Utrilla Gines, E., Mena, O., & Witte, S. J. (2022). Revisiting constraints on WIMPs around primordial black holes. Phys. Rev. D, 106(6), 063538–14pp.
Abstract: While primordial black holes (PBHs) with masses MPBH greater than or similar to 10-11 Mo cannot comprise the entirety of dark matter, the existence of even a small population of these objects can have profound astrophysical consequences. A subdominant population of PBHs will efficiently accrete dark matter particles before matter-radiation equality, giving rise to high-density dark matter spikes. We consider here the scenario in which dark matter is comprised primarily of weakly interacting massive particles (WIMPs) with a small subdominant contribution coming from PBHs, and revisit the constraints on the annihilation of WIMPs in these spikes using observations of the isotropic gamma-ray background (IGRB) and the cosmic microwave background (CMB), for a range of WIMP masses, annihilation channels, cross sections, and PBH mass functions. We find that the constraints derived using the IGRB have been significantly overestimated (in some cases by many orders of magnitude), and that limits obtained using observations of the CMB are typically stronger than, or comparable to, those coming from the IGRB. Importantly, we show that similar to OoMo thorn PBHs can still contribute significantly to the dark matter density for sufficiently low WIMP masses and p-wave annihilation cross sections.
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Wu, J. et al, Algora, A., Agramunt, J., Morales, A. I., Orrigo, S. E. A., Tain, J. L., et al. (2022). First observation of isomeric states in 111Zr, 113Nb, and 115Mo. Phys. Rev. C, 106(6), 064328–5pp.
Abstract: Isomeric states in the neutron-rich nuclei 111Zr [T1/2 = 0.10(7) μs], 113Nb [T1/2 = 0.7(4) μs], 115Mo [T1/2 = 46(3) μs] were first identified at the Radioactive Ion Beam Factory (RIBF) of RIKEN by using in-flight fission and fragmentation of a 238U beam at an energy of 345 MeV/u. This is a brief report of the gamma transitions de -exciting from isomeric states and half-lives measurements, which provides the first spectroscopy in the nuclear region of prolate-to-oblate shape-phase transition around mass A approximate to 110.
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Fernandez-Silvestre, D., Foo, J., & Good, M. R. R. (2022). On the duality of Schwarzschild-de Sitter spacetime and moving mirror. Class. Quantum Gravity, 39(5), 055006–18pp.
Abstract: The Schwarzschild-de Sitter (SdS) metric is the simplest spacetime solution in general relativity with both a black hole event horizon and a cosmological event horizon. Since the Schwarzschild metric is the most simple solution of Einstein's equations with spherical symmetry and the de Sitter metric is the most simple solution of Einstein's equations with a positive cosmological constant, the combination in the SdS metric defines an appropriate background geometry for semi-classical investigation of Hawking radiation with respect to past and future horizons. Generally, the black hole temperature is larger than that of the cosmological horizon, so there is heat flow from the smaller black hole horizon to the larger cosmological horizon, despite questions concerning the definition of the relative temperature of the black hole without a measurement by an observer sitting in an asymptotically flat spacetime. Here we investigate the accelerating boundary correspondence of the radiation in SdS spacetime without such a problem. We have solved for the boundary dynamics, energy flux and asymptotic particle spectrum. The distribution of particles is globally non-thermal while asymptotically the radiation reaches equilibrium.
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Perez-Ramos, R., Sanchis-Lozano, M. A., & Sarkisyan-Grinbaum, E. K. (2022). Searching for hidden matter with long-range angular correlations at e(+)e(-) colliders. Phys. Rev. D, 105(5), 053001–8pp.
Abstract: The analysis of azimuthal correlations in multiparticle production can be useful to uncover the existence of new physics beyond the Standard Model, e.g., Hidden Valley, in e(+)e(-) annihilation at high energies. In this paper, based on previous theoretical studies and using the PYTHIA8 event generator, it is found that both azimuthal and rapidity long-range correlations are enhanced due to the presence of a new stage of matter on top of the QCD partonic cascade. Ridge structures, similar to those observed in hadronic collisions at the LHC, show up providing a possible signature of new physics at future e(+)e(-) colliders.
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Menendez, A., Esperante, D., Garcia-Olcina, R., Torres, J., Perez-Soler, J., Marco, R., et al. (2022). RF Acquisition System Based on μTCA for Testing of High-Gradient Acceleration Cavities. Electronics, 11(5), 720–22pp.
Abstract: The radio frequency (RF) laboratory hosted in the Corpuscular Physics Institute (IFIC) of the University of Valencia is designed to house a high-power and high-repetition-rate facility to test normal conduction RF accelerator cavities in the S-Band (2.9985 GHz) in order to perform R & D activities related to particle accelerator cavities. The system, which manages the entire process of RF signal generation, data acquisition and closed-loop control of the laboratory, is currently based on a modular and compact PXI platform system. This contribution details the development of a platform with similar features, but which is based on open architecture standards at both the hardware and software level. For this purpose, a complete system based on the μTCA platform has been developed. This new system must be able to work with accelerator cavities at other operating frequencies, such as 750 MHz, as well as to explore different options at firmware and software levels based on open-source codes.
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de Anda, F. J., Medina, O., Valle, J. W. F., & Vaquera-Araujo, C. A. (2022). Scotogenic Majorana neutrino masses in a predictive orbifold theory of flavor. Phys. Rev. D, 105(5), 055030–12pp.
Abstract: The use of extra space-time dimensions provides a promising approach to the flavor problem. The chosen compactification of a 6-dimensional orbifold implies a remnant family symmetry A4. This makes interesting predictions for quark and lepton masses, for neutrino oscillations and neutrinoless double beta decay, providing also a very good global description of all flavor observables. Due to an auxiliary Z4 symmetry, we implement a scotogenic Majorana neutrino mass generation mechanism with a viable WIMP dark matter candidate.
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Bruschini, R., & Gonzalez, P. (2022). Is chi(c1)(3872) generated from string breaking? Phys. Rev. D, 105(5), 054028–6pp.
Abstract: We show, from a diabatic analysis of lattice results for string breaking, that mixing of Q (Q) over bar with open-flavor meson-meson configurations may be expressed through a mixing potential which is order 1/m(Q). A relation between the minimum string breaking energy gap and the string tension comes out naturally. Using this relation, and matching the energy gap for b (b) over bar with lattice QCD data, we study the mixing in the c (c) over bar case without any additional parameter. A 1(++) bound state very close below the D-0(D) over bar*(0) threshold, in perfect correspondence with chi(c1)(3872), is predicted.
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Sieber, H., Banerjee, D., Crivelli, P., Depero, E., Gninenko, S. N., Kirpichnikov, D. V., et al. (2022). Prospects in the search for a new light Z0 boson with the NA64 μexperiment at the CERN SPS. Phys. Rev. D, 105(5), 052006–9pp.
Abstract: A light Z0 vector boson coupled to the second and third lepton generations through the L μ- L tau current with mass below 200 MeV provides a very viable explanation in terms of new physics to the recently confirmed og – 2 thorn μanomaly. This boson can be produced in the bremsstrahlung reaction μN – μNZ0 after a high energy muon beam collides with a target. NA64 μis a fixed-target experiment using a 160 GeV muon beam from the CERN Super Proton Synchrotron accelerator looking for Z0 production and its subsequent decays, Z0 – invisible. In this paper, we present the study of the NA64 μsensitivity to search for such a boson. This includes a realistic beam simulation, a detailed description of the detectors and a discussion about the main potential background sources. A pilot run is scheduled in order to validate the simulation results. If those are confirmed, NA64 μwill be able to explore all the remaining parameter space which could provide an explanation for the g – 2 muon anomaly in the L μ- L tau model.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2022). Measurement of the photon polarization in Lambda(0)(b) -> Lambda gamma decays. Phys. Rev. D, 105(5), L051104–11pp.
Abstract: The photon polarization in b -> s gamma transitions is measured for the first time in radiative b -baryon decays exploiting the unique spin structure of Lambda(0)(b)-> Lambda(gamma) decays. A data sample corresponding to an integrated luminosity of 6 fb(-1) collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV is used. The photon polarization is measured to be alpha(gamma) = 0.82(-0.26-0.)(13)(+)(0.17+0.04), where the first uncertainty is statistical and the second systematic. This result is in agreement with the Standard Model prediction and previous measurements in b-meson decays. Charge-parity breaking effects are studied for the first time in this observable and found to be consistent with CP symmetry.
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AbdusSalam, S. S. et al, & Eberhardt, O. (2022). Simple and statistically sound recommendations for analysing physical theories. Rep. Prog. Phys., 85(5), 052201–11pp.
Abstract: Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at Zenodo.
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