We report measurements of the inclusive electron momentum spectra in decays of charged and neutral B mesons, and of the ratio of semileptonic branching fractions B ( B + → X e ν ) and B ( B 0 → X e ν ...) . These were performed on a sample of 231 × 10 6 B ¯¯¯ B events recorded with the BABAR detector at the Υ ( 4 S ) resonance. Events are selected by fully reconstructing a hadronic decay of one B meson and identifying an electron among the decay products of the recoiling ¯¯¯ B meson. We obtain B ( B + → X e ν ) / B ( B 0 → X e ν ) = 1.074 ± 0.041 ( stat ) ± 0.026 ( syst ) .
Search for B → K ν ν ¯ decays Aubert, B.; Lees, J. P.; Prudent, X. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
10/2008, Letnik:
78, Številka:
7
Journal Article
Odprti dostop
We present a search for the decays B → K ∗ ν ¯ ν using 454 × 10 6 B ¯¯¯ B pairs collected at the Υ ( 4 S ) resonance with the BABAR detector at the SLAC PEP-II B -Factory. We first select an event ...sample where one B is reconstructed in a semileptonic or hadronic mode with one charmed meson. The remaining particles in the event are then examined to search for a B → K ∗ ν ¯ ν decay. The charged K ∗ is reconstructed as K * + → K 0 S π + or K * + → K + π 0 ; the neutral K ∗ is identified in K * 0 → K + π − mode. We establish upper limits at 90% confidence level of B ( B + → K * + ν ¯ ν ) < 8 × 10 − 5 , B ( B 0 → K * 0 ν ¯ ν ) < 12 × 10 − 5 , and B ( B → K ∗ ν ¯ ν ) < 8 × 10 − 5 .
We have searched for prompt production of χ c 1 , χ c 2 and X ( 3872 ) in continuum e + e − annihilations using a 386 fb − 1 data sample collected around √ s = 10.6 GeV with the BABAR ...detector using the γ J / ψ decay mode. After accounting for the feed-down from ψ ( 2 S ) → γ χ c 1 , 2 , no significant signal for prompt χ c 1 , 2 production is observed. We present improved upper limits at 90% confidence level on the production cross sections of 77 fb for χ c 1 and 79 fb for χ c 2 , for events where the χ c momentum exceeds 2.0 GeV and there are at least three additional charged tracks. These limits are consistent with NRQCD predictions. We also set an upper limit on the prompt production of X ( 3872 ) through the decay X ( 3872 ) → γ J / ψ .
Search for the decay B + → K s 0 K s 0 π Aubert, B.; Lees, J. P.; Prudent, X. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
3/2009, Letnik:
79, Številka:
5
Journal Article
We search for charmless decays of charged B mesons to the three-body final state K_S^0 K_S^0 pi+. Using a data sample of 423.7 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector, ...corresponding to (465.1 +- 5.1)X10^6 BB-bar pairs, we find no significant signal and determine a 90% confidence level upper limit on the branching fraction of 5.1X10^-7.
Discovering transiting exoplanets with relatively long orbital periods (\(>\)10 days) is crucial to facilitate the study of cool exoplanet atmospheres (\(T_{\rm eq} < 700 K\)) and to understand ...exoplanet formation and inward migration further out than typical transiting exoplanets. In order to discover these longer period transiting exoplanets, long-term photometric and radial velocity campaigns are required. We report the discovery of TOI-2447 b (\(=\) NGTS-29b), a Saturn-mass transiting exoplanet orbiting a bright (T=10.0) Solar-type star (T\(_{\rm eff}\)=5730 K). TOI-2447 b was identified as a transiting exoplanet candidate from a single transit event of 1.3% depth and 7.29 h duration in \(TESS\) Sector 31 and a prior transit event from 2017 in NGTS data. Four further transit events were observed with NGTS photometry which revealed an orbital period of P=69.34 days. The transit events establish a radius for TOI-2447 b of \(0.865 \pm 0.010\rm R_{\rm J}\), while radial velocity measurements give a mass of \(0.386 \pm 0.025 \rm M_{\rm J}\). The equilibrium temperature of the planet is \(414\) K, making it much cooler than the majority of \(TESS\) planet discoveries. We also detect a transit signal in NGTS data not caused by TOI-2447 b, along with transit timing variations and evidence for a \(\sim\)150 day signal in radial velocity measurements. It is likely that the system hosts additional planets, but further photometry and radial velocity campaigns will be needed to determine their parameters with confidence. TOI-2447 b/NGTS-29b joins a small but growing population of cool giants that will provide crucial insights into giant planet composition and formation mechanisms.
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