118611881
A study on the relations between the topological parameter and entanglement
Abstract In this Letter, some relations between the topological parameter d and concurrences of the projective entangled states have been presented. It is shown that for the case with d = n , all the projective entangled states of two n -dimensional quantum systems are the maximally entangled states (i.e. C = 1 ). And for another case with d ≠ n , C both approach 0 when d → + ∞ for n = 2 and 3. Then we study the thermal entanglement and the entanglement sudden death (ESD) for a kind of Yang–Baxter Hamiltonian. It is found that the parameter d influences not only the critical temperature T c but also the maximum entanglement value that the system can arrive at. And we also find that the parameter d has a great influence on the ESD.
122069833
Quantum Phase Transition Like Phenomenon in a Two-Qubit Yang-Baxter System
The quantum phase transition for the “q-deformed” Yang-baxter Hamiltonian has been discussed. The calculation shows when the deformed parameter q approaches 1, there exists a quantum critical point for spectral parameter θ. In this Yang-Baxter system, quantum entanglement and the geometric phase can characterize quantum phase transition.
38483038
Yang-Baxter $${\breve R}$$ matrix, entanglement and Yangian
We present a method to construct “X” form unitary Yang-Baxter $${\breve R}$$ matrices, which act on the tensor product space $${V_{i}^{j_{1}}\otimes V_{i+1}^{j_{2}}}$$ . We can obtain a set of entangled states for (2j1 + 1) × (2j2 + 1)-dimensional system with these Yang-Baxter $${\breve R}$$ matrices. By means of Yang-Baxter approach, a 8 × 8 Yang-Baxter Hamiltonian is constructed. Yangian symmetry and Yangian generators as shift operators for this Yang-Baxter system are investigated in detail.
118568245
Lepton-number violating decays of heavy mesons
The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various ΔL=2 processes for pseudoscalar meson M1 decays to another pseudoscalar meson M2 and two charged leptons ℓ1, ℓ2 ($M_{1}^{+}\rightarrow \ell_{1}^{+}\ell_{2}^{+}M_{2}^{-}$) have been studied extensively. Extending the existing literature on the studies of these kinds of process, we consider the rare decays of heavy mesons to a vector meson or a pseudoscalar meson. These processes have not been searched for experimentally, while they may have sizable decay rates. We calculate their branching fractions and propose to search for these decay modes in the current and forthcoming experiments, in particular at the LHCb.
119169539
Elliptic flow in the Gaussian model of eccentricity fluctuations
Abstract We discuss a specific model of elliptic flow fluctuations due to Gaussian fluctuations in the initial spatial x and y eccentricity components { 〈 ( σ y 2 − σ x 2 ) / ( σ x 2 + σ y 2 ) 〉 , 〈 2 σ x y / ( σ x 2 + σ y 2 ) 〉 } . We find that in this model v 2 { 4 } , elliptic flow determined from 4-particle cumulants, exactly equals the average flow value in the reaction plane coordinate system, 〈 v RP 〉 , the relation which, in an approximate form, was found earlier by Bhalerao and Ollitrault in a more general analysis, but under the same assumption that v 2 is proportional to the initial system eccentricity. We further show that in the Gaussian model all higher order cumulants are equal to v 2 { 4 } . Analysis of the distribution in the magnitude of the flow vector, the Q -distribution, reveals that it is totally defined by two parameters, v 2 { 2 } , the flow from 2-particle cumulants, and v 2 { 4 } , thus providing equivalent information compared to the method of cumulants. The flow obtained from the Q -distribution is again v 2 { 4 } = 〈 v RP 〉 .
119398656
The Instantaneous formulations for Bethe Salpeter equation and radiative transitions between two bound states
The instantaneous formulations for the relativistic Bethe-Salpeter (BS) and the radiative transitions between the bound-states are achieved if the BS kernel is instantaneous. It is shown that the original Salpeter instantaneous equation set up on the BS equation with an instantaneous kernel should be extended to involve the `small (negative energy) component' of the BS wave functions. As a precise example of the extension for the bound states with one kind of quantum number, the way to reduce the novel extended instantaneous equation is presented. How to guarantee the gauge invariance for the radiative transitions which is formulated in terms of BS wave functions, especially, which is formulated in the instantaneous formulation, is shown. It is also shown that to `guarantee' the gauge invariance for the radiative transitions in instantaneous formulation, the novel instantaneous equation for the bound states plays a very important role. Prospects on the applications and consequences of the obtained instantaneous formulations are outlined.
55938998
BEAM DIAGNOSTICS USING BPM SIGNALS FROM INJECTED AND STORED BEAMS IN A STORAGE RING
Many modern light sources are operating in top-off injection mode or are being upgraded to top-off injection mode. The storage ring always has the stored beam and injected beam for top-off injection mode. So the BPM data is the mixture of both beam positions and the injected beam position cannot be measured directly. We propose to use dedicated wide band BPM electronics in the NSLS II storage ring to retrieve the injected beam trajectory with the singular value decomposition (SVD) method. The beam position monitor (BPM) has the capability to measure bunch-by-bunch beam position. Similar electronics can be used to measure the bunch-by-bunch beam current which is necessary to get the injection beam position. The measurement precision of current needs to be evaluated since button BPM sum signal has position dependence. The injected beam trajectory can be measured and monitored all the time without dumping the stored beam. We can adjust and optimize the injected beam trajectory to maximize the injection efficiency. We can also measure the storage ring acceptance by mapping the injected beam trajectory.
110998320
Determination of the Tc distribution for 1000 Transition Edge Sensors
The ZIP detectors deployed in the CDMS II experiment utilize phonon sensors comprising W Transition Edge Sensors (TESs). In order to ensure uniform collection of the athermal phonon signal the TESs are dispersed uniformly on one side of a 1 cm thick, 3 inch diameter, disk. Each quadrant contains 1036 TESs connected in parallel to one series-array SQUID amplifier. The initial superconducting transition temperatures of these TESs tend to be too high for our requirements, and substantial gradients make the operation of the detectors difficult. Hence our implementation of Fe-56 ion implantation, as reported at the previous LTD meeting, to reduce in a controlled manner the transition temperature. However, the successful implementation of this ion-implantation scheme requires accurate knowledge of the initial transition temperature of each TES in a given quadrant. We report on our approaches and techniques employed to address the issue of determining the initial Tc distribution.