38 research outputs found
T violation and the unidirectionality of time
An increasing number of experiments at the Belle, BNL, CERN, DA{\Phi}NE and
SLAC accelerators are confirming the violation of time reversal invariance (T).
The violation signifies a fundamental asymmetry between the past and future and
calls for a major shift in the way we think about time. Here we show that
processes which violate T symmetry induce destructive interference between
different paths that the universe can take through time. The interference
eliminates all paths except for two that represent continuously forwards and
continuously backwards time evolution. Evidence from the accelerator
experiments indicates which path the universe is effectively following. This
work may provide fresh insight into the long-standing problem of modeling the
dynamics of T violation processes. It suggests that T violation has previously
unknown, large-scale physical effects and that these effects underlie the
origin of the unidirectionality of time. It may have implications for the
Wheeler-DeWitt equation of canonical quantum gravity. Finally it provides a
view of the quantum nature of time itself.Comment: 24 pages, 5 figures. Final version accepted for publishing in
Foundations of Physics. The final publication is available at
http://www.springerlink.com/content/y3h4174jw2w78322
Model Analysis of Time Reversal Symmetry Test in the Caltech Fe-57 Gamma-Transition Experiment
The CALTECH gamma-transition experiment testing time reversal symmetry via
the E2/M1 mulipole mixing ratio of the 122 keV gamma-line in Fe-57 has already
been performed in 1977. Extending an earlier analysis in terms of an effective
one-body potential, this experiment is now analyzed in terms of effective one
boson exchange T-odd P-even nucleon nucleon potentials. Within the model space
considered for the Fe-57 nucleus no contribution from isovector rho-type
exchange is possible. The bound on the coupling strength phi_A from effective
short range axial-vector type exchange induced by the experimental bound on
sin(eta) leads to phi_A < 10^{-2}.Comment: 5 pages, RevTex 3.
Search for CP violation in K0 -> 3 pi0 decays
Using data taken during the year 2000 with the NA48 detector at the CERN SPS,
a search for the CP violating decay K_S -> 3 pi0 has been performed. From a fit
to the lifetime distribution of about 4.9 million reconstructed K0/K0bar -> 3
pi0 decays, the CP violating amplitude eta_000 = A(K_S -> 3 pi0)/A(K_L -> 3
pi0) has been found to be Re(eta_000) = -0.002 +- 0.011 +- 0.015 and
Im(eta_000) = -0.003 +- 0.013 +- 0.017. This corresponds to an upper limit on
the branching fraction of Br(K_S -> 3 pi0) < 7.4 x 10^-7 at 90% confidence
level. The result is used to improve knowledge of Re(epsilon) and the CPT
violating quantity Im(delta) via the Bell-Steinberger relation.Comment: 18 pages, 7 figures, submitted to Phys. Lett.
A precision measurement of direct CP violation in the decay of neutral kaons into two pions
The direct CP violation parameter Re(epsilon'/epsilon) has been measured from
the decay rates of neutral kaons into two pions using the NA48 detector at the
CERN SPS. The 2001 running period was devoted to collecting additional data
under varied conditions compared to earlier years (1997-99). The new data yield
the result: Re(epsilon'/epsilon) = (13.7 +/- 3.1) times 10^{-4}. Combining this
result with that published from the 1997, 98 and 99 data, an overall value of
Re(epsilon'/epsilon) = (14.7 +/- 2.2) times 10^{-4} is obtained from the NA48
experiment.Comment: 19 pages, 5 figures, to be published in Physics Letters
Search for direct CP-violation in K+- --> pi+-pi0pi0 decays
A search for direct CP-violation in K+- --> pi+-pi0pi0 decays based on 47.14
million events has been performed by the NA48/2 experiment at the CERN SPS. The
asymmetry in the Dalitz plot linear slopes A_g=(g^+ - g^-)/(g^+ + g^-) is
measured to be A_g=(1.8 +- 2.6).10^{-4}. The design of the experiment and the
method of analysis provide good control of instrumental charge asymmetries in
this measurement. The precision of the result is limited by statistics and is
almost one order of magnitude better than that of previous measurements by
other experiments.Comment: 14 page
A new measurement of direct CP violation in two pion decays of the neutral kaon
The NA48 experiment at CERN has performed a new measurement of direct CP
violation, based on data taken in 1997 by simultaneously collecting K_L and K_S
decays into pi0pi0 and pi+pi-. The result for the CP violating parameter
Re(epsilon'/epsilon) is (18.5 +/- 4.5(stat)} +/- 5.8 (syst))x10^{-4}.Comment: 18 pages, 6 figure
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Search for K_S K_S in J/psi and psi(2S) decays
The CP violating processes J/psi-->K_S K_S and psi(2S)-->K_S K_S are searched
for using samples of 58 million J/psi and 14 million psi(2S) events collected
with the Beijing Spectrometer at the Beijing Electron Positron Collider. No
signal is observed, and upper limits on the decay branching ratios are
determined to be BR(J/psi-->K_S K_S) K_S K_S) <
4.6x10^{-6} at the 95% confidence level.Comment: 6 pages, 4 figures, submitted to Phys. Lett.
Search for electroweak production of single top quarks in collisions.
We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv