119273385
Symmetry and special relativity in Finsler spacetime with constant curvature
Within the framework of projective geometry, we investigate kinematics and symmetry in (alpha, beta) spacetime one special types of Finsler spacetime. The projectively flat (alpha, beta) spacetime with constant flag curvature is divided into four types. The symmetry in type A-Riemann spacetime with constant sectional curvature-is just the one in de Sitter special relativity. The symmetry in type B-locally Minkowski spacetime-is just the one in very special relativity. It is found that type C-Funk spacetime and type D-scaled Berwald's metric spacetime both possess the Lorentz group as its isometric group. The geodesic equation, algebra and dispersion relation in the (alpha, beta) spacetime are given. The corresponding invariant special relativity in the four types of (alpha, beta) spacetime contain two parameters, the speed of light and a geometrical parameter, which may relate to the new physical scale. They all reduce to Einstein's special relativity while the geometrical parameter vanishes. (C) 2012 Elsevier B.V. All rights reserved.
118441255
OPERA SUPERLUMINAL NEUTRINOS AND KINEMATICS IN FINSLER SPACETIME
The OPERA collaboration recently reported that the muon neutrinos could be superluminal. More recently, Cohen and Glashow pointed that such superluminal neutrinos would be suppressed since they lose their energies rapidly via bremsstrahlung. Here, we propose that the Finslerian nature of the space time could account for the superluminal phenomena of particles. The Finsler spacetime permits the existence of the superluminal behavior of particles while the causality still holds. A new dispersion relation is obtained in a class of Finsler spacetimes. It is shown that the superluminal speed is linearly dependent on the energy per unit mass of the particle. We find that such a superluminal speed formula is consistent with the data of the OPERA, MINOS and Fermilab-1979 neutrino experiments as well as the observations on the neutrinos from the SN1987A.
15016243
A Possible scenario of the Pioneer anomaly in the framework of Finsler geometry
The weak field approximation of geodesics in Randers-Finsler space is investigated. We show that a Finsler structure of Randers space corresponds to the constant and sunward anomalous acceleration demonstrated by the Pioneer 10 and 11 data. The additional term in the geodesic equation acts as "electric force", which provides the anomalous acceleration. (C) 2010 Elsevier B.V. All rights reserved.
14726570
Massive domain wall fermions on four-dimensional anisotropic lattices
We formulate the massive domain wall fermions on anisotropic lattices. For the massive domain wall fermion, we find that the dispersion relation assumes the usual form in the low momentum region when the bare parameters are properly tuned. The quark self-energy and the quark field renormalization constants are calculated to one-loop in bare lattice perturbation theory. For light domain wall fermions, we verified that the chiral mode is stable against quantum fluctuations on anisotropic lattices. This calculation serves as a guidance for the tuning of the parameters in the quark action in future numerical simulations.
119115494
Neutrino superluminality without Cherenkov-like processes in Finslerian special relativity
Recently, Cohen and Glashow [A.G. Cohen, S.L. Glashow, Phys. Rev. Lett. 107 (2011) 181803] pointed out that the superluminal neutrinos reported by the OPERA would lose their energy rapidly via the Cherenkov-like process. The Cherenkov-like process for the superluminal particles would be forbidden if the principle of special relativity holds in any frame instead violated with a preferred frame. We have proposed that the Finslerian special relativity could account for the data of the neutrino superluminality (arXiv:1110.6673 [hep-ph]). The Finslerian special relativity preserves the principle of special relativity and involves a preferred direction while consists with the causality. In this Letter, we prove that the energy-momentum conservation is preserved and the energy-momentum is well defined in Finslerian special relativity. The Cherenkov-like process is forbidden in the Finslerian special relativity. Thus, the superluminal neutrinos would not lose energy in their distant propagation. (C) 2012 Elsevier B.V. All rights reserved.
119312663
Unification of Dark Matter and Dark Energy in a Modified Entropic Force Model
In Verlinde's entropic force scenario of gravity, Newton's laws and Einstein equations can be obtained from the first principles and general assumptions. However, the equipartition law of energy is invalid at very low temperatures. We show clearly that the threshold of the equipartition law of energy is related with horizon of the universe. Thus, a one-dimensional Debye (ODD) model in the direction of radius of the modified entropic force (MEF) may be suitable in description of the accelerated expanding universe. We present a Friedmann cosmic dynamical model in the ODD-MEF framework. We examine carefully constraints on the ODD-MEF model from the Union2 compilation of the Supernova Cosmology Project (SCP) collaboration, the data from the observation of the large-scale structure (LSS) and the cosmic microwave background (CMB), i.e. SNe Ia+LSS+CMB. The combined numerical analysis gives the best-fit value of the model parameters zeta similar or equal to 10(-9) and Omega(m0) = 0.224, with chi(2)(min) = 591.156. The corresponding age of the universe agrees with the result of D. Spergel et al. [J.M. Bardeen, B. Carter, and S.W. Hawking, Commun. Math. Phys. 31 (1973) 161] at 95% confidence level. The numerical result also yields an accelerated expanding universe without invoking any kind of dark energy. Taking zeta( 2 pi omega(D)/H-0) as a running parameter associated with the structure scale r, we obtain a possible unified scenario of the asymptotic flatness of the radial velocity dispersion of spiral galaxies, the accelerated expanding universe and the Pioneer 10/11 anomaly in the entropic force framework of Verlinde.
118442016
Extracting the nuclear symmetry potential and energy from neutron-nucleus scattering data
Abstract According to the Hugenholtz–Van Hove theorem, the symmetry energy and its density slope can be decomposed uniquely in terms of the single-nucleon potential in asymmetric nuclear matter which, at normal density, can be constrained by the nucleon optical model potential extracted from analyzing the nucleon–nucleus scattering data. To more accurately extract information on the symmetry energy and its density slope at normal density from neutron–nucleus scattering data, going beyond the well-known Lane potential, we include consistently the second-order terms in isospin asymmetry in both the optical model potential and the symmetry energy decomposition. We find that the strength of the second-order symmetry potential U sym , 2 in asymmetric nuclear matter is significant compared to the first-order one U sym , 1 , especially at high nucleon momentum. While the U sym , 1 at normal density decreases with nucleon momentum, the U sym , 2 is found to have the opposite behavior. Moreover, we discuss effects of the U sym , 1 and U sym , 2 on determining the density dependence of the symmetry energy, and we find that the available neutron–nucleus scattering data favor a softer density dependence of the symmetry energy at normal density with a negligible contribution from the U sym , 2 .
195859510
Front-end electronics for PHENIX time expansion chamber
Front-end electronics (FEE) has been developed for the PHENIX time expansion chamber (TEC), a multi-wire tracking detector with over 20k readout channels. The FEE for the TEC consists of an analog preamplifier shaping amplifier circuit board, a digital front-end module circuit board plus ancillary support boards for timing, control and communication. Signals from each chamber wire are sampled (/spl sim/40 MHz), digitized, buffered, and then formatted as 64 channel serial data packets to be transmitted via 1 GHz optical link. Three custom IC's have been designed for this system: 1) octal preamplifier and shaping amplifier with tail cancellation and dual-gain for large dynamic range with full serial control of gain, shaping time and tail; 2) nonlinear 5 bit flash-ADC with 9 bit dynamic range; 3) digital memory unit for programmable delay and memory depth. The FEE has been installed, commissioned and operated in the PHENIX experiment at Brookhaven National Laboratory.
118410842
$p$-wave chiral superfluidity from an $s$-wave interacting atomic Fermi gas
X iv :1 40 2. 59 95 v1 [ co nd -m at .q ua nt -g as ] 24 F eb 2 01 4 p-wave chiral superfluidity from an s-wave interacting atomic Fermi gas Bo Liu , Xiaopeng Li , Biao Wu, and W. Vincent Liu Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA 2 Condensed Matter Theory Center, University of Maryland, Co llege Park, MD 20742, USA Joint Quantum Institute, University of Maryland, College P ark, MD 20742, USA International Center for Quantum Materials, Peking University, Beijing 100871, China Collaborative Innovation Center of Quantum Matter, Beijin g, China (Dated: February 26, 2014) Abstract Chiralp-wave superfluids are fascinating topological quantum stat e of matter that have been found in the liquid 3He-A phase and arguably in the electronic Sr 2RuO4 superconductor. They are shown fundamentally related to the fractional 5/2 quantum Hall state which supports fractional exotic excita tions. A common understanding is that such states require spin-triplet pai ring of fermions due top-wave interaction. Here we report by controlled theoretical approximation that a cent er-of-mass Wannier p-wave chiral superfluid state can arise from spin-singlet pairing for an s-wave interacting atomic Fermi gas in an optical lattice. De spite a conceptually different origin, it shows topological prop erties similar to the conventional chiral p-wave state. These include a non-zero Chern number and the appeara nc of chiral fermionic zero modes bounded to domain walls. Several signature quantities are calculat ed for the cold atom experimental condition.
119191019
The effects of a family non-universal Z-prime boson on B--->pipi decays
Motivated by the measured large branching ratio of (the so-called ππ puzzle), we investigate the effects of a family nonuniversal Z′ model on the tree-dominated B → ππ decays. We find that the Z′ coupling parameter with a nontrivial new weak phase , which is relevant to the Z′ contributions to the QCD penguin sector △C5, is needed to reconcile the observed discrepancy. Combined with the recent fitting results from B → πK, πK* and ρK decays, the Z′ parameter spaces are severely reduced but still not excluded entirely, implying that both the "ππ" and "πK" puzzles could be accommodated simultaneously within such a family nonuniversal Z′ model.
120176772
Design of the local trigger board for the Daya Bay reactor neutrino experiment
We have designed a local trigger board for the Daya Bay reactor neutrino experiment, which is aimed to measure the neutrino mixing angle sin(2) 2 theta(13) with a precision down to 1% level. The local trigger board processes both the total number of coincident photomultiplier tube (PMT) hits and the PMT energy sum to make trigger decisions. With this design, a high trigger probability is achieved to meet the system requirement. The design of the local trigger board is presented. (C) 2011 Elsevier B.V. All rights reserved.