Search results for "[formula omitted] decay"
showing 10 items of 1452 documents
Search for Gluino-Mediated Bottom Squark Production inpp¯Collisions ats=1.96 TeV
2009
We report on a search for the supersymmetric partner of the bottom quark produced from gluino decays in data from 2.5 fb{sup -1} of integrated luminosity collected by the Collider Detector at Fermilab at {radical}s = 1.96 TeV. Candidate events are selected requiring two or more jets and large missing transverse energy. At least two of the jets are required to be tagged as originating from a b quark to enhance the sensitivity. The results are in good agreement with the prediction of the standard model processes, giving no evidence for gluino decay to sbottom quarks. This result constrains the gluino-pair-production cross section to be less than 40 fb at 95% credibility level for a gluino mas…
Improved Measurement ofB+→ρ+ρ0and Determination of the Quark-Mixing Phase Angleα
2009
We present improved measurements of the branching fraction ${\cal B}$, the longitudinal polarization fraction $f_L$, and the direct {\ensuremath{CP}\xspace} asymmetry {\ensuremath{{\cal A}_{CP}}\xspace} in the $B$ meson decay channel $B^+\to\rho^+\rho^0$. The data sample was collected with the {{\slshape B\kern-0.1em{\smaller A}\kern-0.1em B\kern-0.1em{\smaller A\kern-0.2em R}}} detector at SLAC. The results are ${\cal B} (\Bp\ra\rprz)=(23.7\pm1.4\pm1.4)\times10^{-6}$, $f_L=0.950\pm0.015\pm0.006$, and $\Acp=-0.054\pm0.055\pm0.010$, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the CKM weak phase ang…
The effect of hyperfine mixing in electromagnetic and semileptonic decays of doubly heavy baryons
2010
We consider the role played by hyperfine mixing in electromagnetic and semileptonic decays of doubly heavy baryons, which give rise to large corrections to the decay widths in both cases.
Search for long-lived particles decaying into electron or photon pairs with the D0 detector
2008
In this Letter we report on a search for long-lived particles that decay into final states with two electrons or photons. Such long-lived particles arise in a variety of theoretical models, like hidden valleys and supersymmetry with gauge-mediated breaking. By precisely reconstructing the direction of the electromagnetic shower we are able to probe much longer lifetimes than previously explored. We see no evidence of the existence of such long-lived particles and interpret this search as a quasi model-independent limit on their production cross section, as well as a limit on a long-lived fourth generation quark.
Evidence forB0→ρ0ρ0Decays and Implications for the Cabibbo-Kobayashi-Maskawa Angleα
2007
We search for the decays B(0) --> rho(0)rho(0), B(0) --> rho(0)f(0)(980), and B(0) --> f(0)(980)f(0)(980) in a sample of about 384 x 10(6) Upsilon(4S) --> BB[over] decays collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at Stanford Linear Accelerator Center. We find evidence for B(0) --> rho(0)rho(0) with 3.5 sigma significance and measure the branching fraction B = (1.07 +/- 0.33 +/- 0.19) x 10(-6) and longitudinal polarization fraction f(L) = 0.87 +/- 0.13 +/- 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix unitarity angle alpha due to penguin contributio…
Single and Double Beta-DecayQValues among the TripletZr96,Nb96, andMo96
2016
The atomic mass relations among the mass triplet ^{96}Zr, ^{96}Nb, and ^{96}Mo have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyvaskyla. We report Q values for the ^{96}Zr single and double β decays to ^{96}Nb and ^{96}Mo, as well as the Q value for the ^{96}Nb single β decay to ^{96}Mo, which are Q_{β}(^{96}Zr)=163.96(13), Q_{ββ}(^{96}Zr)=3356.097(86), and Q_{β}(^{96}Nb)=3192.05(16) keV. Of special importance is the ^{96}Zr single β-decay Q value, which has never been determined directly. The single β decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the…
QRPA estimate for the Δ (1232) contribution to the Gamow-Teller decay of heavy nuclei
1991
Abstract The contribution of the Δ (1232) isobars to the nuclear beta decay strength function is estimated in the framework of the charge-changing form of the QRPA. This procedure is applied to neutron-deficient tin isotopes. The results imply that the quenching of the low-energy Gamow-Teller decay strength cannot attributed to the presence of delta admixtures in the nuclear wave function.
Nonsense polarity, RNA processing and decay in phage f1.
2011
Nonsense polarity in most cases depends on activation of cryptic transcription terminators. We found that the strong polar effect observed in the nonsense polar mutant R4 of phage f1, mapping in the 5’ proximal region of gene III, instead depends on enhanced instability of mutant mRNAs, whose pattern can be restored by reduction of RNase E activity. rne -(ts) E. coli strains allowed to explore the mechanisms underlying f1 mRNA processing and degradation. The major gene III species, a 1.8 Kb long molecule, appeared to be a secondary transcript, whose decay is modulated by a REP, located at its 3' end. The RNA pool of a mutagenized phage unable to form that structure, lacks completely that tr…
Results of the measurements carried out in order to verify the validity of the poisson-exponential distribution in radioactive decay events
1978
Abstract Berkson, examining a series of 250,000 disintegration time intervals, found a significant departure of the distribution from the Poisson-exponential law. Therefore he proposed to repeat the experiment using a large number of intervals and to check the interval recordings by using more than one recording instrument simultaneously. Accepting these suggestions we developed two systems of data collecting provided with different controls. In several experiments we collected data for more than one million decay intervals. The results elaborated using the Pearson ξ 2 test reflect a Poisson process of the radioactive decay events.
Radon and material radiopurity assessment for the NEXT double beta decay experiment
2015
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM