117150642
Matter Effect on Neutrino Oscillations from the violation of Universality in Neutrino Neutral Current Interactions
archiveprefix: arXiv primaryclass: hep-ph reportnumber: OCHA-PP-257, YITP-06-01, VPI-IPPAP-06-02 slaccitation: %%CITATION = HEP-PH/0603268;%%
444650
Oblique corrections to the W width.
The lowest-order expression for the partial $W$ width to $e \nu ,~\Gamma (W \to e \nu) = G_\mu M_W^3 /(6 \pi \sqrt{2})$, has no oblique radiative corrections from new physics if the measured $W$ mass is used. Here $G_\mu = (1.16639 \pm 0.00002) \times 10^{-5}$ GeV/$c^2$ is the muon decay constant. For the present value of $M_W = (80.14 \pm 0.27)$ GeV/$c^2$, and with $m_t = 140$ GeV$/c^2$, one expects $\Gamma (W \to e \nu) = (224.4 \pm 2.3)$ MeV. The total width $\Gamma_{\rm tot}(W)$ is also expected to lack oblique corrections from new physics, so that $\Gamma_{\rm tot} (W)/ \Gamma (W \to e \nu) = 3 + 6 [1 + \{\alpha_s (M_W)/\pi \}]$. Present data are consistent with this prediction.
64343483
Position and momentum uncertainties of a particle in a V-shaped potential under the minimal length uncertainty relation
We calculate the uncertainties in the position and momentum of a particle in the 1D potential V (x) = F|x|, F > 0, when the position and momentum operators obey the deformed commutation relation [x,p] = iℏ(1 + βp2), β > 0. As in the harmonic oscillator case, which was investigated in a previous publication, the Hamiltonian Ĥ1 = p2/2m + F|x| admits discrete positive energy eigenstates for both positive and negative mass. The uncertainties for the positive mass states behave as Δx ∼ 1/Δp as in the β = 0 limit. For the negative mass states, however, in contrast to the harmonic oscillator case where we had Δx ∼ Δp, both Δx and Δp diverge. We argue that the existence of the negative mass states and the divergence of their uncertainties can be understood by taking the classical limit of the theory. Comparison of our results is made with previous work by Benczik.
54186542
Position and Momentum Uncertainties of the Normal and Inverted Harmonic Oscillators under the Minimal Length Uncertainty Relation
p 2 ). This deformed commutation relation leads to the minimal length uncertainty relationx � (~/2)(1/�p + ��p), which implies thatx � 1/�p at smallp whilex � �p at largep. We find that the uncertainties of the energy eigenstates of the normal harmonic oscillator (m > 0), derived in Ref. (1), only populate thex � 1/�p branch. The other branch, �x � �p, is found to be populated by the energy eigenstates of the 'inverted' harmonic oscillator (m p 2(~ 2 /k|m|) 1/4 . Correspondence with the classical limit is also discussed.
119450303
Indirect probes of new physics
We summarize the indirect effects of new physics in a variety of processes. We consider precision electroweak measurements, the $g-2$ of the muon, rare decays, meson mixing, CP violation, lepton number violating interactions, double beta decay, and the electric dipole moments of atoms, molecules, and the neutron. We include discussions of both model independent and dependent analyses where applicable.
5643336
Constraints on R-parity violating couplings from lepton universality
We analyze the one loop corrections to leptonic W and Z decays in an R-parity violating extension to the minimal supersymmetric standard model. We find that lepton universality violation in the Z line-shape variables alone would strengthen the bounds on the magnitudes of the {lambda}{sup '} couplings, but a global fit on all data leaves the bounds virtually unchanged at |{lambda}{sub 33k}{sup '}|{<=}0.42 and |{lambda}{sub 23k}{sup '}|{<=}0.50 at the 2{sigma} level. Bounds from W decays are less stringent: |{lambda}{sub 33k}{sup '}|{<=}2.4 at 2{sigma}, as a consequence of the weaker Fermilab experimental bounds on lepton universality violation in W decays. We also point out the potential of constraining R-parity violating couplings from the measurement of the {upsilon} invisible width. (c) 2000 The American Physical Society.
215736286
STATUS AND PERSPECTIVE OF THE NB3AL DEVELOPMENT IN JAPAN
The RHQT process enables to form a stoichiometric Nb3Al with fine-grain structures via a bcc supersaturated solid solution and so that a large Jc is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized Nb3Al strand is about to be commercially available for NMR uses. Another stabilization technique has been developed and likely applicable to accelerator uses. Research activities at the KEK with respect to the low field Jc characterization are also described.
140060327
Nb-3_Al high field accelerator magnet \&
136296280
Characteristics of round and extracted strands of Nb3Al Rutherford cable
Long Nb{sub 3}Al strands with copper stabilizer are promising for future high field accelerator magnets. A 1.2 kilometer Nb{sub 3}Al strand with Cu stabilizer was fabricated at the National Institute for Materials Science in Japan. Using this strand a 30 meter Cu stabilized Nb{sub 3}Al Rutherford cable was made for the first time by a collaboration of NIMS and Fermilab. The Nb{sub 3}Al strands extracted from cable with a relatively low packing factor showed almost no J{sub c} degradation. But the extracted strands from the highly compacted cable showed some degradation in both J{sub c} and n value, which may be caused by local separation of the copper stabilizer. Still, its J{sub c} degradation is lower than that of typical Nb{sub 3}Sn strands. The current limit due to magnetic instability in low field is about 500 A at 4.2 K. The magnetization of the strands, which was measured with balanced coils at 4.2 K, showed large flux jumps, usually around 1.5 T. This value is much larger than the B{sub c2} (4.2 K) of the Nb matrix, which is around 0.4 Tesla. The magnetic instability of the Nb{sub 3}Al strand at low field is not completely understood, but it might be explained by the superconducting coupling current through the Nb matrix.
134388752
Design study of 15-Tesla RHQT Nb3Al block type dipole magnet
The design study of the block type 15-Tesla RHQT Nb{sub 3}Al dipole magnet, and its merits over Nb{sub 3}Sn magnets are presented. The copper stabilized RHQT Nb{sub 3}Al strand is now becoming commercially available for the application to the accelerator magnets. A 1 mm diameter RHQT Nb{sub 3}Al strand with filament size about 50 {mu}, non-copper Jc about 1000 A/mm{sup 2} at 15 Tesla at 4.2K, copper ratio of 50%, can now be produced over several hundred meters. The stress and strain characteristics of the Nb{sub 3}Al strand are superior to the Nb{sub 3}Sn strand. Another advantage is that it can tolerate a longitudinal strain up to 0.55%. The RHQT Nb{sub 3}Al Rutherford cable will have less chance of contamination of the stabilizer, compared to Nb{sub 3}Sn cable. These characteristics of the RHQT Nb{sub 3}Al will be beneficial for designing and producing 15-Tesla dipole magnets. An example 15-Tesla magnet cross section, utilizing the RHQT Nb{sub 3}Sn strand is presented. A systematic investigation on RHQT Nb{sub 3}Al strands, its Rutherford cables, and building a small racetrack magnet for cable testing are proposed.