Mon·Apr 28, 2025Monday·April 28, 2025

1. 01*

   Naive Gaussian approximation in a quark-meson model

   Győző Kovács🇵🇱 · Zsolt Szép🇭🇺 · Péter Kovács🇭🇺 · György Wolf🇭🇺

   A sequence of approximations is derived to go beyond the mean-field level in the case of a simple linear sigma model. A naive, local version of the Gaussian approximation is discussed for the $2+1$ flavor extended Polyakov quark-meson model at finite temperature and chemical potential. Although at small chemical potential the pion mass has an unphysical thermal behavior in the usual parameterizations, it is shown that the pseudocritical temperature decreases in the presence of the thermal pion fluctuations. Compared to the mean-field level, the location of the CEP is only slightly modified, while the critical scaling around the CEP is unaffected.

   hep-phPoS(2026)·1 citation
2. 02*

   Factorization Formula Connecting the Shape Functions of Heavy Meson in QCD and Heavy Quark Effective Theory

   Wei Wang🇨🇳 · Ji Xu🇨🇳 · Qi-An Zhang🇨🇳 · Shuai Zhao🇨🇳

   The shape function of $B$-meson defined in heavy quark effective theory (HQET) plays a crucial role in the analysis of inclusive $B$ decays, and constitutes one of the dominant uncertainties in the determination of CKM matrix element $|V_{ub}|$. On the other hand, the conventional heavy meson shape function defined in QCD is also phenomenologically important and includes shortdistance physics at energy scales of the heavy quark mass. In this work, we derived a factorization formula relating these two kinds of shape functions, which can be invoked to fully disentangle the effects from disparate scales $m_b$ and ${\Lambda }_{\text{QCD}}$, particularly to facilitate the resummation of logarithms $\ln m_b/{\Lambda }_{\text{QCD}}$. In addition, this factorization constitutes an essential component of the recently developed two-step factorization scheme, enabling lattice QCD calculations of lightcone quantities of heavy meson. The results presented here pave the way for first-principles nonperturbative predictions of shape function in the near future.

   hep-phPRD(2025)·10 citations
3. 03*

   A search for $B_{s0}^{\ast }$ and $B_{s1}^{\ast }$ through the $K^{-}p$ interaction

   Min Yuan🇨🇳 · Yin Huang🇨🇳

   Studying heavy-quark hadrons is crucial due to the nonperturbative nature of low-energy QCD, with Heavy-Quark Symmetry (HQS) serving as a key framework for understanding their spin and flavor symmetries. However, a key issue is that the theoretically expected $B^{(\ast )}\bar{K}$ molecular states have not yet been observed, although they are considered the bottom-quark counterparts of the observed ${\bar{D}}^{(\ast )}\bar{K}$ molecular states (corresponding to $D_{s0}(2317/2460{)}^{-}$), which challenges the universality of HQS. The main goal of this work is to search for the theoretically predicted $B\bar{K}$ and $B^{\ast }\bar{K}$ molecular states, namely $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$, via the reactions $K^{-}p\to {\Lambda }_b^0{B}_{s0}^{\ast }$ and $K^{-}p\to {\Lambda }_b^0{B}_{s1}^{\ast }$. Within an effective Lagrangian framework, we compute the relevant cross sections, considering $t$-channel $B^{(\ast )}$ exchanges and $K^{-}p$ initial-state interactions (ISI). The results show that the production cross sections of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$ can reach the order of 0.01~nb, and we suggest that experiments searching for $B_{s0}^{\ast }(5725)$ are best performed at $P_{K^{-}}=12.18\mathrm{GeV}$, while higher energies are most favorable for producing $B_{s1}^{\ast }(5778)$. The ISI play a crucial role, as they not only significantly enhance the production cross sections of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$ (by roughly one order of magnitude) but also markedly affect the angular distributions of the produced particles. We also calculated the production cross sections of the conventional quark-antiquark states $B_{s0}^{\ast }(5700)$ and $B_{s1}^{\ast }(5720)$, which are found to be nearly the same as those of $B_{s0}^{\ast }(5725)$ and $B_{s1}^{\ast }(5778)$. Although their internal structures remain ambiguous, these results can inform future experimental searches at CERN and J-PARC.

   hep-phEPJC(2026)·0 citations
4. 04*

   Fate of the scalar quartic couplings in the inert models

   Priyotosh Bandyopadhyay🇮🇳 · Pram Milan P. Robin🇮🇳

   In this article we consider three inert models, namely the inert singlet model (ISM), inert triplet model (ITM), and inert doublet model (IDM) as beyond Standard Model scenarios, and look into the running of the scalar quartic couplings at one- and two-loop levels. Interestingly, the Landau poles at one-loop and Fixed points at two-loop have been observed for these scenarios, very similar to the ${\varphi }^4$ theory, which is absent in the Standard Model. The role of Higgs portal couplings in attaining these features has been examined. For inert singlet and triplet models, the portal couplings give rise to terms without any residual phases, enhancing this Fixed point behaviour. In the case of the inert doublet model, ${\lambda }_{4,5}$ terms which have the residual phases, spoil this behaviour. Finally, we consider perturbative unitarity constraints to put limits on the scalar quartic couplings for various perturbativity scales in both one- and two-loop. Larger portal couplings, i.e. $\text{gsim}2$, get strong perturbative bounds as low as $10^{2-3}$ GeV.

   hep-phPRD(2025)·4 citations
5. 05*

   Study of $K\pi$ final states from four-body deacy of ${\bar{B}}_s$ meason under perturbation QCD

   Jiao Wu🇨🇳 · Na Wang🇨🇳 · Gang Lü🇨🇳 · Xin-Heng Guo🇨🇳

   In the perturbative QCD framework, we use the quasi-two-body method to study the CP violations and branching ratios in the ${\bar{B}}_s\to [\varphi ({\rho }^0,\omega )\to K^{+}{K}^{-}][K^{\ast 0}\to K^{+}{\pi }^{-}]$ and ${\bar{B}}_s\to [{\rho }^0(\omega ,\varphi )\to ({\pi }^{+}{\pi }^{-})][K^{\ast 0}\to K^{+}{\pi }^{-}]$ decay processes. Owing to the interference effects of ${\rho }^0$, $\omega$, and $\varphi$, new strong phases associated with vector mesons will be generated, resulting in relatively large CP violation within the interference region. Moreover, we provide numerical comparisons of CP violation from resonance effects and non-resonance contributions. In order to provide better theoretical predictions for future experiments, we integrate CP violation over invariant mass to obtain the regional CP violation value. Furthermore, we have calculated the polarization fractions and branching ratios for different intermediate states in the four-body decay process, which may be influenced by vector interference effects. Additionally, we discuss the possibility of observing the predicted CP violation at the LHC.

   hep-phEPJC(2025)·2 citations
6. 06*

   COSINUS model-independent sensitivity to the DAMA/LIBRA dark matter signal

   G. Angloher · M. R. Bharadwaj · A. Böhmer · M. Cababie · I. Colantoni · I. Dafinei · N. Di Marco · C. Dittmar · L. Einfalt · F. Ferella · F. Ferroni · S. Fichtinger and 31 other authors

   COSINUS is a dark matter direct detection experiment using NaI crystals as cryogenic scintillating calorimeters. If no signal is observed, this will constrain the dark matter scattering rate in sodium iodide. We investigate how this constraint can be used to infer that the annual modulation signal observed in the DAMA/LIBRA experiment cannot originate from dark matter nuclear recoil events, independently of the dark matter model. We achieve this by unfolding the DAMA modulation spectrum to obtain the implied unquenched nuclear recoil spectrum, which we then compare to the expected COSINUS sensitivity. We find that assuming zero background in the signal region, a 1$\sigma$, 2$\sigma$ or 3$\sigma$ confidence limit exclusion can be obtained with 57, 130 or 250 kg day of exposure, respectively. A simple background model indicates that in the presence of background, the exposure requirements may increase by $\sim 30\%$.

   hep-phastro-ph.COphysics.ins-detJCAP(2025)·4 citations
7. 07*

   Charm-hadron reconstruction through three body decay in hadronic collisions using Machine Learning

   Neelkamal Mallick🇫🇮 · Hadi Hassan🇫🇮 · D.J. Kim🇫🇮

   Studies of heavy-quark (charm and beauty) production in hadronic and nuclear collisions provide excellent testing grounds for the theory of strong interaction, quantum chromodynamics. Heavy-quarks are produced predominantly in the initial hard partonic interactions, allowing them to witness the entire evolution process. The charm hadrons are produced in two ways. Firstly, the prompt charm hadrons which are formed from the charm quark hadronization which are produced directly from the initial hard-scatterings or the decay of other excited charm states. Secondly, the nonprompt charm hadrons which are produced from the decay of beauty hadrons. The produced charm hadrons then usually decay to light-flavor hadrons or leptons via two or three body decay. The reconstruction of charm hadrons is challenging due to the large combinatorial background as well as the difficulty of distinguishing between prompt and non-prompt charm hadrons. In this work, we use machine learning models--XGboost and Deep Neural Network--to reconstruct ${\Lambda }_c^{+}(udc)$ hadrons via its three body final state decay channel, ${\Lambda }_c^{+}\to p{K}_s^0$ and $K_s^0\to {\pi }^{+}{\pi }^{-}$. Using several experimentally available features of the decay daughters, these models can separate signal from background and identify prompt and nonprompt candidates with nearly 99\% accuracy. This method performs an unbinned track-level reconstruction since the ${\Lambda }_c$ candidates are tagged directly from their decay daughters. The necessary data for this study are simulated in pp collisions at $\sqrt{s}=13.6$~TeV using PYTHIA8 (Monash) model.

   hep-phhep-exnucl-th3 citations
8. 08*

   Machine learning-based b-jet tagging in $pp$ collisions at $\sqrt{s}=13$ TeV

   Hadi Hassan🇫🇮 · Neelkamal Mallick🇫🇮 · D.J. Kim🇫🇮

   Studying heavy-flavor jets in $pp$ collision is important since they can test pQCD calculations and be used as a reference for heavy-ion collisions. Jets in this analysis are reconstructed from charged particles using the anti-$k_{\mathrm{T}}$ algorithm with a resolution parameter $R=$ 0.4 and with pseudorapidity $|\eta |<$ 0.5. Beauty jets are tagged using a machine learning model that uses a convolutional neural network trained on information extracted from the jet, tracks, and secondary vertices. The results show that this model is superior compared to other traditional tagging methods.

   hep-phhep-exnucl-thPRD(2026)·3 citations
9. 09*

   Hanbury Brown-Twiss correlation of $\varphi \varphi$ with in-medium mass modification

   Yong Zhang🇨🇳 · Peng Ru🇨🇳

   We study the impacts of the squeezing effect caused by in-medium mass modification on the Hanbury Brown-Twiss (HBT) correlation of $\varphi \varphi$ using a hydrodynamical source. The squeezing effect reduces the influence of transverse flow on the transverse distribution of $\varphi$ emitting source while expanding the longitudinal source distribution. This trend becomes more noticeable as the transverse momentum increases, resulting in an enlargement of the HBT radii for $\varphi \varphi$ . Notably, this enlargement is particularly evident with higher transverse pair momentum. As a result, the HBT radii of $\varphi \varphi$ increase as transverse pair momentum increases instead of showing a consistent crease, showcasing non-flow behavior of HBT radii in hydrodynamical sources. Both Gaussian fitting and Levy fitting support the conclusion.

   hep-phPRC(2025)·0 citations
10. 10*

    Renormalizing Two-Fermion Operators in the SMEFT via Supergeometry

    Benoît Assi🇺🇸 · Andreas Helset🇨🇭 · Julie Pagès🇺🇸 · Chia-Hsien Shen🇹🇼

    We extend the geometric framework of field-space covariance for loop computations, thereby unifying the treatment of scalars, fermions, and gauge bosons in effective field theories. This allows us to derive a manifestly covariant formula for one-loop UV divergences that includes contributions from mixed boson-fermion graphs. The result is expressed in terms of geometric invariants of the field-space supermanifold. As a demonstration of this formula, we compute the renormalization group equations for two-fermion operators at the dimension-eight level in the Standard Model Effective Field Theory.

    hep-phhep-thJHEP(2025)·21 citations
11. 11*

    Holographic analysis of near-conformal dynamics and light dilaton

    Jesús Cruz Rojas🇰🇷 · Deog Ki Hong🇰🇷 · Sang Hui Im🇰🇷 · Matti Järvinen🇰🇷

    We carry out a detailed analysis of the region slightly outside the conformal window of a non-trivial infrared fixed point in a generic bottom-up holographic setup. We focus on models, which study the dynamics of a scalar field, dual to quark degrees of freedom, in a (nearly) AdS geometry. Such models realize the picture expected for vector-like near-conformal theories from Dyson-Schwinger analysis. The analysis covers a toy model, which allows for analytic solutions, and a more general setup as well, which encompass a complete model for the ultraviolet physics. We analyze the conditions for the appearance of a parametrically light scalar state in the spectrum, which can act as a candidate for the Pseudo-Nambu-Goldstone boson arising from breaking of the approximate conformal symmetry. We also present detailed results for the vacuum structure, correlators, and Ward identities in the near-conformal regime.

    hep-phhep-thJHEP(2025)·3 citations
12. 12*

    Virial theorem for rigidly rotating matter

    Sourav Dey🇮🇳

    The scaling property of the thermodynamic free energy ($\Phi$) of a system at global equilibrium has been examined using a real-time method known as the virial theorem. We demonstrate these scaling properties through a derived relation based on the general structure of equal-time commutators among Poincare charges and their densities. This relation is applicable to any renormalizable fields with spin $\le 1$, excluding gauge fields. In this particular study, we investigate a rigidly rotating solution ($\Omega =\text{const}$) at global equilibrium for massless fermionic matter. It has been shown that the applicability of a hydrodynamic description requires a hierarchy $\Omega R\gg \Omega {\beta }_0$, where $R$ is the radius of the cylindrical-shaped rotating matter and ${\beta }_0=1/T_0$ is the inverse temperature on the rotation axis. Consequently, the thermodynamic free energy $\Phi$ depends on the angular velocity through the product $\Omega R$, a dependency that extends to other thermodynamic variables as well. These findings are consistent with recent lattice QCD simulation results. Furthermore, we compute the moment of inertia for massless fermions and estimate the light quark contribution to the total moment of inertia of the Quark-Gluon Plasma (QGP) produced in heavy-ion collisions.

    ↳ hep-thhep-phnucl-th3 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.