and recovery (n = 77). Participants were asked to share a mental health recovery narrative and to describe the impact of other people's recovery narratives on their own recovery. A change model was generated through iterative thematic analysis of transcripts. RESULTS: Change is initiated when a recipient develops a connection to a narrator or to the events descripted in their narrative. Change is mediated by the recipient recognising experiences shared with the narrator, noticing the achievements or difficulties of the narrator, learning how recovery happens, or experiencing emotional release. Helpful outcomes of receiving recovery narratives are connectedness, validation, hope, empowerment, appreciation, reference shift and stigma reduction. Harmful outcomes are a sense of inadequacy, disconnection, pessimism and burden. Impact is positively moderated by the perceived authenticity of the narrative, and can be reduced if the recipient is experiencing a crisis. CONCLUSIONS: Interventions that incorporate the use of recovery narratives, such as peer support, anti-stigma campaigns and bibliotherapy, can use the change model to maximise benefit and minimise harms from narratives. Interventions should incorporate a diverse range of narratives available through different mediums to enable a range of recipients to connect with and benefit from this material. Service providers using recovery narratives should preserve authenticity so as to maximise impact, for example by avoiding excessive editing

Bose-Einstein Correlations of Three Charged Pions in Hadronic Z^0 Decays

Bose-Einstein Correlations (BEC) of three identical charged pions were studied in 4 x 10^6 hadronic Z^0 decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected for the Coulomb effect, were separated from the known two-pion correlations by a new subtraction procedure. A significant genuine three-pion BEC enhancement near threshold was observed having an emitter source radius of r_3 = 0.580 +/- 0.004 (stat.) +/- 0.029 (syst.) fm and a strength of \lambda_3 = 0.504 +/- 0.010 (stat.) +/- 0.041 (syst.). The Coulomb correction was found to increase the \lambda_3 value by \~9% and to reduce r_3 by ~6%. The measured \lambda_3 corresponds to a value of 0.707 +/- 0.014 (stat.) +/- 0.078 (syst.) when one takes into account the three-pion sample purity. A relation between the two-pion and the three-pion source parameters is discussed.Comment: 19 pages, LaTeX, 5 eps figures included, accepted by Eur. Phys. J.