37,813 research outputs found
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Measurement of CP observables in B-+/- -> D(*)K-+/- and B-+/- -> D(*)pi(+/-) decays
No full textMeasurements of CP observables in B-+/- -> D(*)K-+/- and B-+/- -> D(*)pi(+/-) decays are presented, where D(*) indicates a neutral Dor D* meson that is an admixture of D(*)(0) and (D) over bar(*)(0) states. Decays of the D* meson to the D pi(0)and D gamma final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the Bcandidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K-+/-pi(-/+), K+K- and pi(+)pi(-) final states. The analysis uses a sample of charged Bmesons produced in ppcollisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0fb- 1taken at centre- of- mass energies of root s = 7, 8 and 13 TeV, respectively. The study of B-perpendicular to -> D*K-perpendicular to and B-perpendicular to -> D*pi(perpendicular to) decays using a partial reconstruction method is the first of its kind, while the measurement of B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays is an update of previous LHCb measurements. The B-+/- -> DK +/- results are the most precise to date. (c) 2017 The Author. Published by Elsevier B. V
Measurement of b-hadron masses
No full textMeasurements of b-hadron masses are performed with the exclusive decay modes B +→J/ψK +, B 0→J/ψK +, B0→J/ψKS0, Bs0→J/ψφ and Λb0→J/ψΛ using an integrated luminosity of 35pb -1 collected in pp collisions at a centre-of-mass energy of 7 TeV by the LHCb experiment. The momentum scale is calibrated with J/ψ→μ +μ - decays and verified to be known to a relative precision of 2 ×10 -4 using other two-body decays. The results are more precise than previous measurements, particularly in the case of the Bs0 and Λb0 masses
Measurement of the fragmentation fraction ratio fs/fd and its dependence on B meson kinematics
No full textThe relative production rate of B0s and B 0 mesons is determined with the hadronic decays B0s→D−sπ+ and B 0 → D − K +. The measurement uses data corresponding to 1.0 fb−1 of pp collisions at a centre-of-mass energy of s√=7 TeV recorded in the forward region with the LHCb experiment. The ratio of production rates, f s /f d , is measured to be 0.238 ± 0.004 ± 0.015 ± 0.021, where the first uncertainty is statistical, the second systematic, and the third theoretical. This is combined with a previous LHCb measurement to obtain f s /f d = 0.256 ± 0.020. The dependence of f s /f d on the transverse momentum and pseudorapidity of the B meson is determined using the decays B0s→D−sπ+ and B 0 → D −π+. There is evidence for a decrease with increasing transverse momentum, whereas the ratio remains constant as a function of pseudorapidity. In addition, the ratio of branching fractions of the decays B 0 → D − K + and B 0 → D −π+ is measured to be 0.0822 ± 0.0011 (stat) ± 0.0025 (syst)
Measurement of the B0–B0 oscillation frequency Δmd with the decays B0→D−π+ and B0→ J/ψK∗0
No full textThe B
0
–B
0
oscillation frequency Δmd is measured by the LHCb experiment using a dataset corresponding
to an integrated luminosity of 1.0 fb−1
of proton–proton collisions at √
s = 7 TeV, and is found to be
Δmd
=0.5156±0.0051 (stat.)±0.0033 (syst.) ps−1
. The measurement is based on results from analyses
of the decays B
0
→ D
−π
+ (D
−
→ K
+π
−π
−) and B
0
→ J/ψK
∗0
(J/ψ →μ
+μ
−,K
∗0
→ K
+π
−) and
their charge conjugated modes
D-wave charmonium production in B decays
No full textThe calculation of D-wave charmonium production rates in B meson decays under the NRQCD factorization formalism is presented. We find that the inclusion of the color-octet contributions permits us to detect the D-wave charmonium states in B decays at present experimental facilities. The same amount of signals of the 2(--) D-wave state as that of psi' could be observed at CERN LEP and CESR. We also predict that the relative production rates for four D-wave states are delta(c): delta(1)(c) : delta(2)(c): delta(3)(c) = 2.5:3:5:7, where delta(c), delta(1)(c), delta(2)(c), delta(3)(c) represent, respectively, the 2(-+), 1(--), 2(--), 3(--) states.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)17ARTICLE1329-3345
Inclusive decays B->DX and B->D*X
No full textComplete Author List: Gibbons L, Johnson SD, Kwon Y, Roberts S, Thorndike EH, Jessop CP, Lingel K, Marsiske H, Perl ML, Schaffner SF, Ugolini D, Wang R, Zhou X, Coan TE, Fadeyev V, Korolkov I, Maravin Y, Narsky I, Shelkov V, Staeck J, Stroynowski R, Volobouev I, Ye J, Artuso M, Efimov A, Frasconi F, Gao M, Goldberg M, He D, Kopp S, Horwitz N, Moneti GC, Mountain R, Mukhin Y, Schuh S, Skwarnicki T, Stone S, Thulasidas M, Viehhauser G, Xing X, Bartelt J, Csorna SE, Jain V, Marka S, Freyberger A, Godang R, Kinoshita K, Lai IC, Pomianowski P, Schrenk S, Bonvicini G, Cinabro D, Greene R, Perera LP, Barish B, Chadha M, Chan S, Eigen G, Miller JS, OGrady C, Schmidtler M, Urheim J, Weinstein AJ, Wurthwein F, Asner DM, Bliss DW, Brower WS, Masek G, Paar HP, Sharma V, Gronberg J, Kutschke R, Lange DJ, Menary S, Morrison RJ, Nelson HN, Nelson TK, Qiao C, Richman JD, Roberts D, Ryd A, Witherell MS, Balest R, Behrens BH, Cho K, Ford WT, Park H, Rankin P, Roy J, Smith JG, Alexander JP, Bebek C, Berger BE, Berkelman K, Bloom K, Cassel DG, Cho HA, Coffman DM, Crowcroft DS, Dickson M, Drell PS, Ecklund KM, Ehrlich R, Elia R, Foland AD, Gaidarev P, Gittelman B, Gray SW, Hartill DL, Heltsley BK, Kandaswamy J, Katayama N, Kim PC, Kreinick DL, Lee T, Liu Y, Ludwig GS, Masui J, Mevissen J, Mistry NB, Ng CR, Nordberg E, Ogg M, Patterson JR, Peterson D, Riley D, Soffer A, Ward C, Athanas M, Avery P, Jones CD, Lohner M, Prescott C, Yang S, Yelton J, Zheng J, Brandenburg G, Briere RA, Gao YS, Kim DYJ, Wilson R, Yamamoto H, Browder TE, Li F, Li Y, Rodriguez JL, Bergfeld T, Eisenstein BI, Ernst J, Gladding GE, Gollin GD, Hans RM, Johnson E, Karliner I, Marsh MA, Palmer M, Selen M, Thaler JJ, Edwards KW, Bellerive A, Janicek R, MacFarlane DB, McLean KW, Patel PM, Sadoff AJ, Ammar R, Baringer P, Bean A, Besson D, Coppage D, Darling C, Davis R, Hancock N, Kotov S, Kravchenko I, Kwak N, Anderson S, Kubota Y, Lattery M, ONeill JJ, Patton S, Poling R, Riehle T, Savinov V, Smith A, Alam MS, Athar SB, Ling Z, Mahmood AH, Severini H, Timm S, Wappler F, Anastassov A, Blinov S, Duboscq JE, Fisher KD, Fujino D, Fulton R, Gan KK, Hart T, Honscheid K, Kagan H, Kass R, Lee J, Spencer MB, Sung M, Undrus A, Wanke R, Wolf A, Zoeller MM, Nemati B, Richichi SJ, Ross WR, Skubic P, Wood M, Bishai M, Fast J, Gerndt E, Hinson JW, Menon N, Miller DH, Shibata EI, Shipsey IPJ, Yurko M</p
A pre-post test evaluation of the impact of the PELICAN MDT-TME Development Programme on the working lives of colorectal cancer team members
No full textBackground: the PELICAN Multidisciplinary Team Total Mesorectal Excision (MDT-TME) Development Programme aimed to improve clinical outcomes for rectal cancer by educating colorectal cancer teams in precision surgery and related aspects of multidisciplinary care. The Programme reached almost all colorectal cancer teams across England. We took the opportunity to assess the impact of participating in this novel team-based Development Programme on the working lives of colorectal cancer team members.Methods: the impact of participating in the programme on team members' self-reported job stress, job satisfaction and team performance was assessed in a pre-post course study. 333/568 (59%) team members, from the 75 multidisciplinary teams who attended the final year of the Programme, completed questionnaires pre-course, and 6-8 weeks post-course.Results: across all team members, the main sources of job satisfaction related to working in multidisciplinary teams; whilst feeling overloaded was the main source of job stress. Surgeons and clinical nurse specialists reported higher levels of job satisfaction than team members who do not provide direct patient care, whilst MDT coordinators reported the lowest levels of job satisfaction and job stress. Both job stress and satisfaction decreased after participating in the Programme for all team members. There was a small improvement in team performance.Conclusions: participation in the Development Programme had a mixed impact on the working lives of team members in the immediate aftermath of attending. The decrease in team members' job stress may reflect the improved knowledge and skills conferred by the Programme. The decrease in job satisfaction may be the consequence of being unable to apply these skills immediately in clinical practice because of a lack of required infrastructure and/or equipment. In addition, whilst the Programme raised awareness of the challenges of teamworking, a greater focus on tackling these issues may have improved working lives furthe
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
No full textAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
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