共查询到20条相似文献,搜索用时 15 毫秒
1.
N. G. Deshpande 《Pramana》2003,60(2):353-362
We briefly discuss measurements of angles β and α of the unitarity triangle. We then review rate asymmetries usingSU(3) relationships in the standard model (SM). Some methods to measure angle y usingSU(3) are then discussed. We note that rate forb →
sγ can be used to set limits on extra dimensions in which standard model particles propagate. 相似文献
2.
3.
4.
Aubert B Boutigny D De Bonis I Gaillard JM Jeremie A Karyotakis Y Lees JP Robbe P Tisserand V Palano A Chen GP Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Reinertsen PL Stugu B Abbott B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Clark AR Dardin S Day C Dow SF Elioff T Fan Q Gaponenko I Gill MS Goozen FR Gowdy SJ Gritsan A Groysman Y Jacobsen RG Jared RC Kadel RW Kadyk J Karcher A Kerth LT Kipnis I Kluth S Kolomensky YG Kral JF Lafever R LeClerc C Levi ME Lewis SA 《Physical review letters》2001,86(12):2515-2522
We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst). 相似文献
5.
M. Beneke 《Physics letters. [Part B]》2005,620(3-4):143-150
Neglecting smaller amplitudes the time-dependent CP asymmetry in penguin-dominated transitions (such as B→KS) is expected to equal ±sin(2β), an expectation not borne out by the present average experimental data. I compute and discuss the correction due to the smaller amplitudes in the framework of QCD factorization. 相似文献
6.
7.
8.
9.
G. Amelino-Camelia F. Buccella G. D'Ambrosio A. R. Gallo G. Mangano M. Miragliuolo 《Zeitschrift fur Physik C Particles and Fields》1992,55(1):63-74
We study the time dependence of the integrated asymmetries in strangeness of kaons in the decays in two and three pions and in two photons with the purpose of disentangling theCP violating effects in the decay amplitudes from the ones related to the
mass matrix. We find two cases where they are not reduced by the I=1/2 rule or hidden byCP violation in the mass matrix, namely the strangeness-energy correlation of the charged pions in the prompt decay (
S
) in +-0, and the decays in two photons. The semileptonic decays are also briefly studied. 相似文献
10.
11.
We present a simple isospin invariant parametrization for decay amplitudes which consistently includes CP violation and (quasi-elastic) hadronic final state interactions. We find
that the observed decays do not lead to a significant bound on the angle of the unitarity triangle. On the other hand, we claim that a sizeable CP violation asymmetry in rates is by no means excluded.
Received: 9 June 1998 / Published online: 8 September 1998 相似文献
12.
13.
I. Dunietz 《The European Physical Journal C - Particles and Fields》1999,7(2):197-203
It was recently pointed out that inclusive decays could show mixing-induced CP violation. The totally inclusive asymmetry is expected to be tiny [] because of large cancellations among the asymmetries in the charmless, single charm and double charm final states. Enriching
particular final state configurations could significantly increase the CP-asymmetry and observability. Such studies can extract
fundamental CKM (Cabibbo-Kobayashi-Maskawa) parameters, and (perhaps) even . A superb vertex detector could see CP violation with flavor-tagged mesons within the CKM model. Because the effects could be significantly larger due to new physics, they should be searched
for in existing or soon available data samples.
Received: 3 July 1998 / Published online: 22 October 1998 相似文献
14.
15.
R. Barate et al. 《The European Physical Journal C - Particles and Fields》2001,20(3):431-443
A search for CP violating effects in the mixing of neutral B mesons is performed using a sample of 4.1 million hadronic Z
decays collected with the ALEPH detector from 1991 to 1995. By studying time-dependent asymmetries in flavour-tagged samples
of semileptonic and fully inclusive b-hadron decays, two measurements of the semileptonic asymmetry are extracted. No evidence for CP violation is observed, and the combined value is obtained.
Received: 26 July 2000 / Published online: 8 June 2001 相似文献
16.
Aubert B Barate R Boutigny D Couderc F Karyotakis Y Lees JP Poireau V Tisserand V Zghiche A Grauges E Palano A Pappagallo M Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Battaglia M Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Wenzel WA Barrett M Ford KE Harrison TJ Hart AJ 《Physical review letters》2005,95(13):131802
We present a first measurement of CP asymmetries in neutral B decays to D+D-, and updated CP asymmetry measurements in decays to D(*+)D- and D(*-)D+. We use fully reconstructed decays collected in a data sample of (232+/-3) x 10(6) gamma(4S)-->BB events in the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We determine the time-dependent asymmetry parameters to be SD(*+)(D-)=-0.54+/-0.35+/-0.07, CD(*+)(D-)=0.09+/-0.25+/-0.06, SD(*-)(D+)=-0.29+/-0.33+/-0.07, CD(*-)(D+)=0.17+/-0.24+/-0.04, SD+(D-)=-0.29+/-0.63+/-0.06, and CD+(D-)=0.11+/-0.35+/-0.06, where in each case the first error is statistical and the second error is systematic. 相似文献
17.
18.
19.
20.
There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely
factorization, QCD factorization and the perturbative QCD approach based on k
T factorization, using new parameters and full wave functions. Although they get similar results for many of the branching
ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements
of B factories. 相似文献