Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+

We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D^+ and D^+_s mesons to final states of the form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1 at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^- pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6, B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6, B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5, B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x 10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS

Clinical course and prognosis of the lymphoproliferative disease of granular lymphocytes. A multicenter study.

Lymphoproliferative disease of granular lymphocytes (LDGL) is a recently recognized, relatively rare atypical lymphocytosis characterized by the presence of over 2000 lymphocytes with cytoplasmic azurophilic granules/mm3 in the peripheral blood. The clinical course is heterogeneous, varying from spontaneous regression to progressive, malignant disease. As a consequence, clinical intervention is not standardized. In a worldwide multicenter study, the authors observed 151 patients with LDGL for a mean follow-up time of 29 months. Forty-three patients were asymptomatic at the time of diagnosis. In the remaining cases, clinical symptoms included fever (41 cases), infections (58), neutropenia (47), anemia (17), and thrombocytopenia (12). In 69 cases, LDGL coexisted with an associated disease. Most patients had a nonprogressive clinical course despite the presence of severe symptoms. In 19 patients, death related to LDGL occurred within 48 months. The authors investigated which features at diagnosis were significantly associated with increased mortality. In the univariate analysis, lymph node and liver enlargement, fever at presentation, skin infiltration, a low (less than or equal to 5000/mm3) or high (greater than 20,000/mm3) peripheral leukocyte count, relatively low (less than or equal to 3000) or high (greater than 7000/mm3) absolute peripheral granular lymphocyte (GL) count, and a low (less than or equal to 15%) percentage of HNK-1-positive cells were found to be predictors of increased mortality. In the multivariate analysis, significant independent predictors were fever at diagnosis, a low (less than or equal to 15%) percentage of HNK-1-positive peripheral blood mononuclear cells (PBMC) and a relatively low (less than or equal to 3000) GL count. These results showed that about 25% of the patients with LDGL were diagnosed after a routine blood count and had no clinical symptoms. The remaining patients were symptomatic, with some experiencing a fatal clinical course. The author's analysis of the significant prognostic features of LDGL may help in understanding the heterogeneous nature of this syndrom

Search for CP violation in D+→K−K+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

A model-independent search for direct CP violation in the Cabibbo suppressed decay $D^+ \to K^- K^+\pi^+$ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb$^{-1}$. The normalized Dalitz plot distributions for $D^+$ and $D^-$ are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

First observation of Bs -> D_{s2}^{*+} X mu nu decays

Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays Bs -> Ds+ X mu nu and Bs -> D0 K+ X mu nu are detected. Two structures are observed in the D0 K+ mass spectrum at masses consistent with the known D^+_{s1}(2536) and $D^{*+}_{s2}(2573) mesons. The measured branching fractions relative to the total Bs semileptonic rate are B(Bs -> D_{s2}^{*+} X mu nu)/B(Bs -> X mu nu)= (3.3\pm 1.0\pm 0.4)%, and B(Bs -> D_{s1}^+ X munu)/B(Bs -> X mu nu)= (5.4\pm 1.2\pm 0.5)%, where the first uncertainty is statistical and the second is systematic. This is the first observation of the D_{s2}^{*+} state in Bs decays; we also measure its mass and width.Comment: 8 pages 2 figures. Published in Physics Letters

First observation of the decay Bˉs0→D0K∗0\bar{B}^0_s \to D^0 K^{*0} and a measurement of the ratio of branching fractions B(Bˉs0→D0K∗0)B(Bˉ0→D0ρ0)\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)}

The first observation of the decay $\bar{B}^0_s \to D^0 K^{*0}$ using $pp$ data collected by the LHCb detector at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb$^{-1}$, is reported. A signal of $34.4 \pm 6.8$ events is obtained and the absence of signal is rejected with a statistical significance of more than nine standard deviations. The $\bar{B}^0_s \to D^0 K^{*0}$ branching fraction is measured relative to that of $\bar{B}^0 \to D^0 \rho^0$: $\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)} = 1.48 \pm 0.34 \pm 0.15 \pm 0.12$, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the $B^0$ and $B^0_s$ hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269

Measurement of the eta b(1S) mass and the branching fraction for Gamma(3S) -\u3e gamma eta b(1S)

We report evidence for the ground state of bottomonium, eta(b)(1S), in the radiative decay Gamma(3S) -\u3e gamma eta(b) in e(+)e(-) annihilation data taken with the CLEO III detector. Using 6 X 10(6) Gamma(dS) decays, and assuming Gamma(eta(b)) = 10 +/- 5 MeV/c(2), we obtain B(Gamma(3S) -\u3e gamma eta(b)) = (7.1 +/- 1.8 +/- 1.3) X 10(-4), where the first error is statistical and the second is systematic. The statistical significance is -4 sigma. The mass is determined to be M(eta(b)) = 9391.8 +/- 6.6 +/- 2.0 MeV/c(2), which corresponds to the hyperfine splitting Delta M-hf(1S)(b) = 68.5 +/- 6.6 +/- 2.0 MeV/c(2). Using 9 X 10(6) Gamma(2S) decays, we place an upper limit on the corresponding Gamma(2S) decay, B(Gamma(2S) -\u3e gamma eta(b)) \u3c 8.4 X 10(-4) at 90% confidence level

Measurement of absolute branching fractions of inclusive semileptonic decays of charm and charmed-strange mesons

We have measured the inclusive semileptonic branching fractions of D-0, D+, and D-s(+) mesons. For these measurements, we have used the full CLEO-c open-charm data samples, 818 pb(-1) at E-CM = 3.774 GeV, giving D-0(D) over bar (0) and D+D- events, and 602 pb(-1) at E-CM = 4.170 GeV, giving D-s*D-+/-(s)-/+ events. We obtain B(D-0 -\u3e Xe+nu(e)) = (6.46 +/- 0.09 +/- 0.11)%, B(D+ -\u3e Xe+nu(e)) = (16.13 +/- 0.10 +/- 0.29)%, and B(D-s(+) -\u3e Xe+nu(e)) = (6.52 +/- 0.39 +/- 0.15)%, where the first uncertainties are statistical and the second are systematic. From these and lifetimes obtained elsewhere, we obtain the ratios of semileptonic decay widths Gamma(D+ -\u3e Xe+nu(e))/Gamma(D-0 -\u3e Xe+nu(e)) = 0.985 +/- 0.015 +/- 0.024 and Gamma(D-s(+) -\u3e Xe+nu(e))/Gamma(D-0 -\u3e Xe+nu(e)) = 0.828 +/- 0.051 +/- 0.025. The ratio of D+ and D-0 is consistent with the isospin symmetry prediction of unity, and the ratio of D-s(+) and D-0 differs from unity, as expected

Measurements of D meson decays to two pseudoscalar mesons

Using data collected on the psi(3770) resonance and near the D-s*D-+/-(s)-/+ peak production energy by the CLEO-c detector, we study the decays of the possible D -\u3e PP modes and report measurements of or upper limits on all branching fractions for Cabibbo-favored, singly Cabibbo-suppressed, and doubly Cabibbo-suppressed D -\u3e PP decays except modes involving K-L(0) (and except D-0 -\u3e K+pi(-)). We normalize with respect to the Cabibbo-favored D modes, D-0 -\u3e K-pi(+), D+ -\u3e K-pi(+)pi(+), and D-s(+) -\u3e (K+KS0)

Search for the lepton number violating decays B+→π−μ+μ+B^{+}\to \pi^- \mu^+ \mu^+ and B+→K−μ+μ+B^{+}\to K^- \mu^+ \mu^+

A search is performed for the lepton number violating decay $B^{+}\to h^- \mu^+ \mu^+$, where $h^-$ represents a $K^-$ or a $\pi^-$, using data from the LHCb detector corresponding to an integrated luminosity of $36pb^{-1}$. The decay is forbidden in the Standard Model but allowed in models with a Majorana neutrino. No signal is observed in either channel and limits of $B(B^{+} \to K^- \mu^+ \mu^+) < 5.4\times 10^{-8}$ and $B(B^{+} \to \pi^- \mu^+ \mu^+) < 5.8\times 10^{-8}$ are set at the 95% confidence level. These improve the previous best limits by factors of 40 and 30, respectively