Meson Exchange Current (MEC) Models in Neutrino Interaction Generators

6 pages, 5 figures, 1 table, proceedings of the 8th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt12), Rio de Janeiro, Brazil, 22-27 October 201

Determinantal process starting from an orthogonal symmetry is a Pfaffian process

When the number of particles $N$ is finite, the noncolliding Brownian motion (BM) and the noncolliding squared Bessel process with index $\nu > -1$ (BESQ$^{(\nu)}$) are determinantal processes for arbitrary fixed initial configurations. In the present paper we prove that, if initial configurations are distributed with orthogonal symmetry, they are Pfaffian processes in the sense that any multitime correlation functions are expressed by Pfaffians. The $2 \times 2$ skew-symmetric matrix-valued correlation kernels of the Pfaffians processes are explicitly obtained by the equivalence between the noncolliding BM and an appropriate dilatation of a time reversal of the temporally inhomogeneous version of noncolliding BM with finite duration in which all particles start from the origin, $N \delta_0$, and by the equivalence between the noncolliding BESQ$^{(\nu)}$ and that of the noncolliding squared generalized meander starting from $N \delta_0$.Comment: v2: AMS-LaTeX, 17 pages, no figure, corrections made for publication in J.Stat.Phy

Tests of Lorentz and CPT violation with neutrinos

11 pages, 8 figures, proceedings of the 36th International Conference on High Energy Physics (ICHEP2012), Melbourne, Victoria, Australia, July 4-11, 201211 pages, 8 figures, proceedings of the 36th International Conference on High Energy Physics (ICHEP2012), Melbourne, Victoria, Australia, July 4-11, 2012Lorentz violation is a predicted phenomenon from the Planck scale physics. Although the three active massive neutrino framework with the Standard Model (SM), so-called the neutrino Standard Model (nuSM), is successful, series of signals not understood within the nuSM suggest neutrino physics may be the first place to see the physics beyond the SM, such as Lorentz violation. Especially, neutrino oscillations are the natural interferometer and they are sensitive to the Lorentz violation. The LSND oscillation signal was analyzed under the Standard Model Extension (SME) framework, and it was found that the oscillation data was consistent with no Lorentz violation, but data cannot reject Lorentz violation hypothesis with order ~10^{-17}. By assuming LSND signal was due to the Lorentz violation, a global phenomenological model was made to describe all known oscillation data including the LSND signal. The model also predicted the signal for MiniBooNE at the low energy region. Later, MiniBooNE announced an event excess at the low energy region. However, the oscillation candidate signals from MiniBooNE were consistent with no Lorentz violation. The limit obtained by MiniBooNE and MINOS on the e-mu sector reject the simple scenario to explain LSND signal with Lorentz violation. Meantime, MINOS and IceCube set tight limits on the mu-tau sector Lorentz violation. The last untested channel, the e-tau Lorentz violating mixing, was tested using reactor disappearance data from Double Chooz. However, Double Chooz data was consistent with flat, and sidereal time dependent Lorentz violation hypothesis is rejected. Combinations of all oscillation data from LSND, MiniBooNE, MINOS, IceCube, and Double Chooz provide very tight constraint for a possible Lorentz violation in the neutrino sector in terrestrial level

TESTS OF LORENTZ AND CPT VIOLATION WITH MiniBooNE NEUTRINO OSCILLATION EXCESSES

Preprint of an article submitted for consideration in Modern Physics Letter A \c{opyright} 2012 [copyright World Scientific Publishing Company] http://www.worldscientific.com/worldscinet/mpl

Neutrino Cross Section Measurements for Long-Baseline Accelerator-based Neutrino Oscillation Experiments

8 pages, 8 figures, Proceedings of the XLIIIrd Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, March 1-8, 20088 pages, 8 figures, Proceedings of the XLIIIrd Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Italy, March 1-8, 2008Neutrino oscillations are clear evidence for physics beyond the standard model. The goal of next-generation neutrino oscillation experiments is to find a non-zero $\theta_{13}$, the last mixing matrix element for which we only know an upper limit. For this, next-generation long-baseline neutrino oscillation experiments require an order of magnitude better sensitivities. In particular, accelerator-based experiments such as T2K and NOvA experiments need (1) good neutrino energy reconstruction for the precise measurement of $\Delta m^2_{32}$ and $sin^22\theta_{23}$, and (2) good background prediction to measure $\nu_e$ appearance signals. Current and near future high statistics neutrino experiments, such as K2K, MiniBooNE, SciBooNE, MINOS, and MINERvA help both (1) and (2) by precise signal and background channel measurements

System of Complex Brownian Motions Associated with the O'Connell Process

The O'Connell process is a softened version (a geometric lifting with a parameter $a>0$) of the noncolliding Brownian motion such that neighboring particles can change the order of positions in one dimension within the characteristic length $a$. This process is not determinantal. Under a special entrance law, however, Borodin and Corwin gave a Fredholm determinant expression for the expectation of an observable, which is a softening of an indicator of a particle position. We rewrite their integral kernel to a form similar to the correlation kernels of determinantal processes and show, if the number of particles is $N$, the rank of the matrix of the Fredholm determinant is $N$. Then we give a representation for the quantity by using an $N$-particle system of complex Brownian motions (CBMs). The complex function, which gives the determinantal expression to the weight of CBM paths, is not entire, but in the combinatorial limit $a \to 0$ it becomes an entire function providing conformal martingales and the CBM representation for the noncolliding Brownian motion is recovered.Comment: v3: AMS_LaTeX, 25 pages, no figure, minor corrections made for publication in J. Stat. Phy

TEST FOR LORENTZ AND CPT VIOLATION WITH THE MINIBOONE LOW-ENERGY EXCESS

Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 201

Beyond Standard Model Searches in the MiniBooNE Experiment

29 pages, 18 figures, preprint of an article submitted in Advances in High Energy Physics http://www.hindawi.com/journals/ahep/Janet Conrad thanks the National Science Foundation for support through NSF-PHY-1205175

Testing Lorentz Symmetry with the Double Chooz Experiment

4 pages, 1 figure, presented at the Sixth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 17-21, 20134 pages, 1 figure, presented at the Sixth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 17-21, 2013The Double Chooz reactor-based oscillation experiment searches for an electron antineutrino disappearance signal to investigate the neutrino mass matrix mixing angle theta 13. Double Chooz's reported evidence for this disappearance is generally interpreted as mass-driven mixing through this parameter. However, the electron antineutrino candidates collected by the experiment can also be used to search for a signature of the violation of Lorentz invariance. We study the sidereal time dependence of the antineutrino signal rate and probe Lorentz violation within the Standard-Model Extension (SME) framework. We find that the data prefer the sidereal time independent solution, and a number of limits are applied to the relevant SME coefficients, including the first constraints on those associated with Lorentz violation in the e-tau mixing sector