Tue·Sep 28, 2021Tuesday·September 28, 2021

1. 01*

   Phenomenology of a Born-Infeld extension of the $U(1{)}_{\mathrm{Y}}$ sector at lepton colliders

   P. De Fabritiis🇧🇷 · P. C. Malta🇧🇷 · J. A. Helayël-Neto🇧🇷

   In this work we perform a non-linear extension of the $U(1{)}_{\mathrm{Y}}$ sector of the Standard Model leading to novel quartic effective interactions between the neutral gauge bosons. We study the induced effects through high-energy processes resulting in three photons, namely, Z-boson decay and electron-positron annihilation. Available experimental data on these processes do not yield viable lower bounds on the mass parameter $\sqrt{\beta }$, but we estimate that the range $\sqrt{\beta }\lesssim m_Z$ could be reliably excluded with better statistics in future $e^{-}{e}^{+}$ colliders. We also discuss neutral gauge-boson scatterings, contextualizing our findings with recent results on anomalous quartic gauge couplings.

   hep-phhep-thPRD(2022)·7 citations
2. 02*

   Renormalization of the flavor-singlet axial-vector current and its anomaly in QCD

   Long Chen🇩🇪

   The renormalization constant $Z_J$ of the flavor-singlet axial-vector current with a non-anticommuting ${\gamma }_5$ in dimensional regularization is determined to order ${\alpha }_s^3$ in QCD with massless quarks. In addition, the equality between the $\overline{\mathrm{MS}}$ renormalization constant $Z_{F\tilde{F}}$ associated with the operator $[F\tilde{F}{]}_R$ and that of ${\alpha }_s$ is verified explicitly to hold true at 4-loop order.

   hep-ph1 citation
3. 03*

   Detailed Comparison of Renormalization Scale-Setting Procedures based on the Principle of Maximum Conformality

   Xu-Dong Huang🇨🇳 · Jiang Yan🇨🇳 · Hong-Hao Ma🇨🇳 · Leonardo Di Giustino🇮🇹 · Jian-Ming Shen🇨🇳 · Xing-Gang Wu🇨🇳 · Stanley J. Brodsky🇺🇸

   The {\it Principle of Maximum Conformality} (PMC), which generalizes the conventional Gell-Mann-Low method for scale-setting in perturbative QED to non-Abelian QCD, provides a rigorous method for achieving unambiguous scheme-independent, fixed-order predictions for physical observables consistent with the principles of the renormalization group. In addition to the original multi-scale-setting approach (PMCm), two variations of the PMC have been proposed to deal with ambiguities associated with the uncalculated higher order terms in the pQCD series, i.e. the single-scale-setting approach (PMCs) and the procedures based on ``intrinsic conformality" (PMC${}_{\infty }$). In this paper, we will give a detailed comparison of these PMC approaches by comparing their predictions for three important quantities $R_{e^{+}{e}^{-}}$, $R_{\tau }$, and $\Gamma (H\to b\bar{b})$ up to four-loop pQCD corrections. The PMCs approach determines an overall effective running coupling ${\alpha }_s(Q)$ by the recursive use of the renormalization group equation, whose argument $Q$ represents the actual momentum flow of the process. Our numerical results show that the PMCs method, which involves a somewhat simpler analysis, can serve as a reliable substitute for the full multi-scale PMCm method, and that it leads to more precise pQCD predictions with small residual scale dependence.

   hep-phNPB(2023)·16 citations
4. 04*

   Cracking hadron and nuclear collisions open with ropes and string shoving in PYTHIA8

   Smita Chakraborty🇸🇪

   Enhancement in strangeness yields in heavy-ion collisions is regarded as one of the attributes of the Quark-Gluon Plasma (QGP) along with jet quenching and final-state collectivity. To reproduce these effects in the MC implementation of the Lund string model in \pythia, the inclusion of non-perturbative mechanisms like string shoving and rope hadronization is crucial. In this proceeding, we discuss our latest implementation of these mechanisms and the preliminary results for the strangeness enhancement in high-multiplicity p-p, p-Pb and Xe-Xe. We conclude with remarks on the ongoing development of the model.

   hep-phnucl-thSciPost Phys.Proc.(2022)·3 citations
5. 05*

   Implications of light $Z^{\prime }$ on semileptonic $B(B_s)\to T\{K_2^{\ast }(1430)$ $(f_2^{\prime }(1525))\}{\ell }^{+}{\ell }^{-}$ decays at large recoil

   Manas K. Mohapatra🇮🇳 · Anjan Giri🇮🇳

   We probe the rare semileptonic decays $B_{(s)}\to K_2^{\ast }(1430)(f_2^{\prime }(1525)){\ell }^{+}{\ell }^{-}$ proceeding via $b\to s\ell \ell$ transition in the presence of a light $Z^{\prime }$ boson. We employ the presence of an additional vector type interaction and constrain the new physics coupling parameter using the existing experimental measurements on $R_K$ and $R_{K^{\ast }}$ observables. To understand the sensitivity of the new physics coupling, we investigate the impact of this coupling on various physical observables such as differential branching ratio, the forward-backward asymmetry, the lepton polarization asymmetry, the angular observable $P_5^{\prime }$, and the lepton universality parameters such as the ratio of the branching ratio $R_{f_2^{\prime }(K_2^{\ast })}$ and some important Q parameters of $B_{(s)}\to K_2^{\ast }(1430)(f_2^{\prime }(1525)){\ell }^{+}{\ell }^{-}$ processes at large recoil. We find some noticeable differences of the observables in the presence of light $Z^{\prime }$ contribution.

   hep-phPRD(2021)·15 citations
6. 06*

   Experimental indications of the 3+1 neutrino model with one sterile neutrino

   A. Serebrov🇷🇺 · R. Samoilov🇷🇺 · M. Chaikovskii🇷🇺

   The possibility of the validation of the 3+1 neutrino model is considered in the context of the new result of the Neutrino-4 experiment, the direct observation of the oscillation effect at parameter region $\Delta m_{14}^2=(7.3\pm 0.13_{stat}\pm 1.16_{syst}){\text{eV}}^2$ and ${\sin }^2(2{\theta }_{14})=0.36\pm 0.12_{stat}(2.9\sigma )$, also using LSND anomaly, MiniBooNE anomaly, reactor antineutrino anomaly, and gallium anomaly observed in experiments with radioactive sources GALLEX/GNO and SAGE. We analyze agreement of the neutrino parameter values obtained in the Neutrino-4 experiment with the results of other reactor type experiments NEOS, DANSS, STEREO, PROSPECT, the experiments at accelerators MiniBooNE, LSND, and the IceCube experiment. We present the analysis of the 3+1 neutrino model which demonstrates the agreement among the experiments within current experimental accuracy. Also, current accuracy allows us to make estimations of the effective masses of the neutrinos. The mass of the sterile neutrino obtained in the Neutrino-4 experiment (in assumption $m_2^2\approx \Delta m_{14}^2$) is $m_4=(2.70\pm 0.22)\text{eV}$. Using the estimations of the mixing angles we calculated the values of the electron, muon and tau neutrinos: $m_{4{\nu }_e}^{\text{eff}}=(0.82\pm 0.18)\text{eV},m_{4{\nu }_{\mu }}^{\text{eff}}=(0.41\pm 0.26)\text{eV},m_{4{\nu }_{\tau }}^{\text{eff}}\le 0.60\text{eV}$. These results are compared with the values obtained in the experiments in the direct measurement of the neutrino mass KATRIN and GERDA. The Pontecorvo-Maki-Nakagawa-Sakata matrix with four states and the mixing scheme of the flavor neutrinos with the sterile state are presented.

   hep-phhep-ex3 citations
7. 07*

   Upper Limit on the Proton Lifetime in Minimal Supersymetric SU(5)

   Jason L. Evans🇨🇳 · Tsutomu T. Yanagida🇨🇳

   In minimal supersymmetric SU(5) models, the proton can decay through dimension 5 operators. Since this decay depends directly on the supersymmetric soft masses, it will be constrained by other observables which depend on the soft masses, such as the Higgs mass and the dark matter relic density. In this work, we will examine the upper limit on the proton lifetime in minimal supersymmetric SU(5) with constrained minimal supersymmetric (CMSSM) boundary conditions set at the grand unification scale. We perform a random scan over the variables of the (CMSSM), with of order $10^6$ points, and find that the proton lifetime is within reach of JUNO and Hyper-Kamiokande's experiment.

   hep-phPLB(2022)·8 citations
8. 08*

   Gauge coupling unification in a minimal non-supersymmetric $E_6$ GUT

   Chandini Dash🇮🇳 · Snigdha Mishra🇮🇳 · Sudhanwa Patra🇮🇳 · Purushottam Sahu🇮🇳

   We consider a minimal renormalizable non-supersymmetric $E_6$ Grand Unified Theory using fundamental representation $27$ for fermions and scalars. The scalar with adjoint representation $78$ is also taken for direct breaking of $E_6$ to SM. The proposed model, guided by TeV-scale vector-like fermions and scalar leptoquark offer successful gauge unification even in the absence of any intermediate symmetry. Embedded with threshold corrections, it is shown to be compatible with the present experimental limit on proton decay lifetime. The unique feature of the model shows that, the GUT threshold corrections to the unification mass, is controlled by superheavy gauge bosons only, thereby minimising the uncertainty of the GUT predictions. The scalar leptoquark and vector-like fermions residing in $27$ representation can explain flavor physics anomalies like $R_{D^{(\ast )}}$ as reported by the LHCb collaboration and the muon anomalous magnetic moment reported by the recent muon $g-2$ experiment at Fermilab. The model can also predict a sub-eV scale neutrino at one-loop level via exchange of $W$ and $Z$ gauge bosons through MRIS mechanism.

   hep-phInt.J.Mod.Phys.A(2024)·2 citations
9. 09*

   Correlation Integral vs. second order Factorial Moments and an efficient computational technique

   F. K. Diakonos🇬🇷 · A. S. Kapoyannis🇬🇷

   We develop a mapping between the factorial moments of the second order $F_2$ and the correlation integral $C$. We formulate a fast computation technique for the evaluation of both, which is more efficient, compared to conventional methods, for data containing number of pairs per event which is lower than the estimation points. We find the effectiveness of the technique to be more prominent as the dimension of the embedding space increases. We are able to analyse large amount of data in short computation time and access very low scales in $C$ or extremely high partitions in $F_2$. The technique is an indispensable tool for detecting a very weak signal hidden in strong noise.

   hep-phnlin.CDnucl-thphysics.comp-phEPJC(2022)·7 citations
10. 10*

    Sensitivity of Anomalous Quartic Gauge Couplings via $Z\gamma \gamma$ Production at Future hadron-hadron Colliders

    A. Senol🇹🇷 · O. Karadeniz🇹🇷 · K. Y. Oyulmaz🇹🇷 · C. Helveci🇹🇷 · H. Denizli🇹🇷

    Triple gauge boson production provides a promising opportunity to probe the anomalous quartic gauge couplings in understanding the details of electroweak symmetry breaking at future hadron-hadron collider facilities with increasing center of mass energy and luminosity. In this paper, we investigate the sensitivities of dimension-8 anomalous couplings related to the $ZZ\gamma \gamma$ and $Z\gamma \gamma \gamma$ quartic vertices, defined in the effective field theory framework, via $pp\to Z\gamma \gamma$ signal process with Z-boson decaying to charged leptons at the high luminosity phase of LHC (HL-LHC) and future facilities, namely the High Energy LHC (HE-LHC) and Future Circular hadron-hadron collider (FCC-hh). We analyzed the signal and relevant backgrounds via a cut based method with Monte Carlo event sampling where the detector responses of three hadron collider facilities, the center-of-mass energies of 14, 27 and 100 TeV with an integrated luminosities of 3, 15 and 30 ab${}^{-1}$ are considered for the HL-LHC, HE-LHC and FCC-hh, respectively. The reconstructed 4-body invariant mass of $l^{+}{l}^{-}\gamma \gamma$ system is used to constrain the anomalous quartic gauge coupling parameters under the hypothesis of absence of anomalies in triple gauge couplings. Our results indicate that the sensitivity on anomalous quartic couplings $f_{T8}/{\Lambda }^4$ and $f_{T9}/{\Lambda }^4$ ($f_{T0}/{\Lambda }^4$, $f_{T1}/{\Lambda }^4$ and $f_{T2}/{\Lambda }^4$) at 95$\%$ C.L. for FCC-hh with $L_{int}$ = 30 ab${}^{-1}$ without systematic errors are two (one) order better than the current experimental limits. Considering a realistic systematic uncertainty such as 10$\%$ from possible experimental sources, the sensitivity of all anomalous quartic couplings gets worsen by about 1.2$\%$, 1.7$\%$ and 1.5$\%$ compared to those without systematic uncertainty for HL-LHC, HE-LHC and FCC-hh, respectively.

    hep-phhep-exNPB(2022)·11 citations
11. 11*

    Resummed Higgs boson cross section at next-to SV to $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$

    A. H. Ajjath · Pooja Mukherjee🇮🇳 · V. Ravindran🇮🇳 · Aparna Sankar🇮🇳 · Surabhi Tiwari🇮🇳

    We present the resummed predictions for inclusive cross section for the production of Higgs boson at next-to-next-to leading logarithmic ($\overline{\mathrm{NNLL}}$) accuracy taking into account both soft-virtual ($\mathrm{SV}$) and next-to SV ($\mathrm{NSV}$) threshold logarithms. We derive the $N$-dependent coefficients and the $N$-independent constants in Mellin-$N$ space for our study. Using the minimal prescription we perform the inverse Mellin transformation and match it with the corresponding fixed order results. We report in detail the numerical impact of $N$-independent part of resummed result and explore the ambiguity involved in exponentiating them. By studying the K factors at different logarithmic accuracy, we find that the perturbative expansion shows better convergence improving the reliability of the prediction at $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$ accuracy. For instance, the cross-section at $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$ accuracy reduces by $3.15\%$ as compared to the $\mathrm{NNLO}$ result for the central scale ${\mu }_R={\mu }_F=m_H/2$ at 13 TeV LHC. We also observe that the resummed $\mathrm{SV}+\mathrm{NSV}$ result improves the renormalisation scale uncertainty at every order in perturbation theory. The uncertainty from the renormalisation scale ${\mu }_R$ ranges between $(+8.85\%,-10.12\%)$ at $\mathrm{NNLO}$ whereas it goes down to $(+6.54\%,-8.32\%)$ at $\mathrm{NNLO}+\overline{\mathrm{NNLL}}$ accuracy. However, the factorisation scale uncertainty is worsened by the inclusion of these NSV logarithms hinting the importance of resummation beyond $\mathrm{NSV}$ terms. We also present our predictions for $\mathrm{SV}+\mathrm{NSV}$ resummed result at different collider energies.

    hep-phEPJC(2022)·23 citations
12. 12*

    Gauge Kinetic Mixing and Dark Topological Defects

    Takashi Hiramatsu🇯🇵 · Masahiro Ibe🇯🇵 · Motoo Suzuki🇨🇳 · Soma Yamaguchi🇯🇵

    We discuss how the topological defects in the dark sector affect the Standard Model sector when the dark photon has a kinetic mixing with the QED photon. In particular, we consider the dark photon appearing in the successive gauge symmetry breaking, $\mathrm{SU}(2)\to \mathrm{U}(1)\to {\mathbb{Z}}_2$, where the remaining ${\mathbb{Z}}_2$ is the center of $\mathrm{SU}(2)$. In this model, the monopole is trapped into the cosmic strings and forms the so-called bead solution. As we will discuss, the dark cosmic string induces the QED magnetic flux inside the dark string through the kinetic mixing. The dark monopole, on the other hand, does not induce the QED magnetic flux in the U(1) symmetric phase, even in the presence of the kinetic mixing. Finally, we show that the dark bead solution induces a spherically symmetric QED magnetic flux through the kinetic mixing. The induced flux looks like the QED magnetic monopole viewed from a distance, although QED satisfies the Bianchi identity everywhere, which we call a pseudo magnetic monopole.

    hep-phhep-thJHEP(2021)·13 citations
13. 13*

    The masses of hadrons in the chiral symmetry restored vacuum

    Jisu Kim🇰🇷 · Su Houng Lee🇰🇷

    We calculate the masses of the vector and axial-vector mesons as well as the nucleon and the delta resonance in the chiral symmetry restored vacuum. This is accomplished by separating the quark operators appearing in the QCD sum rules for these hadrons into the chiral symmetric and symmetry breaking parts depending on the contributions of the fermion zero modes. We then extract the vacuum expectation values of all the separated parts of the quark operators using the QCD sum rule relations for these hadrons with their vacuum masses and widths. By taking the chiral symmetry breaking parts to be zero while keeping the symmetric operators to their vacuum values, we obtain the chiral symmetric part of the hadron masses. We find that the masses of chiral partners, such as the $(\rho ,a_1)$ and $(K^{\ast },K_1)$, become degenerate to values between 500 and 600 MeV in the chiral symmetry restored vacuum, while parity partners $(\omega ,f_1)$ that are chiral partners only in the limit where the disconnected diagrams are neglected remain non-degenerate with masses $(655,1060)$ MeV, respectively. The masses of the nucleon and the Delta are also found to reduce to about 500 and 600 MeV, respectively, in the chiral symmetric vacuum. This shows that while chiral symmetry breaking is responsible for the mass difference between chiral partner, both the meson and baryon retain non-trivial fraction of their masses in the chiral symmetry restored vacuum.

    hep-phnucl-exnucl-thPRD(2022)·21 citations
14. 14*

    Phenomenology of the companion-axion model: photon couplings

    Zhe Chen🇦🇺 · Archil Kobakhidze🇦🇺 · Ciaran A. J. O'Hare🇦🇺 · Zachary S. C. Picker🇦🇺 · Giovanni Pierobon🇦🇺

    We study the phenomenology of the 'companion-axion model' consisting of two coupled QCD axions. The second axion is required to rescue the Peccei-Quinn solution to the strong-CP problem from the effects of colored gravitational instantons. We investigate here the combined phenomenology of axion-axion and axion-photon interactions, recasting present and future single-axion bounds onto the companion-axion parameter space. Most remarkably, we predict that future axion searches with haloscopes and helioscopes may well discover two QCD axions, perhaps even within the same experiment.

    hep-phastro-ph.COhep-thEPJC(2022)·17 citations
15. 15*

    Hadron structure from basis light-front quantization

    Chandan Mondal🇨🇳 · Jiangshan Lan🇨🇳 · Kaiyu Fu🇨🇳 · Siqi Xu🇨🇳 · Zhi Hu🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

    We present our recent progress in applying basis light-front quantization approach to investigate the structure of the light mesons and the nucleon.

    hep-phSciPost Phys.Proc.(2022)·7 citations
16. 16*

    New insights into the nucleon's electromagnetic structure

    Yong-Hui Lin🇩🇪 · Hans-Werner Hammer🇩🇪 · Ulf-G. Meißner🇩🇪

    We present a combined analysis of the electromagnetic form factors of the nucleon in the space- and timelike regions using dispersion theory. Our framework provides a consistent description of the experimental data over the full range of momentum transfer, in line with the strictures from analyticity and unitarity. The statistical uncertainties of the extracted form factors are estimated using the bootstrap method, while systematic errors are determined from variations of the spectral functions. We also perform a high-precision extraction of the nucleon radii and find good agreement with previous analyses of spacelike data alone. For the proton charge radius, we find $r_E^p=0.840_{-0.002}^{+0.003}{}_{-0.002}^{+0.002}$~fm, where the first error is statistical and the second one is systematic. The Zemach radius and third moment are in agreement with Lamb shift measurements and hyperfine splittings. The combined data set of space- and timelike data disfavors a zero crossing of ${\mu }_p{G}_E^p/G_M^p$ in the spacelike region. Finally, we discuss the status and perspectives of modulus and phase of the form factors in the timelike region in the context of future experiments as well as the onset of perturbative QCD.

    hep-phhep-exhep-latnucl-ex+1PRL(2022)·131 citations
17. 17*

    High-energy spectra of the atmospheric neutrinos: predictions and measurements

    A. A. Kochanov (1, 2)🇷🇺 · A. D. Morozova (2, 3)🇷🇺 · T. S. Sinegovskaya (4)🇷🇺 · S. I. Sinegovsky (2, 3) ((1) Institute of Solar-Terrestrial Physics, SB Russian Academy of Sciences & Irkutsk State U. (2) Irkutsk State U. (3) Joint Institute for Nuclear Research (4) Irkutsk State Transport U.)🇷🇺

    Statistical analysis is performed of the atmospheric neutrino flux models as compared with the data of Frejus, AMANDA-II, IceCube, ANTARES, and Super-Kamiokande experiments. The analysis enables the evaluation of the confidence level of the flux models in comparison with atmospheric neutrino flux measurements. The flux calculations were performed in the framework of single computational scheme using a set of hadronic models combined with parameterizations of the cosmic rays spectrum by Zatsepin & Sokolskaya, and Hillas & Gaisser. The analysis showed satisfactory agreement of the conventional ${\nu }_{\mu }$ flux models with the measurements. The prompt neutrinos conrtibution obtained with a set of charm production models (QGSM, SIBYLL 2.3c, PROSA, GRRST, BEJKRSS, and GM-VFNS) is statistically negligible in the energy range covered by the neutrino telescopes.

    hep-phastro-ph.HEhep-ex5 citations
18. 18*

    Systematics of the heavy flavor hadronic molecules

    Kan Chen🇨🇳 · Rui Chen🇨🇳 · Lu Meng🇩🇪 · Bo Wang🇨🇳 · Shi-Lin Zhu🇨🇳

    With a quark level interaction, we give a unified description of the loosely bound molecular systems composed of the heavy flavor hadrons $(\bar{D},{\bar{D}}^{\ast })$, $({\Lambda }_c,{\Sigma }_c,{\Sigma }_c^{\ast })$, and $({\Xi }_c,{\Xi }_c^{\prime },{\Xi }_c^{\ast })$. Using the $P_c$ states as inputs to fix the interaction strength of light quark-quark pairs, we reproduce the observed $P_{cs}$ and $T_{cc}^{+}$ states and predict another narrow $T_{cc}^{\prime +}$ state with quantum numbers $[D^{\ast }{D}^{\ast }{]}_{J=1}^{I=0}$. If we require a satisfactory description of the $T_{cc}^{+}$ and $P_c$ states simultaneously, our framework prefers the assignments of the $P_c(4440)$ and $P_c(4457)$ as the $[{\Sigma }_c{\bar{D}}^{\ast }{]}_{J=1/2}^{I=1/2}$ and $[{\Sigma }_c{\bar{D}}^{\ast }{]}_{J=3/2}^{I=1/2}$ states, respectively. We propose the isospin criterion to explain naturally why the experimentally observed $T_{cc}$, $P_c$, and $P_{cs}$ molecular candidates prefer the lowest isospin numbers. We also predict the loosely bound states for the bottom di-hadrons.

    hep-phhep-exEPJC(2022)·94 citations
19. 19*

    Determination of ${\alpha }_S$ beyond $NNLO$ using the event shape averages

    Adam Kardos🇭🇺 · Gábor Somogyi🇭🇺 · Andrii Verbytskyi🇩🇪

    In this proceedings we discuss a prescription to extract the QCD strong coupling constant at $N^{3}LO$ precision in perturbative QCD using a combination of $\mathcal{O}({\alpha }_S^3)$ calculations in pQCD and estimations of the $\mathcal{O}({\alpha }_S^4)$ corrections from the data. The method is applied to a set of event shape averages measured in experiments at the LEP, PETRA, PEP and TRISTAN colliders. In our analysis we account for hadronization effects with models from modern Monte Carlo event generators and analytic hadronization models. We conclude that the precision of the ${\alpha }_S$ extraction cannot be improved significantly only with pQCD predictions of higher orders, and further progress in these studies requires a significant advances in the studies and modeling of hadronization process.

    hep-phSciPost Phys.Proc.(2022)·1 citation
20. 20*

    Flavour non-universal Pati-Salam unification and neutrino masses

    Julie Pagès🇨🇭

    The B anomalies, by their distinctive flavour structure i.e. $U(2{)}^5$, bring a new piece to the long-standing flavour puzzle. The three-site flavour non-universal Pati-Salam (PS) model, which unifies quarks and leptons, provides through the ratios of vacuum expectation values (VEV) acquired at different scales, a combined explanation of the charged and neutral current B anomalies as well as of the mass hierarchies of the Standard Model (SM). The mixings, in new, flavour non-universal, gauge interactions, as well as in the Yukawa couplings, are obtained through suppressed nearest-neighbour interactions. In this three-site model context, the inverse seesaw mechanism is realised, with the minimal addition of three fermion singlets $S_L^{(i)}$ and where $U(1{)}_F$ fermion number is broken dynamically via new singlet scalars ${\Phi }_i$, yielding an anarchic light neutrino mass matrix in consistency with data, despite the $U(2{)}^5$ flavour symmetry observed in the Yukawa matrices. A prediction of this model is Pontecorvo-Maki-Nakagawa-Sakata (PMNS) unitarity violation with a $33$ entry close to experimental bounds. The full model finds a natural 5D interpretation with three (almost equidistant) defects in a warped extra dimension, where the exponential hierarchies in VEV ratios of the 4D Lagrangian arise from O(1) differences in the 5D field bulk masses. This proceeding is based on arXiv:2012.10492.

    hep-phNuovo Cim.C(2021)·0 citations
21. 21*

    Can QCD Axion Stars explain Subaru HSC microlensing?

    Enrico D. Schiappacasse🇫🇮 · Tsutomu T. Yanagida🇨🇳

    A non-negligible fraction of the QCD axion dark matter may form gravitationally bound Bose Einstein condensates, which are commonly known as axion stars or axion clumps. Such astrophysical objects have been recently proposed as the cause for the single candidate event reported by Subaru Hyper Suprime-Cam (HSC) microlensing search in the Andromeda galaxy. Depending on the breaking scale of the Peccei-Quinn symmetry and the details of the dark matter scenario, QCD axion clumps may form via gravitational condensation during radiation domination, in the dense core of axion miniclusters, or within axion minihalos around primordial black holes. We analyze all these scenarios and conclude that the microlensing candidate detected by the Subaru HSC survey is likely not caused by QCD axion stars.

    hep-phastro-ph.COPRD(2021)·8 citations
22. 22*

    The hidden side of scalar-triplet models with spontaneous CP violation

    P.M. Ferreira🇵🇹 · B.L. Gonçalves🇵🇹 · F.R. Joaquim🇵🇹

    Scalar triplet extensions of the Standard Model provide an interesting playground for the explanation of neutrino mass suppression through the type-II seesaw mechanism. Propelled by the possible connections with leptonic CP violation, we explore under which conditions spontaneous CP violation can arise in models with extra scalar triplets. The minimal model satisfying such conditions requires adding two such triplets to the SM field content. For this model, the scalar mass spectrum in both the CP-conserving and spontaneous CP-violating scenarios is studied. In the former case, a decoupling limit for the new scalars can be achieved, while this is not the case when CP is spontaneously broken. In particular, we show that the existence of two light neutral scalars with masses below a few tenths of GeVs is unavoidable in the CP-violating case. Using matrix theory theorems, we derive upper bounds for the masses of those light scalars and briefly examine whether they can still be experimentally viable. Other interesting features of the scalar mass spectrum are discussed as, e.g., the existence of relations among the charged and neutral scalar masses.

    hep-phJHEP(2022)·13 citations
23. 23*

    Freezing out critical fluctuations

    Maneesha Pradeep🇺🇸 · Krishna Rajagopal🇺🇸 · Misha Stephanov🇺🇸 · Yi Yin🇨🇳

    We introduce a novel freeze-out procedure connecting the hydrodynamic evolution of a droplet of quark-gluon plasma (QGP) that has, as it expanded and cooled, passed close to a posited critical point on the QCD phase diagram with the subsequent kinetic description in terms of observable hadrons. The procedure converts out-of-equilibrium critical fluctuations described by extended hydrodynamics, known as Hydro+, into cumulants of hadron multiplicities that can be subsequently measured. We introduce a critical sigma field whose fluctuations cause correlations between observed hadrons due to the couplings of the sigma field to the hadrons. We match the QGP fluctuations obtained via solving the Hydro+ equations describing the evolution of critical fluctuations before freeze-out to the correlations of the sigma field. In turn, these are imprinted onto fluctuations in the multiplicities of hadrons, most importantly protons, after freeze-out via a generalization of the familiar half-a-century-old Cooper-Frye freeze-out prescription which we introduce. This framework allows us to study the effects of critical slowing down and the consequent deviation of the observable predictions from equilibrium expectations quantitatively. We can also quantify the suppression of cumulants due to the conservation of baryon number. We demonstrate the prescription in practice by freezing out the Hydro+ simulation in a simplified azimuthally symmetric and boost invariant background discussed in Rajagopal, Ridgway, Weller, Yin, 2019.

    hep-phnucl-thPoS(2022)·8 citations
24. 24*

    $Z^{\prime }$-explorer 2.0: reconnoitering the dark matter landscape

    Victor Martin Lozano🇩🇪 · Rosa Maria Sanda Seoane🇦🇷 · Jose Zurita🇪🇸

    We introduce version 2.0 of $Z^{\prime }$-explorer, a software tool which provides a simple, fast and user-friendly test of models with an extra $U(1)$ gauge boson ($Z^{\prime }$) against experimental LHC results. The main novelty of the second version is the inclusion of missing energy searches, as the first version only included final states into SM particles. Hence $Z^{\prime }$-explorer 2.0 is able to test dark matter models where the $Z^{\prime }$ acts as an s-channel mediator between the Standard Model and the dark sector, a widespread benchmark employed by the ATLAS and CMS experimental collaborations. To this end, we perform here the first public reinterpretation of the most recent ATLAS mono-jet search with 139 fb${}^{-1}$. In addition, the corresponding searches in the visible final states have also been updated. We illustrate the power of our code by re-obtaining public plots, and also showing novel results. In particular, we study the cases where the $Z^{\prime }$ couples strongly to top quarks (top-philic), where dark matter couples with a mixture of vector and axial-vector couplings, and also perform a scan in the parameter space of a string inspired Stückelberg model. $Z^{\prime }$-explorer 2.0 is publicly available on GitHub.

    hep-phComput.Phys.Commun.(2023)·13 citations
25. 25*

    Revisiting Inclusive Decay Widths of Charmed Mesons

    Daniel King🇬🇧 · Alexander Lenz🇩🇪 · Maria Laura Piscopo🇩🇪 · Thomas Rauh🇨🇭 · Aleksey V. Rusov🇩🇪 · Christos Vlahos🇬🇧

    Determining for the first time the Darwin operator contribution for the non-leptonic charm-quark decays and using new non-perturbative results for the matrix elements of $\Delta C=0$ four-quark operators, including eye-contractions, we present a comprehensive study of the lifetimes of charmed mesons and inclusive semileptonic decay rates as well as the ratios, within the framework of the Heavy Quark Expansion (HQE). We find good agreement with experiment for the ratio $\tau (D^{+})/\tau (D^0)$, for the total $D_s^{+}$-meson decay rate, for the semileptonic rates of all three mesons $D^0$, $D^{+}$ and $D_s^{+}$, and for the semileptonic ratio ${\Gamma }_{sl}^{D^{+}}/{\Gamma }_{sl}^{D^0}$. The total decay rates of the $D^0$ and $D^{+}$ mesons are underestimated in our HQE approach and we suspect that this is due to missing higher-order QCD corrections to the free charm quark decay and the Pauli interference contribution. For the $SU(3{)}_F$ breaking ratios $\tau (D_s^{+})/\tau (D^0)$ and ${\Gamma }_{sl}^{D_s^{+}}/{\Gamma }_{sl}^{D^0}$ our predictions lie closer to one than experiment. This might originate from the poor knowledge of the non-perturbative parameters ${\mu }_G^2$, ${\mu }_{\pi }^2$ and ${\rho }_D^3$ in the $D^0$ and $D_s^{+}$ systems. These parameters could be determined by experimental studies of the moments of inclusive semileptonic $D$ meson decays.

    hep-phJHEP(2022)·58 citations
26. 26*

    Presenting Unbinned Differential Cross Section Results

    Miguel Arratia🇺🇸 · Anja Butter🇩🇪 · Mario Campanelli🇬🇧 · Vincent Croft🇺🇸 · Aishik Ghosh🇺🇸 · Dag Gillberg🇨🇦 · Kristin Lohwasser🇬🇧 · Bogdan Malaescu🇫🇷 · Vinicius Mikuni🇺🇸 · Benjamin Nachman🇺🇸 · Juan Rojo🇳🇱 · Jesse Thaler🇺🇸 · Ramon Winterhalder🇧🇪

    Machine learning tools have empowered a qualitatively new way to perform differential cross section measurements whereby the data are unbinned, possibly in many dimensions. Unbinned measurements can enable, improve, or at least simplify comparisons between experiments and with theoretical predictions. Furthermore, many-dimensional measurements can be used to define observables after the measurement instead of before. There is currently no community standard for publishing unbinned data. While there are also essentially no measurements of this type public, unbinned measurements are expected in the near future given recent methodological advances. The purpose of this paper is to propose a scheme for presenting and using unbinned results, which can hopefully form the basis for a community standard to allow for integration into analysis workflows. This is foreseen to be the start of an evolving community dialogue, in order to accommodate future developments in this field that is rapidly evolving.

    hep-phhep-exphysics.data-anJINST(2022)·63 citations
27. 27*

    Sliding Naturalness: Cosmological Selection of the Weak Scale

    Raffaele Tito D'Agnolo🇫🇷 · Daniele Teresi🇨🇭

    We present a cosmological solution to the electroweak hierarchy problem. After discussing general features of cosmological approaches to naturalness, we extend the Standard Model with two light scalars very weakly coupled to the Higgs and present the mechanism, which we recently introduced in a companion paper to explain jointly the electroweak hierarchy and the strong-CP problem. In this work we show that this solution can be decoupled from the strong-CP problem and discuss its possible implementations and phenomenology. The mechanism works with any standard inflationary sector, it does not require weak-scale inflation or a large number of e-folds, and does not introduce ambiguities related to eternal inflation. The cutoff of the theory can be as large as the Planck scale, both for the Cosmological Constant and for the Higgs sector. Reproducing the observed dark matter relic density fixes the couplings of the two new scalars to the Standard Model, offering a target to future axion or fifth force searches. Depending on the specific interaction of the scalars with the Standard Model, the mechanism either yields rich phenomenology at colliders or provides a novel joint solution to the strong-CP problem. We highlight what predictions are common to most realizations of cosmological selection of the weak scale and will allow to test this general framework in the near future.

    hep-phastro-ph.COhep-exhep-thJHEP(2022)·44 citations
28. 28*

    Background Field Method and Generalized Field Redefinitions in Effective Field Theories

    Andrea Quadri🇮🇹

    We study the non-linear background field redefinitions arising at the quantum level in a spontaneously broken effective gauge field theory. The non-linear field redefinitions are crucial for the symmetric (i.e. fulfilling all the relevant functional identities of the theory) renormalization of gauge-invariant operators. In a general $R_{\xi }$-gauge the classical background-quantum splitting is also non-linearly deformed by radiative corrections. In the Landau gauge these deformations vanish to all orders in the loop expansion.

    ↳ hep-thhep-ph0 citations
29. 29*

    On Warped String Vacuum Profiles and Cosmologies, II. Non-Supersymmetric Strings

    J. Mourad🇫🇷 · A. Sagnotti🇮🇹

    We investigate the effects of the leading tadpole potentials of 10D tachyon-free non-supersymmetric strings in warped products of flat geometries of the type M(p+1) x R x T(10-p-2) depending on a single coordinate. In the absence of fluxes and for p<8, there are two families of these vacua for the orientifold disk-level potential, both involving a finite internal interval. Their asymptotics are surprisingly captured by tadpole-free solutions, isotropic for one family and anisotropic at one end for the other. In contrast, for the heterotic torus-level potential there are four types of vacua. Their asymptotics are always tadpole-dependent and isotropic at one end lying at a finite distance, while at the other end, which can lie at a finite or infinite distance, they can be tadpole-dependent isotropic or tadpole-free anisotropic. We then elaborate on the general setup for including symmetric fluxes, and present the three families of exact solutions that emerge when the orientifold potential and a seven-form flux are both present. These solutions include a pair of boundaries, which are always separated by a finite distance. In the neighborhood of one, they all approach a common supersymmetric limit, while the asymptotics at the other boundary can be tadpole-free isotropic, tadpole-free anisotropic or again supersymmetric. We also discuss corresponding cosmologies, with emphasis on their climbing or descending behavior at the initial singularity. In some cases the toroidal dimensions can contract during the cosmological expansion.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2021)·40 citations
30. 30*

    Holographic Representations of Supertranslation Eigenstates

    Nikhil Kalyanapuram🇺🇸

    We construct by direct computation holographic presentations of supertranslation vacua given a set of supermomenta. To do this, we make use of two-dimensional dual models recently discovered by the author, which encode soft dynamics of gravity at leading order. In particular, the two-dimensional models are used to define soft currents, of which the supertranslation vacua are eigenstates. Operationally, the eigenstates are determined by the bare vacuum state dressed by exponential operators that generalize the dressing due to Faddeev and Kulish.

    ↳ hep-thhep-ph1 citation
31. 31*

    Spin Multipole Expansion of the Memory Effect

    Nikhil Kalyanapuram🇺🇸

    Using two-dimensional duals of soft dynamics in QED and gravity, we perform an expansion of the respective memory effects in spin multipoles.

    ↳ hep-thgr-qchep-phmath-ph+11 citation
32. 32*

    Explanation of nearby SNRs for primary electron excess and proton spectral bump

    Tian-Peng Tang🇨🇳 · Zi-Qing Xia🇨🇳 · Zhao-Qiang Shen🇨🇳 · Lei Zu🇨🇳 · Lei Feng🇨🇳 · Qiang Yuan🇨🇳 · Yi-Zhong Fan🇨🇳 · Jian Wu🇨🇳

    Several groups have reported a possible excess of primary electrons at high energies with the joint fit of the positron fraction and total electron/positron spectra. With the latest release of high-precision electron/positron spectra measured by AMS-02, we further confirm this excess by fitting $\Delta \Phi$ $(i.e.,{\mathrm{\Phi }}_{{\mathrm{e}}^{-}}-{\mathrm{\Phi }}_{{\mathrm{e}}^{+}})$ data in this work. Then we investigate the contribution of a single nearby supernova remnant to the primary electron excess and find that Monogem can reasonably account for this excess. Moreover, we predict that the electron spectrum may harden again at a few TeVs due to Vela's contribution. DAMPE, which can accurately measure electrons at TeV scale, is expected to provide the robust test of this new spectral feature in the near future. Finally, we fit the proton spectrum data of DAMPE with Monogem or Loop I. We find that both the primary electron excess and the proton spectral bump could be mainly generated by Monogem.

    ↳ astro-ph.HEhep-phPLB(2022)·5 citations
33. 33*

    Identifying the QCD Phase Transitions via the Gravitational Wave Frequency from Supernova Explosion

    Zhan Bai🇨🇳 · Wei-jie Fu🇨🇳 · Yu-xin Liu🇨🇳

    We investigate the non-radial oscillations of newly born neutron stars (NSs) and strange quark stars (SQSs). This is done with the relativistic nuclear field theory with hyperon degrees of freedom employed to describe the equation of state for the stellar matter in NSs, and with both the MIT bag model and the Nambu--Jona-Lasinio model adopted to construct the configurations of the SQSs. We find that the gravitational-mode ($g$-mode) eigenfrequencies of newly born SQSs are significantly lower than those of NSs, which is independent of models implemented to describe the equation of state for the strange quark matter. Meanwhile, the eigenfrequencies of the other modes of non-radial oscillations, e.g., fundamental ($f$)- and pressure ($p$)-modes, are much larger than those of the $g$-mode, and is related to the stiffness of the equation of states (EoSs). In the light of the first direct observation of gravitational waves, it is promising to employ the gravitational waves to identify the QCD phase transition in high density strong interaction matter.

    ↳ nucl-thhep-phApJ(2021)·11 citations
34. 34*

    On asymmetric dark matter constraints from the asteroseismology of a subgiant star

    João Rato🇵🇹 · José Lopes🇵🇹 · Ilídio Lopes🇵🇹

    The asteroseismic modelling of solar-like stars has proved to be valuable in constraining dark matter. In this work we study for the first time the influence of asymmetric dark matter (ADM) in the evolution of a subgiant star (KIC 8228742) by direct comparison with observational data. Both spectroscopic and seismic data are analysed with a new approach to the stellar calibration method, in which DM properties can also be considered as free inputs. In another phase of this study, a calibrated standard stellar model (without DM) is used as the benchmark for DM models. We find that the latter models consistently outperform the former for $10^{-40}\le {\sigma }_{\mathrm{SD}}<10^{-38}$ cm${}^2$, hinting that the presence of ADM in stars of this type does not go against observations. Moreover, we show that stellar seismology allows us to suggest exclusion limits that complement the constraints set by direct detection experiments. Different seismic observables are proposed to study DM properties and $\Delta {\Pi }_{\ell }$ is found to be the most reliable, having the potential to build future DM exclusion diagrams. This new methodology can be a powerful tool in the analysis of the data coming from the next generation of asteroseismic missions.

    ↳ astro-ph.SRhep-phMNRAS(2021)·10 citations
35. 35*

    Real valued functions for BFKL eigenvalue

    Mohammad Joubat🇮🇱 · Alex Prygarin🇮🇱

    We consider known expressions for the eigenvalue of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation in $N=4$ super Yang-Mills theory as a real valued function of two variables anomalous dimension and the conformal spin. We define new real valued functions of two complex conjugate variables that have a definite complexity analogous to the weight of the nested harmonic sums. We argue that those functions span a general space of functions for the BFKL eigenvalue at any order of the perturbation theory.

    ↳ hep-thhep-phUniverse(2021)·2 citations
36. 36*

    Graph-based clustering of gamma-ray bursts

    Mariusz Tarnopolski🇵🇱

    Aims. An attempt to classify gamma-ray bursts (GRBs) with a low level of supervision using the state-of-the-start approaches stemming from graph theory was undertaken. Methods. Graph-based classification methods, relying on different variants of the $k$-nearest neighbour graph, were applied to various GRB samples in the duration-hardness ratio parameter space to infer the optimal partitioning. Results. In most cases it is found that both two and three groups are feasible, with the outcome being more ambiguous with an increasing sample size. Conclusions. There is no clear indication of the presence of a third GRB class; however, such a possibility cannot be ruled out with the employed methodology. There are no hints at more than three classes though.

    ↳ astro-ph.HEastro-ph.IMhep-phAstron.Astrophys.(2022)·10 citations
37. 37*

    Rotation and deformation of strangeon stars in the Lennard-Jones model

    Yong Gao🇨🇳 · Xiao-Yu Lai🇨🇳 · Lijing Shao🇨🇳 · Ren-Xin Xu🇨🇳

    The strong interactions at low energy scales determine the state of the supranuclear matter in the pulsar-like compact objects. It is proposed that the bulk strong matter could be composed of strangeons, which are quark clusters with a nearly equal number of three light-flavor quarks. In this work, to characterize the strong-repulsive interactions at short distances and the non-relativistic nature of the strangeons, the Lennard-Jones model is used to describe the equation of state (EoS) of strangeon stars (SSs). We investigate the static, the slowly rotating, and the tidally deformed SSs in detail. The corrections resulted from the finite surface densities are considered crucially in the perturbative approaches. We also study the universal relations between the moments of inertia, the tidal deformabilities, and the quadrupole moments. Those results are ready to be used for various purposes in astrophysics, and possible constraints from contemporary observations on the parameter space of the Lennard-Jones model are discussed. Future observations of the pulsars' radio signals, the X-ray emissions from the hot spots on the surface of the stars, and the gravitational waves (GWs) from binary mergers can give tighter constraints or even verify or falsify the existence of SSs.

    ↳ gr-qcastro-ph.HEhep-phnucl-thMNRAS(2021)·38 citations
38. 38*

    Ultra-light axions and the kinetic Sunyaev-Zel'dovich Effect

    Gerrit S. Farren🇬🇧 · Daniel Grin🇺🇸 · Andrew H. Jaffe🇬🇧 · Renée Hložek🇨🇦 · David J. E. Marsh🇩🇪

    Measurements of secondary cosmic microwave background (CMB) anisotropies, such as the Sunyaev-Zel'dovich (SZ) effect, will enable new tests of neutrino and dark sector properties. The kinetic SZ (kSZ) effect is produced by cosmological flows, probing structure growth. Ultra-light axions (ULAs) are a well-motivated dark-matter candidate. Here the impact of ULA dark matter (with mass $10^{-27}\mathrm{eV}$ to $10^{-23}\mathrm{eV}$) on kSZ observables is determined, applying new analytic expressions for pairwise cluster velocities and Ostriker-Vishniac signatures in structure-suppressing models. For the future CMB-S4 and ongoing DESI galaxy surveys, the kSZ effect (along with primary anisotropies) will probe ULA fractions ${\eta }_a={\Omega }_{\mathrm{axion}}/{\Omega }_{\mathrm{DM}}$ as low as $\sim 5\%$ if $m_a\simeq 10^{-27}\mathrm{eV}$ (at 95\% C.L.), with sensitivity extending up to $m_a\simeq 10^{-25}\mathrm{eV}$. If reionization and the primary CMB can be adequately modeled, Ostriker-Vishniac measurements could probe values ${\eta }_a\simeq 10^{-3}$ if $10^{-27}\mathrm{eV}\lesssim m_a\lesssim 10^{-24}\mathrm{eV}$, or ${\eta }_a\simeq 1$ if $m_a\simeq 10^{-22}\mathrm{eV}$, within the fuzzy dark matter window.

    ↳ astro-ph.COgr-qchep-phPRD(2022)·32 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.