Thu·Nov 9, 2023Thursday·November 9, 2023

1. 01*

   Viscosity of non equilibrium hot $\&$ dense QCD drop formed at LHC

   J. R. Alvarado García🇲🇽 · I. Bautista🇲🇽 · A. Fernández Téllez🇲🇽 · P. Fierro🇲🇽

   We compute the bulk, $\zeta$, and shear, $\eta$, viscosity over entropy density, $s$, for the QCD matter formed in small collision systems at LHC. We consider a scenario of the String Percolation Model by proposing a global form of the color reduction factor that describes both the thermodynamic limit and its maximum deviation due to small-bounded effects. Our method involves estimations at vanishing baryon-chemical potential, assuming local equilibrium for string clusters in the initial state. To compute $\eta /s$, we employed a kinetic approach that accounts QCD states as an ideal gas of partons, while $\zeta /s$ is computed by using two different approaches: a simple kinetic formula and the causal dissipative relativistic fluid dynamics formulation. Our results align with Lattice QCD computations and Bayesian methods and are consistent with holographic conjecture bounds. Furthermore, our findings support the notion of a strongly interacting medium, similar to that observed in nuclear collisions, albeit with a phase transition occurring outside the thermodynamic limit.

   hep-phnucl-thPRD(2023)·3 citations
2. 02*

   Semileptonic and nonleptonic weak decays of $\psi (1S,2S)$ and ${\eta }_c(1S,2S)$ to $D_{(s)}$ in the covariant light-front approach

   Zhi-Jie Sun🇨🇳 · Zhi-Qing Zhang🇨🇳 · You-Ya Yang🇨🇳 · Hao Yang🇨🇳

   In addition to the strong and electromagnetic decay modes, the $\psi (1S,2S)$ and ${\eta }_c(1S,2S)$ can also decay via the weak interaction. Such weak decays can be detected by the high-luminosity heavy-flavor experiments. At present, some of the semileptonic and nonleptonic $J/\Psi$ weak decays have been measured at BESIII. Researching for these charmonium weak decays to $D_{(s)}$ meson can provide a platform to check of the standard model (SM) and probe new physics (NP). So we investigate the semileptonic and nonleptonic weak decays of $\psi (1S,2S)$ and ${\eta }_c(1S,2S)$ to $D_{(s)}$ within the covariant light-front quark model (CLFQM). With form factors of the transitions $\psi (1S,2S)\to D_{(s)}$ and ${\eta }_c(1S,2S)\to D_{(s)}$ calculated under the CLFQM, we predict and discuss some physical observables, such as the branching ratios, the longitudinal polarizations $f_L$ and the forward-backward asymmetries $A_{FB}$. One can find that the Cabibbo-favored semi-leptonic decay channels $\psi (1S,2S)\to D_s^{-}{\ell }^{+}{\nu }_{\ell }$ with $\ell =e,\mu$ and the nonleptonic decay modes $\psi (1S,2S)\to D_s^{-}{\rho }^{+}$ have relatively large branching ratios of the order $\mathcal{O}(10^{-9})$, which are most likely to be accessible at the future high-luminosity experiments.

   hep-phEPJC(2024)·18 citations
3. 03*

   The decay contribution to the parity-odd fragmentation functions

   Yan-Lei Pan🇨🇳 · Kai-Bao Chen🇨🇳 · Yu-Kun Song🇨🇳 · Shu-Yi Wei🇨🇳

   Parity violation in QCD is a consequence of the so-called QCD $\theta$-vacuum. As a result, parity-odd fragmentation functions are introduced and they bring in new observables in the back-to-back dihadron productions in $e^{+}{e}^{-}$-annihilation experiments [Phys.Rev.Lett. 106 (2011) 042001]. The experimental measurements on the corresponding parity-odd fragmentation functions can shed light on the local CP violation effect in QCD. On the other hand, the weak interaction also violates the parity symmetry. Therefore, the weak decay of heavier hadrons can also contribute to the parity-odd effects in fragmentation functions. In this paper, we investigate the weak decay contribution to these parity-odd fragmentation functions and compute their contribution to these new observables. In principle, the decay contribution should/can be excluded in the theoretical analysis and experimental measurements. However, this is usually not the common practice so far. Furthermore, in light of that the value of the $\theta$-parameter is extremely small ($\theta <3\times 10^{-10}$), the weak-parity-violating contributions become an important background in identifying the strong-parity-violating term. In this paper, we focus on the weak decay contribution of parity-odd fragmentation functions and demonstrate their sizable contribution in a numerical estimate.

   hep-phhep-exPLB(2024)·2 citations
4. 04*

   Spatial distribution of Angular Momentum Inside a Quark State Dressed with a Gluon

   Ravi Singh🇮🇳 · Sudeep Saha🇮🇳 · Asmita Mukherjee🇮🇳 · Nilmani Mathur🇮🇳

   We investigate the different decompositions of the angular momentum in QCD for a relativistic spin $1/2$ composite state, namely a quark dressed with a gluon. We use light-front Hamiltonian perturbation theory, and in the light-front gauge, use the two-component framework by eliminating the constrained degrees of freedom. We also investigate the different decompositions of the angular momentum at the level of two-dimensional densities in the front form, including the effect of the so-called potential term. In this work, we consider the contribution coming from the quark part of the energy-momentum tensor. We contrast the different decompositions and also compare with other calculations in the literature. We also present the gravitational form factor related to the antisymmetric part of the energy-momentum tensor.

   hep-phPRD(2024)·5 citations
5. 05*

   Analysis of $D{D}^{\ast }$ and ${\bar{D}}^{(\ast )}{\Xi }_{cc}^{(\ast )}$ molecule by one boson exchange model based on Heavy quark symmetry

   Tatsuya Asanuma🇯🇵 · Yasuhiro Yamaguchi🇯🇵 · Masayasu Harada🇯🇵

   Numerous exotic hadrons with heavy quarks have been reported in the experiments. In such states, symmetries of heavy quarks are considered to play a significant role. In particular, the superflavor symmetry, or also called the heavy quark anti-diquark symmetry is one of the interesting symmetries, which links a quark $Q$ to an anti-diquark $\bar{Q}\bar{Q}$ having the same color representation as $Q$. In this paper, we study a $\bar{D}{\Xi }_{cc}$ molecular state as a superflavor partner of the doubly charm tetraquark $T_{cc}$ reported by LHCb recently. $T_{cc}$ locating slightly below the $D{D}^{\ast }$ threshold is a candidate of the hadronic molecule. Thus by replacing the singly charm meson $D^{(\ast )}$ with the doubly charm baryon ${\Xi }_{cc}^{(\ast )}$, superflavor symmetry predicts the existence of the ${\bar{D}}^{(\ast )}{\Xi }_{cc}^{(\ast )}$ bound state. We employ the one boson exchange model respecting with the heavy quark spin symmetry where the parameter is obtained to reproduce the $T_{cc}$ binding energy. We apply this model with superflavor symmetry to the ${\bar{D}}^{(\ast )}{\Xi }_{cc}^{(\ast )}$ molecule and predict a bound state with $I(J^P)=0({\frac{1}{2}}^{-})$. If the pentaquark state corresponding to ${\bar{D}}^{(\ast )}{\Xi }_{cc}^{(\ast )}$ molecular state is observed in future experiments as predicted in this work, it is more likely that $T_{cc}$ is a $D{D}^{\ast }$ molecular state.

   hep-phnucl-thPRD(2024)·19 citations
6. 06*

   High-$p_T$ Azimuthal Correlations of Z+jet and Multi-jet Production

   S. Taheri Monfared🇩🇪 · L. I. Estevez Banos🇩🇪

   In this study, we present our latest findings regarding azimuthal distributions in vector boson + jets and multi-jet production at the Large Hadron Collider (LHC). These findings result from matching next-to-leading order (NLO) perturbative matrix elements with transverse momentum dependent (TMD) parton branching. We conduct a comprehensive comparative analysis of azimuthal correlations between Z boson-jet and jet-jet systems in the back-to-back region. These distinct azimuthal correlation patterns can help identify potential factorization-breaking effects in this region. Such effects depend on the different color and spin structures of the final states and their interactions with the initial states.

   hep-phPoS(2024)·0 citations
7. 07*

   Searches for new physics models via the same-sign diboson (SSdB) + ${E/}_T$ and precise measurement of top quark features at the LHC

   Dibyashree Sengupta🇮🇹

   Till today, although the Standard Model (SM) is the most celebrated theory that explains nature almost completely, there are still some phenomena observed in nature that the SM cannot explain. That is why it is needed to look for theories beyond the Standard Model (BSM). While the ATLAS/CMS experiments discovered a Standard Model-like Higgs boson at the Large Hadron Collider (LHC), no compelling new physics signal has been seen yet. Several searches have been performed at the LHC to look for new physics signal. One such novel signal is the same-sign diboson (SSdB) + ${E/}_T$ which is a rather clean signal with negligibly small SM background. Such a unique signature can be observed in more than one well-motivated BSM scenarios, namely: (i) natural SUSY models, (ii) type-III seesaw model and (iii) type-II seesaw/Georgi-Machacek model. In the first part of this poster I present the discovery prospects of this signal that has been analyzed in these BSM models in current and future runs of the LHC beside providing ways to distinguish among these different BSM models. Furthermore, the LHC, being a "top quark factory", helps in precise measurement of various properties of the top quark. Deviation from the SM prediction in measuring these properties of the top quark can, very efficiently, shed light on new physics signal. In the second part of this poster I present a work in progress where we aim to show how precise measurement of quantities related to top quark features can indicate towards a new physics signal.

   hep-phPoS(2024)·0 citations
8. 08*

   NLO Analysis of Small-$k_T$ Region in Drell-Yan Production with Parton Branching

   S. Taheri Monfared🇩🇪

   The Parton-Branching Method (PB) facilitates the determination of Transverse Momentum Dependent (TMD) parton densities across a wide \kt\ range, spanning small to large transverse momentum scales. In the small $k_T$ region, both intrinsic parton motion and resummed ultra-soft gluons are significant contributors. Our analysis highlights their crucial role in shaping integrated and TMD parton densities. Using PB-derived TMD parton densities and a NLO calculation in MC@NLO style, we compute the transverse momentum spectrum of Drell-Yan pairs across a broad mass range. The spectrum's sensitivity to the intrinsic $k_T$ distribution allows us to fine-tune parametric parameters. Starting from the PB-NLO-HERAI+II-2018 set2 TMD parton distributions, we determine the intrinsic $k_T$ distribution width, resulting in a slightly wider profile than the default set. Importantly, this width remains independent of Drell-Yan pair mass and center-of-mass energy ($\sqrt{s}$), distinguishing our approach.

   hep-phPoS(2024)·1 citation
9. 09*

   Next-to-next-to-leading-order QCD corrections to double $J/\psi$ production at the $B$ factories

   Xu-Dong Huang🇨🇳 · Bin Gong🇨🇳 · Rui-Chang Niu🇨🇳 · Huai-Min Yu🇨🇳 · Jian-Xiong Wang🇨🇳

   In this paper, we study the next-to-next-to-leading-order (NNLO) QCD corrections for the process $e^{+}{e}^{-}\to J/\psi +J/\psi$ at the $B$ factories. By including the NNLO corrections, the cross section turns negative due to the poor convergence of perturbative expansion. Consequently, to obtain a reasonable estimation for the cross section, the square of the amplitude up to NNLO is used. In addition, the contributions from the bottom quark and the light-by-light part, which are usually neglected, are also included. The final cross section is obtained as $1.76_{-1.66}^{+2.42}\mathrm{fb}$ at a center-of-mass energy of $\sqrt{s}=10.58$ GeV. Our result for total cross section and differential cross section could be compared with precise experimental measurement in future at the $B$ factories.

   hep-phJHEP(2024)·14 citations
10. 10*

    AdlerPy: A Python Package for the Perturbative Adler Function

    Rodolfo Ferro Hernández🇩🇪

    In this letter, I give availability to the source code AdlerPy which will allow to easily use the Adler function. As an application, I use the mass-dependent perturbative expression for the Adler function to compute several observables and relevant Standard Model parameters.

    hep-phhep-lat4 citations
11. 11*

    Beyond the Standard Model prospects for kaon physics at future experiments

    G. D'Ambrosio🇮🇹 · F. Mahmoudi🇫🇷 · S. Neshatpour🇫🇷

    Rare kaon decays offer a powerful tool for investigating new physics in $s\to d$ transitions. Currently, many of the interesting decay modes are either measured with rather large uncertainties compared to their theoretical predictions or have not yet been observed. The future HIKE programme at CERN will provide unprecedented sensitivity to rare kaon decays, allowing for strong constraints on new physics scenarios with lepton flavour universality violation. We present the overall picture that emerges from a study of the different decay modes with a global analysis considering projections based on the HIKE programme, both with and without KOTO-II future measurements. We also highlight the most relevant decays and identify that in addition to the "golden channel", $K^{+}\to {\pi }^{+}\nu \bar{\nu }$, the rare $K_L\to {\pi }^0\ell \bar{\ell }$ decay, especially in the electron sector offers strong constraints on short-distance physics.

    hep-phhep-exJHEP(2024)·18 citations
12. 12*

    Extracting Halo Independent Information from Dark Matter Electron Scattering Data

    Elias Bernreuther🇺🇸 · Patrick J. Fox🇺🇸 · Benjamin Lillard🇺🇸 · Anna-Maria Taki🇺🇸 · Tien-Tien Yu🇺🇸

    Direct detection experiments and the interpretation of their results are sensitive to the velocity structure of the dark matter in our galactic halo. In this work, we extend the formalism that deals with such astrophysics-driven uncertainties, originally introduced in the context of dark-matter-nuclear scattering, to include dark-matter-electron scattering interactions. Using mock data, we demonstrate that the ability to determine the correct dark matter mass and velocity distribution is depleted for recoil spectra which only populate a few low-lying bins, such as models involving a light mediator. We also demonstrate how this formalism allows one to test the compatibility of existing experimental data sets (e.g. SENSEI and EDELWEISS), as well as make predictions for possible future experiments (e.g. GaAs-based detectors).

    hep-phastro-ph.COJCAP(2024)·6 citations
13. 13*

    A global analysis of the SMEFT under the minimal MFV assumption

    Riccardo Bartocci🇩🇪 · Anke Biekötter🇩🇪 · Tobias Hurth🇩🇪

    We present comprehensive global fits of the SMEFT under the $\text{minimal}$ minimal flavour violation (MFV) hypothesis, i.e. assuming that only the flavour-symmetric and CP-invariant operators are relevant at the high scale. The considered operator set is determined by theory rather than the used datasets. We establish global limits on these Wilson coefficients using leading order and next-to-leading order SMEFT predictions for electroweak precision observables, Higgs, top, flavour and dijets data as well as measurements from parity violation experiments and lepton scattering. Our investigations reveal an intriguing crosstalk among different observables, underscoring the importance of combining diverse observables from various energy scales in global SMEFT analyses.

    hep-phJHEP(2024)·59 citations
14. 14*

    Dark Radiation from the Primordial Thermal Bath in Momentum Space

    Francesco D'Eramo🇮🇹 · Fazlollah Hajkarim🇺🇸 · Alessandro Lenoci🇩🇪

    Motivated by the stunning projections for future CMB surveys, we evaluate the amount of dark radiation produced in the early Universe by two-body decays or binary scatterings with thermal bath particles via a rigorous analysis in momentum space. We track the evolution of the dark radiation phase space distribution, and we use the asymptotic solution to evaluate the amount of additional relativistic energy density parameterized in terms of an effective number of additional neutrino species $\Delta N_{\mathrm{eff}}$. Our approach allows for studying light particles that never reach equilibrium across cosmic history, and to scrutinize the physics of the decoupling when they thermalize instead. We incorporate quantum statistical effects for all the particles involved in the production processes, and we account for the energy exchanged between the visible and invisible sectors. Non-instantaneous decoupling is responsible for spectral distortions in the final distributions, and we quantify how they translate into the corresponding value for $\Delta N_{\mathrm{eff}}$. Finally, we undertake a comprehensive comparison between our exact results and approximated methods commonly employed in the existing literature. Remarkably, we find that the difference can be larger than the experimental sensitivity of future observations, justifying the need for a rigorous analysis in momentum space.

    hep-phastro-ph.COJCAP(2024)·18 citations
15. 15*

    Classes of complete dark photon models constrained by Z-Physics

    Miguel P. Bento🇵🇹 · Howard E. Haber🇺🇸 · João P. Silva🇵🇹

    Dark Matter models that employ a vector portal to a dark sector are usually treated as an effective theory that incorporates kinetic mixing of the photon with a new U(1) gauge boson, with the $Z$ boson integrated out. However, a more complete theory must employ the full SU(2)${}_L\times$U(1)${}_Y\times$U(1)${}_{Y^{\prime }}$ gauge group, in which kinetic mixing of the $Z$ boson with the new U(1) gauge boson is taken into account. The importance of the more complete analysis is demonstrated by an example where the parameter space of the effective theory that yields the observed dark matter relic density is in conflict with a suitably defined electroweak $\rho$-parameter that is deduced from a global fit to $Z$ physics data.

    hep-phastro-ph.COPLB(2024)·13 citations
16. 16*

    Quark confinement in an equiparticle quark model: application to stellar matter

    Isabella Marzola🇧🇷 · Sérgio B. Duarte🇧🇷 · César H. Lenzi🇧🇷 · Odilon Lourenço🇧🇷

    We perform an improvement in a thermodynamical consistent model with density dependent quark masses ($m_{u,d,s}^{\prime }$) by introducing effects of quark confinement/deconfinement phase transition, at high density regime and zero temperature, by means of the traced Polyakov loop ($\Phi$). We use realistic values for the current quark masses, provided by the Particle Data Group, and replace the constants of the interacting part of $m_{u,d,s}^{\prime }$ by functions of $\Phi$, leading to a first order phase transition structure, for symmetric and stellar quark matter, with $\Phi$ being the order parameter. We show that the improved model points out the direction of the chiral symmetry restoration due to the emergence of a deconfined phase. In another application, we construct quark stars mass-radius profiles, obtained from this new model, and show to be possible to satisfy recent astrophysical observational data coming from the LIGO and Virgo Collaboration, and the NICER mission concerning the millisecond pulsars PSR J0030+0451, and PSR J0740+6620.

    ↳ astro-ph.HEhep-phnucl-thPRD(2023)·4 citations
17. 17*

    Dynamics of causal hydrodynamic fluctuations in an expanding system

    Shin-ei Fujii🇯🇵 · Tetsufumi Hirano🇯🇵

    We develop a framework of causal hydrodynamic fluctuations in one-dimensional expanding system performing linearisation of the hydrodynamic equations around the boost invariant solution. Through the description of space-time evolution of thermodynamic variables and flow velocity, we find a novel phenomenon that the structure of thermodynamic variables is almost frozen. We also show that two-particle correlation functions of final hadrons after freezeout are closely related with the mass of hadrons and properties of the medium such as viscosity, relaxation time and equation of state.

    ↳ nucl-thhep-phnucl-exEPJ Web Conf.(2024)·1 citation
18. 18*

    Fully-heavy baryons $QQQ$ in vacuum and hot QCD medium

    Jiaxing Zhao🇫🇷 · Shuzhe Shi🇨🇳

    We study the properties of fully-heavy baryons in the vacuum and the hot QCD medium, which is created in relativistic heavy-ion collisions. Masses and wave functions of ${\Omega }_{ccc}$, ${\Omega }_{ccb}$, ${\Omega }_{bbc}$, and ${\Omega }_{bbb}$ up to the second radial excited states are obtained by solving the three-body Schrödinger equation with Hyperspherical Harmonics method. With parameters completely fixed by fitting quarkonium boundstates in vacuum, we predicted the masses for $1S$, $2S$, and $3S$ states of fully-heavy baryons. We also computed the temperature dependence of baryon masses and the thermal widths in a hot QCD medium. These properties are important to precise study of fully-heavy baryon production in heavy ion collisions.

    ↳ nucl-thhep-phPRC(2024)·13 citations
19. 19*

    New approach to finding invisible states in $e^{+}{e}^{-}$ annihilation and application to BESIII data

    Glennys R. Farrar🇺🇸 · Qi-Ming Li🇨🇳 · Chang-Zheng Yuan🇨🇳

    We compare precision $e^{+}{e}^{-}$ to ${\mu }^{+}{\mu }^{-}$ cross section measurements by BESIII in the E_cm =3.8-4.6 GeV range, to predictions based on measured R_had data. The consistency is poor (p-value <0.012). Allowing for resonance contributions not seen in R_had gives an excellent fit, with the state at 4421 MeV ( 4.6 sigma) giving insight into the psi(4415) and the 3.1 sigma structure at 4211 MeV, if confirmed, being a new, very narrow resonance. This analysis shows the power of precision $e^{+}{e}^{-}$ to ${\mu }^{+}{\mu }^{-}$ measurements to uncover or probe otherwise difficult to access states.

    ↳ hep-exhep-lathep-phPRD(2024)·3 citations
20. 20*

    Comparing Repeated Gravitational-Wave Bursts Emitted by Cosmic Strings

    Imene Belahcene🇨🇳 · Wen-Biao Han🇨🇳

    The principal energy loss mechanism in a Nambu-Goto cosmic string network involves loop production and the subsequent gravitational-wave emission. Recently, it has been shown that the loop oscillations produce repeated gravitational-wave bursts emitted at cusps. The calculations are extended to estimate the number of burst repeaters, including kink emissions and kink-kink collisions. Our findings indicate that despite the potentially large number of kinks, we anticipate observing a higher number of burst repeaters from cusps for both LIGO-Virgo-KAGRA and the Laser Interferometer Space Antenna. We also conduct calculations using the second main loop distribution model in the current literature. We find that this model predicts a notably higher number of repeaters, which provides a reason to include it in future data analysis. These results offer insights into the potential observability of different loop features for future detectors, such as the space-based laser interferometers Taiji and TianQin.

    ↳ gr-qchep-ph0 citations
21. 21*

    Light Fields during Inflation from BOSS and Future Galaxy Surveys

    Daniel Green🇺🇸 · Yi Guo🇺🇸 · Jiashu Han🇺🇸 · Benjamin Wallisch🇸🇪

    Primordial non-Gaussianity generated by additional fields present during inflation offers a compelling observational target for galaxy surveys. These fields are of significant theoretical interest since they offer a window into particle physics in the inflaton sector. They also violate the single-field consistency conditions and induce a scale-dependent bias in the galaxy power spectrum. In this paper, we explore this particular signal for light scalar fields and study the prospects for measuring it with galaxy surveys. We find that the sensitivities of current and future surveys are remarkably stable for different configurations, including between spectroscopic and photometric redshift measurements. This is even the case at non-zero masses where the signal is not obviously localized on large scales. For realistic galaxy number densities, we demonstrate that the redshift range and galaxy bias of the sample have the largest impact on the sensitivity in the power spectrum. These results additionally motivated us to explore the potentially enhanced sensitivity of Vera Rubin Observatory's LSST through multi-tracer analyses. Finally, we apply this understanding to current data from the last data release of the Baryon Oscillation Spectroscopic Survey (BOSS DR12) and place new constraints on light fields coupled to the inflaton.

    ↳ astro-ph.COhep-phhep-thJCAP(2024)·41 citations
22. 22*

    Cosmological Phase Transitions and the Swampland

    Victoria Venken🇬🇧

    I consider the Festina Lente Swampland bound and argue taking thermal effects, as for instance occur during reheating, into account significantly strengthens the implications of this bound. I argue that the confinement scale should be higher than a scale proportional to the vacuum energy, while Festina Lente without thermal effects only bounds the confinement scale to be above the Hubble scale. For Higgsing of nonabelian gauge fields, I find that the magnitude of the Higgs mass should be heavier than a bound proportional to the Electroweak scale (or generally the scale set by the Higgs VEV). The measured values of the Higgs in the SM satisfy the bound. A way to avoid the bound being violated during inflation is to have a large number of species becoming light. If one wants the inflationary scale to lie below the species scale in this case, this bounds the inflationary scale to be $\ll 10^5$ GeV. These bounds have phenomenological implications for BSM physics such as GUTs, suggesting for example a weak or absent gravitational wave signature from the GUT Higgsing phase transition.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2024)·6 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.