1 / 16

E XPERIMENTAL U PDATE ON |V cb | (EXCLUSIVE)

E XPERIMENTAL U PDATE ON |V cb | (EXCLUSIVE). Arantza Oyanguren. ( DELPHI - Valencia ). CKM WORKSHOP ‘03. 1. l. n l. q 2. b. c. V cb. |V cb | FROM B  D * l - . From the s.l. decay width:. Known function (Phase space). Form factor of the B  D * transition 

moana-christian
Download Presentation

E XPERIMENTAL U PDATE ON |V cb | (EXCLUSIVE)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EXPERIMENTALUPDATE ON|Vcb| (EXCLUSIVE) Arantza Oyanguren ( DELPHI - Valencia ) CKM WORKSHOP ‘03

  2. 1 l nl q2 b c Vcb |Vcb| FROM BD*l- From the s.l. decay width: Known function (Phase space) Form factor of the B D* transition  Normalized by HQET (mQ  ) at q2max (w = 1)   1/ mQ and QCD corrections  FD*(1)=1 FD*(1)= 0.91  0.04* * PDG ‘02 CKM ‘03 A. Oyanguren

  3. 2 (4S) BB DELPHI OPAL ALEPH Z  bb SIGNAL RECONSTRUCTION BABAR pB ~ 30 GeV BELLE pB ~ 1 GeV CLEO pB ~ 0.3 GeV CKM ‘03 A. Oyanguren

  4. 3 B  D*l- K- + K- + + - K- +0 Ks0 + - SIGNAL RECONSTRUCTION @ LEP p 1.0 GeV @ (4S)p 0.1 GeV D*-lepton candidates : D0 soft m= m(D0)-m(D0) ~ m(soft) Inclusive D0 Exclusive D0 OPAL BABAR CKM ‘03 A. Oyanguren

  5. 4 wRECONSTRUCTION Efficiency: E, p conservation, vertex info... From decay products From missing energy Measured @ LEP:~ 0.07- 0.13 w Resolution:  @ (4S): ~ 0.03 ALEPH w CKM ‘03 A. Oyanguren

  6. 5 D*l(73.5%) D**l(7.5%) Fake lep (0.3%) Uncorr (6.2%) Correlated (1.5%) Contin.(3.2%) Fake D* (7.75%)  data D*l D**l Comb. Bg. b  D*+ X l_ l ElectronsK DELPHI events/0.27 BABAR topology info cosB,D*l BACKGROUND Disentangling D*’s coming from D** states... @ (4S) @ LEP ~ 66% charged particles events/01 OPAL CKM ‘03 A. Oyanguren

  7. 6 w w FITS TO|Vcb|  Parametrization of the form factor F(w) from I.Caprini, L. Lellouch, M. Neubert[NPB 530, 153 ‘98]* as a function of the slope form factor2 and the form factor ratios R1 and R2 (measured by CLEO[PRL 76, 3898 ‘96]).  Fitd/dwto extractF(1)|Vcb|and2 BELLE CLEO Entries/0.05 FD*(1)|Vcb| * See also C.G. Boyd, B. Grinstein, R.F. Lebed[PRD 56, 6895 ‘97] CKM ‘03 A. Oyanguren

  8. 7 STATISTICS Analyzed events : OPAL D*l candidates DELPHI CLEO ALEPH BELLE Statistical error BABAR ALEPH DELPHI OPAL CLEO BELLE (partial stat.) BABAR (expected) Vcb/Vcb (%) CKM ‘03 A. Oyanguren

  9. 8a BABAR (BR) BELLE PLB 526, 247 ‘02 SYSTEMATICS @ LEP Moriond EW ‘03 hep-ex/0112028 CLEO @ (4S) CKM ‘03 A. Oyanguren

  10. 8b @ LEP SYSTEMATICS hep-ex/0112028 CKM ‘03 A. Oyanguren

  11. 8c SYSTEMATICS @ (4S) CLEO CKM ‘03 A. Oyanguren

  12. 8d BABAR (BR) SYSTEMATICS @ (4S) Moriond EW ‘03 BELLE PLB 526, 247 ‘02 CKM ‘03 A. Oyanguren

  13. 9 UPDATED WORLD AVERAGE Winter ‘03 F(1)|Vcb| = (38.1  1.0) 10-3 r2 =1.57  0.14 PDG ‘03 F(1)|Vcb| = (38.8  0.5(stat).  0.9(sys.)) 10-3 r2 =1.49  0.05(stat.)  0.14(sys.) 2/d.o.f.=1.7 CL=6.9% Analyses rescaled to common parameters:http://www.slac.stanford.edu/xorg/hfag/semi/pdg03/common.param Using F(1)=0.91  0.04 |Vcb|= (42.6  0.6(stat)  1.0(sys)  2.1(th.)) 10-3 (Thanks to E. Barberio and U. Langenegger (HFAG) for the averages) CKM ‘03 A. Oyanguren

  14. 10 |Vcb| FROM BDl- CLEO BELLE D0, D+ D+ ALEPH D+ BELLE Winter ‘03 G(1)|Vcb| = (41.9  3.7) 10-3 rD2 =1.15  0.16 Using G(1)=1.00  0.07 PDG ‘03 G(1)|Vcb| = (42.4  3.7) 10-3 rD2 =1.14  0.16 2/d.o.f.=0.06 CL=99% |Vcb|= (42.4  3.7(exp.)  3.0(th.))10-3 CKM ‘03 A. Oyanguren

  15. 11 CONCLUSIONS |Vcb| from exclusive measurements limited by systematics from several sources and theory  large systematics are correlated between experiments: B(b B0), B((4S) B0 B0), D BR’s, D** contribution, R1 and R2 form factors... CKM ‘03 A. Oyanguren

  16. 12 PERSPECTIVES Waiting for BABAR results,and BELLE with larger analyzed statistics, waiting for more accurate lattice computations of FD*(1) and GD(1),  the control of the main systematics by additio-nal measurements  and CLEO-c results on D BR’s CKM ‘03 A. Oyanguren

More Related