共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
《Physics letters. [Part B]》1986,167(1):138-140
A new value of the upper limit for the branching ratio of the decay of K0S into e+e− has been experimentally obtained using a lead glass detector. The value is BR (K0S → e+e−) < 1.1 × 10−4 (90% CL). 相似文献
3.
The KLOE- collaboration A. Anastasi D. Babusci G. Bencivenni M. Berlowski C. Bloise F. Bossi P. Branchini A. Budano L. Caldeira Balkest?hl B. Cao F. Ceradini P. Ciambrone F. Curciarello E. Czerwinski G. D’Agostini E. Danè V. De Leo E. De Lucia A. De Santis P. De Simone A. Di Cicco A. Di Domenico R. Di Salvo D. Domenici A. D’Uffizi A. Fantini G. Felici S. Fiore A. Gajos P. Gauzzi G. Giardina S. Giovannella E. Graziani F. Happacher L. Heijkenskj?ld W. Ikegami Andersson T. Johansson D. Kaminska W. Krzemien A. Kupsc S. Loffredo G. Mandaglio M. Martini M. Mascolo R. Messi S. Miscetti G. Morello D. Moricciani P. Moskal M. Papenbrock A. Passeri V. Patera E. Perez del Rio A. Ranieri P. Santangelo I. Sarra M. Schioppa M. Silarski F. Sirghi L. Tortora G. Venanzoni W. Wislicki M. Wolke 《Journal of High Energy Physics》2016,2016(5):19
4.
N. P. Hessey E. C. Booth W. J. Fickinger K. P. Gall M. D. Hasinoff D. Horváth J. Lowe E. K. McIntyre D. F. Measday J. P. Miller A. J. Noble B. L. Roberts D. K. Robinson M. Sakitt M. Salomon D. A. Whitehouse 《Zeitschrift fur Physik C Particles and Fields》1989,42(2):175-183
We have measured the weak radiative decay branching ratio (∑ + →pγ)/(∑ + →pπ0). The experiment was carried out at Brookhaven National Laboratory using a low-energy separatedK ? beam stopping in liquid hydrogen. The∑ + was tagged by observing the pion fromK ? K + p→∑ +π? in a range telescope, and the gamma was detected in a segmented NaI detector. The result is (2.81±0.39 ?0.43 +0.21 )×10?3, which is consistent with previous measurements. This corresponds to a branching ratio for (∑ + →pγ)/(∑ + → all) of (1.45±0.20 ?0.22 +0.11 )×10?3, where the quoted errors are statistical and systematic, respectively. A total of 408 signal events were observed, doubling the previous world total. 相似文献
5.
V. Dorofeev R. Dzhelyadin A. Ekimov Yu. Gavrilov Yu. Gouz A. Ivashin V. Kabachenko I. Kachaev A. Karyukhin Yu. Khokhlov V. Konstantinov M. Makouski V. Matveev A. Myagkov V. Nikolaenko A. Ostankov B. Polyakov D. Ryabchikov N. Shalanda M. Soldatov A. A. Solodkov A. V. Solodkov O. Solovianov E. Starchenko A. Zaitsev 《The European Physical Journal A - Hadrons and Nuclei》2008,38(2):149-154
The isospin-violating decay f
1(1285) → π+π-π0 has been studied at the VES facility. This study is based on the statistics acquired in π-
Be interactions at 27, 36.6 and 41 GeV/c in the diffractive reaction π-
N → (f
1π-)N . The f
1(1285) → π+π-π0 decay is observed. The preliminary ratio of decay probabilities BR(f
1(1285) → π+π-π0) to BR(f
1(1285) → ηπ+π-).
BR(η → γγ) is ∼ 2% .
Original article based on material presented at HADRON 2007. 相似文献
6.
7.
V. Dorofeev A. Ekimov Yu. Gouz A. Ivashin I. Kachaev A. Karyukhin Yu. Khokhlov V. Konstantinov V. Matveev V. Nikolaenko B. Polyakov D. Ryabchikov N. Shalanda M. Soldatov A. A. Solodkov A. V. Solodkov O. Solovianov A. Zaitsev 《The European Physical Journal A - Hadrons and Nuclei》2011,47(5):1-7
The isospin symmetry-breaking (ISB) decay f 1(1285) → π+π?π0 has been studied at the VES facility. The branching ratio is measured: $\frac{{BR\left( {f_1 \to \pi ^ + \pi ^ - \pi ^0 } \right)}} {{BR\left( {f_1 \to \eta \pi ^ + \pi ^ - } \right)}} = 0.86 \pm 0.16_{ - 0.20}^{ + 0.70} \%Low-energy resonances in 31P(p, α 28Si and 35Cl(p, α)32S were studied directly in order to gain a better understanding of reaction cycling in the Si-Ar region in novae. New resonance strengths at E c.m. = 600 and 622 keV in 31P(p, α)28Si were measured (ωγ p, α = (2.2#x00B1;0.7) × 10?2 eV and ωγ p, α = (0.99±0.08) eV, respectively) as well as the E c.m. = 610 keV resonance in 35Cl(p, α)32S [ωγ p, α = (1.2±0.2) × 10?2 eV], the lowest energy that any resonance in this reaction has been observed, directly or indirectly. The strengths of these resonances were found to be lower than previously determined, resulting in even weaker cycling in the Si-Ar region. 相似文献
8.
《Physics letters. [Part B]》2004,578(3-4):276-284
Using the NA48 detector at the CERN SPS, 31 KS→π0γγ candidates with an estimated background of 13.7±3.2 events have been observed. This first observation leads to a branching ratio of BR(KS→π0γγ)z>0.2=(4.9±1.6stat±0.9syst)×10−8 in agreement with Chiral Perturbation Theory predictions. 相似文献
9.
It is shown that the contribution of diagrams with intermediate state vector mesons to the KL 0
amplitude, intensively discussed in literature in recent years, is close to zero provided that theSU(3) group breaking is taken into account. At the same time, the contribution of scalar mesons in the intermediate state is essential. The obtained estimates for Br(KL 0) conform with the recent experimental data Br(KL
0
)=(2·1 ± 0·6)×10–6.Dedicated to the memory of our friend Prof. M. Gmitro.We wish to thank S. B. Gerasimov and A. B. Govorkov for useful discussions. 相似文献
10.
A. M. Blik A. M. Gorin S. V. Donskov V. N. Kolosov A. A. Lednev V. A. Lishin Yu. V. Mikhailov V. A. Polyakov V. D. Samoylenko A. E. Sobol V. P. Sugonyaev G. V. Khaustov 《Physics of Atomic Nuclei》2009,72(2):231-236
The parameters of the Dalitz diagram for the decay η′ → ηπ 0 π 0 in a generalized and a linear representation were determined by using a statistical sample of 15 × 103 events. A charge-exchange reaction at a momentum of 32 GeV/c was a source of monoenergetic η′ mesons. The experiment was performed with the aid of the GAMS-4π spectrometer. 相似文献
11.
Arnold R Augier C Baker J Barabash AS Basharina-Freshville A Blondel S Bongrand M Broudin-Bay G Brudanin V Caffrey AJ Chapon A Chauveau E Durand D Egorov V Flack R Garrido X Grozier J Guillon B Hubert P Hugon C Jackson CM Jullian S Kauer M Klimenko A Kochetov O Konovalov SI Kovalenko V Lalanne D Lamhamdi T Lang K Liptak Z Lutter G Mamedov F Marquet Ch Martin-Albo J Mauger F Mott J Nachab A Nemchenok I Nguyen CH Nova F Novella P Ohsumi H Pahlka RB Perrot F Piquemal F Reyss JL Richards B Ricol JS 《Physical review letters》2011,107(6):062504
We report results from the NEMO-3 experiment based on an exposure of 1275 days with 661 g of (130)Te in the form of enriched and natural tellurium foils. The ββ decay rate of (130)Te is found to be greater than zero with a significance of 7.7 standard deviations and the half-life is measured to be T(?)(2ν) = [7.0 ± 0.9(stat) ± 1.1(syst)] × 10(20) yr. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay. 相似文献
12.
M. N. Achasov K. I. Beloborodov A. V. Berdyugin A. G. Bogdanchikov A. V. Bozhenok D. A. Bukin S. V. Burdin A. V. Vasil’ev T. V. Dimova A. A. Drozdetskii V. P. Druzhinin V. B. Golubev V. N. Ivanchenko A. A. Korol’ M. S. Korostelev S. V. Koshuba A. P. Lysenko I. N. Nesterenko E. V. Pakhtusova A. A. Sal’nikov S. I. Serednyakov V. A. Sidorov Z. K. Silagadze A. G. Skripkin Yu. V. Usov V. V. Sharyi Yu. M. Shatunov 《JETP Letters》2001,73(9):451-452
The η→3π0 decay was studied with the SND detector at the VEPP-2Me + e ? collider. The parameter that describes deviation of the Dalitz plot of events from a uniform distribution was found to be α=?0.010±0.021±0.010. 相似文献
13.
V. Fanti A. Lai L. Musa A. Nappi M.G. Setzu 《Zeitschrift fur Physik C Particles and Fields》1997,76(4):653-657
The rate of the decay of the neutral K meson into K L 0 → μμγ has been measured with the NA48 detector at the CERN SPS. A total of 59 events has been observed with an estimated background of 14 events. The overall Kaon flux was determined to be 1.2 × 109. This observation corresponds to a branching ratio of (3.4 ± 0.6stat ± 0.4sys × 10-7. Using this branching ratio the parameter αK* describing the relative strength of the two contributing amplitudes to this decay, through intermediate pseudoscalar or vectorlike mesons, was measured to be αK* = -0.04+ -0.21 +0.24 . 相似文献
14.
V. M. Aulchenko M. N. Achasov S. E. Baru K. I. Beloborodov A. V. Berdyugin A. G. Bogdanchikov A. V. Bozhenok A. D. Bukin D. A. Bukin A. V. Vasilev V. B. Golubev T. V. Dimova V. P. Druzhinin V. N. Ivanchenko I. A. Koop A. A. Korol S. V. Koshuba A. P. Lysenko A. V. Otboev E. V. Pakhtusova A. A. Salnikov S. I. Serednyakov V. A. Sidorov Z. K. Silagadze V. V. Shary Yu. M. Shatunov 《Journal of Experimental and Theoretical Physics》2003,97(1):24-33
The process e + e ? → η′γ, η′ → η π0π0, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 ?4.2 +5.0 ±1.5)×10?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π+π?η, one finally obtains B(?→η ′γ)=(6.7 ?2.4 +2.8 ±0.8)×10?5. 相似文献
15.
16.
17.
A. Kreutz M. Holder M. Rost R. Werthenbach K. J. Peach H. Blümer R. Heinz K. Kleinknecht P. Mayer B. Panzer B. Renk H. Rohrer A. Wagner E. Augé D. Fournier L. Iconomidou-Fayard O. Perdereau A. C. Schaffer L. Serin L. Bertanza A. Bigi P. Calafiura M. Calvetti R. Carosi R. Casali C. Cerri I. Mannelli V. Marzulli A. Nappi G. M. Pierazzini 《Zeitschrift fur Physik C Particles and Fields》1995,65(1):67-74
Improved branching ratios were measured for theK
L30 decay in a neutral beam at the CERN SPS with the NA31 detector:
相似文献
18.
Aaij R Abellan Beteta C Adeva B Adinolfi M Adrover C Affolder A Ajaltouni Z Albrecht J Alessio F Alexander M Alkhazov G Alvarez Cartelle P Alves AA Amato S Amhis Y Anderson J Appleby RB Aquines Gutierrez O Archilli F Arrabito L Artamonov A Artuso M Aslanides E Auriemma G Bachmann S Back JJ Bailey DS Balagura V Baldini W Barlow RJ Barschel C Barsuk S Barter W Bates A Bauer C Bauer T Bay A Bediaga I Belogurov S Belous K Belyaev I Ben-Haim E Benayoun M Bencivenni G Benson S Benton J Bernet R 《Physical review letters》2012,108(18):181806
The angular distributions and the partial branching fraction of the decay B0 → K*0 μ+ μ- are studied by using an integrated luminosity of 0.37 fb(-1) of data collected with the LHCb detector. The forward-backward asymmetry of the muons, A(FB), the fraction of longitudinal polarization, F(L), and the partial branching fraction dB/dq2 are determined as a function of the dimuon invariant mass. The measurements are in good agreement with the standard model predictions and are the most precise to date. In the dimuon invariant mass squared range 1.00-6.00 GeV2/c4, the results are A(FB)=-0.06(-0.14)(+0.13)±0.04, F(L)=0.55±0.10±0.03, and dB/dq2=(0.42±0.06±0.03)×10(-7) c4/GeV2. In each case, the first error is statistical and the second systematic. 相似文献
19.
《Physics letters. [Part B]》1987,197(4):561-564
We have searched for the decay τ-→Π-ηvτ using the MARK II detector at the PEP e+e- storage ring. No evidence for the decay is found; the upper limit for the branching ratio is B(τ-→Π-ηvτ)<1.0% at the 95% confidence level. 相似文献
20.
《The European Physical Journal C - Particles and Fields》2006,47(3):589-596
We describe the method of measuring the integrated luminosity of the e+e- collider DAΦNE, the Frascati φ-factory. The measurement is done with the KLOE detector selecting large angle Bhabha scattering
events and normalizing them to the effective cross section. The e+e-→e+e-(γ) cross section is calculated using different event generators which account for the
radiative initial and final state corrections, and the φ resonance contribution. The accuracy of the measurement is 0.6%,
where 0.3% comes from systematic errors related to the event counting and 0.5% from theoretical evaluations of the cross section. 相似文献
|