Light from thermal black body radiators such as stars exhibits photon bunching behaviour at sufficiently short time-scales. However, with available detector bandwidths, this bunching signal is difficult to be directly used for intensity interferometry with sufficient statistics in astronomy. Here we present an experimental technique to increase the photon bunching signal in blackbody radiation via spectral filtering of the light source. Our measurements reveal strong temporal photon bunching in light from blackbody radiation, including the Sun. Such filtering techniques may revive the interest in intensity interferometry as a tool in astronomy.

Conventional ground-based astronomical observations suffer from image distortion due to atmospheric turbulence. This can be minimized by choosing suitable geographic locations or adaptive optical techniques, and avoided altogether by using orbital platforms outside the atmosphere. One of the promises of optical intensity interferometry is its independence from atmospherically induced phase fluctuations. By performing narrowband spectral filtering on sunlight and conducting temporal intensity interferometry using actively quenched avalanche photon detectors (APDs), the Solar g (2) (τ ) signature was directly measured. We observe an averaged photon bunching signal of g (2) (τ ) = 1.693 ± 0.003 from the Sun, consistently throughout the day despite fluctuating weather conditions, cloud cover and elevation angle. This demonstrates the robustness of the intensity interferometry technique against atmospheric turbulence and opto-mechanical instabilities, and the feasibility to implement measurement schemes with both large baselines and long integration times.

As shown recently, one can obtain additional information from the measured charged particle multiplicity distributions, P (N ), by extracting information from the modified combinants, C j . This information is encoded in their specific oscillatory behavior, which can be described only by some combinations of compound distributions such as the Binomial Distribution. This idea has been applied to pp and pp processes thus far. In this note we show that an even stronger effect is observed in the C j deduced from e + e − collisions. We present its possible explanation in terms of the Generalised Multiplicity Distribution (GMD) proposed some time ago.

As shown recently, one can obtain additional information from the measured charged particle multiplicity distributions, P (N ), by investigating the so called modified combinants, C j , extracted from them. This information is encoded in the observed specific oscillatory behavior of C j , which phenomenologically can be described only by some combinations of compound distributions based on the Binomial Distribution. So far this idea has been checked in pp and e + e − processes (where observed oscillations are spectacularly strong). In this paper we continue observation of multiparticle production from the modified combinants perspective by investigating dependencies of the observed oscillatory patterns on type of colliding particles, their energies and the phase space where they are observed. We also offer some tentative explanation based on different types of compound distributions and stochastic branching processes.

We propose a hybrid quantum architecture for engineering a photonic Mott insulator-superfluid phase transition in a 2D square lattice of superconducting transmission line resonator (TLR) coupled to a single nitrogenvacancy (NV) center encircled by a persistent current qubit. The localization-delocalization transition results from the interplay between the on-site repulsion and the nonlocal tunneling. The phase boundary in the case of photon hopping with real-valued and complex-valued amplitudes can be obtained using the mean-field approach. Also, the quantum jump technique is employed to describe the phase diagram when the dissipative effects are considered. The unique feature of our architecture is the good tunability of effective on-site repulsion and photon-hopping rate, and the local statistical property of TLRs which can be analyzed readily using present microwave techniques. Our work opens new perspectives in quantum simulation of condensed-matter and many-body physics using a hybrid spin circuit QED system. The experimental challenges are realizable using current available technologies.

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We study the evolution of Lee-Yang zeros structure of generalized multiplicity distribution (GMD) in high energy collision. Starting our study with electron-positron e + e − scattering data, we extend the study by Chan and Chew (Z. Phys. C 55:503, 1992) on TASSO and AMY multiplicity data for √ s = 14, 22, 34.8, 43.6 and 57 GeV to the ones from DELPHI and OPAL Collaboration for √ s = 91, 133, 161, 172, 183 and 189 GeV. We compare the results with the Lee-Yang structure for proton-antiproton pp at √ s = 200, 546 and 900 GeV from UA5 Collaboration. Our preliminary result shows that there is indeed a change in the shape and size of the Lee-Yang zeros with increasing energy, accompanied by the development of the so-called "ear"-like structure in the Lee-Yang plot. We expect that the development of this "ear"-like structure is related to the "shoulder" structure in the multiplicity data, which further indicates an ongoing phase transition from soft to semihard scattering. We also extend our prediction to LHC's √ s = 14 TeV. Insert your abstract here.

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