1
|
Cmpd10357 to treat B-cell acute lymphoblastic leukemia. Exp Hematol 2023; 119-120:8-13.e1. [PMID: 36621746 PMCID: PMC10033359 DOI: 10.1016/j.exphem.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 12/12/2022] [Accepted: 12/20/2022] [Indexed: 01/07/2023]
Abstract
B-cell acute lymphoblastic leukemia (B-ALL) is the most common type of cancer found in children. Although the overall survival rates are now >80%, 15%-20% of pediatric patients relapse, with survival rates subsequently dropping to 5%-10%. Cmpd10357, 3-amino-5-arylamino-6-chloro-N- (diaminomethylene) pyrazine-2-carboximide, is a highly potent, cell-permeant compound recently shown to have cytotoxic effects on solid tumors, including human breast cancer and high-grade gliomas, independent of their proliferative status. Cmpd10357 demonstrated concentration-dependent cytotoxicity in two human B-ALL cell lines, JM1 and Reh, at half-maximal inhibitory concentrations (IC50) of 3.2 and 3.3 μM, respectively. Cmpd10357, at a dose of 5 mg/kg, significantly prolonged survival in our B-ALL xenograft mouse model, with a median survival time of 49.0 days compared with 45.5 days in the control group (p < 0.05). The cytotoxicity of Cmpd10357 demonstrated caspase-independent, nonapoptotic cancer cell demise associated with the nuclear translocation of apoptosis-inducing factor (AIF). The cytotoxicity of Cmpd10357 in B-ALL cells was inhibited by Necrostatin-1 but not by Necrosulfonamide. These studies suggest that an AIF-mediated, caspase-independent necrosis mechanism of Cmpd10357 in B-ALL could be used in combination with traditional apoptotic chemotherapeutic agents.
Collapse
|
2
|
Abstract
We discovered a new type of dendritic spine. It is found on space-specific neurons in the barn owl inferior colliculus, a site of experience-dependent plasticity. Connectomic analysis revealed dendritic protrusions of unusual morphology including topological holes, hence termed "toric" spines (n = 76). More significantly, presynaptic terminals converging onto individual toric spines displayed numerous active zones (up to 49) derived from multiple axons (up to 11) with incoming trajectories distributed widely throughout 3D space. This arrangement is suited to integrate input sources. Dense reconstruction of two toric spines revealed that they were unconnected with the majority (∼84%) of intertwined axons, implying a high capacity for information storage. We developed an ex vivo slice preparation and provide the first published data on space-specific neuron intrinsic properties, including cellular subtypes with and without toric-like spines. We propose that toric spines are a cellular locus of sensory integration and behavioral learning.
Collapse
|
3
|
184 Effects of cyanidin supplementation on invitro maturation of pig oocytes. Reprod Fertil Dev 2020. [DOI: 10.1071/rdv32n2ab184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Oxidative stress can have a negative effect on oocyte maturation during invitro production of pig embryos. Imbalance of reactive oxygen species and antioxidant levels can affect the progression of oocyte maturation up to the point of fertilization. Antioxidants are effective in maintaining more ideal reactive oxygen species levels, which help to protect oocytes from potential harmful effects of oxidative stress. Berries from the elder plant (Sambucus sp.) contain high levels of a broad spectrum of antioxidants. One of these antioxidants, cyanidin, when supplemented to maturation medium at 100μM concentrations, reduces reactive oxygen species formation and improves IVF and early embryonic development in pigs. However, changes in the enzyme mechanisms of action during oocyte maturation due to cyanidin supplementation are unknown. Therefore, the objective of this study was to characterise the intracellular oocyte enzyme mechanisms between oocytes supplemented with 100μM cyanidin during 40 to 44h of maturation (n=600) and oocytes without supplementation of cyanidin during maturation (n=558). At the end of maturation, oocytes were evaluated for either glutathione peroxidase (n=300), catalase (n=564), or superoxide dismutase (n=294) activities. Glutathione peroxidase activity was determined by following the rate of NADPH oxidation, catalase activity was determined by following the rate of hydrogen peroxide decomposition, and superoxide dismutase activity was determined by following the reduction rate of cytochrome c, utilising the xanthine-xanthine oxidase system. Data were analysed using ANOVA and Tukey's test. There were no significant differences between oocytes matured with 100μM cyanidin and those that were not when comparing glutathione peroxidase and superoxide dismutase activities. Supplementation of 100μM cyanidin to maturation medium increased (P<0.05) catalase activity in oocytes (0.78±0.15 units/oocyte) compared with no cyanidin supplementation (0.14±0.11 units/oocyte). These results indicate that supplementing 100μM cyanidin to the maturation medium of pig oocytes could reduce the negative effects of oxidative stress by increasing intracellular catalase activity during oocyte maturation.
Collapse
|
4
|
181 The effects of aging in the oocyte induced by trichostatin A. Reprod Fertil Dev 2020. [DOI: 10.1071/rdv32n2ab181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Successful fertilization and embryonic development decreases for an aged oocyte that is not fertilized during the optimal window of time after ovulation. If fertilization of an aged oocyte does occur, the developing embryo is prone to have a delay through meiosis and a decrease in cleavage and blastocyst formation. Trichostatin A (TSA) prohibits the breakdown of the germinal vesicle during meiosis. The objective of this study was to create an invitro model to study the effects of aging in pig oocytes. Oocytes (n=1489) were matured with or without TSA (100ngmL−1) for 24 or 48h followed by an additional 16h of maturation without TSA. A portion of the oocytes were evaluated for stage of meiosis (MI and MII) before maturation (n=95), after the first part of maturation (OMI; 24 or 48h, n=363), or after completing maturation (OMII; 16h, n=230). The remaining oocytes (n=801) were fertilized for 6 to 8h and potential embryos developed. A portion of the embryos were evaluated for fertilization characteristics 12h after IVF (n=400). Remaining embryos (n=401) were evaluated for cleavage by 48h and blastocyst formation by 144h, after IVF. Data were analysed using ANOVA and Tukey's test. Oocytes matured without TSA for 64h had a significantly higher (P<0.05) percentage of oocytes at the MI stage of meiosis compared with all other treatment groups (16.00±6.80), and oocytes matured without TSA for 40h had a significantly higher (P<0.05) percentage of oocytes at the MII stage of meiosis compared with all other treatment groups (14.7±11.30). The results (Table 1) indicate that supplementation of TSA to OMI significantly decreased fertilization penetration rates compared with not supplementing TSA for 24h. However, the percent of embryos cleaved by 48h after IVF was significantly higher in oocytes matured for 40h compared with those matured for 64h. The percent of embryos reaching the blastocyst stage of development by 144h after IVF was significantly lower in oocytes matured for 64h compared with those matured for 40h without TSA. In conclusion, these results suggest that supplementation of TSA during early maturation delays meiosis and decreases fertilization, and increasing maturation time causes a decrease in early embryonic development. By supplementing TSA during early maturation and increasing the length of maturation by 24h, we have created an invitro model to study the effects of aging in pig oocytes.
Table 1.Fertilization and developmental characteristics of oocytes1
Amount of TSA added during OMI (ngmL−1)
Length of OMI (h)
Oocytes penetrated (%)
Polyspermicoocytes2 (%)
Oocytes with MPN2 (%)
Cleavage (%)
Day 7 blastocyst (%)
0
24
83.00±3.80a
15.70±4.00
75.90±4.70
77.20±4.20a
27.70±4.20a
0
48
72.00±4.50ab
20.80±4.80
76.40±5.00
58.00±5.00bc
12.00±5.00b
100
24
65.00±4.80b
30.80±5.80
73.80±5.50
68.00±4.70ab
21.00±4.70ab
100
48
56.00±5.00b
30.40±6.20
62.50±6.50
46.00±5.00c
8.00±5.00b
a,bMeans with different superscripts in the same column differ (P<0.05).
1TSA, trichostatin A; OMI, oocyte maturation 1.
2Percent of the number of oocytes penetrated.
Collapse
|
5
|
PSI-22 The effects of cyanidin supplementation during oocyte maturation on the in vitro production of pig embryos. J Anim Sci 2019. [DOI: 10.1093/jas/skz122.428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Oxidative stress has a negative effect on embryonic development during the in vitro production of pig embryos. The imbalance of reactive oxygen species and antioxidants impact oocyte maturation. Berries from the elder plant (Sambucus sp.) have been identified as containing high levels of a broad spectrum of antioxidants. One of the predominant antioxidant classes of compounds found in elderberry extract is anthocyanin, which includes the antioxidant cyanidin. Therefore, the objective of this study was to determine the effects of cyanidin supplementation to the media during oocyte maturation. Oocytes (n = 815, r=3) were supplemented with 100 or 200 μM cyanidin during 40–44 h of maturation and then evaluated at the end of maturation for the formation of reactive oxygen species, fertilization characteristics, and rates of embryonic cleavage and blastocyst development at 48 h and 144 h after IVF, respectively. There were no significant differences between no cyanidin supplementation and 200 μM cyanidin supplementation when comparing reactive oxygen species generation at the end of oocyte maturation. Supplementation of 100 μM cyanidin significantly decreased (P < 0.05) reactive oxygen species generation in oocytes compared to the other groups. There were no significant differences between no cyanidin supplementation and 200 μM cyanidin supplementation when comparing penetration and polyspermic penetration rates and male pronuclear formation. Supplementation of 100 μM cyanidin significantly decreased (P < 0.05) polyspermic penetration rates and significantly increased (P < 0.05) male pronuclear formation rates compared to the other groups. There were no significant differences between the treatment groups when comparing the percentage of cleaved embryos by 48 h after IVF. Supplementation of 100 μM cyanidin significantly increased (P < 0.05) the blastocyst formation rates by 144 h after IVF compared to all other treatment groups. These results indicate that supplementing 100 μM cyanidin to the media during oocyte maturation reduces reactive oxygen species formation and improves in vitro fertilization and early embryonic development in pigs.
Collapse
|
6
|
PSI-21 The effects of kuromanin supplementation during oocyte maturation on the in vitro production of pig embryos. J Anim Sci 2019. [DOI: 10.1093/jas/skz122.427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
The imbalance of reactive oxygen species levels and antioxidants impact oocyte matruation. Elderberries (Sambucus sp.) have been identified as possessing the ability to alleviate oxidative stress. An antioxidant class found in elderberry is anthocyanidin, which includes kuromanin. The objective of this study was to determine the effects of kuromanin supplementation to the media during oocyte maturation. Oocytes (n = 692, r=3) were supplemented with 100 or 200 μM kuromanin during 40-44 h of maturation and then evaluated at the end of maturation for the formation of reactive oxygen species, fertilization characteristics, and rates of embryonic cleavage and blastocyst development at 48 h and 144 h after IVF, respectively. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing reactive oxygen species generation at the end of oocyte maturation. Supplementation of 200 μM kuromanin significantly increased (P < 0.05) reactive oxygen species generation in oocytes compared to the other groups. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing penetration and polyspermic penetration rates and male pronuclear formation. Supplementation of 200 μM kuromanin significantly decreased (P < 0.05) penetration and polyspermic penetration rates and male pronuclear formation compared to the other groups. There were no significant differences between no kuromanin supplementation and 100 μM kuromanin supplementation when comparing the percentage of cleaved embryos by 48 h after IVF and the percentage of those reaching the blastocyst stage by 144 h after IVF. Supplementation of 200 μM kuromanin significantly decreased (P < 0.05) the cleavage rates by 48 h after IVF and the blastocyst formation rates by 144 h after IVF compared to all other treatment groups. These results indicate that supplementing 200 μM kuromanin is detrimental to oocyte maturation and lower levels (100 μM) do not have a significant effect compared to not supplementing the oocytes when evaluating in vitro fertilization and early embryonic development characteristics.
Collapse
|
7
|
146 Quercetin supplementation during boar semen thawing and incubation improves the in vitro production of pig embryos. Reprod Fertil Dev 2019. [DOI: 10.1071/rdv31n1ab146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Elevated levels of reactive oxygen species in the in vitro environment cause oxidative stress, which leads to membrane damage, decreased fertility, and morphological deformities of spermatozoa. Antioxidants, such as quercetin (a polyphenol flavonoid), are often supplemented to reduce the effects of oxidative stress on spermatozoa. Supplementing frozen-thawed boar semen with quercetin improves sperm forward progressive motility, viability and lipid peroxidation up to 10h after thawing. However, the effects of fertilizing with quercetin-supplemented sperm are unknown. Therefore, the objective of this study was to determine the effects of supplementing quercetin (0.25, 0.50, 0.75mM) during the thawing and incubation of frozen-thawed boar semen on oocyte fertilization characteristics (n=400) and subsequent embryonic development (n=1340) at 48 and 144h for cleavage and blastocyst formation, respectively. Oocytes from aspired aspirated mature follicles (3-6mm diameter) were obtained from a local abattoir and matured in medium 199 for 40 to 44h at 38.5°C in an atmosphere of 5% CO2. Fertilization was performed using pooled frozen-thawed semen from 3 different boars, and co-incubation of the sperm (2×105 sperm mL−1) and oocytes (30 oocytes/well) lasted for 6 to 8h at 38.5°C in an atmosphere of 5% CO2. Data were analysed using ANOVA with the main effects including treatment, well and replicate. Chi-squared analysis was used to determine percentages of embryos reaching the different developmental stages for each treatment. There were no differences in penetration rates and male pronuclear formation between treatment groups; however, supplementation of 0.25 (18.18±10.63%), 0.50 (20.93±9.89%) and 0.75mM (18.07±12.02%) quercetin significantly decreased (P<0.05) polyspermic penetration rates compared with no supplementation (40.00±11.34%). Embryos produced from frozen-thawed boar sperm supplemented with 0.25 and 0.50mM quercetin had a significantly higher percentage (P<0.05) of embryos reaching the 2-cell stage of development by 48h after IVF (75.00±7.89%, 68.75±2.23%, respectively) compared with 0.75mM quercetin supplementation (64.62±3.88%) and no supplementation (62.97±4.11%). Supplementation of 0.25 (44.12±6.23%), 0.50 (43.75±7.02%) and 0.75mM (43.08±2.98%) quercetin to the sperm significantly increased (P<0.05) the percentage of embryos reaching the blastocyst stage of development by 144h after IVF compared with no supplementation (28.27±8.07%). These results indicate that supplementing frozen-thawed boar semen with quercetin decreases the incidence of polyspermic penetration and improves early embryonic development in pigs.
Collapse
|
8
|
Observation of B(s)(0) → J/ψ f1(1285) decays and measurement of the f1(1285) mixing angle. PHYSICAL REVIEW LETTERS 2014; 112:091802. [PMID: 24655242 DOI: 10.1103/physrevlett.112.091802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Indexed: 06/03/2023]
Abstract
Decays of B(s)(0) and B(0) mesons into J/ψ π+π-π+π- final states, produced in pp collisions at the LHC, are investigated using data corresponding to an integrated luminosity of 3 fb-1 collected with the LHCb detector. B(s)(0) → J/ψ f1(1285) decays are seen for the first time, and the branching fractions are measured. Using these rates, the f1(1285) mixing angle between strange and nonstrange components of its wave function in the qq structure model is determined to be ±(24.0-2.6-0.8+3.1+0.6)°. Implications on the possible tetraquark nature of the f1(1285) are discussed.
Collapse
|
9
|
Adsorption and diffusion of the antiparkinsonian drug amantadine in carbon nanotubes. MOLECULAR SIMULATION 2014. [DOI: 10.1080/08927022.2013.841908] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
10
|
Measurements of indirect CP asymmetries in D0 → K- K+ and D0 → π- π+ decays. PHYSICAL REVIEW LETTERS 2014; 112:041801. [PMID: 24580438 DOI: 10.1103/physrevlett.112.041801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Indexed: 06/03/2023]
Abstract
A study of indirect CP violation in D0 mesons through the determination of the parameter AΓ is presented using a data sample of pp collisions, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector and recorded at the center-of-mass energy of 7 TeV at the LHC. The parameter AΓ is the asymmetry of the effective lifetimes measured in decays of D0 and D0 mesons to the CP eigenstates K- K+ and π- π+. Fits to the data sample yield AΓ(KK)=(-0.35±0.62±0.12)×10(-3) and AΓ(ππ)=(0.33±1.06±0.14)×10(-3), where the first uncertainties are statistical and the second systematic. The results represent the world's best measurements of these quantities. They show no difference in AΓ between the two final states and no indication of CP violation.
Collapse
|
11
|
Measurement of CP violation in the phase space of B± → K+ K- π± and B± → π+ π- π± decays. PHYSICAL REVIEW LETTERS 2014; 112:011801. [PMID: 24483886 DOI: 10.1103/physrevlett.112.011801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Indexed: 06/03/2023]
Abstract
The charmless decays B± → K+ K- π± and B± → π+ π- π± are reconstructed in a data set of pp collisions with an integrated luminosity of 1.0 fb(-1) and center-of-mass energy of 7 TeV, collected by LHCb in 2011. The inclusive charge asymmetries of these modes are measured to be A(CP)(B± → K+ K- π±) = -0.141±0.040 (stat)±0.018 (syst)±0.007(J/ψ K±) and A(CP)(B± → π+ π- π±) = 0.117±0.021 (stat)±0.009 (syst)±0.007(J/ψ K±), where the third uncertainty is due to the CP asymmetry of the B± → J/ψK± reference mode. In addition to the inclusive CP asymmetries, larger asymmetries are observed in localized regions of phase space.
Collapse
|
12
|
Differences in the postgraduate medical training system in rheumatology between the United Kingdom and Japan. Mod Rheumatol 2014; 11:83-5. [DOI: 10.3109/s101650170051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
13
|
Measurement of D0-D0 mixing parameters and search for CP violation using D0 → K+ π- decays. PHYSICAL REVIEW LETTERS 2013; 111:251801. [PMID: 24483738 DOI: 10.1103/physrevlett.111.251801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Indexed: 06/03/2023]
Abstract
Measurements of charm mixing parameters from the decay-time-dependent ratio of D0 → K+ π- to D0 → K- π+ rates and the charge-conjugate ratio are reported. The analysis uses data, corresponding to 3 fb(-1) of integrated luminosity, from proton-proton collisions at 7 and 8 TeV center-of-mass energies recorded by the LHCb experiment. In the limit of charge-parity (CP ) symmetry, the mixing parameters are determined to be x'2=(5.5±4.9)×10(-5), y'=(4.8±1.0)×10(-3), and RD=(3.568±0.066)×10(-3). Allowing for CP violation, the measurement is performed separately for D0 and D0 mesons yielding AD=(-0.7±1.9)%, for the direct CP-violating asymmetry, and 0.75<|q/p|<1.24 at the 68.3% confidence level, for the parameter describing CP violation in mixing. This is the most precise determination of these parameters from a single experiment and shows no evidence for CP violation.
Collapse
|
14
|
Measurement of J/ ψ polarization in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2631. [PMID: 25814848 PMCID: PMC4370894 DOI: 10.1140/epjc/s10052-013-2631-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/15/2013] [Indexed: 05/28/2023]
Abstract
An angular analysis of the decay J/ψ→μ+μ- is performed to measure the polarization of prompt J/ψ mesons produced in pp collisions at [Formula: see text]. The dataset corresponds to an integrated luminosity of 0.37 fb-1 collected with the LHCb detector. The measurement is presented as a function of transverse momentum, pT, and rapidity, y, of the J/ψ meson, in the kinematic region 2
Collapse
|
15
|
Measurement of form-factor-independent observables in the decay B0→K(*0)μ(+)μ(-). PHYSICAL REVIEW LETTERS 2013; 111:191801. [PMID: 24266467 DOI: 10.1103/physrevlett.111.191801] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Indexed: 06/02/2023]
Abstract
We present a measurement of form-factor-independent angular observables in the decay B(0)→K*(892)(0)μ(+)μ(-). The analysis is based on a data sample corresponding to an integrated luminosity of 1.0 fb(-1), collected by the LHCb experiment in pp collisions at a center-of-mass energy of 7 TeV. Four observables are measured in six bins of the dimuon invariant mass squared q² in the range 0.1<q²<19.0 GeV²/c(4). Agreement with recent theoretical predictions of the standard model is found for 23 of the 24 measurements. A local discrepancy, corresponding to 3.7 Gaussian standard deviations is observed in one q² bin for one of the observables. Considering the 24 measurements as independent, the probability to observe such a discrepancy, or larger, in one is 0.5%.
Collapse
|
16
|
Observation of the decay B(c)(+) → B(s)(0)π+. PHYSICAL REVIEW LETTERS 2013; 111:181801. [PMID: 24237507 DOI: 10.1103/physrevlett.111.181801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 06/02/2023]
Abstract
The result of a search for the decay B(c)(+) → B(s)(0) π+ is presented, using the B(s)(0) → D(s)(-)π+ and B(s)(0) → J/ψ Ø channels. The analysis is based on a data sample of pp collisions collected with the LHCb detector, corresponding to an integrated luminosity of 1 fb(-1) taken at a center-of-mass energy of 7 TeV, and 2 fb(-1) taken at 8 TeV. The decay B(c)(+) → B(s)(0)π+ is observed with significance in excess of 5 standard deviations independently in both decay channels. The measured product of the ratio of cross sections and branching fraction is [σ(B(c)(+))/σ(B(s)(0))] × B(B(c)(+)→ B(s)(0)π+) = [2.37 ± 0.31 (stat)± 0.11 (syst)(-0.13)(+0.17)(τ(B)(c)(+)))] × 10(-3), in the pseudorapidity range 2<η(B)<5, where the first uncertainty is statistical, the second is systematic, and the third is due to the uncertainty on the B(c)(+) lifetime. This is the first observation of a B meson decaying to another B meson via the weak interaction.
Collapse
|
17
|
Measurement of the CP asymmetry in B(+)→K(+)μ(+)μ(-) decays. PHYSICAL REVIEW LETTERS 2013; 111:151801. [PMID: 24160590 DOI: 10.1103/physrevlett.111.151801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Indexed: 06/02/2023]
Abstract
A measurement of the CP asymmetry in B(+)→K(+)μ(+)μ(-) decays is presented using pp collision data, corresponding to an integrated luminosity of 1.0 fb(-1), recorded by the LHCb experiment during 2011 at a center-of-mass energy of 7 TeV. The measurement is performed in seven bins of μ(+)μ(-) invariant mass squared in the range 0.05<q2<22.00 GeV2/c4, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are corrected for using the B(+)→J/ψK(+) decay as a control mode. Averaged over all the bins, the CP asymmetry is found to be A(CP)=0.000±0.033 (stat)±0.005 (syst)±0.007 (J/ψK), where the third uncertainty is due to the CP asymmetry of the control mode. This is consistent with the standard model prediction.
Collapse
|
18
|
Search for the lepton-flavor-violating decays B(s)0→e(±)μ(∓) and B0→e(±)μ(∓). PHYSICAL REVIEW LETTERS 2013; 111:141801. [PMID: 24138232 DOI: 10.1103/physrevlett.111.141801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 06/02/2023]
Abstract
A search for the lepton-flavor-violating decays B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) is performed with a data sample, corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at √s=7 TeV, collected by the LHCb experiment. The observed number of B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be B(B(s)0→e(±)μ(∓))<1.1(1.4)×10(-8) and B(B0→e(±)μ(∓))<2.8(3.7)×10(-9) at 90% (95%) confidence level (C.L.). These limits are a factor of 20 lower than those set by previous experiments. Lower bounds on the Pati-Salam leptoquark masses are also calculated, M(LQ)(B(s)0→e(±)μ(∓))>101 TeV/c(2) and M(LQ)(B0→e(±)μ(∓))>126 TeV/c(2) at 95% C.L., and are a factor of 2 higher than the previous bounds.
Collapse
|
19
|
Observation of a resonance in B+ → K+ μ+ μ- decays at low recoil. PHYSICAL REVIEW LETTERS 2013; 111:112003. [PMID: 24074076 DOI: 10.1103/physrevlett.111.112003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 08/20/2013] [Indexed: 06/02/2023]
Abstract
A broad peaking structure is observed in the dimuon spectrum of B+ → K+ μ+ μ- decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with interference between the B+ → K+ μ+ μ- decay and a resonance and has a statistical significance exceeding six standard deviations. The mean and width of the resonance are measured to be 4191(-8)(+9) MeV/c2 and 65(-16)(+22) MeV/c2, respectively, where the uncertainties include statistical and systematic contributions. These measurements are compatible with the properties of the ψ(4160) meson. First observations of both the decay B+ → ψ(4160)K+ and the subsequent decay ψ(4160) → μ+ μ- are reported. The resonant decay and the interference contribution make up 20% of the yield for dimuon masses above 3770 MeV/c2. This contribution is larger than theoretical estimates.
Collapse
|
20
|
Precision measurement of the Λb(0) baryon lifetime. PHYSICAL REVIEW LETTERS 2013; 111:102003. [PMID: 25166658 DOI: 10.1103/physrevlett.111.102003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Indexed: 06/03/2023]
Abstract
The ratio of the Λb(0) baryon lifetime to that of the B(0) meson is measured using 1.0 fb(-1) of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The Λb(0) baryon is observed for the first time in the decay mode Λb(0)→J/ψpK-, while the B(0) meson decay used is the well known B(0)→J/ψπ+ K- mode, where the π+ K- mass is consistent with that of the K(*0)(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B(0) meson lifetime, the Λb(0) lifetime is found to be 1.482±0.018±0.012 ps. In both cases, the first uncertainty is statistical and the second systematic.
Collapse
|
21
|
Measurement of CP violation in the phase space of B±→K± π+ π- and B±→K± K+ K- decays. PHYSICAL REVIEW LETTERS 2013; 111:101801. [PMID: 25166651 DOI: 10.1103/physrevlett.111.101801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Indexed: 06/03/2023]
Abstract
The charmless decays B±→K± π+ π- and B±→K± K+ K- are reconstructed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected by LHCb in 2011. The inclusive charge asymmetries of these modes are measured as ACP(B±→K± π+ π-)=0.032±0.008 (stat)±0.004 (syst)±0.007(J/ψK±) and ACP(B±→K± K+ K-)=-0.043±0.009 (stat)±0.003 (syst)±0.007(J/ψK±), where the third uncertainty is due to the CP asymmetry of the B±→J/ψK± reference mode. The significance of ACP(B±→K± K+ K-) exceeds three standard deviations and is the first evidence of an inclusive CP asymmetry in charmless three-body B decays. In addition to the inclusive CP asymmetries, larger asymmetries are observed in localized regions of phase space.
Collapse
|
22
|
Measurement of the Bs(0)→μ+ μ- branching fraction and search for B(0)→μ+ μ- decays at the LHCb experiment. PHYSICAL REVIEW LETTERS 2013; 111:101805. [PMID: 25166655 DOI: 10.1103/physrevlett.111.101805] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 06/03/2023]
Abstract
A search for the rare decays Bs(0)→μ+ μ- and B(0)→μ+ μ- is performed at the LHCb experiment. The data analyzed correspond to an integrated luminosity of 1 fb(-1) of pp collisions at a center-of-mass energy of 7 TeV and 2 fb(-1) at 8 TeV. An excess of Bs(0)→μ+ μ- signal candidates with respect to the background expectation is seen with a significance of 4.0 standard deviations. A time-integrated branching fraction of B(Bs(0)→μ+ μ-)=(2.9(-1.0)(+1.1))×10(-9) is obtained and an upper limit of B(B(0)→μ+ μ-)<7.4×10(-10) at 95% confidence level is set. These results are consistent with the standard model expectations.
Collapse
|
23
|
First measurement of the CP-violating phase in Bs(0) → ϕϕ decays. PHYSICAL REVIEW LETTERS 2013; 110:241802. [PMID: 25165914 DOI: 10.1103/physrevlett.110.241802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Indexed: 06/03/2023]
Abstract
A first flavor-tagged measurement of the time-dependent CP-violating asymmetry in B(s)(0) → ϕϕ decays is presented. In this decay channel, the CP-violating weak phase arises due to CP violation in the interference between B(s)(0)-B(s)(0) mixing and the b → sss gluonic penguin decay amplitude. Using a sample of pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected at a center-of-mass energy of 7 TeV with the LHCb detector, 880 B(s)(0) → ϕϕ signal decays are obtained. The CP-violating phase is measured to be in the interval [-2.46,-0.76] rad at a 68% confidence level. The p value of the standard model prediction is 16%.
Collapse
|
24
|
Measurements of the branching fractions of [Formula: see text] decays. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2462. [PMID: 25814862 PMCID: PMC4370952 DOI: 10.1140/epjc/s10052-013-2462-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/16/2013] [Indexed: 06/04/2023]
Abstract
The branching fractions of the decay [Formula: see text] for different intermediate states are measured using data, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb experiment. The total branching fraction, its charmless component [Formula: see text] and the branching fractions via the resonant [Formula: see text] states ηc (1S) and ψ(2S) relative to the decay via a J/ψ intermediate state are [Formula: see text] Upper limits on the B+ branching fractions into the ηc (2S) meson and into the charmonium-like states X(3872) and X(3915) are also obtained.
Collapse
|
25
|
First observation of CP violation in the decays of B(s)0 mesons. PHYSICAL REVIEW LETTERS 2013; 110:221601. [PMID: 23767711 DOI: 10.1103/physrevlett.110.221601] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Indexed: 06/02/2023]
Abstract
Using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1) and collected by LHCb in 2011 at a center-of-mass energy of 7 TeV, we report the measurement of direct CP violation in B(s)(0)→K(-)π(+) decays, A(CP)(B(s)(0)→K(-)π(+)=0.27±0.04 (stat)±0.01 (syst), with significance exceeding 5 standard deviations. This is the first observation of CP violation in the decays of B(s)(0) mesons. Furthermore, we provide an improved determination of direct CP violation in B(0)→K(+)π(-) decays, A(CP)(B(0)→K(+)π(-)=-0.080±0.007 (stat)±0.003 (syst), which is the most precise measurement of this quantity to date.
Collapse
|
26
|
Determination of the X(3872) meson quantum numbers. PHYSICAL REVIEW LETTERS 2013; 110:222001. [PMID: 23767712 DOI: 10.1103/physrevlett.110.222001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Indexed: 06/02/2023]
Abstract
The quantum numbers of the X(3872) meson are determined to be J(PC)=1(++) based on angular correlations in B(+)→X(3872)K(+) decays, where X(3872)→π(+)π(-)J/ψ and J/ψ→μ(+)μ(-). The data correspond to 1.0 fb(-1) of pp collisions collected by the LHCb detector. The only alternative assignment allowed by previous measurements J(PC)=2(-+) is rejected with a confidence level equivalent to more than 8 Gaussian standard deviations using a likelihood-ratio test in the full angular phase space. This result favors exotic explanations of the X(3872) state.
Collapse
|
27
|
Search for rare B(0)((s))→μ(+)μ(-)μ(+)μ(-) decays. PHYSICAL REVIEW LETTERS 2013; 110:211801. [PMID: 23745860 DOI: 10.1103/physrevlett.110.211801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Indexed: 06/02/2023]
Abstract
A search for the decays B(0)((s))→μ(+)μ(-)μ(+)μ(-) and B(0)→μ(+)μ(-)μ(+)μ(-) is performed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(B(s)(0)→μ(+)μ(-)μ(+)μ(-))<1.6(1.2)×10(-8) and B(B(0)→μ(+)μ(-)μ(+)μ(-))<6.6(5.3)×10(-9) at 95% (90%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the B((s))(0) meson to decay into a scalar (S) and pseudoscalar particle (P), where S and P have masses of 2.5 GeV/c and 214.3 MeV/c, respectively, both resonances decay into μ(+)μ(-). The branching fraction limits for these decays are B(B(s)(0)→SP)<1.6(1.2)×10(-8) and B(B(0)→SP)<6.3(5.1)×10(-9) at 95% (90%) confidence level.
Collapse
|
28
|
Measurement of the forward energy flow in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2421. [PMID: 25814858 PMCID: PMC4370758 DOI: 10.1140/epjc/s10052-013-2421-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/22/2013] [Indexed: 05/26/2023]
Abstract
The energy flow created in pp collisions at [Formula: see text] is studied within the pseudorapidity range 1.9<η<4.9 with data collected by the LHCb experiment. The measurements are performed for inclusive minimum-bias interactions, hard scattering processes and events with an enhanced or suppressed diffractive contribution. The results are compared to predictions given by Pythia-based and cosmic-ray event generators, which provide different models of soft hadronic interactions.
Collapse
|
29
|
Measurement of the Λ(b)(0), Ξ (b)(-), and Ω(b((-) Baryon masses. PHYSICAL REVIEW LETTERS 2013; 110:182001. [PMID: 23683191 DOI: 10.1103/physrevlett.110.182001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Indexed: 06/02/2023]
Abstract
Bottom baryons decaying to a J/ψ meson and a hyperon are reconstructed using 1.0 fb(-1) of data collected in 2011 with the LHCb detector. Significant Λ(b)(0) → J/ψΛ, Ξ(b((-) → J/ψΞ(-) and Ω(b)(-) → J/ψΩ(-) signals are observed and the corresponding masses are measured to be M(Λ(b)(0))=5619.53 ± 0.13(stat.) ± 0.45(syst.) MeV/c(2), M(Ξ(b)(-)) = 5795.8 ± 0.9(stat.) ± 0.4(syst.) MeV/c(2), M(Ω(b)(-)) = 6046.0 ± 2.2(stat.) ± 0.5(syst.) MeV/c(2) , while the differences with respect to the Λ(b)(0) mass are M(Ξ(b)(-))-M(Λ(b)(0))=176.2 ± 0.9(stat.) ± 0.1(syst.) MeV/c(2), M(Ω(b)(-))-M(Λ(b)(0))=426.4 ± 2.2(stat.) ± 0.4(syst.) MeV/c(2). These are the most precise mass measurements of the Λ(b)(0), Ξ(b)(-) and Ω(b)(-) baryons to date. Averaging the above Λ(b)(0) mass measurement with that published by LHCb using 35 pb(-1) of data collected in 2010 yields M(Λ(b)(0)) = 5619.44 ± 0.13(stat.)± 0.38(syst.) MeV/c(2).
Collapse
|
30
|
First observation of the decay Bs2*(5840)(0)→B*+ K- and studies of excited Bs(0) mesons. PHYSICAL REVIEW LETTERS 2013; 110:151803. [PMID: 25167250 DOI: 10.1103/physrevlett.110.151803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 02/11/2013] [Indexed: 06/03/2023]
Abstract
The properties of the orbitally excited (L=1) Bs(0) states are studied by using 1.0 fb(-1) of pp collisions at sqrt[s]=7 TeV collected with the LHCb detector. The first observation of the Bs2*(5840)(0) meson decaying to B*+ K- is reported, and the corresponding branching fraction measured relative to the B+ K- decay mode. The Bs1(5830)(0)→B*+ K- decay is observed as well. The width of the Bs2*(5840)(0) state is measured for the first time, and the masses of the two states are determined with the highest precision to date. The observation of the Bs2*(5840)(0)→B*+ K- decay favors the spin-parity assignment J(P)=2+ for the Bs2*(5840)(0) meson. In addition, the most precise measurement of the mass difference m(B*+)-m(B+)=45.01±0.30(stat)±0.23(syst) MeV/c(2) is obtained.
Collapse
|
31
|
Abstract
We report a measurement of the time-dependent ratio of D(0) → K(+) π- to D(0) → K(-) π(+) decay rates in D(*+)-tagged events using 1.0 fb(-1) of integrated luminosity recorded by the LHCb experiment. We measure the mixing parameters x('2) = (-0.9 ± 1.3) × 10(-4), y' = (7.2 ± 2.4) × 10(-3), and the ratio of doubly-Cabibbo-suppressed to Cabibbo-favored decay rates R(D) = (3.52 ± 0.15) × 10^{-3}, where the uncertainties include statistical and systematic sources. The result excludes the no-mixing hypothesis with a probability corresponding to 9.1 standard deviations and represents the first observation of D0-D0 oscillations from a single measurement.
Collapse
|
32
|
Measurement of the CP asymmetry in B(0)→K(*0)μ(+)μ(-) decays. PHYSICAL REVIEW LETTERS 2013; 110:031801. [PMID: 23373912 DOI: 10.1103/physrevlett.110.031801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Indexed: 06/01/2023]
Abstract
A measurement of the CP asymmetry in B(0)→K(*0)μ(+)μ(-) decays is presented, based on 1.0 fb(-1) of pp collision data recorded by the LHCb experiment during 2011. The measurement is performed in six bins of invariant mass squared of the μ(+)μ(-) pair, excluding the J/ψ and ψ(2S) resonance regions. Production and detection asymmetries are removed using the B(0)→J/ψK(*0) decay as a control mode. The integrated CP asymmetry is found to be -0.072±0.040(stat)±0.005(syst), consistent with the standard model.
Collapse
|
33
|
First evidence for the decay B(s)(0)→μ+ μ-. PHYSICAL REVIEW LETTERS 2013; 110:021801. [PMID: 23383888 DOI: 10.1103/physrevlett.110.021801] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Indexed: 06/01/2023]
Abstract
A search for the rare decays B(s)(0)→μ+ μ- and B(0)→μ+ μ- is performed with data collected in 2011 and 2012 with the LHCb experiment at the Large Hadron Collider. The data samples comprise 1.1 fb(-1) of proton-proton collisions at sqrt[s]=8 TeV and 1.0 fb(-1) at sqrt[s]=7 TeV. We observe an excess of B(s)(0)→μ+ μ- candidates with respect to the background expectation. The probability that the background could produce such an excess or larger is 5.3×10(-4) corresponding to a signal significance of 3.5 standard deviations. A maximum-likelihood fit gives a branching fraction of B(B(s)(0)→μ+ μ-)=(3.2(-1.2)(+1.5))×10(-9), where the statistical uncertainty is 95% of the total uncertainty. This result is in agreement with the standard model expectation. The observed number of B(0)→μ+ μ- candidates is consistent with the background expectation, giving an upper limit of B(B(0)→μ+ μ-)<9.4×10(-10) at 95% confidence level.
Collapse
|
34
|
Measurements of B(c)+ production and mass with the B(c)+ → J/ψπ+ decay. PHYSICAL REVIEW LETTERS 2012; 109:232001. [PMID: 23368183 DOI: 10.1103/physrevlett.109.232001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Indexed: 06/01/2023]
Abstract
Measurements of B(c)(+) production and mass are performed with the decay mode B(c)(+)→J/ψπ(+) using 0.37 fb(-1) of data collected in pp collisions at √[s]=7 TeV by the LHCb experiment. The ratio of the production cross section times branching fraction between the B(c)(+)→J/ψπ(+) and the B(+)→J/ψK(+) decays is measured to be (0.68±0.10(stat)±0.03(syst)±0.05(lifetime))% for B(c)(+) and B(+) mesons with transverse momenta p(T)>4 GeV/c and pseudorapidities 2.5<η<4.5. The B(c)(+) mass is directly measured to be 6273.7±1.3(stat)±1.6(syst) MeV/c(2), and the measured mass difference with respect to the B(+) meson is M(B(c)(+))-M(B(+))=994.6±1.3(stat)±0.6(syst) MeV/c(2).
Collapse
|
35
|
Abstract
Using pp collision data corresponding to 1.0 fb(-1) integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λ(b)(0)π(+)π(-) spectrum with masses 5911.97±0.12(stat)±0.02(syst)±0.66(Λ(b)(0) mass) MeV/c(2) and 5919.77±0.08(stat)±0.02(syst)±0.66(Λ(b)(0) mass) MeV/c(2). The significances of the observations are 5.2 and 10.2 standard deviations, respectively. These states are interpreted as the orbitally excited Λ(b)(0) baryons, Λ(b)(*0)(5912) and Λ(b)(*0)(5920).
Collapse
|
36
|
Measurement of the B¯(s)(0) effective lifetime in the J/ψf0(980) final state. PHYSICAL REVIEW LETTERS 2012; 109:152002. [PMID: 23102295 DOI: 10.1103/physrevlett.109.152002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Indexed: 06/01/2023]
Abstract
The effective lifetime of the B ¯(s)(0) meson in the decay mode B¯(s)(0)→J/ψf(0)(980) is measured using 1.0 fb(-1) of data collected in pp collisions at √s=7 TeV with the LHCb detector. The result is 1.700±0.040±0.026 ps, where the first uncertainty is statistical and the second systematic. As the final state is CP-odd, and CP violation in this mode is measured to be small, the lifetime measurement can be translated into a measurement of the decay width of the heavy B¯(s)(0) mass eigenstate, Γ(H)=0.588±0.014±0.009 ps(-1).
Collapse
|
37
|
Observation of B0→D¯(0)K(+)K(-) and evidence for B(s)(0)→D¯(0)K(+)K(-). PHYSICAL REVIEW LETTERS 2012; 109:131801. [PMID: 23030081 DOI: 10.1103/physrevlett.109.131801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Indexed: 06/01/2023]
Abstract
The first observation of the decay B0→D¯(0)K(+)K(-) is reported from an analysis of 0.62 fb(-1) of pp collision data collected with the LHCb detector. Its branching fraction is measured relative to that of the topologically similar decay B(0)→D ¯(0)π(+)π(-) to be (B(B(0)→D¯(0)K(+)K(-))/B(B(0)→D¯(0)π(+)π(-))=0.056±0.011±0.007,where the first uncertainty is statistical and the second is systematic. The significance of the signal is 5.8σ. Evidence, with 3.8σ significance, for B(s)(0)→D¯(0)K(+)K(-) decays is also presented. The relative branching fraction is measured to be B(B(s)(0)→D¯(0)K(+)K(-))/B(B(0)→D¯(0)K(+)K(-))=0.90±0.27±0.20. These channels are of interest to study the mechanisms behind hadronic B decays, and open new possibilities for CP violation analyses with larger data sets.
Collapse
|
38
|
Cardiorespiratory and metabolic responses associated with children’s physical activity during self-paced games. Can J Physiol Pharmacol 2012; 90:1269-76. [DOI: 10.1139/y2012-106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to explore the possibility of identifying clusters of children’s games based on estimated energy expenditures and (or) intensity when performed in a guided active play format. The study also investigated whether the identified active play game clusters were repeatable when the games were performed on different days. Children (9.7 ± 1.1 years; n = 12) were assessed for oxygen consumption, heart rate, energy expenditure (EE), and metabolic equivalent (MET) on a treadmill (at 4, 6, and 8 km·h–1(0% grade)). HR and ActiGraph GT1M accelerometer (ACC) generated linear regression equations were used to estimate EE. The ACC (3 s epochs) were used for estimating METs in assigning percent time at medium–vigorous physical activity (%MVPA) of 10 self-paced games. The results showed a consistent range of EEs (ACC-equation) from 13.57 kcal·(5 min)–1to 25.00 kcal·(5 min)–1(p < 0.05); EEs (HR-equation) from 29.72 to 42.49 kcal·(5 min)–1(p < 0.05); and %MVPA from 10% to 34% (p < 0.05) (from ACC equations) across all games. These were reproducible from day to day (p > 0.05). This study confirms the existence of active play children’s game clusters that might be useful in formatting guided active play in a dose–response manner for children.
Collapse
|
39
|
Measurement of relative branching fractions of B decays to ψ(2 S) and J/ ψ mesons. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2012; 72:2118. [PMID: 25814846 PMCID: PMC4370872 DOI: 10.1140/epjc/s10052-012-2118-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 07/06/2012] [Indexed: 06/04/2023]
Abstract
The relative rates of B-meson decays into J/ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ([Formula: see text]) are measured to be [Formula: see text] where the third uncertainty is from the ratio of the ψ(2S) and J/ψ branching fractions to μ+μ-.
Collapse
|
40
|
Measurement of ψ(2 S) meson production in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2012; 72:2100. [PMID: 25814845 PMCID: PMC4370818 DOI: 10.1140/epjc/s10052-012-2100-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/22/2012] [Indexed: 05/28/2023]
Abstract
The differential cross-section for the inclusive production of ψ(2S) mesons in pp collisions at [Formula: see text] has been measured with the LHCb detector. The data sample corresponds to an integrated luminosity of 36 pb-1. The ψ(2S) mesons are reconstructed in the decay channels ψ(2S)→μ+μ- and ψ(2S)→J/ψπ+π-, with the J/ψ meson decaying into two muons. Results are presented both for promptly produced ψ(2S) mesons and for those originating from b-hadron decays. In the kinematic range pT(ψ(2S))≤16 GeV/c and 2<y(ψ(2S))≤4.5 we measure [Formula: see text] where the last uncertainty on the prompt cross-section is due to the unknown ψ(2S) polarization. Recent QCD calculations are found to be in good agreement with our measurements. Combining the present result with the LHCb J/ψ measurements we determine the inclusive branching fraction [Formula: see text] where the last uncertainty is due to the [Formula: see text], [Formula: see text] and [Formula: see text] branching fraction uncertainties.
Collapse
|
41
|
First observation of the decay B(c)+ → J/ψπ(+) π- π+. PHYSICAL REVIEW LETTERS 2012; 108:251802. [PMID: 23004586 DOI: 10.1103/physrevlett.108.251802] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Indexed: 06/01/2023]
Abstract
The decay B(c)(+) → J/ψπ(+) π(-) π(+) is observed for the first time, using 0.8 fb(-1) of pp collisions at sqrt[s] = 7 TeV collected by the LHCb experiment. The ratio of branching fractions B(B(c)(+) → J/ψπ(+) π(-) π(+))/B(B(c)(+)→J/ψπ^{+}) is measured to be 2.41 ± 0.30 ± 0.33, where the first uncertainty is statistical and the second is systematic. The result is in agreement with theoretical predictions.
Collapse
|
42
|
Determination of the sign of the decay width difference in the B(s)(0) system. PHYSICAL REVIEW LETTERS 2012; 108:241801. [PMID: 23004259 DOI: 10.1103/physrevlett.108.241801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Indexed: 06/01/2023]
Abstract
The interference between the K+ K- S-wave and P-wave amplitudes in B(s)(0) → J/ψK+ K- decays with the K+ K- pairs in the region around the ϕ(1020) resonance is used to determine the variation of the difference of the strong phase between these amplitudes as a function of K+ K- invariant mass. Combined with the results from our CP asymmetry measurement in B(s)(0) → J/ψϕ decays, we conclude that the B(s)(0) mass eigenstate that is almost CP = +1 is lighter and decays faster than the mass eigenstate that is almost CP = -1. This determines the sign of the decay width difference ΔΓ(s) ≡ Γ(L) - Γ(H) to be positive. Our result also resolves the ambiguity in the past measurements of the CP violating phase ϕ(s) to be close to zero rather than π. These conclusions are in agreement with the standard model expectations.
Collapse
|
43
|
Strong constraints on the rare decays B(s)(0) → μ+ μ- and B0 → μ+ μ-. PHYSICAL REVIEW LETTERS 2012; 108:231801. [PMID: 23003947 DOI: 10.1103/physrevlett.108.231801] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Indexed: 06/01/2023]
Abstract
A search for B(s)(0) → μ+ μ- and B0 → μ+ μ decays is performed using 1.0 fb(-1) of pp collision data collected at sqrt[s] = 7 TeV with the LHCb experiment at the Large Hadron Collider. For both decays, the number of observed events is consistent with expectation from background and standard model signal predictions. Upper limits on the branching fractions are determined to be B(B(s)(0) → μ+ μ-) < 4.5(3.8)×10(-9) and B(B0 → μ+ μ-) < 1.0(0.81)×10(-9) at 95% (90%) confidence level.
Collapse
|
44
|
Opposite-side flavour tagging of B mesons at the LHCb experiment. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2012; 72:2022. [PMID: 25814835 PMCID: PMC4371096 DOI: 10.1140/epjc/s10052-012-2022-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/26/2012] [Indexed: 05/28/2023]
Abstract
The calibration and performance of the opposite-side flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B+→J/ψK+, B0→J/ψK∗0 and B0→D∗-μ+νμ decay modes with 0.37 fb-1 of data collected in pp collisions at [Formula: see text] during the 2011 physics run. The opposite-side tagging power is determined in the B+→J/ψK+ channel to be (2.10±0.08±0.24) %, where the first uncertainty is statistical and the second is systematic.
Collapse
|
45
|
Measurement of ϒ production in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2012; 72:2025. [PMID: 25814836 PMCID: PMC4370820 DOI: 10.1140/epjc/s10052-012-2025-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/20/2012] [Indexed: 05/28/2023]
Abstract
The production of ϒ(1S), ϒ(2S) and ϒ(3S) mesons in proton-proton collisions at the centre-of-mass energy of [Formula: see text] is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The ϒ mesons are reconstructed in the decay mode ϒ→μ+μ- and the signal yields are extracted from a fit to the μ+μ- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the ϒ transverse momentum pT and rapidity y, over the range pT <15 GeV/c and 2.0
Collapse
|
46
|
First evidence of direct CP violation in charmless two-body decays of Bs0 mesons. PHYSICAL REVIEW LETTERS 2012; 108:201601. [PMID: 23003138 DOI: 10.1103/physrevlett.108.201601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Indexed: 06/01/2023]
Abstract
Using a data sample corresponding to an integrated luminosity of 0.35 fb-1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs0} mesons to K±π∓ pairs, ACP(Bs0→Kπ)=0.27±0.08(stat)±0.02(syst), with a significance of 3.3σ. Furthermore, we report the most precise measurement of CP violation in the decays of B0 mesons to K±π∓ pairs, ACP(B0→Kπ)=-0.088±0.011(stat)±0.008(syst), with a significance exceeding 6σ.
Collapse
|
47
|
Differential branching fraction and angular analysis of the decay B0 → K*0 μ+ μ-. PHYSICAL REVIEW LETTERS 2012; 108:181806. [PMID: 22681061 DOI: 10.1103/physrevlett.108.181806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Indexed: 06/01/2023]
Abstract
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.
Collapse
|
48
|
First observation of the decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-). PHYSICAL REVIEW LETTERS 2012; 108:161801. [PMID: 22680708 DOI: 10.1103/physrevlett.108.161801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Indexed: 06/01/2023]
Abstract
First observations of the Cabibbo-suppressed decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B(B(0) → D(+)K(-)π(+)π(-))/B(B(0) → D(+)π(-)π(+)π(-))=(5.9±1.1±0.5)×10(-2) and B(B(-) → D(0)K(-)π(+)π(-))/B(B(-) → D(0)π(-)π(+)π(-))=(9.4±1.3±0.9)×10(-2), where the uncertainties are statistical and systematic, respectively. The B(-) → D(0)K(-)π(+)π(-) decay is particularly interesting, as it can be used in a similar way to B(-) → D(0)K(-) to measure the Cabibbo-Kobayashi-Maskawa phase γ.
Collapse
|
49
|
Observation of B(s)(0) → J/ψf(2)'(1525) in J/ψK+ K- final states. PHYSICAL REVIEW LETTERS 2012; 108:151801. [PMID: 22587241 DOI: 10.1103/physrevlett.108.151801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Indexed: 05/31/2023]
Abstract
The decay B(s)(0) → J/ψK+ K- is investigated using 0.16 fb(-1) of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/ψϕ channel is well known, final states at higher K+ K- masses have not previously been studied. In the K+ K- mass spectrum we observe a significant signal in the f(2)'(1525) region as well as a nonresonant component. After subtracting the nonresonant component, we find B(B(s)(0) → J/ψf(2)'(1525))/B(B(s)(0) → J/ψϕ) = (26.4 ± 2.7 ± 2.4)%.
Collapse
|
50
|
Evidence for CP violation in time-integrated D0→h(-)h(+) decay rates. PHYSICAL REVIEW LETTERS 2012; 108:111602. [PMID: 22540460 DOI: 10.1103/physrevlett.108.111602] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Indexed: 05/31/2023]
Abstract
A search for time-integrated CP violation in D(0)→h(-)h(+) (h=K, π) decays is presented using 0.62 fb(-1) of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the D(*+)→D(0)π(+) and D(*-)→D[over ¯](0)π(-) decay chains. The difference in CP asymmetry between D(0)→K(-)K(+) and D(0)→π(-)π(+), ΔA(CP)≡A(CP)(K(-)K(+))-A(CP)(π(-)π(+)), is measured to be [-0.82±0.21(stat)±0.11(syst)]%. This differs from the hypothesis of CP conservation by 3.5 standard deviations.
Collapse
|