Skip to main content
eScholarship
Open Access Publications from the University of California

Measurement of the B0→ X-u ℓ+νℓ decays near the kinematic endpoint of the lepton spectrum and search for violation of isospin symmetry

  • Author(s): Aubert, B
  • Bona, M
  • Boutigny, D
  • Karyotakis, Y
  • Lees, JP
  • Poireau, V
  • Prudent, X
  • Tisserand, V
  • Zghiche, A
  • Garra Tico, J
  • Grauges, E
  • Lopez, L
  • Palano, A
  • Pappagallo, M
  • Eigen, G
  • Stugu, B
  • Sun, L
  • Abrams, GS
  • Battaglia, M
  • Brown, DN
  • Button-Shafer, J
  • Cahn, RN
  • Groysman, Y
  • Jacobsen, RG
  • Kadyk, JA
  • Kerth, LT
  • Kolomensky, YG
  • Kukartsev, G
  • Lopes Pegna, D
  • Lynch, G
  • Mir, LM
  • Orimoto, TJ
  • Osipenkov, IL
  • Ronan, MT
  • Tackmann, K
  • Tanabe, T
  • Wenzel, WA
  • Del Amo Sanchez, P
  • Hawkes, CM
  • Watson, AT
  • Koch, H
  • Schroeder, T
  • Walker, D
  • Asgeirsson, DJ
  • Cuhadar-Donszelmann, T
  • Fulsom, BG
  • Hearty, C
  • Mattison, TS
  • McKenna, JA
  • Khan, A
  • Saleem, M
  • Teodorescu, L
  • Blinov, VE
  • Bukin, AD
  • Druzhinin, VP
  • Golubev, VB
  • Onuchin, AP
  • Serednyakov, SI
  • Skovpen, YI
  • Solodov, EP
  • Todyshev, KY
  • Bondioli, M
  • Curry, S
  • Eschrich, I
  • Kirkby, D
  • Lankford, AJ
  • Lund, P
  • Mandelkern, M
  • Martin, EC
  • Stoker, DP
  • Abachi, S
  • Buchanan, C
  • Foulkes, SD
  • Gary, JW
  • Liu, F
  • Long, O
  • Shen, BC
  • Vitug, GM
  • Zhang, L
  • Paar, HP
  • Rahatlou, S
  • Sharma, V
  • Berryhill, JW
  • Campagnari, C
  • Cunha, A
  • Dahmes, B
  • Hong, TM
  • Kovalskyi, D
  • Richman, JD
  • Beck, TW
  • Eisner, AM
  • Flacco, CJ
  • Heusch, CA
  • Kroseberg, J
  • Lockman, WS
  • Schalk, T
  • Schumm, BA
  • Seiden, A
  • Wilso, MG
  • Winstrom, LO
  • et al.
Creative Commons Attribution 4.0 International Public License
Abstract

We present the first measurement of the B0 → X-u ℓ+νℓ partial branching fraction in the endpoint region of the lepton momentum spectrum, above the threshold for B → Xcℓνℓ decays. The analysis is based on a sample of 383 million γ(4S) decays into BB pairs collected with the BABAR detector at the PEP-II e+e- storage rings. We select B0B0 events by partially reconstructing one B meson via the B0 → Dz.ast;+ℓ- ̄νℓ decays then select B0 → X- u ℓ+νℓ decays identifying a second high momentum lepton. In the momentum interval ranging from 2.3 to 2.6 GeV/c we measure the partial branching fraction πB(B0 → Xuℓν) = (1.30 ± 0.21stat ± 0.07syst) × 10-4 where the first error is statistical and the second is systematic. By comparing this measurement with the one obtained from untagged B decays we obtain R+/0 = ΔB(B0 → Xuℓν)/ ΔB(B+ → Xuℓν) = 1.18 ± 0.35stat ± 0.17syst. Using this measurement we extract a limit on the contributions from processes breaking isospin symmetry in charmless semileptonic B decays.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View