K+ -> pi+ mu+ mu- in E865 at BNL

dc.creatorThompson, Julia A.
dc.date1999-04-25
dc.date.accessioned2026-07-07T06:28:23Z
dc.date.available2026-07-07T06:28:23Z
dc.descriptionPreliminary values for the K+ -> pi+ mu+ mu- branching ratio and form factor are reported, based on 400 events, a factor of 2 more in total events and 100 times the present world sample of fully reconstructed events. The results are consistent with previous results on the pi+ e+ e- mode. However, the relatively large slope of the form factor in q^2, lambda = 0.182+/-0.01+/-0.007, required to fit the pi+ e+ e- data and to give consistency between the pi+ e+ e- and pi+ mu+ mu- branching ratios, is larger than expected in simple models of the decays. The K+ -> pi+ mu+ mu- branching ratio we find, (9.23 +/- 0.6 stat +/- 0.58 syst)x10^-8, is the most precise measurement of this mode and is approximately 3.2 sigma larger than the previous measurement. These pi+ l+ l- results are inconsistent with O(p^4) Chiral Perturbation Theory but compatible with O(p^6). Systematic studies for both modes are still in progress.
dc.description5 pages, sprocl.sty, psfig.tex, 4 embedded figures. Presented at WIN '99 in Capetown, South Africa, January 1999
dc.identifierhttps://arxiv.org/abs/hep-ex/9904026
dc.identifierhttp://arxiv.org/abs/hep-ex/9904026
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/97682
dc.subjectHigh Energy Physics - Experiment
dc.titleK+ -> pi+ mu+ mu- in E865 at BNL
dc.typetext

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