Speed of particles and a relativity of locality in κ-Minkowski quantum spacetime

The last decade of research on κ-Minkowski noncommutative spacetime has been strongly characterized by a controversy concerning the speed of propagation of massless particles. Most arguments suggested that this speed should depend on the momentum of the particle strongly enough to be of interest for some ongoing experimental studies. But the only explicit derivations of worldlines in κ-Minkowski predicted no momentum dependence for the speed of massless particles. We return to this controversy equipped with the recent understanding that in some quantum spacetimes coincidences of events assessed by an observer who is distant from the events can be artifactual. We therefore set up our investigation in such a way that we never rely on the assessment of coincidences of events by distant observers. This allows us to verify explicitly that in κ-Minkowski simultaneously-emitted massless particles of different momentum are detected at different times, and establish a linear dependence of the detection times on momentum.     

Measurement of the branching ratios for the decays J/ψ → ϱπ and J/ψ → γη′

Decays of the J/ψ (3.1) resonance into final states with two charged hadrons and two photons are investigated. Branching ratios for the decays J/ψ → ?π and J/ψ → γη′ are determined to be

$\text{Г(J/ψ → pφ)}\text{Г(J/ψ → all)}\text{= (1.0± 0.2) ·10}{}^{\mathrm{?2}}\text{,}\text{Г(J/ψ → γη′)}\text{ГJ/ψ → all)}\text{= (2.0± 0.7) ·}{}^{\mathrm{?3}}$

Upper limits for the same decay modes of ψ′ (3.7) are also determined.     

The property of κ-deformed statistics for a relativistic gas in an electromagnetic field: κ parameter and κ-distribution

We investigate the physical property of the κ parameter and the κ-distribution in the κ-deformed statistics, based on Kaniadakis entropy, for a relativistic gas in an electromagnetic field. We derive two relations for the relativistic gas in the framework of κ-deformed statistics, which describe the physical situation represented by the relativistic κ-distribution function, provide a reasonable connection between the parameter κ  , the temperature four-gradient and the four-vector potential gradient, and thus present for the case κ≠0$\kappa \ne 0$ one clearly physical meaning. It is shown that such a physical situation is a meta-equilibrium state of the system, but has a new physical characteristic.     

Zero-energy states bound to a magnetic π-flux vortex in a two-dimensional topological insulator

We show that the existence of a pair of zero-energy modes bound to a vortex carrying a π-flux is a generic feature of the topologically non-trivial phase of the M–B model, which was introduced to describe the topological band insulator in HgTe quantum wells. We explicitly find the form of the zero-energy states of the corresponding Dirac equation, which contains a novel momentum-dependent mass term and describes a generic topological transition in a band insulator. The obtained modes are exponentially localized in the vortex-core, with the dependence of characteristic length on the parameters of the model matching the dependence extracted from a lattice version of the model. We consider in full generality the short-distance regularization of the vector potential of the vortex, and show that a particular choice yields the modes localized and simultaneously regular at the origin. Finally, we also discuss a realization of two-dimensional spin-charge separation through the vortex zero-modes.     

Quantum interferences in coherent population trapping of a cold double Λ-type atom

We investigate quantum interferences in coherent population trapping of a cold double Λ-type four-level atomic system driven by two counterpropagating laser fields. We study both decoherence and enhanced-coherence actions resulting from the multi-transition pathways in building up the trapping state, and analyze the system operating with and without external coherences in various configurations of the atomic dipole moments.     

Secure four-site distribution and quantum communication of χ−type entangled states

The research of multi-particle entanglement is a hot topic because of its important applications and far-reaching effects on vast aspects of quantum information. The article is devoted to the χ − type entangled state, a peculiar four-particle entangled state, which is different from a four-particle GHZ or W state under stochastic local operations and classical communication (SLOCC). Secure four-site distribution using decoy particles is proposed. Moreover, applying it, several communication protocols are presented, including four-party hierarchical quantum secret sharing, supervisory three-party asymmetric deterministic secure quantum communication, etc. The security of the four-site distribution and the communication protocols are also analyzed.     

High-resolution spectroscopy of the ν8 band of methylene bromide using a quantum cascade laser

A continuous wave cavity ringdown spectrometer with a Fabry-Perot quantum cascade laser has been used to collect a rotationally-resolved infrared spectrum of the ν₈ vibrational band of methylene bromide in a slit nozzle expansion. In our laboratory, previous observations of the vibrational band were limited by spectral coverage to only the P and Q-branches and by the 24 MHz step-size of the laser [1]. The issue of limited spectral coverage has been resolved using a Fresnel rhomb and a wire grid polarizer to protect the laser from the destabilizing effects of back-reflection from the ringdown cavity. The frequency step-size of the spectrometer has been reduced from 24 MHz to 2 MHz. With both of these instrument enhancements, we have been able to record the R-branch of the vibrational band, and can resolve many lines that were previously blended in spectra acquired using a pinhole expansion nozzle. Significant hyperfine splitting was observed for the low-J transitions in the P and R-branches. It was possible to neglect the effects of hyperfine splitting for transitions involving J″ > 2 in the spectral assignment, and simulations using the constants obtained by fitting to Watson’s S-reduced Hamiltonian for CH₂⁷⁹Br⁸¹Br, and the A-reduced form for CH₂⁷⁹Br₂ and CH₂⁸¹Br₂, provide a good match to experimental spectra. A total of 297 transitions have been assigned for all three isotopologues, with a standard deviation of 0.00024 cm⁻¹(∼7 MHz).     

A study of the reactions π+p→ K+∑+ and K−p→π−∑+ at 10 GeV/c

For the first time, the reactions π⁺p→K⁺∑⁺ and K^?p→π^?∑⁺ have been studied in the same apparatus. This has been done at an adequately high momentum (10.1 GeV/c) to allow a check of the prediction of exchange degeneracy, that the differential cross sections should be converging at high energy. We have measured the cross section for momentum transfers t between t_min and t = ?0.3 (GeV/c)². We find that for both reactions the differential cross section shows an exponential fall, with no deviations right in to t =t_min (where some other experiments have shown a dip in the cross section). Furthermore, we find the magnitude of the differential cross sections to be closely similar at t = 0, with a ratio

$\text{R=}\text{(}\text{d}\text{σ}\text{d}\text{t)}{}_{\mathrm{t=0}}\text{(}\text{K}{}^{\mathrm{?}}\text{p}\text{→π}{}^{\mathrm{?}}\text{∑}{}^{\mathrm{+}}\text{)}\text{(}\text{d}\text{σ}\text{d}\text{t)}{}_{\mathrm{t=0}}\text{(π}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^{\mathrm{+}}\text{∑}{}^{\mathrm{+}}$

However, the slope for the positive reaction is about 19% steeper than that for the negative reaction.     

Controllable spontaneous emission from a double Λ-type four-level atom in an anisotropic photonic crystal

The spontaneous emission behavior of a double Λ-type four-level atom embedded in a photonic crystal (PC) with anisotropic dispersion relations is investigated. It is shown that some interesting phenomena such as the spectral-line enhancement, the spectral-line narrowing, the spectral-line suppression and the spontaneous emission cancellation can be observed by adjusting the density of states of the photonic-band-gap (PBG) reservoir and the combination of two pump intensities. The proposed scheme can be achieved by use of coherent pump fields into the transitions from the upper levels to the ground level in rubidium atom confined in a PC. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission.     

High resolution study of AsHD2: Ground state and the three bending fundamental bands ν3, ν4, and ν6

For the first time the infrared spectrum of the AsHD₂ molecule has been measured in the region of the bending fundamental bands ν₃, ν₄, and ν₆ on a Fourier transform spectrometer with a resolution of 0.0024 cm⁻¹ and analyzed. More than 5500 transitions with J^max = 26 have been assigned and used both to obtain “ground state combination differences” and for the determination of upper state ro-vibrational energies of the triad (001000), (000100), and (000001). Rotational parameters including centrifugal distortion coefficients up to octic terms of the ground vibrational state were calculated by fitting more than 500 “ground state combination differences” with J^max and . The obtained set of 24 parameters provides a rms-deviation of 0.00011 cm⁻¹. The upper energies were fitted with 52 parameters of an effective Hamiltonian which takes into account strong resonance interactions between all vibrational states of the triad (001000), (000100), and (000001). The rms-deviation for the energy levels considered in the fit is 0.00014 cm⁻¹.     

The ν1, ν4 and 3ν6 bands of methyl chloride in the 3.4-μm region: Line positions and intensities

Methyl chloride (CH₃Cl) is one of the most abundant chlorine-containing molecules in the atmosphere. For this reason a recent update was performed in HITRAN in the 640-2600 cm⁻¹ region based on the line parameters generated in Nikitin et al. [Nikitin A, Champion JP, Bürger H. J Mol Spectrosc 2005;230:174-84] with the intensities scaled to existing experimental data. CH₃Cl has a rather strong signature around 3000 cm⁻¹ which was used recently by the Atmospheric Chemistry Experiment (ACE) satellite mission to produce the first study of the global distribution of methyl chloride in the upper troposphere and stratosphere. However, it was mentioned that the CH₃Cl line positions and intensities spectroscopic parameters are of very low quality in this spectral region in the public access HITRAN or GEISA databases. We present a complete update of the line positions and line intensities for the ν₁, ν₄, 3ν₆ bands of CH₃ ³⁵Cl and CH₃ ³⁷Cl in the 3.4 μm region. For this task, Fourier transform spectra have been recorded at high resolution at the Laboratoire de Dynamique, Interactions et Réactivité in France. Measurements of line positions and line intensities have been retrieved for both isotopologues ¹²CH₃ ³⁵Cl and ¹²CH₃ ³⁷Cl in the ν₁, ν₄, 3ν₆ bands. The theoretical model accounts for the interactions coupling the (ν₁=1; ?=0), (ν₄=1; ?=±1) and (ν₆=3; ?=±1) energy levels, together with additional resonances involving several dark states.     

Microstructure and magnetic properties of a two-phase alloy of α-Fe and metastable Fe3B

Applying the hypercooling technique, the metastable-phase Fe₃B, instead of the stable-phase Fe₂B, is formed directly in the bulk Fe-B eutectic alloy melt and can be further preserved at room temperature. Measurement of magnetic properties shows that, for the bulk Fe-B eutectic alloy with Fe₃B phase, the intrinsic coercivity and retentivity become smaller, and the saturation magnetization is larger, than the stable eutectic alloy (α-Fe/Fe₂B) and some Fe-B amorphous alloys.     

CO2 laser-microwave double resonance and stark lamb-dip spectroscopy of the ν5 band of CDF3

The LMDR (laser-microwave double resonance) spectroscopy with an intense electric field was applied to the ν₅ (CF₃ degenerate stretch) fundamental band of CDF₃. The dipole moments and polarizability anisotropies in the ground and ν₅ vibrational states were determined as follows.

     

16.

The reaction pp→(Λ⁰K⁺)p at 50 and 30 GeV/c: Partial-wave analysis,Deck model and double Regge exchange     

W.E. Cleland  A. Delfosse  P.-A. Dorsaz  J.-L. Gloor  M.N. Kienzle-Focacci  G. Mancarella  A.D. Martin  M. Martin  B. Morel  P. Muhlemann  C. Nef  T. Pal  J. Rutschmann  H. Zeidler 《Nuclear Physics B》1984,239(1):27-51

     

17.

Study of vibration-rotation levels in formamide with high resolution FTIR spectroscopy: The ν₁₂, 2ν₁₂, ν₁₁, and ν₉ bands     

Lajos Sztraka  Veli-Matti Horneman 《Journal of Molecular Spectroscopy》2009,255(2):172-182

The far infrared and infrared spectra of formamide (HCONH₂) have been recorded at high resolution (0.00125 cm⁻¹) in the region of 90-1060 cm⁻¹. Over 20,000 transitions from the out-of-plane NH₂ wagging motion (n₁₂ = 1 ← 0 fundamental, n₁₂ = 2 ← 0 overtone, n₁₂ = 2 ← 1 difference bands), torsion (n₁₁ = 1 ← 0 bands), and out-of-phase NCO/NH₂ bend (n₉ = 1 ← 0 bands) have been assigned. Molecular parameters have been obtained for the ground state and the unperturbed n₁₂ = 1 state. The least-squares fit calculations were completed with the microwave data available in the literature. The complicated resonance system between the n₁₂ = 2, n₁₁ = 1, and n₉ = 1 states has been investigated carefully. Thus, we have been able to verify almost all resonances (avoided crossing) existing in the region J, K investigated. In the coupled Hamiltonian used for the fit, all Watson’s reduced parameters, including the octic ones and 16 Coriolis coupling parameters were taken into account. The rms deviation obtained from the fit was 0.000247 cm⁻¹.     

18.

Absorption spectrum of trideuteromethane between 8 and 11.5 μm: Analysis of the ν₃ and ν₆ bands     

J. Dupre-Maquaire  G. Tarrago 《Journal of Molecular Spectroscopy》1982,96(1):156-169

The analysis of the absorption spectrum of ¹²CD₃H, previously reported for the region 1200–1400 cm^?1 concerned with the ν₅ band, is now extended to cover the region 872–1213 cm^?1 including the two bands ν₃ and ν₆. These are centered at 1004.553 and 1035.917 cm^?1, respectively, and strongly coupled by a Coriolis interaction. A formulation taking this interaction into account rigorously was used; as a result, the energies for the upper states v₃ = 1 and v₆ = 1 are derived as eigenvalues of an effective Hamiltonian

(J. Mol. Spectrosc.79, 31–46 (1980)). The fit of the upper-state constants based on 1434 observed transitions including J′ and K′ values up to 22 leads to a set of 22 significant values which reproduce the observed wavenumbers with a standard deviation of 0.007 cm^?1 close to the experimental uncertainties.     

19.

Coupling of a Tl₂Ba₂CaCu₂O₈ Thin Film Intrinsic Josephson Junction and a Fabry–Perot Resonator          下载免费PDF全文

FAN Bin  WANG Zheng  YUE Hong-Wei  YAN Shao-Lin  JI Lu  HE Ming  SONG Feng-Bin  FANG Lan  ZHAO Xin-Jie 《中国物理快报》2011,28(3)

     

20.

The high-resolution infrared spectrum of thiophene between 600 and 1200 cm: A spectroscopic and theoretical study of the fundamental bands ν₆, ν₇, ν₁₃, and the c-Coriolis interacting dyad ν₅, ν₁₉     

F. Hegelund  R. Wugt Larsen 《Journal of Molecular Spectroscopy》2008,247(1):100-114

The Fourier transform infrared spectrum of gaseous thiophene, C₄H₄S, has been recorded in the 600-1200 cm⁻¹ spectral region with a resolution of ca. 0.0030 cm⁻¹. Five fundamental bands ν₁₃ (B₁, 712.1 cm⁻¹), ν₇ (A₁; 840.0 cm⁻¹), ν₆ (A₁; 1036.4 cm⁻¹), ν₅ (A₁; 1081.5 cm⁻¹) and ν₁₉ (B₂; 1084.0 cm⁻¹) have been analysed by the standard Watson model (A-reduction). Ground state rotational and quartic centrifugal distortion constants have been obtained from a simultaneous fit of ground state combination differences from four of these bands and previous microwave transitions. Upper state spectroscopic constants have been obtained for all five bands from single band fits using the Watson model. A strong c-Coriolis resonance perturbs the close lying ν₅ and ν₁₉ bands. We have analysed this dyad system by a model including first and second order Coriolis resonance using the theoretically predicted Coriolis coupling constant . From this analysis we locate the previously unobserved ν₁₉ band at 1083.969 cm⁻¹. The rotational constants, ground state quartic centrifugal distortion constants, anharmonic frequencies, and vibration-rotational constants (α-constants) predicted by quantum chemical calculations using a cc-pVTZ basis with B3LYP methodology, are compared with the present experimental data, where there is generally good agreement. A complete set of anharmonic frequencies and α-constants for all fundamental levels of the molecule is given.     

	Ground	$\text{ν}{}_5$
μ (D)	1.653 511 (29)	1.658 514 (23)
α (Å3)	?0.77 (32)	?0.58 (48)

Study of vibration-rotation levels in formamide with high resolution FTIR spectroscopy: The ν12, 2ν12, ν11, and ν9 bands

The far infrared and infrared spectra of formamide (HCONH₂) have been recorded at high resolution (0.00125 cm⁻¹) in the region of 90-1060 cm⁻¹. Over 20,000 transitions from the out-of-plane NH₂ wagging motion (n₁₂ = 1 ← 0 fundamental, n₁₂ = 2 ← 0 overtone, n₁₂ = 2 ← 1 difference bands), torsion (n₁₁ = 1 ← 0 bands), and out-of-phase NCO/NH₂ bend (n₉ = 1 ← 0 bands) have been assigned. Molecular parameters have been obtained for the ground state and the unperturbed n₁₂ = 1 state. The least-squares fit calculations were completed with the microwave data available in the literature. The complicated resonance system between the n₁₂ = 2, n₁₁ = 1, and n₉ = 1 states has been investigated carefully. Thus, we have been able to verify almost all resonances (avoided crossing) existing in the region J, K investigated. In the coupled Hamiltonian used for the fit, all Watson’s reduced parameters, including the octic ones and 16 Coriolis coupling parameters were taken into account. The rms deviation obtained from the fit was 0.000247 cm⁻¹.     

Absorption spectrum of trideuteromethane between 8 and 11.5 μm: Analysis of the ν3 and ν6 bands

The analysis of the absorption spectrum of ¹²CD₃H, previously reported for the region 1200–1400 cm^?1 concerned with the ν₅ band, is now extended to cover the region 872–1213 cm^?1 including the two bands ν₃ and ν₆. These are centered at 1004.553 and 1035.917 cm^?1, respectively, and strongly coupled by a Coriolis interaction. A formulation taking this interaction into account rigorously was used; as a result, the energies for the upper states v₃ = 1 and v₆ = 1 are derived as eigenvalues of an effective Hamiltonian

(J. Mol. Spectrosc.79, 31–46 (1980)). The fit of the upper-state constants based on 1434 observed transitions including J′ and K′ values up to 22 leads to a set of 22 significant values which reproduce the observed wavenumbers with a standard deviation of 0.007 cm^?1 close to the experimental uncertainties.     

The high-resolution infrared spectrum of thiophene between 600 and 1200 cm: A spectroscopic and theoretical study of the fundamental bands ν6, ν7, ν13, and the c-Coriolis interacting dyad ν5, ν19

The Fourier transform infrared spectrum of gaseous thiophene, C₄H₄S, has been recorded in the 600-1200 cm⁻¹ spectral region with a resolution of ca. 0.0030 cm⁻¹. Five fundamental bands ν₁₃ (B₁, 712.1 cm⁻¹), ν₇ (A₁; 840.0 cm⁻¹), ν₆ (A₁; 1036.4 cm⁻¹), ν₅ (A₁; 1081.5 cm⁻¹) and ν₁₉ (B₂; 1084.0 cm⁻¹) have been analysed by the standard Watson model (A-reduction). Ground state rotational and quartic centrifugal distortion constants have been obtained from a simultaneous fit of ground state combination differences from four of these bands and previous microwave transitions. Upper state spectroscopic constants have been obtained for all five bands from single band fits using the Watson model. A strong c-Coriolis resonance perturbs the close lying ν₅ and ν₁₉ bands. We have analysed this dyad system by a model including first and second order Coriolis resonance using the theoretically predicted Coriolis coupling constant . From this analysis we locate the previously unobserved ν₁₉ band at 1083.969 cm⁻¹. The rotational constants, ground state quartic centrifugal distortion constants, anharmonic frequencies, and vibration-rotational constants (α-constants) predicted by quantum chemical calculations using a cc-pVTZ basis with B3LYP methodology, are compared with the present experimental data, where there is generally good agreement. A complete set of anharmonic frequencies and α-constants for all fundamental levels of the molecule is given.