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A Studen,
E Chesi,
V Cindro,
N H Clinthorne,
E Cochran,
B Grošičar,
M Grkovski,
K Honscheid,
H Kagan,
C Lacasta,
G Llosa,
M Mikuž,
V Stankova,
P Weilhammer, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Silicon based devices can extend PET-MR and SPECT-MR imaging to applications, where their advantages in performance outweigh benefits of high statistical counts.Silicon is in many ways an excellent detector material with numerous advantages, among others: excellent energy and spatial resolution, mature processing technology, large signal to noise ratio, relatively low price, availability, versatility and malleability. The signal in silicon is also immune to effects of magnetic field at the level normally used in MR devices. Tests in fields up to 7 T were performed in a study to determine effects of magnetic field on positron range in a silicon PET device. The curvature of positron tracks in direction perpendicular to the field's orientation shortens the distance between emission and annihilation point of the positron. The effect can be fully appreciated for a rotation of the sample for a fixed field direction, compressing range in all dimensions. A popular Ga-68 source was used showing a factor of 2 improvement in image noise compared to zero field operation. There was also a little increase in noise as the reconstructed resolution varied between 2.5 and 1.5 mm.A speculative applications can be recognized in both emission modalities, SPECT and PET.Compton camera is a subspecies of SPECT, where a silicon based scatter as a MR compatible part could inserted into the MR bore and the secondary detector could operate in less constrained environment away from the magnet. Introducing a Compton camera also relaxes requirements of the radiotracers used, extending the range of conceivable photon energies beyond 140.5 keV of the Tc-99m.In PET, one could exploit the compressed sub-millimeter range of positrons in the magnetic field. To exploit the advantage, detectors with spatial resolution commensurate to the effect must be used with silicon being an excellent candidate. Measurements performed outside of the MR achieving spatial resolution below 1 mm are reported.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2013; 702:88-90. · 1.21 Impact Factor
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N H Clinthorne,
K Brzezinski,
E Chesi,
E Cochran,
M Grkovski,
B Grošičar,
K Honscheid,
S Huh,
H Kagan,
C Lacasta,
V Linhart,
M Mikuž,
S Smith,
V Stankova,
A Studen,
P Weilhammer, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been a successful in achieving ~5mm FWHM spatial resolution in human studies and ~1mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches. Foremost is its high spatial resolution in 3D: our past studies show that there is little diffculty in localizing 511 keV photon interactions to ~0.3mm. Since spatial resolution and reconstructed image noise trade off in a highly non-linear manner that depends on the PET instrument response, if high spatial resolution is the goal, silicon may outperform standard PET detectors even though it has lower sensitivity to 511 keV photons. To evaluate silicon in a variety of PET "magnifying glass" configurations, an instrument has been constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors can be inserted to emulate dual-ring or imaging probe geometries. Recent results have demonstrated 0.7 mm FWHM resolution using pad detectors having 16×32 arrays of 1.4mm square pads and setups have shown promising results in both small animal and PET imaging probe configurations. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2013; 699(21):216-220. · 1.21 Impact Factor
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A. Studen,
E. Chesi,
V. Cindro,
N.H. Clinthorne,
E. Cochran,
B. Grosicar,
K. Honscheid,
S.S. Huh,
H. Kagan,
C. Lacasta,
G. Llosa,
V. Linhart,
M. Mikuz,
V. Stankova,
P. Weilhammer, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: PET probes are showing a lot of promise in extending performance of the conventional PET ring. The underlying idea is to supplement basic PET data with information collected in the finely segmented probe placed close to the region of interest. The benefit is two fold: a) data collected near the object are less prone to errors related to scattering and acolinearity and b) the object itself is magnified in the proximity focus. The principle would be beneficial to clinical applications where spatial resolution below the current limit is required in a narrow field of view. The probe should therefore have excellent spatial resolution, should be compact and robust and should be able to handle large count rates of the clinical environments. Based on those we decided to explore devices with high-resistivity silicon as the sensitive material. They provide high spatial resolution, are compact and robust, and can handle the foreseen rates. We constructed a prototype, based on 1 mm thick silicon wafers, cut into 40 by 26 mm<sup>2</sup> detectors further segmented into 1 × 1 mm<sup>2</sup> square pads, effectively providing 1 mm<sup>3</sup> sensitive voxels. For a module, two such detectors were placed in a back-to-back arrangement, providing filling factor in excess of 70 %. Stacking multiple modules is foreseen to compensate for low stopping power of silicon. The sensors are read out by 128 channel VATAGP7, GM-Ideas sourced application sensitive integrated circuit. Each module requires 16 chips, placed on 4 custom made PCB boards (hybrids) which are read independently. The modules were characterized and will be placed in a test PET ring. A simple point sources and phantoms will be imaged to confirm the predicted benefits.
Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE; 12/2010
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A Studen,
D Burdette,
E Chesi,
V Cindro,
N H Clinthorne,
E Cochran,
B Grosicar,
H Kagan,
C Lacasta,
V Linhart,
M Mikuz,
V Stankova,
P Weilhammer, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an (22)Na source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns.
Radiation Protection Dosimetry 03/2010; 139(1-3):199-203. · 0.82 Impact Factor
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A. Studen,
D. Burdette,
E. Chesi,
V. Cindro,
N.H. Clinthorne,
E. Cochran,
B. Grosicar,
K. Honscheid,
H. Kagan,
C. Lacasta,
G. Llosa,
V. Linhart,
M. Mikuz,
V. Stankova,
Z. Weilhammer, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: This paper reports the characterization of a detector module, the building block to be used for the MADEIRA PET probe prototype. The prototype will be used in synchronization with a conventional PET ring, amplifying the basic image with a subset of events with high spatial resolution. For image improvement, the crucial parameters are the spatial and timing resolution of the probe, while the energy resolution can be used in event classification. The final prototype is made of high-resistivity silicon detectors, 1 mm thick with 1040 square pads with a size of 1 mm. The performance was characterized on an evaluation module featuring the same electronics and sensor material, save for sensor geometry where a sensor with 256 square pads with a side of 1.4 mm was used. The pads were read out with VATAGP7, a Gamma Medica-Ideas designed application specific integrated circuit (ASIC). The ASIC provides a logic trigger signal and an analog output for every out of 128 input channels. The measurement of the timing resolution was performed, using a positron source and a timing reference detector. A similar measurement was performed with a test pulse, ie. a charge injection into the ASIC, to study inherent resolution of the firststage electronics. We calibrated the analog output of the ASIC using standard gamma sources (<sup>241</sup>Am), and we determined the overall energy resolution. The comparators were calibrated by a test pulse, looking at the rate of triggers versus threshold. The gain variation was compensated with internal 3-bit DACs. The evaluation module was successfully characterized, exhibiting energy resolution of 1.5 keV FWHM after gain alignment. The spread of the comparator levels can be decreased below 1 keV. The timing performance allows timing windows of 20 ns to be used. Based on the performance of the evaluation module we conclude that the final prototype can be used as a PET insert probe.
Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE; 12/2009
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V. Linhart,
V. Borshchov,
D. Burdette,
E. Chesi,
V. Cindro,
N.H. Clinthorne,
E. Cochran,
B. Grosicar,
K. Honscheid,
H. Kagan,
C. Lacasta,
O. Listratenko,
G. Llosa,
M. Mikuz,
M. Protsenko,
V. Stankova,
A. Studen,
I. Tymchuk,
P. Weilhammer, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: Detection and spectroscopy tests of the first functional unit of a self-dependent silicon detection module constructed on the base of micro-cable and TAB technology are presented. The tests were performed using pulse-height analysis of the signals induced by gamma rays in the silicon sensor. Good shapes of the spectra and satisfactory spectroscopy resolution (given by FWHM which is less than 2 keV) correspond with results on wire bonded modules. This fact demonstrates that the micro-cable technology does not degrade performance of the detection modules and the TAB is a prospective technology for construction of small stack of self-triggered spectroscopy system suitable for medical applications where very dense packaging of sensors and front-end electronics into small volumes is necessary.
Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE; 12/2009
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V. Stankova,
J. Bernabeu,
V. Borshchov,
D. Burdette,
E. Chesi,
N. H. Clinthorne,
Y. K. Dewaraja,
K. Honscheid,
H. Kagan,
C. Lacasta, [......],
V. Linhart,
M. Mikuz,
M. Protsenko,
W. L. Rogers,
V. Starkov,
A. Studen,
P. Weilhammer,
L. Zhang,
G. Zinovjev, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: Recent progress in the development of micro-cables for very densely packed silicon pad detector modules to be used in a Compton Prostate Probe is reported. The purpose of this development is to optimize the packaging and interconnection of 1mm thick silicon sensors with their readout electronics in such a way that the assembly thickness is dominated by the sensor thickness. The sensor-chip interconnections are based on aluminum polyimide micro-cables. Development of micro-cables demonstrate that TAB technology can replace wire bonding technology, which does not allow optimally dense packaging, with TAB bonded modules which have electronically equally good performance. That gives us a motivation for the development of a detector-cable and chipcable assembly TABed to a very thin PCB module by a two layer detector cable achieving a total height of only 1.2mm.
Nuclear Science Symposium Conference Record, 2008. NSS '08. IEEE; 11/2008
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N Gabyshev,
K Abe,
I Adachi,
H Aihara,
Y Asano,
V Aulchenko,
T Aushev,
A M Bakich,
U Bitenc,
I Bizjak, [......],
H Yamamoto,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
C C Zhang,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Using a sample of 152 x 10(6) BB pairs accumulated with the Belle detector at the KEKB e+e- collider, we study the decay mechanism of three-body charmed decay B- --> Lambdac+ ppi-. The intermediate two-body decay B--->Sigmac (2455)0 p is observed for the first time with a branching fraction of (3.7 +/- 0.7 +/- 0.4 +/- 1.0) x 10(-5) and a statistical significance of 8.4sigma. We also observe a low-mass enhancement in the (Lambdac+p) system, which can be parametrized as a Breit-Wigner function with a mass of (3.35(-0.02)(+0.01) +/-0.02) GeV/c2 and a width of (0.07(-0.03)(+0.04) +/-0.04) GeV/c2. We measure its branching fraction to be (3.9(-0.7)(+0.8) +/- 0.4 +/- 1.0) x 10(-5) with a statistical significance of 6.2sigma. The errors are statistical, systematic, and that of the Lambdac+-->pK- pi+ decay branching fraction.
Physical Review Letters 12/2006; 97(24):242001. · 7.37 Impact Factor
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I Bizjak,
K Abe,
H Aihara,
Y Asano,
S Bahinipati,
A M Bakich,
Y Ban,
E Barberio,
M Barbero,
A Bay, [......],
Q L Xie,
B D Yabsley,
A Yamaguchi,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element /Vub/, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e+ e- asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Gamma(4S). The signal for b --> u semileptonic decay is distinguished from the b --> c background using the hadronic mass Mx, the leptonic invariant mass squared q2 and the variable P+ [triple bond] Ex - /px/. The results are obtained for events with p(l)* > or = 1 GeV/c, in three kinematic regions (1) Mx < 1.7 GeV/c2, (2) Mx < 1.7 GeV/c2 combined with q2 > 8 GeV2/c2, and by (3) P+ < 0.66 GeV/c. The matrix element /Vub/ is found to be (4.09 +/- 0.19 +/- 0.20(+0.14) -0.15 +/- 0.18) x 10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively.
Physical Review Letters 12/2005; 95(24):241801. · 7.37 Impact Factor
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C. Lacasta,
J. Bernabeu,
V. Borshchov,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
Y.K. Dewaraja,
K. Honscheid,
H. Kagan,
A. Listratenko, [......],
M. Mikuz,
P. Modesto,
M. Protsenko,
W.L. Rogers,
V. Starkov,
A. Studen,
P. Weilhammer,
L. Zhang,
G. Zinovjev, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: This contribution describes the work made towards packaging optimization in the frame of the development of an endorectal probe for imaging the prostate. This application is based on the concept of electronic collimation for single gamma detection taking advantage of the Compton scattering of the photons in a stack of 1 mm thick silicon pad detectors and their later absorption in an external detector. This concept allows to remove the mechanical collimators used in the usual gamma cameras and, therefore, provides the possibility of improving both sensitivity and resolution. Packaging of the silicon sensors and their associated electronics is of paramount importance in this application. To address this important aspect of the device we have explored the tape automated bonding (TAB) technique for the connection of the silicon sensors to the readout electronics and for routing the signals to the outside. TAB offers an elegant solution not only for a flexible and compact interconnection between the readout ASICs and the sensors but also for ASIC selection and testing prior to the assembly of the detector and their associated readout electronics
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
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C. Lacasta,
J. Bernabeu,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
Y.K. Dewaraja,
K. Honscheid,
H. Kagan,
G. Llosa,
M. Mikuz,
P. Modesto,
W.L. Rogers,
A. Studen,
P. Weilhammer,
L. Zhang, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: A first prototype of a Compton prostate probe has been built using a stack of five 4times1 cm<sup>2</sup>, 1 mm thick silicon pad detectors as a scatter detector, surrounded by three scintillation detectors in which the absorption of the scattered photons takes place. The silicon pad dimensions are 1.4times1.4 mm which provide the required spatial resolution. The energy resolution in the silicon sensors is about 1.4 keV FWHM as determined from several gamma sources. The results obtained validate the simulation predictions that foresee an improvement over current SPECT techniques by a factor 16-40 in sensitivity and 4-5 in spatial resolution simultaneously for an intra-rectal probe built employing this concept and placed at 2 cm from the prostate
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
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T. Ziegler,
H. Aihara,
Y. Asano,
T. Aso,
A. Bakich,
M. Barbero,
T. Browder,
M.C. Chang,
Y. Chao,
K.F. Chen, [......],
C.C. Wang,
M.Z. Wang,
M. Watanabe,
Y. Watanabe,
H. Yamamoto,
Y. Yamashita,
M. Yamauchi,
R. Yang,
Y. Yasu, D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: In autumn 2003, data taking with the new silicon vertex detector SVD2.0 in Belle started at the KEK-B energy-asymmetric e<sup>+</sup>e<sup>-</sup> collider in Tsukuba, Japan. The detector works as expected, however, it was decided to produce replacement ladders for the inner two layers of the vertex detector which are most exposed to the high radiation dose from the beam. The new ladders do not merely reproduce the existing design but include some significant improvements. The readout electronics is implemented on a hybrid board with a new heat transfer scheme in order to dissipate the heat produced in the front-end readout chip. The flex circuits that connect the double-sided silicon sensors (DSSDs) with the hybrid boards were redesigned using a 2-layer technique which improved the production quality and lowered their costs significantly. Production and testing will be finished in summer 2005 and will provide Belle with spare ladders as well as new expertise for possible future projects for example the high luminosity B-factory.
IEEE Transactions on Nuclear Science 11/2005; · 1.45 Impact Factor
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K Abe,
I Adachi,
H Aihara,
K Arinstein,
Y Asano,
T Aushev,
A M Bakich,
Y Ban,
E Barberio,
M Barbero, [......],
A Yamaguchi,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar,
D Zürcher
[show abstract]
[hide abstract]
ABSTRACT: We present a new measurement of the time-dependent CP-violating parameters in B(0)--> pi(+)pi(-) decays with 275 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Gamma(4S) resonance. We find 666 +/- 43 B(0) --> pi(+)pi(-) events and measure the CP-violating parameters: S(pipi) = -0.67 +/- 0.16(stat) +/- 0.06(syst) and A(pipi) = +0.56 +/- 0.12(stat) +/- 0.06(syst). We find evidence for large direct CP violation with a significance greater than 4 standard deviations for any S(pipi) value. Using isospin relations, we obtain 95.4% confidence intervals for the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2) of 0 degree < phiv(2) < 19 degrees and 71 degrees < phi(2) < 180 degrees.
Physical Review Letters 10/2005; 95(10):101801. · 7.37 Impact Factor
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R Itoh,
Y Onuki,
K Abe,
I Adachi,
H Aihara,
Y Asano,
T Aushev,
A M Bakich,
Y Ban,
E Barberio, [......],
B D Yabsley,
A Yamaguchi,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: CP violation in B-->J/PsiK* decays is studied using an angular analysis in a data sample of 253 fb(-1) recorded with the Belle detector at the KEKB e(+)e(-) collider. The flavor separated measurements of the decay amplitudes indicate no evidence for direct CP violation. T-odd CP violation is studied using the asymmetries in triple product correlations, and the results are consistent with the standard model null predictions. The time-dependent angular analysis gives the following values of CP-violating parameters: sin(2phi(1) = 0.24 +/- 0.31 +/- 0.05 and cos(2phi(1)=0.56 +/- 0.79 +/- 0.11.
Physical Review Letters 09/2005; 95(9):091601. · 7.37 Impact Factor
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J Zhang,
K Abe,
I Adachi,
H Aihara,
K Arinstein,
Y Asano,
T Aushev,
T Aziz,
S Bahinipati,
A M Bakich, [......],
Y Watanabe,
Q L Xie,
B D Yabsley,
A Yamaguchi,
Y Yamashita,
Heyoung Yang,
J Ying,
L M Zhang,
Z P Zhang, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: We present the results of a study of the charmless vector-vector decay B+ --> rho+ K*0, based on 253 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. We obtain the branching fraction B(B+ --> rho+ K*0) = [8.9 +/- 1.7(stat) +/- 1.2(syst)] x 10(-6). We also perform a helicity analysis of the rho and K* vector mesons, and obtain the longitudinal polarization fraction f(L)(B+ --> rho+ K*0) = 0.43 +/- 0.11(stat)(-0.02)(+0.05) (syst).
Physical Review Letters 09/2005; 95(14):141801. · 7.37 Impact Factor
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K Sumisawa,
Y Ushiroda,
M Hazumi,
K Abe,
I Adachi,
H Aihara,
Y Asano,
V Aulchenko,
T Aushev,
A M Bakich, [......],
A Yamaguchi,
H Yamamoto,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of CP-violation parameters in the B0 --> K(s)0K(s)0K(s)0 decay based on a sample of 275 x 10(6) BB pairs collected at the upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in the decay B0 --> K(s)0K(s)0K(s)0, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters are obtained from the asymmetry in the distributions of the proper-time interval between the two B decays: S = +1.26 +/- 0.68(stat) +/- 0.20(syst) and [symbol: see text] = +0.54 +/- 0.34(stat) +/- 0.09(syst).
Physical Review Letters 08/2005; 95(6):061801. · 7.37 Impact Factor
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Y-J Lee,
M-Z Wang,
K Abe,
H Aihara,
Y Asano,
V Aulchenko,
T Aushev,
S Bahinipati,
A M Bakich,
I Bedny, [......],
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Ying,
C C Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar,
D Zürcher
[show abstract]
[hide abstract]
ABSTRACT: We report the first observation of the radiative hyperonic B decay B+ --> plambdagamma, using a 140 fb(-1) data sample recorded on upsilom(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. The measured branching fraction is [symbol: see text](B+ --> plambdagamma) = (2.16(+0.58)(-0.53) +/- 0.20) x 10(-6). We examine its M(plambda) distribution and observe a peak near threshold. This feature is expected by the short-distance b --> sgamma transition. A search for B+ --> pepsilon0gamma yields no significant signal, and we set a 90% confidence-level upper limit on the branching fraction of [symbol: see textB+ --> pepsilon0gamma <4.6 x 10(-6).
Physical Review Letters 08/2005; 95(6):061802. · 7.37 Impact Factor
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G Majumder,
K Abe,
I Adachi,
H Aihara,
Y Asano,
V Aulchenko,
T Aushev,
S Bahinipati,
A M Bakich,
S Banerjee, [......],
A Yamaguchi,
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Ying,
C C Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: We report evidence for B(0) --> D(0)D(-) and the first observation of the decay modes B(-) --> D(0)D(-) and B(-) --> D(0)D(*-) based on a sample of 152 x 10(6) BB events collected by the Belle detector at KEKB. The branching fractions for B(0) --> D(+) D(-), B--->D(0)D(-), and B--> D(0)D(*-) are found to be (1.91 +/- 0.51 +/- 0.30) x10(-4), (4.83 +/- 0.78 +/- 0.58) x 10(-4), and (4.57 +/- 0.71 +/- 0.56) x 10(-4), respectively. Charge asymmetries in the B---> D(0)D(-) and B(-) --> D(0)D(*-) channels are consistent with zero.
Physical Review Letters 07/2005; 95(4):041803. · 7.37 Impact Factor
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K Abe,
I Adachi,
H Aihara,
M Akatsu,
D Anipko,
Y Asano,
T Aushev,
T Aziz,
S Bahinipati,
A M Bakich, [......],
Y Yamashita,
M Yamauchi,
J Ying,
Y Yusa,
C C Zhang,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar
[show abstract]
[hide abstract]
ABSTRACT: We report on the first observation of D0/1(2420)-->D0pi- pi+ and D+/1(2420-->D+ pi- pi+ decays (where the contribution from the dominant known D1-->D*pi decay mode is excluded) in the B- -->D0/1pi-) and (-)B0-->D+/1pi- decays, respectively. The observation is based on 15.2 x 10(7) B(-)B events collected with the Belle detector at the KEKB collider. We also set 90% confidence level upper limits for the branching fractions of the four following decays: B- -->D0/1pi-, D01-->D(*0)pi- pi+, (-)B0-->D+/1pi-, D+/1-->D(*+) pi- pi+, B- -->D(*0)2(2460)pi-, D(*0)2 -->D(*0) pi- pi+, (-)B0-->D(*+)2(2460)pi-, D(*+)2-->D(*+)pi- pi+.
Physical Review Letters 06/2005; 94(22):221805. · 7.37 Impact Factor
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K-F Chen,
K Abe,
H Aihara,
Y Asano,
V Aulchenko,
T Aushev,
S Bahinipati,
A M Bakich,
I Bedny,
U Bitenc, [......],
Y Yamashita,
M Yamauchi,
Heyoung Yang,
J Ying,
J Zhang,
L M Zhang,
Z P Zhang,
V Zhilich, D Zontar,
D Zürcher
[show abstract]
[hide abstract]
ABSTRACT: We present measurements of decay amplitudes and triple-product correlations in B-->phiK* decays based on 253 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. The decay amplitudes for the three different helicity states are determined from the angular distributions of final-state particles. The longitudinal polarization amplitudes are found to be 0.45 +/- 0.05 +/- 0.02 for B0-->phiK(*0) and 0.52 +/- 0.08 +/- 0.03 for B+ -->phiK(*+) decays. CP- and T-odd CP-violating triple-product asymmetries are measured to be consistent with zero.
Physical Review Letters 06/2005; 94(22):221804. · 7.37 Impact Factor
