15,939 research outputs found
Recent CP violation results from Belle
We summarize recent results on an array of CP violation measurements
performed by the Belle experiment using the data collected near the Y(4S) and
Y(5S) resonances at the KEKB asymmetric-energy e+e- collider.Comment: 8 pages, 5 postscript figures, contributed to the Proceedings of the
Rencontres de Moriond EW 2012, La Thuile, Aosta valley, Ital
Looking for Exotica at the B Factories
Current experiments at the B factories, designed to perform precision
measurements of matter-antimatter asymmetry in the B meson system, have a much
broader physics reach especially in the sector of quarkonium spectroscopy. Here
we present a minireview on the new charmonium-like states observed at the B
factories including the X(3872) and Y(4260).Comment: 12 pages, 8 postscript figures, contributed to the Proceedings of the
17th DAE-BRNS High Energy Physics Symposium, IIT, Kharagpur, Indi
Charmless Hadronic B Decays at BABAR
We report recent measurements of branching fractions and charge asymmetries
of charmless hadronic B decays using the data collected with the BABAR detector
at the PEP-II asymmetric energy e+e- collider.Comment: 7 pages, 4 postscript figures, 3 tables, contributed to the
Proceedings of XII International Conference on Hadron Spectroscopy
(HADRON07), Frascati, Ital
Charm at Belle II - Status and Prospects
High-precision flavor physics measurements play a complementary role to the
direct searches for new physics by CMS and ATLAS experiments at LHC. Such
measurements will be performed with the Belle II detector at the upgraded KEKB
accelerator (SuperKEKB) in Japan. The physics potential with emphasis on the
charm sector, current status and future prospects of the Belle II experiment
are presented in these proceedings.Comment: 8 pages, 3 postscript figures, to appear in the proceedings of the
6th International Workshop on Charm Physics (CHARM 2013
CP violation and hints for new physics at the B factories
We report the latest results on CP violation measurements and the tantalizing
hints of potential new physics effects obtained at the B factories.Comment: 10 pages, 6 postscript figures, contributed to the Proceedings of the
5th International Conference on Flavor Physics (ICFP09), Hanoi, Vietna
Exotic, LFV and LNV Decays at the B Factories
I review the latest results on exotic, lepton flavor violating (LFV) and
lepton number violating (LNV) decays of the B, D mesons and the tau leptons,
obtained at the two B-factory experiments, Belle and BaBar. Where appropriate,
results from other experiments are also described.Comment: 8 pages, 5 figures, 2 tables, Proceedings of CKM2010, the 6th
International Workshop on the CKM Unitarity Triangle, University of Warwick,
UK, 6-10 September 201
New Hadron Spectroscopy with BABAR
We review hadron spectroscopy at BABAR with emphasis on recent results from
the studies of the X(3872) state, inclusive charmonia on recoil, double
charmonium production, and the broad structure observed at around 4.26 GeV/c^2.
These results are preliminary, unless otherwise specified.Comment: 6 pages, 6 postscript figures, contributed to the Proceedings of
Frontier Science 200
Alternative Scenarios for the Fragmentation of a Gluonic Lund String
The assumptions in the Lund model suffice to prescribe a unique stochastic
process for the fragmentation of a string into a set of hadrons, so long as the
string is "flat", ie as long as the state described by the string consists only
of a quark and an antiquark stretching a constant force field between them.
Emission of gluons causes the string to trace more complicated surfaces in
Minkowski space, and some form of generalization of the 1+1 dimensional model
is required. One such generalizaiotn has been developed and implemented as a
Monte Carlo routine "JETSET" by Torbj\"orn Sj\"ostrand, which has been hightly
successful in describing experimental data. But there are theoretical reasons
to believe that the fragmentation scheme employed in JETSET is not entirely
satisfactory; most notably, non-adherance to the Lund Area law, and certain
problems in handling transverse momenta. A few alternative scenarios, which we
have examined in detail and implemented in separate computer programs, will be
presented here, with comparisons to JETSET in certain simple cases. Our effort
has been to preserve the area law for the fragmentation of a gluonic string,
while we explored the possibility of allowing the fragmentation process to
reshape the string surface slightly.Comment: 7 pages, 3 figures, to appear in the Proceedings of the XXX'th
International Symposium on Multiparticle Dynamics (Oct 9-15, 2000), Lake
Balaton, Hungar
Unfolding of event-by-event net-charge distributions in heavy-ion collision
We discuss a method to obtain the true event-by-event net-charge multiplicity
distributions from a corresponding measured distribution which is subjected to
detector effects such as finite particle counting efficiency. The approach is
based on the Bayes method for unfolding of distributions. We are able to
faithfully unfold back the measured distributions to match with their
corresponding true distributions obtained for a widely varying underlying
particle production mechanism, beam energy and collision centrality.
Particularly the mean, variance, skewness, kurtosis, their products and ratios
of net-charge distributions from the event generators are shown to be
successfully unfolded from the measured distributions constructed to mimic a
real experimental distribution. We demonstrate the necessity to account for
detector effects before associating the higher moments of net-charge
distributions with physical quantities or phenomena. The advantage of this
approach being that one need not construct new observable to cancel out
detector effects which loose their ability to be connected to physical
quantities calculable in standard theories
Baryogenesis from primordial tensor perturbations
During inflation primordial quantum fluctuations of the spacetime metric
become classical and there is a spontaneous CPT violation by the spin
connection coupling terms of the metric with fermions. The energy levels of the
left and the right chirality neutrinos is split which gives rise to a net
lepton asymmetry at equilibrium. A net baryon asymmetry of the same magnitude
can be generated from this lepton asymmetry either by a GUT, symmetry or
by electroweak sphaleron processes which preserve symmetry.
If the amplitude of the primordial tensor perturbations is of the order of
(as is expected from inflation models) and the lepton/baryon number
violating processes freeze out at the GUT era then a
baryon number asymmetry of the correct magnitude can be generated.Comment: 9 pages Latex fil
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