Wed·Aug 31, 2022Wednesday·August 31, 2022

1. 01*

   Matter-antimatter Asymmetry, CP Violation and the Time Operator in Relativistic Quantum Mechanics

   M. Bauer🇲🇽

   The matter antimatter asymmetry in the Universe is one of the outstanding problems in physics.and cosmology. CP violation (CPV) is a necessary condition for generating such asymmetry but the amount predicted in the Standard Model (SM) from quark oscillations is too small by several orders of magnitude. The dynamical time operator derived together with Dirac's Hamiltonian from the Dirac canonical quantization of special relativity is shown to exhibit a CPV inversely dependent on mass. Applying to all fermions, it follows that extended Standard Models (ESM) with massive neutrinos contains a much larger CPV as the electron and muon neutrino masses are six to nine orders smaller than the up and down quarks masses. Furthermore, it also follows that the CPV differs between neutrino and antineutrino, in agreement with the T2K observations.

   hep-ph3 citations
2. 02*

   Back-to-back inclusive dijets in DIS at small $x$: Sudakov suppression and gluon saturation at NLO

   Paul Caucal🇺🇸 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸 · Raju Venugopalan🇺🇸

   Back-to-back dijet cross-sections in deeply inelastic scattering (DIS) at small $x_{\mathrm{Bj}}$ are suppressed by many-body multiple scattering and screening effects arising from gluon saturation at high parton densities. They are similarly sensitive in these kinematics to large Sudakov logarithms from soft gluon radiation. Uncovering novel physics in this DIS channel therefore requires understanding the interplay of the two phenomena. In this work, we compute the small $x_{\mathrm{Bj}}$ inclusive dijet DIS cross-section in back-to-back kinematics at next-to-leading order (NLO) in the Color Glass Condensate effective field theory (CGC EFT). Our result includes, for the first time, all real and virtual NLO contributions to the impact factor. These include all Sudakov double and single logarithm contributions, as well as all other finite $\mathcal{O}({\alpha }_s)$ terms that contribute at this order. We demonstrate explicitly that resummations of small $x$ and Sudakov logarithms can be performed simultaneously in the CGC EFT. This requires that the JIMWLK kernel for small $x$ evolution of the Weizsäcker-Williams (WW) gluon distribution satisfies a kinematic constraint imposed by lifetime ordering of successive gluon emissions; the corresponding modifications to the kernel, corresponding to resummations of large double transverse logarithms, are precisely of the type required to stabilize JIMWLK evolution beyond leading logarithmic accuracy. We compute the azimuthal harmonics of the NLO back-to-back distributions and show their sensitivity to both the unpolarized and linearly polarized WW gluon distributions. Finally, we discuss how TMD factorization is broken by an emergent saturation scale at small $x$.

   hep-phhep-thnucl-thJHEP(2022)·88 citations
3. 03*

   Full off-shell NLO QCD predictions for $t\bar{t}b\bar{b}$ at the LHC

   Manfred Kraus🇺🇸

   We report on state-of-the-art theoretical predictions for $pp\to t\bar{t}b\bar{b}$ including full off-shell effects in the di-lepton decay channel at NLO QCD accuracy. We briefly discuss the impact of NLO QCD corrections on differential distributions and also asses theoretical uncertainties from scale and PDF dependence. Furthermore, we propose a simple kinematic reconstruction in order to distinguish $b$ jets originating from top-quark decays from arising from gluon splittings.

   hep-phPoS(2023)·0 citations
4. 04*

   The study of the singly anti-charmed pentaquark production in b-factory

   Xiao-Hui Hu🇨🇳 · Ye Xing🇨🇳

   The b-factories, such as BelleII, BarBar and LHCb, emphasize the increasing importance of exotic hadron research. In this paper, we discuss the possible production of singly anti-charmed pentaquark states $\bar{c}qqqq$ from $B$ mesons in the b-factory under SU(3) symmetry analysis. Discussions of both possibilities have been driven by the hypothesis that the pentaquark state considered in this work, known as the lowest lying state $P_{\bar{c}}$, could be bound or unbound. We find the golden channels for the production of the pentaquark ground states, such as $B^0\to P_{\bar{c}sudu}^{(\prime )0}{\Sigma }^0$. We further estimate the branching ratios for the production of the ground states $P_{\bar{c}}$ from $B$ meson decays. Thus, multiple channels are available for experiments, which may remove certain obstacles to the discovery of new pentaquark states.

   hep-phCPC(2024)·3 citations
5. 05*

   Comparison of $t\bar{t}W$ theory predictions in the $3\ell$ channel

   Manfred Kraus🇺🇸

   We report on our recent comparison of various theoretical approaches to predict fiducial signatures for $pp\to t\bar{t}W$ in the $3\ell$ decay channel at $\mathcal{O}({\alpha }_s^3{\alpha }^6)$ and $\mathcal{O}({\alpha }_s{\alpha }^8)$. The comparison includes fixed-order predictions including full off-shell effects as well as predictions based only on the double-resonant contributions by employing the Narrow-Width-Approximation. Furthermore, we include parton-shower matched predictions using the MG5 and POWHEG-BOX frameworks.

   hep-phPoS·0 citations
6. 06*

   Collider Searches for Heavy Neutral Leptons: beyond simplified scenarios

   Asmaa Abada🇫🇷 · Pablo Escribano🇪🇸 · Xabier Marcano🇪🇸 · Gioacchino Piazza🇫🇷

   With very few exceptions, the large amount of available experimental bounds on heavy neutral leptons - HNL - have been derived relying on the assumption of the existence of a single (usually Majorana) sterile fermion state that mixes with only one lepton flavour. However, most of the extensions of the Standard Model involving sterile fermions predict the existence of several HNLs, with complex mixing patterns to all flavours. Consequently, most of the experimental bounds for HNLs need to be recast before being applied to a generic scenario. In this work, we focus on LHC searches of heavy neutral leptons and discuss how to reinterpret the available bounds when it comes to consider mixings to all active flavours, not only in the case with a single HNL, but also in the case when more heavy neutral leptons are involved. In the latter case, we also consider the possibility of interference effects and show how the bounds on the parameter space should be recast.

   hep-phhep-exEPJC(2022)·56 citations
7. 07*

   Bethe-Salpeter kernel and properties of strange-quark mesons

   Zhen-Ni Xu🇨🇳 · Zhao-Qian Yao🇨🇳 · Si-Xue Qin🇨🇳 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳

   Focusing on the continuum meson bound-state problem, a novel method is used to calculate closed-form Bethe-Salpeter kernels that are symmetry consistent with any reasonable gluon-quark vertex, ${\Gamma }_{\nu }$, and therewith deliver a Poincaré-invariant treatment of the spectrum and decay constants of the ground- and first-excited states of $u$, $d$, $s$ mesons. The predictions include masses of as-yet unseen states and many unmeasured decay constants. The analysis reveals that a realistic, unified description of meson properties (including level orderings and mass splittings) requires a sound expression of emergent hadron mass in bound-state kernels; alternatively, that such properties may reveal much about the emergence of mass in the standard model.

   hep-phhep-exhep-latnucl-ex+1EPJA(2023)·33 citations
8. 08*

   Estimation of compositeness with correction terms

   Tomona Kinugawa🇯🇵 · Tetsuo Hyodo🇯🇵

   The compositeness $X$ is defined as the probability to observe the composite structure such as the hadronic molecule component in a bound state. One of the model-independent approaches to calculate $X$ is the weak-binding relation. However, when the scattering length $a_0$ is larger than the radius of the bound state $R$, the central value of the compositeness $X$ becomes larger than unity, which cannot be interpreted as a probability. For the systems with $a_0>R$, we need to estimate the compositeness with the correction terms. For the reasonable determination of the compositeness, we first present the quantitative estimation of the correction terms. Because the exact value of the compositeness should be contained in its definition domain $0\le X\le 1$, we propose the reasonable estimation method with the uncertainty band by excluding the region outside of the definition domain of the compositeness. We finally estimate the compositeness of physical systems, and obtain the result which we can interpret as the fraction of the composite component.

   hep-phnucl-thEPJ Web Conf.(2022)·0 citations
9. 09*

   The Velocity-Dependent $J$-factor of the Milky Way Halo: Does What Happens in the Galactic Bulge Stay in the Galactic Bulge?

   Kenny Kiriu🇺🇸 · Jason Kumar🇺🇸 · Jack Runburg🇺🇸

   We consider the angular distribution of the photon signal which could arise from velocity-dependent dark matter annihilation within the Galactic bulge. We find that, for the case of Sommerfeld-enhanced annihilation, dark matter annihilation within the bulge is dominated by slow speed particles which never leave the bulge, allowing one to find a simple analytic relationship between the dark matter profile within the Galactic bulge and the angular distribution. On the other hand, for the case $p$- or $d$-wave annihilation, we find that the small fraction of high-speed particles which can leave the bulge provide a significant, often dominant, contribution to dark matter annihilation within the bulge. For these scenarios, fully understanding dark matter annihilation deep within the Galactic bulge, and the angular distribution of the resulting photon signal, requires an understanding of the dark matter profile well outside the bulge. We consider the Galactic Center excess in light of these results, and find that an explanation of this excess in terms of $p$-wave annihilation would require the dark matter profile within the bulge to have a much steeper profile than usually considered, but with uncertainties related to the behavior of the profile outside the bulge.

   hep-phastro-ph.GAastro-ph.HEJCAP(2022)·8 citations
10. 10*

    The tetra-heavy baryonium spectra

    Bing-Dong Wan🇨🇳 · Cong-Feng Qiao🇨🇳

    In this work, we investigate the spectra of the prospective tetracharm and tetrabottom baryonium, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The non-perturbative contributions up to dimension 10 are taken into account. Numerical results indicate that there might exist 4 possible tetracharm baryonium states with masses $(7.33\pm 0.12)$, $(7.42\pm 0.13)$, $(7.68\pm 0.17)$, and $(7.76\pm 0.12)$ GeV for the quantum numbers of $0^{-+}$, $1^{--}$, $0^{++}$, and $1^{++}$, respectively. The corresponding tetrabottom partners are found lying respectively at $(19.41\pm 0.15)$, $(19.48\pm 0.15)$, $(19.77\pm 0.19)$ and $(19.84\pm 0.19)$ GeV. Additionally, we also analyze the spectra of the ${\bar{\Xi }}_{bc}{\Xi }_{bc}$ and ${\bar{\Xi }}_{cc}{\Xi }_{bb}$ baryonium states, which lie in the range of $13.77-14.40$ GeV and $13.39-14.14$ GeV, respectively. The possible baryonium decay modes are analyzed, which are hopefully measurable in LHC experiments.

    hep-ph16 citations
11. 11*

    $t\bar{t}H$ Interactions and T-odd Correlations at Hadron Colliders

    Apurba Tiwari🇮🇳 · Sudhir Kumar Gupta🇮🇳

    We explore $\mathcal{C}P$-violation effects of Higgs-top interactions in the associated production of a Higgs boson with top-pair in the dileptonic decay modes of top-quark originating from proton proton collisions $pp\to t\bar{t}H\to (l^{+}{\nu }_{l}b)(l^{-}\overline{{\nu }_l}\bar{b})H$ at NLO in QCD matched to parton shower via T-odd observables using momenta of various particles involved in the process. In particular, we predict the constraints on the $\mathcal{C}P$-violating $t\bar{t}H$ coupling obtained through the production asymmetries associated with the T-odd observables in the dileptonic decay channel of the $t\bar{t}$ pair for the LHC with centre-of-mass energy of 13 TeV and an integrated luminosity of 139 fb${}^{-1}$. We also present the corresponding limits for future hadron colliders, namely the High Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC-HH). Our estimates of the $t\bar{t}H$ interaction strength reveal that the upper bound on pseudoscalar coupling $c_p$ corresponding to the largest asymmetry would be of about $1.96\times 10^{-2}$ at 2.5$\sigma$ C.L. for $c_s$ = 1 at the LHC with $\sqrt{S}$ = 13 TeV for an integrated luminosity of 139 fb${}^{-1}$. The respective limits for HL-LHC and FCC-hh with the projected Luminosities of 3 ab${}^{-1}$ and 30 ab${}^{-1}$ are found to be to $3.4\times 10^{-3}$ and $1.6\times 10^{-4}$ respectively at 2.5$\sigma$ C.L.

    hep-phhep-exJ.Phys.G(2024)·4 citations
12. 12*

    Analysis of coupled-channel potentials with quark and hadron degrees of freedom

    Ibuki Terashima🇯🇵 · Tetsuo Hyodo🇯🇵

    The quark-antiquark potentials are known to be confining in the absence of the $\bar{q}q$ pair creation. On the other hand, the inter-hadron potentials vanish at large distance, because the interaction range is limited by the inverse pion mass. When the $\bar{q}q$ pair creation and annihilation are switched on, the channel coupling occurs between the quark and hadron degrees of freedom, modifying the behavior of potentials. In this work, we investigate the properties of the effective potentials obtained by eliminating one of the channels. We show that the coupling to the eliminated channel induces a non-local and energy dependent effective potential, irrespective of the properties of the transition potential. In addition, when the hadron channel having continuous scattering eigenstates is eliminated, the resulting inter-quark potential contains an imaginary part above the threshold to describe the decay effect into the meson pair.

    hep-phnucl-thEPJ Web Conf.(2022)·1 citation
13. 13*

    Searches for QCD instantons with forward proton tagging

    M. Tasevsky🇨🇿 · V. A. Khoze🇬🇧 · D. L. Milne🇬🇧 · M. G. Ryskin🇷🇺

    We study the possibility to observe heavy ($M_{\mathrm{inst}}>60$ GeV) QCD instantons at the LHC in events with one or two tagged leading protons including fast simulation of detector and pile-up effects. We show that the expected instanton signal in a single-tagged configuration is strongly affected by central detector and pile-up effects. For double-tagged approach, where larger integrated luminosities and hence larger pile-up contaminations need to be considered, the combinatorial background overwhelms the expected signal. We suggest that additional time information about tracks at central and forward rapidities would be crucial for potential improvements.

    hep-phEPJC(2023)·8 citations
14. 14*

    Production of loosely-bound hadron molecules from bottomonium decays

    Davide Marietti🇮🇹 · Alessandro Pilloni🇮🇹 · Umberto Tamponi🇮🇹

    We present multiple results on the production of loosely-bound molecules in bottomonium annihilations and $e^{+}{e}^{-}$ collisions at $\sqrt{s}=10.58$ GeV. We perform the first comprehensive test of several models for deuteron production against all the existing data in this energy region. We fit the free parameters of the models to reproduce the observed cross sections, and we predict the deuteron spectrum and production and the cross section for the $e^{+}{e}^{-}\to d\bar{d}+X$ process both at the ${\rm Y}(1,2,3S)$ resonances and at $\sqrt{s}=10.58$ GeV. The predicted spectra show differences but are all compatible with the uncertainties of the existing data. These differences could be addressed if larger datasets are collected by the Belle~II experiment. Fixing the source size parameter to reproduce the deuteron data, we then predict the production rates for $H$ dibaryon and hypertriton in this energy region using a simple coalescence model. Our prediction on $H$ dibaryon production rate is below the limits set by the direct search at the Belle experiment, but in the range accessible to the Belle~II experiment. The systematic effect due to the MC modelling of quarks and gluon fragmentation into baryons is reduced deriving a new tuning of the \pythia MonteCarlo generator using the available measurement of single- and double-particle spectra in ${\rm Y}$ decays.

    hep-phPRD(2022)·4 citations
15. 15*

    Updated constraints on WIMP dark matter by radio observations of M31 -- all annihilation channels

    Andrei E. Egorov🇷🇺

    The present work derived the robust constraints on annihilating WIMP parameters utilizing new radio observations of M31, as well as new studies of its DM distribution and other properties. The characteristics of emission due to DM annihilation were computed in the frame of 2D galactic model employing GALPROP code adapted specifically for M31. This enabled us to refine various inaccuracies of previous studies on the subject. DM constraints were obtained for all possible annihilation channels except $\chi \chi \to \gamma \gamma ,\nu \bar{\nu }$. A wide variety of radio data was utilized in the frequency range $\approx$(0.1--10) GHz. As the result the thermal WIMP lighter than fiducially $\approx$(40--70) GeV was excluded in the case of light primary annihilation products $\chi \chi \to {\tau }^{+}{\tau }^{-},{\mu }^{+}{\mu }^{-},gg,c\overline{c},u\overline{u},d\overline{d},s\overline{s},e^{+}{e}^{-},b\overline{b}$ (and an arbitrary combination of them). Heavier WIMP, which can annihilate to $W^{+}{W}^{-},Z^0{Z}^0,t\overline{t},hh$; can not be probed at the level of thermal cross section, unless one assumes the optimistic cases of DM density and magnetic field distributions in M31. In summary, $m_x\gtrsim 40$ GeV represents the fiducial channel-independent mass limit for the thermal WIMP with the full uncertainty range estimated to be $\approx$(20--90) GeV. The obtained exclusions are competitive to those from Fermi-LAT observations of dwarfs and AMS-02 measurements of antiprotons. Our constraints significantly restrict the opportunity to explain the gamma-ray outer halo of M31 by annihilating DM. And, finally, we questioned the possibility claimed in other studies to robustly constrain heavy thermal WIMP with $m_x>100$ GeV by radio data on M31.

    hep-phastro-ph.COastro-ph.GAPoS(2023)·3 citations
16. 16*

    Geometric scaling in leading neutron events at HERA

    Arjun Kumar🇮🇳

    This analysis provides new fits of the GBW model and the impact parameter-dependent saturation model (bSat or IP-Sat) to the leading neutron structure function HERA data in one pion exchange approximation. Both parametrizations of the dipole cross section provide good descriptions of the considered data. It is shown here for the first time that the experimental leading neutron production HERA data exhibits geometric scaling, which in this context means that the total ${\gamma }^{\ast }{\pi }^{\ast }$ cross section is a function of only one dimensionless variable $\tau =Q^2/Q_s^2(x)$. The geometric scaling region extends over a broad range of $Q^2$ and can be attributed to the presence of a saturation boundary which manifests at $Q^2\ge Q_s^2$. The scaling behaviour in leading neutron events is profoundly similar to what has been observed for the inclusive DIS events.

    hep-phPRD(2023)·4 citations
17. 17*

    The gluon condensation in hadron collisions

    Wei Zhu🇨🇳 · Qihui Chen🇨🇳 · Zhiyi Cui🇨🇳 · Jianhong Ruan🇨🇳

    Gluons may converge to a stable state at a critical momentum in hadrons. This gluon condensation is predicted by a nonlinear QCD evolution equation. We review the understanding of the gluon condensation and present a clear physical picture that produces the gluon condensation from the colour glass condensate. We summarize the applications of the GC effect in the $p-p(A)$ collisions and predict that the $p-Pb$ and $Pb-Pb$ collisions at the LHC are close to the energy region of the gluon condensation. We warn that for the next generation of hadron colliders with the increasing of the collision energy, the extremely strong gamma-rays will be emitted in a narrow space of the accelerator due to the gluon condensation effect. Such artificial mini gamma-ray bursts in the laboratory may damage the detectors.

    hep-phNPB(2022)·10 citations
18. 18*

    Production of Tensor Glueball in Ultraperipheral $pp$, $AuAu$ and $PbPb$ Collisions

    Wei Kou🇨🇳 · Xurong Chen🇨🇳

    In this work, we discuss the production of a tensor glueball in the proton-proton and nuclei-nuclei ultraperipheral collisions (UPCs). The cross section is calculated in the equivalent photon approximation (EPA). The total UPCs cross section is related to the matrix elements of $\gamma \gamma \to {\pi }^0{G}_2$ process, which can be described as in terms of neutral pion and tensor glueball $G_2$'s distribution amplitudes. The predictions for the rapidity distributions of UPCs cross sections and total cross sections are presented. The theoretical uncertainty of the whole calculation is considered. We consider the decay modes of the final-state tensor glueball and estimate the corresponding number of events. We estimate that there are about 10 tensor glueball $G_2\to \varphi \varphi$ signal events in $PbPb$ collisions at the LHC. We also argue that the lead-lead UPC experiments at future HE-LHC and FCC experiments will provide larger opportunities to measure tensor glueballs.

    hep-phhep-exEPJC(2023)·1 citation
19. 19*

    Gravitation Wave signal from Asteroid mass Primordial Black Hole Dark Matter

    Diptimoy Ghosh🇮🇳 · Arvind Kumar Mishra🇮🇳

    Primordial Black Holes (PBHs) in the mass range $\sim 10^{17}-10^{22}$g are currently unconstrained, and can constitute the full Dark Matter (DM) density of the universe. Motivated by this, in the current work, we aim to relate the existence of PBHs in the said mass range to the production of observable Gravitational Waves (GWs) in the upcoming GW detectors. We follow a relatively model-independent approach assuming that the PBHs took birth in a radiation dominated era from enhanced primordial curvature perturbation at small scales produced by inflation. We show that the constraints from CMB and BAO data allow for the possibility of PBHs being the whole of DM density of the universe. Finally, we derive the GW spectrum induced by the enhanced curvature perturbations and show that they are detectable in the future GW detectors like eLISA, BBO and DECIGO.

    hep-phastro-ph.COPRD(2024)·13 citations
20. 20*

    On electric fields in hot QCD: perturbation theory

    Gergely Endrődi🇩🇪 · Gergely Markó🇩🇪

    We investigate the response of a hot gas of quarks to external electric fields via leading-order perturbation theory. In particular, we discuss how equilibrium is maintained in the presence of the electric field and calculate the electric susceptibility, providing its high-temperature expansion for arbitrary quark mass. Furthermore, we point out that there is a mismatch between this, direct determination of the susceptibility at zero field and the weak-field expansion of the effective action at nonzero electric fields, as obtained using Schwinger's exact propagator. We discuss the origin of this mismatch and elaborate on the generalization of our results to full QCD in electric fields.

    hep-phhep-lathep-thJHEP(2022)·18 citations
21. 21*

    The massless three-loop Wilson coefficients for the deep-inelastic structure functions $F_2,F_L,x{F}_3$ and $g_1$

    J. Blümlein🇩🇪 · P. Marquard🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇩🇪

    We calculate the massless unpolarized Wilson coefficients for deeply inelastic scattering for the structure functions $F_2(x,Q^2),F_L(x,Q^2),x{F}_3(x,Q^2)$ in the $\overline{\mathsf{MS}}$ scheme and the polarized Wilson coefficients of the structure function $g_1(x,Q^2)$ in the Larin scheme up to three--loop order in QCD in a fully automated way based on the method of arbitrary high Mellin moments. We work in the Larin scheme in the case of contributing axial--vector couplings or polarized nucleons. For the unpolarized structure functions we compare to results given in the literature. The polarized three--loop Wilson coefficients are calculated for the first time. As a by--product we also obtain the quarkonic three--loop anomalous dimensions from the $O(1/\epsilon )$ terms of the unrenormalized forward Compton amplitude. Expansions for small and large values of the Bjorken variable $x$ are provided.

    hep-phhep-exhep-thJHEP(2022)·88 citations
22. 22*

    Observability of spontaneous collapse in flavor oscillations and its relation to the CP and CPT symmetries

    Kyrylo Simonov🇦🇹

    Spontaneous collapse models aim at solving the measurement problem of quantum mechanics by introducing collapse of wave function as an ontologically objective mechanism that suppresses macroscopic superpositions. In particular, the strength of collapse depends on the mass of the system. Flavor oscillating systems such as neutral mesons feature superpositions of states of different masses and, hence, could be used to test the validity of spontaneous collapse models. Recently, it has been shown that the mass-proportional CSL model causes exponential damping of the neutral meson oscillations which, however, is not strong enough to be observed in the present accelerator facilities. In this Letter, we study how the violation of the $\mathcal{C}\mathcal{P}$ symmetry in mixing changes the spontaneous collapse effect on flavor oscillations and its observability.

    hep-phquant-phPLA(2022)·3 citations
23. 23*

    Global constraint on the jet transport coefficient from single hadron, dihadron and $\gamma$-hadron spectra in high-energy heavy-ion collisions

    Man Xie🇨🇳 · Weiyao Ke🇺🇸 · Hanzhong Zhang🇨🇳 · Xin-Nian Wang🇺🇸

    Modifications of large transverse momentum single hadron, dihadron, and $\gamma$-hadron spectra in relativistic heavy-ion collisions are direct consequences of parton-medium interactions in the quark-gluon plasma (QGP). The interaction strength and underlying dynamics can be quantified by the jet transport coefficient $\hat{q}$. We carry out the first global constraint on $\hat{q}$ using a next-to-leading order pQCD parton model with higher-twist parton energy loss and combining world experimental data on single hadron, dihadron, and $\gamma$-hadron suppression at both RHIC and LHC energies with a wide range of centralities. The global Bayesian analysis using the information field (IF) priors provides the most stringent constraint on $\hat{q}(T)$. We demonstrate in particular the progressive constraining power of the IF Bayesian analysis on the strong temperature dependence of $\hat{q}$ using data from different centralities and colliding energies. We also discuss the advantage of using both inclusive and correlation observables with different geometric biases. As a verification, the obtained $\hat{q}(T)$ is shown to describe data on single hadron anisotropy at high transverse momentum well. Predictions for future jet quenching measurements in oxygen-oxygen collisions are also provided.

    hep-phnucl-thPRC(2024)·34 citations
24. 24*

    Axion wind detection with the homogeneous precession domain of superfluid helium-3

    Christina Gao🇺🇸 · W.P. Halperin🇺🇸 · Yonatan Kahn🇺🇸 · Man Nguyen🇺🇸 · Jan Schütte-Engel🇺🇸 · J.W. Scott🇺🇸

    Axions and axion-like particles may couple to nuclear spins like a weak oscillating effective magnetic field, the "axion wind." Existing proposals for detecting the axion wind sourced by dark matter exploit analogies to nuclear magnetic resonance (NMR) and aim to detect the small transverse field generated when the axion wind resonantly tips the precessing spins in a polarized sample of material. We describe a new proposal using the homogeneous precession domain (HPD) of superfluid helium-3 as the detection medium, where the effect of the axion wind is a small shift in the precession frequency of a large-amplitude NMR signal. We argue that this setup can provide broadband detection of multiple axion masses simultaneously, and has competitive sensitivity to other axion wind experiments such as CASPEr-Wind at masses below $10^{-7}$ eV by exploiting precision frequency metrology in the readout stage.

    hep-phcond-mat.supr-conPRL(2022)·29 citations
25. 25*

    Study of the $b\to d\ell \ell$ transitions in the Standard Model and test of New Physics sensitivities

    Aritra Biswas🇮🇳 · Soumitra Nandi🇮🇳 · Sunando Kumar Patra🇮🇳 · Ipsita Ray🇮🇳

    After incorporating all the available experimental data and the most up-to-date Lattice and light cone sum rule (LCSR) inputs on the form factors, we analyze the exclusive $b\to u\ell {\nu }_{\ell }$ and $b\to d\ell \ell$ decays simultaneously. We have extracted the shape of all the associated form factors using which we provide predictions in the standard model for the branching ratios, direct CP asymmetries and isospin asymmetry for $B\to \pi \ell \ell$ and various angular observables for $B\to \rho \ell \ell$ transitions. Also, we have tested the sensitivities of these observables towards physics beyond the standard model (BSM).For the $B\to \rho \ell \ell$ decays, we have defined tagged and untagged observables and predicted them in the SM and BSM. In the context of BSM, we have found some compelling information. The respective predictions in a few benchmark scenarios are given, which can be tested in the experiments at the LHCb and the Belle.

    hep-phhep-exhep-latJHEP(2023)·14 citations
26. 26*

    Probing Muon $g-2$ at a Future Muon Collider

    Jason Arakawa🇺🇸 · Arvind Rajaraman🇺🇸 · Taotao Sui🇺🇸 · Tim M.P. Tait🇺🇸

    The $4.2\sigma$ discrepancy in the $(g-2)$ of the muon provides a hint that may indicate that physics beyond the standard model is at play. A multi-TeV scale muon collider provides a natural testing ground for this physics. In this paper, we discuss the potential to probe the BSM parameter space that is consistent with solving the $(g-2{)}_{\mu }$ discrepancy in the language of the SMEFT, utilizing the statistical power provided by fitting event rates collected running at multiple energies. Our results indicate the importance of including interference between the BSM and the SM amplitudes, and illustrates how a muon collider running at a handful of lower energies and with less total collected luminosity can better significantly constrain the space of relevant SMEFT coefficients than would be possible for a single high energy run.

    hep-phSciPost Phys.(2024)·10 citations
27. 27*

    The trap in the early Universe: impact on the interplay between gravitational waves and LHC physics in the 2HDM

    Thomas Biekötter🇩🇪 · Sven Heinemeyer🇪🇸 · José Miguel No🇪🇸 · María Olalla Olea-Romacho🇩🇪 · Georg Weiglein🇩🇪

    We analyze the thermal history of the 2HDM and determine the parameter regions featuring a first-order electroweak phase transition (FOEWPT) and also much less studied phenomena like high-temperature electroweak (EW) symmetry non-restoration and the possibility of vacuum trapping (i.e. the Universe remains trapped in an EW-symmetric vacuum throughout the cosmological evolution, despite at $T=0$ the EW breaking vacuum is deeper). We show that the presence of vacuum trapping impedes a first-order EW phase transition in 2HDM parameter-space regions previously considered suitable for the realization of electroweak baryogenesis. Focusing then on the regions that do feature such a first-order transition, we show that the 2HDM parameter space that would yield a stochastic gravitational wave signal potentially detectable by the future LISA observatory is very contrived, and will be well probed by direct searches of 2HDM Higgs bosons at the HL-LHC, and (possibly) also via measurements of the self-coupling of the Higgs boson at 125 GeV. This has an important impact on the interplay between LISA and the LHC regarding the exploration of first-order phase transition scenarios in the 2HDM: the absence of new physics indications at the HL-LHC would severely limit the prospects of a detection by LISA. Finally, we demonstrate that as a consequence of the predicted enhancement of the self-coupling of the Higgs boson at 125 GeV the ILC would be able to probe the majority of the 2HDM parameter space yielding a FOEWPT through measurements of the self-coupling, with a large improvement in precision with respect to the HL-LHC.

    hep-phJCAP(2023)·86 citations
28. 28*

    Exploiting stellar explosion induced by the QCD phase transition in large-scale neutrino detectors

    Tetyana Pitik🇩🇰 · Daniel Heimsoth🇺🇸 · Anna M. Suliga🇺🇸 · A. B. Balantekin🇺🇸

    The centers of the core-collapse supernovae are one of the densest environments in the Universe. Under such conditions, it is conceivable that a first-order phase transition from ordinary nuclear matter to the quark-gluon plasma occurs. This transition releases a large amount of latent heat that can drive a supernova explosion and may imprint a sharp signature in the neutrino signal. We show how this snap feature, if observed at large-scale neutrino detectors, can set competitive limits on the neutrino masses and assist the localization of the supernova via triangulation. The 95\%C.L. limit on the neutrino mass can reach 0.16~eV in Ice-Cube, 0.22~eV in Hyper-Kamiokande, and 0.58~eV in DUNE, for a supernova at a distance of 10 kpc. For the same distance and in the most optimistic neutrino conversion case, the triangulation method can constrain the $1\sigma$ angular uncertainty of the supernova localization within $\sim 0.3^{\circ }-9.0^{\circ }$ in the considered pairs of the detectors, leading to an improvement up to an order of magnitude with respect to the often considered in the literature rise time of the neutronization burst.

    hep-phastro-ph.HEPRD(2022)·11 citations
29. 29*

    Neutrino propagation in the neutron star with uncertainties from nuclear, hadron, and particle physics

    Parada T. P. Hutauruk🇰🇷 · Hana Gil🇰🇷 · Seung-il Nam🇰🇷 · Chang Ho Hyun🇰🇷

    In the present work, we investigate the neutral-current neutrino-nucleon scattering in the nuclear medium using various energy-density functional (EDF) models such as the KIDS (Korea-IBS-Daegu-SKKU) and SLy4, together with the quark-meson coupling (QMC) model for the nucleon form factors at finite density. The differential cross section (DCS) and neutrino mean free path (NMFP) are computed numerically, considering the density-dependent nucleon form factors (DDFF) and neutrino structural properties such as the neutrino magnetic moment (NMM) and its electric charge radius (NCR). It turns out that the DDFF decreases the scattering cross-section, while the NCR increases it considerably. The effect of the NMM turns out to be almost negligible. We also observe that the value of the neutron effective mass is of importance in the neutron-star cooling process, indicating that for the neutron effective mass larger than the mass in free space, the neutrino can interact with matter at densities $\rho \gtrsim 1.5{\rho }_0$ in the neutron star with radius 13 km.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPTEP(2023)·2 citations
30. 30*

    Constraining first-order phase transitions with curvature perturbations

    Jing Liu🇨🇳 · Ligong Bian🇨🇳 · Rong-Gen Cai🇨🇳 · Zong-Kuan Guo🇨🇳 · Shao-Jiang Wang🇨🇳

    We investigate the curvature perturbations induced by the randomness of the quantum tunneling process during cosmological first-order phase transitions (PTs) and for the first time ultilize curvature perturbations to constrain the PT parameters. We find that the observations of the cosmic microwave background spectrum distortion and the ultracompact minihalo abundance can give strict constraints on the PTs below 100GeV, especially for the low-scale PTs and the weak PTs. The current constraint on the PT parameters is largely extended by the results in this work.

    ↳ astro-ph.COgr-qchep-phPRL(2023)·64 citations
31. 31*

    The challenge of ruling out inflation via the primordial graviton background

    Sunny Vagnozzi🇮🇹 · Abraham Loeb🇺🇸

    Recent debates around the testability of the inflationary paradigm raise the question of how to model-independently discriminate it from competing scenarios. We argue that a detection of the Cosmic Graviton Background (CGB), the relic radiation from gravitons decoupling around the Planck time, would rule out the inflationary paradigm, as realistic inflationary models would dilute the CGB to an unobservable level. The CGB contribution to the effective number of relativistic species, $\Delta N_{\mathrm{eff},g}\approx 0.054$, is well within the reach of next-generation cosmological probes. We argue that detecting the high-frequency stochastic gravitational wave background associated to the CGB will be challenging but potentially feasible. We briefly discuss expectations within alternatives to inflation, focusing on bouncing cosmologies and emergent scenarios.

    ↳ astro-ph.COgr-qchep-phhep-thApJL(2022)·66 citations
32. 32*

    UV asymptotics of $n$-point correlators of twist-$2$ operators in SU($N$) Yang-Mills theory

    Marco Bochicchio🇮🇹 · Mauro Papinutto🇮🇹 · Francesco Scardino🇮🇹

    The generating functional $\mathcal{W}[J_{\mathcal{O}}]$ of Euclidean correlators of twist-$2$ operators in SU($N$) Yang-Mills theory admits the 't Hooft large-$N$ expansion: $\mathcal{W}[J_{\mathcal{O}}]={\mathcal{W}}_{sphere}[J_{\mathcal{O}}]+{\mathcal{W}}_{torus}[J_{\mathcal{O}}]+\cdots$. Nonperturbatively, ${\mathcal{W}}_{sphere}[J_{\mathcal{O}}]$ is a sum of tree diagrams involving glueball propagators and vertices, while ${\mathcal{W}}_{torus}[J_{\mathcal{O}}]$ is a sum of glueball one-loop diagrams. Moreover, it has been predicted that ${\mathcal{W}}_{torus}[J_{\mathcal{O}}]$ should admit the structure of the logarithm of a functional determinant summing glueball one-loop diagrams. We work out in a closed form the ultraviolet (UV) asymptotics of ${\mathcal{W}}_{sphere}[J_{\mathcal{O}},\lambda ]\sim {\mathcal{W}}_{asymsphere}[J_{\mathcal{O}},\lambda ]$ and ${\mathcal{W}}_{torus}[J_{\mathcal{O}},\lambda ]\sim {\mathcal{W}}_{asymtorus}[J_{\mathcal{O}},\lambda ]$ in the coordinate representation as all the coordinates of the correlators are uniformly rescaled by a factor $\lambda \to 0$. Remarkably, we verify the above prediction that ${\mathcal{W}}_{asymtorus}[J_{\mathcal{O}},\lambda ]$ -- being asymptotic in the UV to ${\mathcal{W}}_{torus}[J_{\mathcal{O}},\lambda ]$ -- admits the structure of the logarithm of a functional determinant as well. Hence, the computation above sets strong UV asymptotic constraints on the nonperturbative solution of large-$N$ YM theory and it may be a pivotal guide for the search of such a solution.

    ↳ hep-thhep-phPRD(2023)·8 citations
33. 33*

    Linear confinement in the partially-deconfined phase

    Vaibhav Gautam🇬🇧 · Masanori Hanada🇬🇧 · Jack Holden🇬🇧 · Enrico Rinaldi🇺🇸

    We consider the partially-deconfined saddle of large-$N$ pure Yang-Mills theory lying between confined and deconfined phases, in which the color degrees of freedom split into confined and deconfined sectors. Based on the microscopic mechanism of deconfinement, we argue that a flux tube is formed in the confined sector and a linear confinement potential is generated. The string tension should not depend on the size of the confined sector. We provide evidence by studying the finite-temperature strong-coupling lattice gauge theory. In particular, we make analytic predictions assuming linear confinement in the confined sector, and then confirm these by numerical simulations. We discuss some implications of the conjecture to QCD and holography.

    ↳ hep-thhep-lathep-phJHEP(2023)·8 citations
34. 34*

    Early or phantom dark energy, self-interacting, extra, or massive neutrinos, primordial magnetic fields, or a curved universe: An exploration of possible solutions to the $H_0$ and ${\sigma }_8$ problems

    Helena García Escudero🇺🇸 · Jui-Lin Kuo🇺🇸 · Ryan E. Keeley🇺🇸 · Kevork N. Abazajian🇺🇸

    In this paper we explore the existing tensions in the local cosmological expansion rate, $H_0$, and amplitude of the clustering of large-scale structure at $8h^{-1}\mathrm{Mpc}$, ${\sigma }_8$, as well as models that claim to alleviate these tensions. We consider seven models: evolving dark energy ($w$CDM), extra radiation ($N_{\mathrm{eff}}$), massive neutrinos, curvature, primordial magnetic fields (PMF), self-interacting neutrino models, and early dark energy (EDE). We test these models against three data sets that span the full range of measurable cosmological epochs, have significant precision, and are well-tested against systematic effects: the Planck 2018 cosmic microwave background data, the Sloan Digital Sky Survey baryon acoustic oscillation scale measurements, and the Pantheon catalog of Type Ia supernovae. We use the recent SH0ES $H_0$ measurement and several measures of ${\sigma }_8$ (and its related parameter $S_8={\sigma }_8\sqrt{{\Omega }_{\mathrm{m}}/0.3}$). We find that four models are above the "strong" threshold in Bayesian model selection, $w$CDM, $N_{\mathrm{eff}}$, PMF, and EDE. However, only EDE also relieves the $H_0$ tension in the full data sets to below 2$\sigma$. Contrarily, no model alleviates the $S_8/{\sigma }_8$ tension in the full data set, nor does better than $\Lambda$CDM in the combined case of both $H_0$ and $S_8/{\sigma }_8$ tensions.

    ↳ astro-ph.COhep-phPRD(2022)·49 citations
35. 35*

    Hyperon bulk viscosity and $r$-modes of neutron stars

    O. P. Jyothilakshmi🇮🇳 · P. E. Sravan Krishnan🇮🇳 · Prashant Thakur🇮🇳 · V. Sreekanth🇮🇳 · T. K. Jha🇮🇳

    We propose and apply a new parameterization of the modified chiral effective model to study rotating neutron stars with hyperon cores in the framework of the relativistic mean-field theory. The inclusion of mesonic cross couplings in the model has improved the density content of the symmetry energy slope parameters, which are in agreement with the findings from recent terrestrial experiments. The bulk viscosity of the hyperonic medium is analyzed to investigate its role in the suppression of gravitationally driven $r$-modes. The hyperonic bulk viscosity coefficient caused by non-leptonic weak interactions and the corresponding damping timescales are calculated and the $r$-mode instability windows are obtained. The present model predicts a significant reduction of the unstable region due to a more effective damping of oscillations. We find that from $\sim 10^8$ K to $\sim 10^9$ K, hyperonic bulk viscosity completely suppresses the $r$-modes leading to a stable region between the instability windows. Our analysis indicates that the instability can reduce the angular velocity of the star up to $\sim$0.3~${\Omega }_K$, where ${\Omega }_K$ is the Kepler frequency of the star.

    ↳ astro-ph.HEhep-phnucl-thMNRAS(2022)·21 citations
36. 36*

    Astrometric Microlensing of Primordial Black Holes with Gaia

    Himanshu Verma🇮🇳 · Vikram Rentala🇮🇳

    The Gaia space telescope allows for unprecedented accuracy for astrometric measurements of stars in the Galaxy. In this work, we explore the sensitivity of Gaia to detect primordial black hole (PBH) dark matter through the distortions that PBHs would create in the apparent trajectories of background stars, an effect known as astrometric microlensing (AML). We present a novel calculation of the lensing probability, and we combine this with the existing publicly released Gaia eDR3 stellar catalog to predict the expected rate of AML events that Gaia will see. We also compute the expected distribution of a few event observables, which will be useful for reducing backgrounds. Assuming that the astrophysical background rate of AML like events due to other sources is negligible, we then compute the potential exclusion that could be set on the parameter space of PBHs with a monochromatic mass function. We find that Gaia is sensitive to PBHs in the range of $0.4M_{\odot }$ - $5\times 10^7{M}_{\odot }$, and has peak sensitivity to PBHs of $\sim 10M_{\odot }$ for which it can rule out as little as a fraction $3\times 10^{-4}$ of dark matter composed of PBHs. With this exquisite sensitivity, Gaia has the potential to rule out a PBH origin for the gravitational wave signals seen at LIGO/Virgo. Our novel calculation of the lensing probability includes for the first time, the effect of intermediate duration lensing events, where the lensing event lasts for a few years, but for a period which is still shorter than the Gaia mission lifetime. The lower end of our predicted mass exclusion is especially sensitive to this class of events. As and when time-series data for Gaia is released, and once we have a better understanding of the backgrounds, our prediction of the lensing rate and event observable distributions will be useful to estimate the true exclusion/discovery of the PBH parameter space utilizing this data.

    ↳ astro-ph.GAastro-ph.COhep-phJCAP(2023)·12 citations
37. 37*

    (Quasi-) de Sitter solutions across dimensions and the TCC bound

    David Andriot🇫🇷 · Ludwig Horer🇫🇷

    In this work, we investigate the existence of string theory solutions with a $d$-dimensional (quasi-) de Sitter spacetime, for $3\le d\le 10$. Considering classical compactifications, we derive no-go theorems valid for general $d$. We use them to exclude (quasi-) de Sitter solutions for $d\ge 7$. In addition, such solutions are found unlikely to exist in $d=6,5$. For each no-go theorem, we further compute the $d$-dependent parameter $c$ of the swampland de Sitter conjecture, $M_p\frac{|\nabla V|}{V}\ge c$. Remarkably, the TCC bound $c\ge \frac{2}{\sqrt{(d-1)(d-2)}}$ is then perfectly satisfied for $d\ge 4$, with several saturation cases. However, we observe a violation of this bound in $d=3$. We finally comment on related proposals in the literature, on the swampland distance conjecture and its decay rate, and on the so-called accelerated expansion bound.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2023)·45 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.