1,095 research outputs found
Combined potential of future long-baseline and reactor experiments
We investigate the determination of neutrino oscillation parameters by
experiments within the next ten years. The potential of conventional beam
experiments (MINOS, ICARUS, OPERA), superbeam experiments (T2K, NOvA), and
reactor experiments (D-CHOOZ) to improve the precision on the ``atmospheric''
parameters , , as well as the sensitivity to
are discussed. Further, we comment on the possibility to
determine the leptonic CP-phase and the neutrino mass hierarchy if
turns out to be large.Comment: 4 pages, 4 figures, Talk given by T.S. at the NOW2004 workshop, Conca
Specchiulla (Otranto, Italy), 11--17 Sept. 200
Review of Final LEP Results or A Tribute to LEP
After a comment on the performance of LEP some highlights of the LEP1 and
LEP2 physics programmes are reviewed. The talk concentrates on the precision
measurements at the Z resonance, two fermion production above the Z, W+W-
production, ZZ production, indirect limits on the Higgs mass, LEP contributions
to the exploration of the CKM matrix, and on the LEP measurements of alpha_s.Comment: Proceedings of the XX International Symposium on Lepton and Photon
Interactions at High Energies Rome, Italy, July 200
Future Precision Neutrino Oscillation Experiments and Theoretical Implications
Future neutrino oscillation experiments will lead to precision measurements
of neutrino mass splittings and mixings. The flavour structure of the lepton
sector will therefore at some point become better known than that of the quark
sector. This article discusses the potential of future oscillation experiments
on the basis of detailed simulations with an emphasis on experiments which can
be done in about ten years. In addition, some theoretical implications for
neutrino mass models will be briefly discussed.Comment: Talk given at Nobel Symposium 2004: Neutrino Physics, Haga Slott,
Enkoping, Sweden, 19-24 Aug 200
Synergies between the first-generation JHF-SK and NuMI superbeam experiments
We discuss synergies in the combination of the first-generation JHF to
Super-Kamiokande and NuMI off-axis superbeam experiments. With synergies we
mean effects which go beyond simply adding the statistics of the two
experiments. As a first important result, we do not observe interesting synergy
effects in the combination of the two experiments as they are planned right
now. However, we find that with minor modifications, such as a different NuMI
baseline or a partial antineutrino running, one could do much richer physics
with both experiments combined. Specifically, we demonstrate that one could,
depending on the value of the solar mass squared difference, either measure the
sign of the atmospheric mass squared difference or CP violation already with
the initial stage experiments. Our main results are presented in a way that can
be easily interpreted in terms of the forthcoming KamLAND result.Comment: 29 pages, 10 figure
Teleology and Realism in Leibniz's Philosophy of Science
This paper argues for an interpretation of Leibniz’s claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibniz’s fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibniz’s thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibniz’s use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibniz’s use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz
Reactor Neutrino Experiments Compared to Superbeams
We present a detailed quantitative discussion of the measurement of the
leptonic mixing angle with a future reactor neutrino
oscillation experiment consisting of a near and far detector. We perform a
thorough analysis of the impact of various systematical errors and compare the
resulting physics potential to the one of planned first-generation superbeam
experiments. Furthermore, we investigate the complementarity of both types of
experiments. We find that, under realistic assumptions, a determination of
down to is possible with reactor experiments.
They are thus highly competitive to first-generation superbeams and may be able
to test on shorter timescales. In addition, we find that
the combination of a KamLAND-size reactor experiment with one or two superbeams
could substantially improve the ability to access the neutrino mass hierarchy
or the leptonic CP phase.Comment: Typo in Eq. (9) corrected. 36 pages, 12 figure
High intensity neutrino oscillation facilities in Europe
The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fréjus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of μ+ and μ− beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He6 and Ne18, also stored in a ring. The far detector is also the MEMPHYS detector in the Fréjus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive
The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines
The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of
kton liquid double phase TPC complemented by a magnetised iron
calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km
from CERN. The conventional neutrino beam is produced by 400 GeV protons
accelerated at the SPS accelerator delivering 700 kW of power. The long
baseline provides a unique opportunity to study neutrino flavour oscillations
over their 1st and 2nd oscillation maxima exploring the behaviour, and
distinguishing effects arising from and matter. In this paper we
show how this comprehensive physics case can be further enhanced and
complemented if a neutrino beam produced at the Protvino IHEP accelerator
complex, at a distance of 1160 km, and with modest power of 450 kW is aimed
towards the same far detectors. We show that the coupling of two independent
sub-MW conventional neutrino and antineutrino beams at different baselines from
CERN and Protvino will allow to measure CP violation in the leptonic sector at
a confidence level of at least for 50\% of the true values of
with a 20 kton detector. With a far detector of 70 kton, the
combination allows a sensitivity for 75\% of the true values of
after 10 years of running. Running two independent neutrino
beams, each at a power below 1 MW, is more within today's state of the art than
the long-term operation of a new single high-energy multi-MW facility, which
has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure
Search for Branons at LEP
We search, in the context of extra-dimension scenarios, for the possible
existence of brane fluctuations, called branons. Events with a single photon or
a single Z-boson and missing energy and momentum collected with the L3 detector
in e^+ e^- collisions at centre-of-mass energies sqrt{s}=189-209$ GeV are
analysed. No excess over the Standard Model expectations is found and a lower
limit at 95% confidence level of 103 GeV is derived for the mass of branons,
for a scenario with small brane tensions. Alternatively, under the assumption
of a light branon, brane tensions below 180 GeV are excluded
Study of Spin and Decay-Plane Correlations of W Bosons in the e+e- -> W+W- Process at LEP
Data collected at LEP at centre-of-mass energies \sqrt(s) = 189 - 209 GeV are
used to study correlations of the spin of W bosons using e+e- -> W+W- -> lnqq~
events. Spin correlations are favoured by data, and found to agree with the
Standard Model predictions. In addition, correlations between the W-boson decay
planes are studied in e+e- -> W+W- -> lnqq~ and e+e- -> W+W- -> qq~qq~ events.
Decay-plane correlations, consistent with zero and with the Standard Model
predictions, are measured
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