Tue·Jun 7, 2022Tuesday·June 7, 2022

1. 01*

   A holographic bottom-up description of light nuclide spectroscopy and stability

   Miguel Angel Martin Contreras🇨🇱 · Saulo Diles🇧🇷 · Alfredo Vega🇨🇱

   This work explores a holographic proposal to describe light nuclide spectroscopy by considering extensions to the well-known bottom-up AdS/QCD proposals, the hardwall and softwall models. We also propose an alternative description inspired by the Woods-Saxon potential. We find the static dilaton associated with this potential in this Wood-Saxon-like model. We compute the nuclide spectra finding that, despite their pure AdS/QCD origin, hardwall and softwall, as monoparametric models, have good accuracy and precision since the RMS error is near 11 $\%$ and 4 $\%$ respectively. In the case of the Wood-Saxon model, the RMS was around 1 $\%$. We also discuss configurational entropy as a tool to categorize which model is suitable to describe nuclides in terms of stability. We found that configurational entropy resembles a stability line, independent from nuclear spin, for symmetric light nuclides when considering softwall and Wood-Saxon-like models. For the hardwall case, configurational entropy, despite increasing with the constituent number, depends on the nuclear spin. Thus, the Woods-Saxon-like model emerges as the best choice to describe light nuclide spectroscopy in the bottom-up scenario.

   hep-phhep-thnucl-thPLB(2022)·13 citations
2. 02*

   Open charm and bottom meson-nucleon potentials à la nuclear force

   Yasuhiro Yamaguchi🇯🇵 · Shigehiro Yasui🇯🇵 · Atsushi Hosaka🇯🇵

   We discuss the interaction of an open heavy meson ($\bar{D}$ and ${\bar{D}}^{\ast }$ for charm or $B$ and $B^{\ast }$ for bottom) and a nucleon ($N$) by considering the $\pi$, $\sigma$, $\rho$, and $\omega$ exchange potentials. We construct a potential model by respecting chiral symmetry for light quarks and spin symmetry for heavy quarks. Model parameters are adjusted by referring the phenomenological nuclear (CD-Bonn) potentials reproducing the low-energy $NN$ scatterings. We show that the resulting interaction may accommodate $\bar{D}N$ and $BN$ bound states with quantum number $I(J^P)=0(1/2^{-})$, and a $BN$ bound state with $I(J^P)=1(1/2^{-})$. We find that, in the present potential model, the $\sigma$ exchange potential plays an important role.

   hep-phnucl-thPRD(2022)·9 citations
3. 03*

   Radiation backreaction in axion electrodynamics

   Andras Patkos🇭🇺

   Energy-momentum conservation of classical axion-electrodynamics is carefully analyzed in the Hamiltonian formulation of the theory. The term responsible for the energy transfer between the electromagnetic and the axion sectors is identified. As a special application the axion-to-light Primakoff-process in the background of a static magnetic field is worked out and the radiative self-damping of the axion oscillations is characterized quantitatively. The damping time turns out comparable to the age of the Universe in the preferred axion mass range.

   hep-phphysics.class-phSymmetry(2022)·10 citations
4. 04*

   Triple Regge exchange and transverse single-spin asymmetries of the very forward neutral pion production in polarized $p+p$ collisions

   Hee-Jin Kim🇰🇷 · Samson Clymton🇰🇷 · Hyun-Chul Kim🇰🇷

   Recently, the RHICf Collaboration measured the transverse single-spin asymmetries of the very forward neutral pion in polarized $p+p$ collisions at $\sqrt{s}=510$ GeV, produced at large pseudorapidity ($\eta \gtrsim 6$). The data show large asymmetries both in longitudinal momentum fraction $x_F$ and transverse momentum $p_T$ at $p_T<1\mathrm{GeV}/c$. Employing baryonic triple Regge exchanges, we describe the complete RHICf data for the first time and show that the neutral pion production at low $p_T$ can be interpreted as a diffractive one.

   hep-phhep-exPRD(2022)·3 citations
5. 05*

   ($\gamma$, ${\chi }_{cJ}(J=0,1)$) and ($\gamma$, ${\eta }_c$) production in electron-positron annihilation at $\sqrt{s}=10.6$ GeV and $4.6$ GeV in the framework of Bethe-Salpeter equation

   Shashank Bhatnagar🇮🇳 · Vaishali Guleria🇮🇳

   In present work we study the production of ground and excited charmonium states in $e^{-}{e}^{+}\to \gamma {\chi }_{cJ}(nP)(J=0,1)$, and $e^{-}{e}^{+}\to \gamma {\eta }_c(nS)$, through leading order (LO) diagrams, which proceed through exchange of a virtual photon that couples to $\gamma$ and ${\eta }_c/{\chi }_{cJ}$ through the triangular quark loop diagram, in the framework of $4\times 4$ Bethe-Salpeter equation (BSE), at center of mass energies $\sqrt{s}=10.6$ GeV(Belle energy), and 4.6 GeV (BESIII energy). The amplitude simplifies to a general form required by Lorentz-covariance, in terms of its form factors. The cross sections for these processes with leading order (tree level) diagrams alone at $\sqrt{s}$=10.6 GeV provide a sizable contribution, which might be mainly due to the BSE being a fully relativistic approach that incorporates the relativistic effect of quark spins and can also describe internal motion of constituent quarks within the hadron in a relativistically covariant manner. Our results are compared with recent Belle data at 10.6 GeV, and BESIII data at 4.6 GeV, as well as other models. Plots of cross sections versus the center-of mass energy, $\sqrt{s}$ reveal mild fluctuations in their behaviour for all the three processes in the low energy ($\sqrt{s}$ = 4 - 6 GeV) region, and are analyzed in terms of the form factors.

   hep-phNPA(2024)·14 citations
6. 06*

   Thermally corrected masses and freeze-in dark matter: a case study

   Nabarun Chakrabarty🇮🇳 · Partha Konar🇮🇳 · Rishav Roshan and🇰🇷 · Sudipta Show🇮🇳

   If coupled \emph{feebly} to the Standard Model bath, a dark matter can evade the severe constraints from the direct search experiments. At the same time, such interactions help produce dark matter via the freeze-in mechanism. The freeze-in scenario becomes more interesting if one also includes the thermal masses of the different particles involved in the dark matter phenomenology. Incorporating such thermal corrections opens up the possibility of dark matter production via forbidden channels that remain kinematically disallowed in the standard freeze-in setup. Motivated by this, we investigate such freeze-in production of the dark matter in a minimally extended $U(1{)}_{L_{\mu }-L_{\tau }}$ framework that remains consistent with the recent muon $(g-2)$ data. Here, the role of the dark matter is played by the scalar with a non-trivial charge under the additional symmetry $U(1{)}_{L_{\mu }-L_{\tau }}$. This scalar dark matter obtains a thermally corrected mass at high temperatures for a not-so-small self-coupling. We show that the thermal correction to the dark matter mass plays a significant role in the dark matter phenomenology.

   hep-phPRD(2023)·17 citations
7. 07*

   Waterfall stiff period can generate observable primordial gravitational waves

   Konstantinos Dimopoulos🇬🇧

   A toy-model is studied, which considers two flat directions meeting at an enhanced symmetry point such that they realise the usual hybrid inflation mechanism. The kinetic term of the waterfall field features a pole at its Planckian vacuum expectation value (VEV), as with $\alpha$-attractors. Consequently, after the phase transition which terminates hybrid inflation, the waterfall field never rolls to its VEV. Instead, it drives a stiff period, where the barotropic parameter of the Universe $w\approx 1/2$ results in a peak in the spectrum of primordial gravitational waves, which will be observable by the forthcoming LISA mission as well as by Advanced LIGO.

   hep-phastro-ph.COgr-qchep-thJCAP(2022)·14 citations
8. 08*

   Rational form of amplitude and its asymptotic factorization

   S.M. Troshin🇷🇺 · N.E. Tyurin🇷🇺

   We provide arguments for the use of the rational form of unitarization, its relation with the diffraction peak shrinkage and asymptotics of the inelastic cross--section. The particular problems of the Regge model and the exponential form of unitarization with a factorized eikonal are discussed as well. Central role belongs to the asymptotic amplitude factorization resulting from Mandelstam analyticity and its symmetry over the scattering variables.

   hep-phSymmetry(2022)·3 citations
9. 09*

   Connected and Disconnected Sea Partons from CT18 Parametrization of PDFs

   Tie-Jiun Hou🇹🇼 · Mengshi Yan🇨🇳 · Jian Liang🇨🇳 · Keh-Fei Liu🇺🇸 · C.-P. Yuan🇺🇸

   The separation of the connected and disconnected sea partons, which were uncovered in the Euclidean path-integral formulation of the hadronic tensor, is accommodated with an alternative parametrization of the non-perturbative parton distribution functions in the CT18 global analysis. This is achieved with the help of the distinct small $x$ behaviours of these two sea partons and the constraint from the lattice calculation of the ratio of the strange momentum fraction to that of the $\bar{u}$ or $\bar{d}$ in the disconnected insertion. The whole dataset of CT18 is used in this CT18CS fit. The impact of the recent SeaQuest data on the $\bar{d}(x)-\bar{u}(x)$ distribution of CT18CS is also discussed. The separate momentum fractions for the valence, the connected sea and disconnected sea of $u$ and $d$, the strange and the gluon partons are presented at $\mu =1.3$ GeV for the first time. They can be compared term-by-term with systematic error controlled lattice calculations.

   hep-phhep-latPRD(2022)·8 citations
10. 10*

    Charged Higgs contribution to rare top-quark decay

    S. Slabospitskii🇷🇺

    The calculation of the rare $t$-quark decay $t\to bWb\bar{b}$ within the Standard Model as well as the charged Higgs contribution to this decay is presented. The role of possible background processes is discussed. It is shown that this decay provides an additional possibility for charged Higgs searches.

    hep-phhep-ex3 citations
11. 11*

    Exclusive Lepton Pair Production at the Electron-Ion Collider -- A Powerful Research Tool

    Janusz J. Chwastowski🇵🇱 · Krzysztof Piotrzkowski🇵🇱 · Mariusz Przybycien🇵🇱

    The two-photon exclusive production of lepton pairs at the Electron-Ion Collider will open interesting research directions thanks to a very high luminosity and clean experimental conditions. A survey of the scientific potential of such studies is reported. In particular, we consider unique measurements of the proton elastic electromagnetic form-factors and a possibility of studying the anomalous electromagnetic dipole moments of $\tau$ leptons.

    hep-phhep-exEPJC(2022)·6 citations
12. 12*

    New determination of $|V_{\mathrm{cb}}|$ using the three-loop QCD corrections for the $B\to D^{\ast }$ semi-leptonic decays

    Hua Zhou🇨🇳 · Qing Yu🇨🇳 · Xu-Chang Zheng🇨🇳 · Hai-Bing Fu🇨🇳 · Xing-Gang Wu🇨🇳

    We present a new determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\mathrm{cb}}|$ by using the three-loop perturbative QCD corrections for the $B\to D^{\ast }$ semi-leptonic decay. The decay width of $B\to D^{\ast }$ semi-leptonic decay can be factorized as perturbatively calculable short-distance part and the non-perturbative but universal long-distance part. We adopt the principle of maximum conformality (PMC) single-scale setting approach to deal with the perturbative series so as to achieve a precise fixed-order prediction for the short-distance parameter ${\eta }_A$. By applying the PMC, an overall effective ${\alpha }_s$ value is achieved by recursively using the renormalization group equation, which inversely results in a precise scale-invariant pQCD series. Such scale-invariant series also provides a reliable basis for predicting the contributions from uncalculated perturbative terms. We then obtain ${\eta }_A=0.9225_{-0.0168}^{+0.0117}$, where the error is the squared average of those from $\Delta {\alpha }_s(M_Z)=\pm 0.0010$ and the uncertainties caused by the uncalculated higher-order perturbative terms. By using the data of $B\to D^{\ast }\ell {\bar{\nu }}_{\ell }$, we finally obtain $|V_{\mathrm{cb}}{|}_{\mathrm{PMC}}=(40.60_{-0.57}^{+0.53})\times 10^{-3}$, which is consistent with the PDG value within errors.

    hep-phNPA(2023)·3 citations
13. 13*

    On the three-point order parameters of chiral symmetry breaking

    Tomas Kadavy🇨🇿 · Karol Kampf🇨🇿 · Jiri Novotny🇨🇿

    The nonlocal order parameters of the QCD chiral symmetry breaking, namely the nonanomalous three-point Green functions of the quark bilinears belonging to the odd intrinsic parity sector, are studied within the framework of the Resonance chiral theory. The general form of these correlators is then matched with various high energy constraints: the leading and sub-leading OPE for all three momenta simultaneously large, the leading OPE for two momenta large and the leading and sub-leading Brodsky-Lepage limit for the corresponding transition form factor. In order to satisfy these constraints, the Resonance chiral theory has to be enlarged with additional resonance multiplets and with higher derivative operators as well. We discuss a minimal extension of this kind in detail and present corresponding correlators in a closed form. The remaining free parameters are then constrained from lattice data. As a phenomenological application, we discuss the pion-pole contribution to the muon $g-2$ and the decay ${\pi }^0\to e^{+}{e}^{-}$.

    hep-phJHEP(2023)·7 citations
14. 14*

    Non-Standard Interaction of atmospheric neutrino in future experiments

    Pouya Bakhti🇰🇷 · Meshkat Rajaee🇰🇷 · Seodong Shin🇰🇷

    We show the prospects of probing neutral-current non-standard interaction (NSI) in the propagation of atmospheric neutrinos in future large-volume neutrino experiments including DUNE, HK, KNO, and ORCA. For DUNE, we utilize its ability of identifying the tau neutrino event and combine the ${\nu }_{\tau }$ appearance with the ${\nu }_{\mu }$ disappearance. Based on our simulated results, the ten years of data taking of the atmospheric neutrinos can enormously improve the bounds on the NSI parameters ${\epsilon }_{\mu \tau },|{\epsilon }_{\mu \mu }-{\epsilon }_{\tau \tau }|$, ${\epsilon }_{e\mu }$, ${\epsilon }_{e\tau }$ and $|{\epsilon }_{\mu \mu }-{\epsilon }_{ee}|$ by a couple of orders of magnitudes. In addition, we show the expected correlations between the CP-violation phase ${\delta }_{CP}$ and the NSI parameters ${\epsilon }_{e\mu },{\epsilon }_{e\tau }$, and $|{\epsilon }_{ee}-{\epsilon }_{\mu \mu }|$ and confirm the potentials of DUNE, HK, KNO (combined with HK) in excluding the "No CP violation" hypothesis at 1$\sigma$, 2$\sigma$, and 3$\sigma$, respectively.

    hep-phhep-exPRD(2022)·4 citations
15. 15*

    Asymptotic safety and gauged baryon number

    Jens Boos🇺🇸 · Christopher D. Carone🇺🇸 · Noah L. Donald🇺🇸 · Mikkie R. Musser🇺🇸

    We consider a model with gauged baryon number that may be rendered asymptotically safe when gravitational effects above the Planck scale are taken into account. We study the ultraviolet fixed points in this theory and determine the restrictions on the parameter space of the model at the TeV scale following from the requirement that the asymptotic fixed points are reached. Assuming that the new gauge symmetry is broken at the TeV scale, we comment on the phenomenological implications of these restrictions.

    hep-phhep-thPRD(2022)·19 citations
16. 16*

    Recombination mechanism for $D^0$-meson production and $D^0-\overline{D^0}$ production asymmetry in the LHCb $p+{}^{20}Ne$ fixed-target experiment

    Rafal Maciula🇵🇱 · Antoni Szczurek🇵🇱

    We discuss production of neutral $D$ mesons in proton-proton collisions at the LHC (fixed target mode) in the framework of the BJM recombination model. We present rapidity and transverse momentum distributions of $D$ mesons and compare the recombination contribution to the dominant gluon-gluon fusion mechanism. Both the direct production, as dictated by the matrix element, and fragmentation of the associated $c$ or $\bar{c}$ are included. The latter mechanism generates $D$ mesons with smaller rapidities than those produced directly. We calculate the $D^0+{\bar{D}}^0$ meson distributions relevant for fixed target $p+{}^{4}He$ collisions at $\sqrt{s}$ = 86.6 GeV as well as for $p+{}^{20}Ne$ collisions at $\sqrt{s}$ = 69 GeV. The recombination component is consistent with the LHCb data and in addition results in production asymmetry. The asymmetries in $D^0-\overline{D^0}$ production as a function of rapidity and transverse momentum are shown and the cancellation of terms for direct production and associated $c/\bar{c}$ fragmentation is discussed.

    hep-phPLB(2022)·17 citations
17. 17*

    BBN Photodisintegration Constraints on Gravitationally Produced Vector Bosons

    Chee Sheng Fong🇧🇷 · Moinul Hossain Rahat🇺🇸 · Shaikh Saad🇨🇭

    Gravitational production of massive particles due to cosmic expansion can be significant during the inflationary and reheating period of the Universe. If the particle also has non-gravitational interactions that do not significantly affect its production, numerous observational probes open up, including cosmological probes. In this work, we focus on the gravitational production of light vector bosons that couple feebly to the Standard Model (SM) particles. Due to the very feeble coupling, the light vector bosons never reach thermal equilibrium, and if the Hubble scale at the end of inflation is above $10^8$ GeV, the gravitational production can overwhelm the thermal production via the freeze-in mechanism by many orders of magnitude. As a result, much stronger constraints from the Big Bang Nucleosynthesis (BBN) can be placed on the lifetime and mass of the vector bosons compared to the scenario where only thermal production is considered. As an example, we study the sub-GeV scale dark photons, which couple to the SM only through kinetic mixing, and derive constraints on the mass and kinetic mixing parameter of the dark photon from the photodisintegration effects on the light element abundances relevant at the end of the BBN when the cosmic age was around $10^4$ s.

    hep-phastro-ph.COJHEP(2022)·6 citations
18. 18*

    A unified picture of medium-induced radiation

    Johannes Hamre Isaksen🇳🇴 · Adam Takacs🇳🇴 · Konrad Tywoniuk🇳🇴

    We revisit the picture of jets propagating in the quark-gluon plasma. In addition to vacuum radiation, partons scatter on the medium constituents resulting in induced emissions. Analytical approaches to including these interactions have traditionally dealt separately with multiple, soft, or rare, hard scatterings. A full description has so far only been available using numerical methods. We achieve full analytical control of the relevant scales and map out the dominant physical processes in the full phase space. To this aim, we extend existing expansion schemes for the medium-induced spectrum to the Bethe--Heitler regime. This covers the whole phase space from early to late times, and from hard splittings to emissions below the thermal scale. Based on the separation of scales, a space-time picture naturally emerges: at early times, induced emissions start to build from rare scatterings with the medium. At a later stage, induced emissions due to multiple soft scatterings result in a turbulent cascade that rapidly degrades energy down to, and including, the Bethe--Heitler regime. We quantify the impact of such an improved picture, compared to the current state-of-the-art factorization that includes only soft scatterings, by both analytical and numerical methods for the medium-induced energy distribution function. Our work serves to improve our understanding of jet quenching from small to large systems and for future upgrades of Monte Carlo generators.

    hep-phhep-exnucl-exnucl-thJHEP(2023)·25 citations
19. 19*

    Building a Culture of Equitable Access and Success for Marginalized Members in Today's Particle Physics Community

    Kétévi A. Assamagan🇺🇸 · Olivia M. Bitter🇺🇸 · Mu-Chun Chen🇺🇸 · Ami Choi🇺🇸 · Jessica Esquivel🇺🇸 · Kathryn Jepsen🇺🇸 · Tiffany R. Lewis🇺🇸 · Azwinndini Muronga🇿🇦 · Fernanda Psihas🇺🇸 · Lucianne Walkowicz🇺🇸 · Yuanyuan Zhang🇺🇸

    Diversity, Equity, Inclusion, and Accessibility (DEIA) are not only called for to ensure morality and justice in our society, they also support ongoing and future excellence in particle physics. Over the past decade, the particle physics community has devised programs to support DEIA along multiple axes, and the way we think about measuring and implementing these initiatives has evolved. DEIA in physics is a broad topic, so in this paper we focus on the experiences of marginalized communities and outline ways different stakeholders can build a culture of equitable access for the success of marginalized individuals. Specifically, we identify urgent needs in the following areas: (1) We need to acquire a better understanding of the status quo, both quantitatively and qualitatively, to assess the effectiveness of existing programs and to develop best practices; (2) we need to develop effective and inclusive ways to engage marginalized communities; (3) we need to create infrastructure to better support members of marginalized communities, on an academic, financial and personal level; (4) we need to create an environment conducive to equitable access and success by establishing community expectations, fostering inclusion in social interactions, and holding individuals and institutions accountable; and (5) we need to establish a mechanism to monitor progress in the area of DEIA, including the implementation of the recommendations enumerated in this paper and others during the Snowmass 2021 process.

    ↳ physics.soc-phhep-exhep-phhep-th+16 citations
20. 20*

    Neutrino spin oscillations in gravitational fields in higher dimensions

    S.A. Alavi🇮🇷 · T. Fallahi. Serish🇮🇷

    Neutrino physics in one of the most active fields of research with important implications for particle physics, cosmology and astrophysics. On the other hand, motivated by some theories including string theory, formulation of physical theories in more than four space-time dimensions has been the subject of increasing attention in recent years. Interaction of neutrinos with gravitational fields is one of the interesting phenomena which can lead to transition between different helicity states (spin oscillations). We study neutrino spin oscillations in Schwarzschild and RN backgrounds in higher dimensional gravitational fields. We calculate the transition probability as a function of time and also study the dependence of the oscillation frequency on the orbital radius. The results help us to better understand the behavior of gravity and neutrinos in higher dimensions.

    ↳ gr-qcastro-ph.HEhep-phhep-thMod.Phys.Lett.A(2022)·4 citations
21. 21*

    Ratios of collective flow observables in high-energy isobar collisions are insensitive to final state interactions

    Chunjian Zhang🇺🇸 · Somadutta Bhatta🇺🇸 · Jiangyong Jia🇺🇸

    The ratios of bulk observables, such as harmonic flow $v_2$ and $v_3$, between high-energy ${}^{96}$Ru+${}^{96}$Ru and ${}^{96}$Zr+${}^{96}$Zr collisions were recently argued to be a clean probe of the nuclear structure differences between ${}^{96}$Ru and ${}^{96}$Zr. Using a transport model simulation of isobar collisions, we quantify this claim from the dependence of the ratios $v_{2,\mathrm{Ru}}/v_{2,\mathrm{Zr}}$ and $v_{3,\mathrm{Ru}}/v_{3,\mathrm{Zr}}$ on various final state effects, such as the shear viscosity, hadronization and hadronic cascade. Although the $v_2$ and $v_3$ change by more than 50% when varying the final state effects, the ratios are unchanged. In addition, these ratios are independent of the transverse momentum $p_{\mathrm{T}}$ and hadron species, despite of up to a factor of two change in $v_n$. The ratio of mean transverse momentum $⟨p_{\mathrm{T}}⟩$ is found to be controlled by the nuclear skin and nuclear radius, but is only slightly impacted by the final state effects. Therefore, these isobar ratios serve as a clean probe of the initial condition of the quark-gluon plasma, which in turn is controlled by the collective structure of the colliding nuclei.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2022)·42 citations
22. 22*

    Do we need dense matter equation of state in curved spacetime for neutron stars?

    Jianing Li🇨🇳 · Tao Guo🇨🇳 · Jiaxing Zhao🇨🇳 · Lianyi He🇨🇳

    Neutron stars are regarded as natural laboratories for the study of dense strong interaction matter. The equation of state (EoS) of dense matter computed in flat spacetime is used to predict the structure of neutron stars by solving the Tolman-Oppenheimer-Volkoff (TOV) equation. Recently, it has been reported that the curved spacetime effect or specifically gravitational time dilation effect on the EoS of dense matter leads to a significant increase of the maximum mass limit of neutron stars [Phys. Rev. D \textbf{104}, 123005 (2021) and J. Cosmol. Astropart. Phys. 02 (2021) 026]. However, in this work, we show that to study the hydrostatic equilibrium of dense matter within the framework of general relativity and relativistic fluid dynamics, the grand canonical EoS of dense matter, $p(T,\mu )$, should be the same as that computed in flat spacetime, otherwise it is not consistent with local thermodynamic relations and energy-momentum conservation of the fluid. The gravitation influences the pressure $p$ only through enhancing the temperature $T$ and the chemical potential $\mu$, known as Tolman's law and Klein's law. We rewrite the TOV equation as an alternative version so that the grand canonical EoS computed by using field theoretical methods can be used as a direct input. This may provide a tool to study the grand canonical EoS of dense matter via deep learning.

    ↳ gr-qcastro-ph.HEhep-phnucl-thPRD(2022)·16 citations
23. 23*

    Relativistic Ritz approach to hydrogen-like atoms I: theoretical considerations

    David M. Jacobs🇺🇸

    The Rydberg formula along with the Ritz quantum defect ansatz has been a standard theoretical tool used in atomic physics since before the advent of quantum mechanics, yet this approach has remained limited by its non-relativistic foundation. Here I present a long-distance relativistic effective theory describing hydrogen-like systems with arbitrary mass ratios, thereby extending the canonical Ritz-like approach. Fitting the relativistic theory to the hydrogen energy levels predicted by bound-state QED indicates that it is superior to the canonical, nonrelativistic approach. An analytic analysis reveals nonlinear consistency relations within the bound-state QED level predictions that relate higher-order corrections to those at lower order, providing guideposts for future perturbative calculations as well as insights into the asymptotic behavior of Bethe logarithms. Applications of the approach include fitting to atomic spectroscopic data, allowing for the determination the fine-structure constant from large spectral data sets and also to check for internal consistency of the data independently from bound-state QED.

    ↳ physics.atom-phhep-phquant-phPRA(2022)·6 citations
24. 24*

    Comprehensive simulation of heavy-ion collisions at non-zero baryon chemical potential

    A. De🇺🇸 · J. I. Kapusta🇺🇸 · M. Singh🇺🇸 · T. Welle🇺🇸

    We present results of hydrodynamic modelling of Au-Au collisions from $\sqrt{s_{NN}}$ = 7.7 to 200 GeV. Our simulations have three novel components. Firstly, we use a Linear EXtrapolation of Ultrarelativistic nucleon-nucleon Scattering to nucleus-nucleus collisions (LEXUS) inspired Monte-Carlo initial state model. Secondly, we use a crossover equation of state at finite baryon densities without a critical point. Finally, we use departure functions derived from the quasiparticle theory of transport coefficients for hadronic matter at non-zero baryon densities.

    ↳ nucl-thhep-phPRC(2022)·17 citations
25. 25*

    Primordial black hole constraints with Hawking radiation -- a review

    Jérémy Auffinger🇫🇷

    Primordial black holes are under intense scrutiny since the detection of gravitational waves from mergers of solar-mass black holes in 2015. More recently, the development of numerical tools and the precision observational data have rekindled the effort to constrain the black hole abundance in the lower mass range, that is $M<10^{23}$g. In particular, primordial black holes of asteroid mass $M\sim 10^{17}-10^{23}$g may represent 100\% of dark matter. While the microlensing and stellar disruption constraints on their abundance have been relieved, Hawking radiation of these black holes seems to be the only detection (and constraining) mean. Hawking radiation constraints on primordial black holes date back to the first papers by Hawking. Black holes evaporating in the early universe may have generated the baryon asymmetry, modified big bang nucleosynthesis, distorted the cosmic microwave background, or produced cosmological backgrounds of stable particles such as photons and neutrinos. At the end of their lifetime, exploding primordial black holes would produce high energy cosmic rays that would provide invaluable access to the physics at energies up to the Planck scale. In this review, we describe the main principles of Hawking radiation, which lie at the border of general relativity, quantum mechanics and statistical physics. We then present an up-to-date status of the different constraints on primordial black holes that rely on the evaporation phenomenon, and give, where relevant, prospects for future work. In particular, non-standard black holes and emission of beyond the Standard Model degrees of freedom is currently a hot subject.

    ↳ astro-ph.COastro-ph.HEgr-qchep-ph+1PPNP(2023)·108 citations
26. 26*

    Radiative Decay Width of $J/\psi \to \gamma {\eta }_{(2)}$ from $N_f=2$ Lattice QCD

    Xiangyu Jiang🇨🇳 · Feiyu Chen🇨🇳 · Ying Chen · Ming Gong🇨🇳 · Ning Li🇨🇳 · Zhaofeng Liu🇨🇳 · Wei Sun🇨🇳 · Renqiang Zhang🇨🇳

    The large radiative production rate for pseudoscalar mesons in the $J/\psi$ radiative decay remains elusive. We present the first lattice QCD calculation of partial decay width of $J/\psi$ radiatively decaying into ${\eta }_{(2)}$, the $\mathrm{SU}(2)$ flavor singlet pseudoscalar meson, which confirms QCD ${\mathrm{U}}_{\mathrm{A}}(1)$ anomaly enhancement to the coupling of gluons with flavor singlet pseudoscalar mesons. The lattice simulation is carried out using $N_f=2$ lattice QCD gauge configurations at the pion mass $m_{\pi }\approx 350$ MeV. In particular, the distillation method has been utilized to calculate light quark loops. The results are reported here with the mass $m_{{\eta }_{(2)}}=718(8)$ MeV and the decay width $\Gamma (J/\psi \to \gamma {\eta }_{(2)})=0.385(45)$ keV. By assuming the dominance of ${\mathrm{U}}_{\mathrm{A}}(1)$ anomaly and flavor singlet-octet mixing angle $\theta =-24.5^{\circ }$, the production rates for the physical $\eta$ and ${\eta }^{\prime }$ in $J/\psi$ radiative decay are predicted to be $1.15(14)\times 10^{-3}$ and $4.49(53)\times 10^{-3}$, respectively, which agree well with the experimental measurement data. Our study manifests the potential of lattice QCD studies on the light hadron production in $J/\psi$ radiative decays.

    ↳ hep-lathep-exhep-phPRL(2023)·16 citations
27. 27*

    CMB spectral distortions revisited: a new take on $\mu$ distortions and primordial non-Gaussianities from FIRAS data

    Federico Bianchini🇺🇸 · Giulio Fabbian🇺🇸

    Deviations from the blackbody spectral energy distribution of the CMB are a precise probe of physical processes active both in the early universe (such as those connected to particle decays and inflation) and at later times (e.g. reionization and astrophysical emissions). Limited progress has been made in the characterization of these spectral distortions after the pioneering measurements of the FIRAS instrument on the COBE satellite in the early 1990s, which mainly targeted the measurement of their average amplitude across the sky. Since at present no follow-up mission is scheduled to update the FIRAS measurement, in this work we re-analyze the FIRAS data and produce a map of $\mu$-type spectral distortion across the sky. We provide an updated constraint on the $\mu$ distortion monopole $|⟨\mu ⟩|<47\times 10^{-6}$ at 95\% confidence level that sharpens the previous FIRAS estimate by a factor of $\sim 2$. We also constrain primordial non-Gaussianities of curvature perturbations on scales $10\lesssim k\lesssim 5\times 10^4$ through the cross-correlation of $\mu$ distortion anisotropies with CMB temperature and, for the first time, the full set of polarization anisotropies from the Planck satellite. We obtain upper limits on $f_{\mathrm{NL}}\lesssim 3.6\times 10^6$ and on its running $n_{\mathrm{NL}}\lesssim 1.4$ that are limited by the FIRAS sensitivity but robust against galactic and extragalactic foreground contaminations. We revisit previous similar analyses based on data of the Planck satellite and show that, despite their significantly lower noise, they yield similar or worse results to ours once all the instrumental and astrophysical uncertainties are properly accounted for. Our work is the first to self-consistently analyze data from a spectrometer and demonstrate the power of such instrument to carry out this kind of science case with reduced systematic uncertainties.

    ↳ astro-ph.COhep-phPRD(2022)·81 citations
28. 28*

    Particle creation: Schwinger + Unruh + Hawking

    G.E. Volovik🇫🇮

    We discuss the interconnection between the Schwinger pair creation in electric field, Hawking radiation and particle creation in the Unruh effect. All three processes can be described in terms of the entropy and temperature. These thermodynamic like processes can be combined. We consider the combined process of creation of charged and electrically neutral particles in the electric field, which combine the Schwinger and Unruh effects. We also consider the creation of the charged black and white holes in electric field, which combines the Schwinger effect and the black hole entropy. The combined processes obey the sum rules for the entropy and for the inverse temperature. Some contributions to the entropy and to the temperature are negative, which reflects the quantum entanglement between the created objects.

    ↳ gr-qccond-mat.otherhep-phPisma Zh.Eksp.Teor.Fiz.(2022)·9 citations
29. 29*

    Cosmology with the Redshift-Space Galaxy Bispectrum Monopole at One-Loop Order

    Oliver H. E. Philcox🇺🇸 · Mikhail M. Ivanov🇺🇸 · Giovanni Cabass🇺🇸 · Marko Simonović🇨🇭 · Matias Zaldarriaga🇺🇸 · Takahiro Nishimichi🇯🇵

    We study the cosmological information content of the redshift-space galaxy bispectrum monopole at one-loop order in perturbation theory. We incorporate all effects necessary for comparison to data: fourth-order galaxy bias, infrared resummation (accounting for the non-linear evolution of baryon acoustic oscillations), ultraviolet counterterms, non-linear redshift-space distortions, stochastic contributions, projection, and binning effects. The model is implemented using FFTLog, and validated with the PT Challenge suite of $N$-body simulations, whose large volume allows for high-precision tests. Focusing on the mass fluctuation amplitude, ${\sigma }_8$, and galaxy bias parameters, we find that including one-loop corrections allow us to significantly extend the range of scales over which the bispectrum can be modeled, and greatly tightens constraints on bias parameters. However, this does not lead to noticeable improvements in the ${\sigma }_8$ errorbar due to the necessary marginalization over a large number of nuisance parameters with conservative priors. Analyzing a BOSS-volume likelihood, we find that the addition of the one-loop bispectrum may lead to improvements on primordial non-Gaussianity constraints by $\lesssim 30\%$ and on ${\sigma }_8$ by $\approx 10\%$, though we caution that this requires pushing the analysis to short scales where the galaxy bias parameters may not be correctly recovered; this may lead to biases in the recovered parameter values. We conclude that restrictive priors from simulations or higher-order statistics such as the bispectrum multipoles will be needed in order to realize the full information content of the galaxy bispectrum.

    ↳ astro-ph.COhep-phhep-thPRD(2022)·127 citations
30. 30*

    Improved Modeling of the Discrete Component of the Galactic Interstellar Gamma-ray Emission and Implications for the Fermi-LAT Galactic Center Excess

    Christopher M. Karwin🇺🇸 · Alex Broughton🇺🇸 · Simona Murgia🇺🇸 · Alexander Shmakov🇺🇸 · Mohammadamin Tavakoli🇺🇸 · Pierre Baldi🇺🇸

    The aim of this work is to improve models for the gamma-ray discrete or small-scale structure related to H2 interstellar gas. Reliably identifying this contribution is important to disentangle gamma-ray point sources from interstellar gas, and to better characterize extended gamma-ray signals. Notably, the Fermi-LAT Galactic center (GC) excess, whose origin remains unclear, might be smooth or point-like. If the data contain a point-like contribution that is not adequately modeled, a smooth GC excess might be erroneously deemed to be point-like. We improve models for the H2-related gamma-ray discrete emission for a $50^{\circ }\times 1^{\circ }$ region along the Galactic plane via H2 proxies better suited to trace these features. We find that these are likely to contribute significantly to the gamma-ray Fermi-LAT data in this region, and the brightest ones are likely associated with detected Fermi-LAT sources, a compelling validation of this methodology. We discuss prospects to extend this methodology to other regions of the sky and implications for the characterization of the GC excess.

    ↳ astro-ph.HEastro-ph.GAhep-phPRD(2023)·6 citations
31. 31*

    Deep Learning Models of the Discrete Component of the Galactic Interstellar Gamma-Ray Emission

    Alexander Shmakov🇺🇸 · Mohammadamin Tavakoli🇺🇸 · Pierre Baldi🇺🇸 · Christopher M. Karwin🇺🇸 · Alex Broughton🇺🇸 · Simona Murgia🇺🇸

    A significant point-like component from the small scale (or discrete) structure in the H2 interstellar gas might be present in the Fermi-LAT data, but modeling this emission relies on observations of rare gas tracers only available in limited regions of the sky. Identifying this contribution is important to discriminate gamma-ray point sources from interstellar gas, and to better characterize extended gamma-ray sources. We design and train convolutional neural networks to predict this emission where observations of these rare tracers do not exist and discuss the impact of this component on the analysis of the Fermi-LAT data. In particular, we evaluate prospects to exploit this methodology in the characterization of the Fermi-LAT Galactic center excess through accurate modeling of point-like structures in the data to help distinguish between a point-like or smooth nature for the excess. We show that deep learning may be effectively employed to model the gamma-ray emission traced by these rare H2 proxies within statistical significance in data-rich regions, supporting prospects to employ these methods in yet unobserved regions.

    ↳ astro-ph.HEastro-ph.GAcs.LGhep-phPRD(2023)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.