Improved measurement of the form factors in the decay lambda+c-->lambda + nue

J W Hinson; G S Huang; J Lee; D H Miller; V Pavlunin; R Rangarajan; B Sanghi; E I Shibata; I P J Shipsey; D Cronin-Hennessy; C S Park; W Park; J B Thayer; E H Thorndike; T E Coan; Y S Gao; F Liu; R Stroynowski; M Artuso; C Boulahouache; S Blusk; E Dambasuren; O Dorjkhaidav; R Mountain; H Muramatsu; R Nandakumar; T Skwarnicki; S Stone; J C Wang; S E Csorna; I Danko; G Bonvicini; D Cinabro; M Dubrovin; S McGee; A Bornheim; E Lipeles; S P Pappas; A Shapiro; W M Sun; A J Weinstein; R A Briere; G P Chen; T Ferguson; G Tatishvili; H Vogel; M E Watkins; N E Adam; J P Alexander; K Berkelman; V Boisvert; D G Cassel; J E Duboscq; K M Ecklund; R Ehrlich; R S Galik; L Gibbons; B Gittelman; S W Gray; D L Hartill; B K Heltsley; L Hsu; C D Jones; J Kandaswamy; D L Kreinick; A Magerkurth; H Mahlke-Krüger; T O Meyer; N B Mistry; J R Patterson; D Peterson; J Pivarski; S J Richichi; D Riley; A J Sadoff; H Schwarthoff; M R Shepherd; J G Thayer; D Urner; T Wilksen; A Warburton; M Weinberger; S B Athar; P Avery; L Breva-Newell; V Potlia; H Stoeck; J Yelton; K Benslama; C Cawlfield; B I Eisenstein; G D Gollin; I Karliner; N Lowrey; C Plager; C Sedlack; M Selen; J J Thaler; J Williams; K W Edwards; D Besson; S Anderson; V V Frolov; D T Gong; Y Kubota; S Z Li; R Poling; A Smith; C J Stepaniak; J Urheim; Z Metreveli; K K Seth; A Tomaradze; P Zweber; S Ahmed; M S Alam; J Ernst; L Jian; M Saleem; F Wappler; K Arms; E Eckhart; K K Gan; C Gwon; K Honscheid; H Kagan; R Kass; T K Pedlar; E von Toerne; H Severini; P Skubic; S A Dytman; J A Mueller; S Nam; V Savinov; CLEO Collaboration

doi:10.1103/PhysRevLett.94.191801

Improved measurement of the form factors in the decay lambda+c-->lambda + nue

Phys Rev Lett. 2005 May 20;94(19):191801. doi: 10.1103/PhysRevLett.94.191801. Epub 2005 May 17.

Authors

J W Hinson¹, G S Huang, J Lee, D H Miller, V Pavlunin, R Rangarajan, B Sanghi, E I Shibata, I P J Shipsey, D Cronin-Hennessy, C S Park, W Park, J B Thayer, E H Thorndike, T E Coan, Y S Gao, F Liu, R Stroynowski, M Artuso, C Boulahouache, S Blusk, E Dambasuren, O Dorjkhaidav, R Mountain, H Muramatsu, R Nandakumar, T Skwarnicki, S Stone, J C Wang, S E Csorna, I Danko, G Bonvicini, D Cinabro, M Dubrovin, S McGee, A Bornheim, E Lipeles, S P Pappas, A Shapiro, W M Sun, A J Weinstein, R A Briere, G P Chen, T Ferguson, G Tatishvili, H Vogel, M E Watkins, N E Adam, J P Alexander, K Berkelman, V Boisvert, D G Cassel, J E Duboscq, K M Ecklund, R Ehrlich, R S Galik, L Gibbons, B Gittelman, S W Gray, D L Hartill, B K Heltsley, L Hsu, C D Jones, J Kandaswamy, D L Kreinick, A Magerkurth, H Mahlke-Krüger, T O Meyer, N B Mistry, J R Patterson, D Peterson, J Pivarski, S J Richichi, D Riley, A J Sadoff, H Schwarthoff, M R Shepherd, J G Thayer, D Urner, T Wilksen, A Warburton, M Weinberger, S B Athar, P Avery, L Breva-Newell, V Potlia, H Stoeck, J Yelton, K Benslama, C Cawlfield, B I Eisenstein, G D Gollin, I Karliner, N Lowrey, C Plager, C Sedlack, M Selen, J J Thaler, J Williams, K W Edwards, D Besson, S Anderson, V V Frolov, D T Gong, Y Kubota, S Z Li, R Poling, A Smith, C J Stepaniak, J Urheim, Z Metreveli, K K Seth, A Tomaradze, P Zweber, S Ahmed, M S Alam, J Ernst, L Jian, M Saleem, F Wappler, K Arms, E Eckhart, K K Gan, C Gwon, K Honscheid, H Kagan, R Kass, T K Pedlar, E von Toerne, H Severini, P Skubic, S A Dytman, J A Mueller, S Nam, V Savinov; CLEO Collaboration

Affiliation

¹ Purdue University, West Lafayette, Indiana 47907, USA.

PMID: 16090160
DOI: 10.1103/PhysRevLett.94.191801

Abstract

Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay lambda(+)(c)lambda--> e(+)nu(e). By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R= f(2)/f(1) = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole mass, M(pole) = [2.21 +/- 0.08(stat) +/- 0.14(syst)] GeV/c(2), and the decay asymmetry parameter of the lambda(+)(c), alpha (lambda(c)) = -0.86 +/-0.03(stat) +/- 0.02(syst), for q(2) = 0.67 (GeV/c(2))(2). We compare the angular distributions of the lambda(+)(c) and lambda(-)(c) and find no evidence for CP violation: A(lambda(c)) = (alpha(lambda(c)) + alpha (lambda(c)))/(alpha(lambda(c))-alpha(lambda(c))) = 0.00 +/- 0.03(stat) +/- 0.01(syst) +/- 0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A(lambda), for ppi(-).