Observation of Upsilon(2S)-->etaUpsilon(1S) and search for related transitions.
نویسندگان
چکیده
We report the first observation of Upsilon(2S)-->etaUpsilon(1S), with a branching fraction B=(2.1(-0.6)+0.7(stat)+/-0.3(syst)) x 10(-4) and a statistical significance 5.3sigma. Data were acquired with the CLEO III detector at the CESR e+e(-) symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10(-4) are B(Upsilon(2S)-->pi0Upsilon(1S)) < 1.8, B(Upsilon(3S)-->etaUpsilon(1S)) < 1.8, B(Upsilon(3S)-->pi0Upsilon(1S)) < 0.7, and B(Upsilon(3S)-->pi0Upsilon(2S)) < 5.1.
منابع مشابه
Observation of Υ(2S) → ηΥ(1S) and search for related transitions
We report the first observation of Υ(2S) → ηΥ(1S), with branching fraction B = (2.1 −0.6 (stat.)± 0.3 (syst.))×10−4 and statistical significance 5.3σ. Data were acquired with the CLEO III detector at the CESR e+e− symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10−4 are B[Υ(2S) → π0Υ(1S)] < 1.8, B[Υ...
متن کاملObservation of the Hadronic transitions chi(b1,2)(2P)-->omegaUpsilon(1S).
The CLEO Collaboration has made the first observations of hadronic transitions among bottomonium (bbmacr;) states other than the dipion transitions among Upsilon(nS) states. In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S)-->gammaomegaUpsilon(1S) that is consistent with radiative decays Upsilon(3S)-->gammachi(b1,2)(2P), followed by chi(b1,2)(2P)-->omegaUpsilon(1S...
متن کاملPossibility of Exotic States in the Upsilon system
Recent data from Belle show unusually large partial widths Υ(5S) → Υ(1S)ππ and Υ(5S) → Υ(2S)ππ. The Z(4430) narrow resonance also reported by Belle in ψπ spectrum has the properties expected of a c̄cud̄ charged isovector tetraquark T c̄c . The analogous state T b̄b in the bottom sector might mediate anomalously large cascade decays in the Upsilon system, Υ(mS) → T b̄b π → Υ(nS)ππ, with a tetraquark-...
متن کاملRecent BaBar Studies of Bottomonium States
We present studies in bottomonium spectroscopy carried out with samples of (98±1) million Υ(2S) and (121±1) million Υ(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy ee collider at SLAC. Precise measurements of the branching fractions for χb1,2(1P, 2P ) → γΥ(1S) and χb1,2(2P ) → γΥ(2S) transitions, and searches for radiative decay to the ηb(1S) and ηb(2S) states are ...
متن کاملPhoton transitions in Upsilon(2S) and Upsilon(3S) decays.
We have studied the inclusive photon spectra in Upsilon(2S) and Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S) --> gammachi(bJ)(1P) and Upsilon(3S) --> gammachi(bJ)(2P) (J = 0, 1, 2). We measure the rate for a rare E1 transiti...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 101 19 شماره
صفحات -
تاریخ انتشار 2008