15,400 research outputs found
Determining the phases alpha and gamma from time-dependent CP violation in B0 decays to rho(omega) + pseudoscalar
A method is proposed for the determination of the unitarity angle alpha
through tree penguin interference. The modes needed would be of the form
B0/B0-bar -> rho0 M and B0/B0-bar -> omega M where M is spin-0 uu-bar/dd-bar
meson, for instance M=pi0, eta, eta',a0 or f0. An analogous method can also
determine gamma using M=KS or K_L. The validity of the theoretical
approximations used may be tested by over determining alpha with several modes.
If two or more modes are used, the determination has a four-fold ambiguity but
additional information from pure penguin decays or theoretical estimates may be
used to reduce the ambiguity to alpha, alpha+pi. The method as applied to
determining gamma is probably less promising.Comment: 17 pages, 2 figures; Small change with respect to the references and
a postscript bug in the figures fixe
Scalar Mediated FCNC at the First Muon Collider
In the most general two-Higgs doublet model (generally referred to as Model
III), tree level flavor changing neutral couplings exist. It has been noted
that the most natural value for such a coupling is of the order of the
geometric mean of the Yukawa couplings of the two fermions. Bounds on those
couplings that involve the second and third generations, from and
physics, are very weak and are not sensitive to this "natural" value. In
this paper, it is pointed out that the process \mu\mu ---> \mu\tau, at a muon
collider tuned to the scalar resonance, will easily reach this sensitivity if
the scalar mass is below 140 GeV. Hundreds of events are expected for an
integrated luminosity of an inverse femtobarn, and there appears to be no
background. Failure to observe this process, if the scalar is below 140 GeV,
would effectively rule out Model III.Comment: Paragraph added and other wording changed in introduction, some
wording changes in text. Calculation unaffected. Version to appear in Phys.
Lett.
Witch 54 Flight
An Air Force colonel pilot faces an emergency on her refueling plane and saves the day.
Articles, stories, and other compositions in this archive were written by participants in the Mighty Pen Project. The program, developed by author David L. Robbins, and in partnership with Virginia Commonwealth University and the Virginia War Memorial in Richmond, Virginia, offers veterans and their family members a customized twelve-week writing class, free of charge. The program encourages, supports, and assists participants in sharing their stories and experiences of military experience so both writer and audience may benefit
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University of Massachusetts Amherst Response to Draft Desirable Characteristics of Repositories for Managing and Sharing Data Resulting From Federally Funded Research
Response to the Office of Science and Technology Policy\u27s Draft Desirable Characteristics of Repositories for Managing and Sharing Data Resulting from Federally Funded Research.
Original call for public response is available at https://www.federalregister.gov/documents/2020/01/17/2020-00689/request-for-public-comment-on-draft-desirable-characteristics-of-repositories-for-managing-an
Conflicts of Jurisdiction in the Antitrust Field: The Example of Export Cartels
Förbehandling av bioslam för ökad biogasproduktion Eftersom bioslam från aktivslamsteget i reningsprocessen ger en lägre metanproduktion än primärslam bör förbehandlingen ske på bioslam. Effekten av olika förbehandlingsmetoder är dock svårbedömd och ofta erhålls inget positivt energiutbyte då energin av ökad produktion av biogas kan vara mindre än tillförd energi vid behandlingen. Vissa förbehandlingsmetoder som ozonering kan vid överdosering oxidera substrat och ge minskad biogasproduktion Litteraturstudien kompletterades med mätning av biometanpotential efter förbehandling av bioslam (Khayi, 2014). Som förbehandlingsmetoder valdes frysning (djupfryst och lättfryst) och uppvärmning. Vid 35 dagars rötning producerade djupfryst slam 221 Nml CH4/g VS, lättfryst 115 Nml CH4/g VS, det uppvärmt 181 Nml CH4/g VS och det obehandlade (referens) 148 Nml CH4/g VS (Nml, normalmilliliter är gasvolym omräknad till en atmosfärs tryck). Djupfrysning och uppvärmning ökade biogasproduktionen medan lättfrysning gav minskad biogasproduktion. Uppgradering av biogas Vid uppgradering separeras koldioxid från biogasen varvid metangas erhålles. Uppgradering kan ske genom att koldioxiden absorberas av ett fast (PSA-teknik med zeoliter eller aktivt kol) eller flytande medium (vattenskrubber, polyetylenglykol eller monoetanolamin) eller med membranteknik. Investeringskostnaden för uppgradering är starkt beroende av storleken på anläggningen snarare än av vilken teknik som används, men vid små är investeringskostnaden för membranteknik något lägre. Genom intern metananrikning i rötkammaren kan metanhalten i den producerade biogasen ökas. Detta åstadkommes genom att koldioxid avdrivs från slam som sedan återförs till rötkammaren.QC 20140902</p
Feasibility study of model-independent approach to phi_3 measurement using Dalitz plot analysis
We present results of a feasibility study of a model-independent way to
measure the angle phi_3 of the unitarity triangle. The method involves B->DK
decays where the neutral D decays to the K_S Pi+ Pi- final state, together with
the sample of decays of CP-tagged D mesons (produced, e. g. in psi(3770)->DDbar
process) to the same final state. We consider different approaches to the
extraction of phi_3 and obtain the expected statistical accuracy of the phi_3
measurement as a function of B and D_CP statistics.Comment: 8 pages, 6 figures. Accepted by Eur. Phys. J. C. Replaced by journal
versio
Getting beta-alpha without penguins
Oscillation effects in B0 -> Ks D0 and related processes are considered to
determine delta=beta-alpha+pi. We suggest that D0 decays to CP eigenstates used
in concert with inclusive D0 decays provide a powerful method for determining
delta cleanly i.e. without any complication from penguin processes. The CP
asymmetry is expected to be <=40% for D0 decays to non-CP eigenstates and <=80%
for decays to CP eigenstates. This method can lead to a fairly accurate
determination of delta with O(10^8-10^9) B-mesons.Comment: 4 pages 1 figure; Version 2: minor changes; references added; Some
changes in response to Referee Comment
Enhanced effects on extracting \gamma from untagged B^0 and B_s decays
The weak phase \gamma can be determined using untagged B^0\to DK_S or B_s\to
D\phi, D\eta^{(')} decays. In the past, the small lifetime difference y\equiv
\Delta\Gamma/(2\Gamma) has been neglected in B^0, while the CP violating
parameter \epsilon\equiv 1-|q/p|^2 has been neglected in both B^0-\bar B^0 and
B_s-\bar B_s mixing. We estimate the effect of neglecting y and \epsilon. We
find that in D decays to flavor states this introduces a systematic error,
which is enhanced by a large ratio of Cabibbo-allowed to doubly
Cabibbo-suppressed D decay amplitudes.Comment: one reference added, to be submitted for publication in Physics
Letters
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