Tue·May 10, 2022Tuesday·May 10, 2022

1. 01*

   Momentum distribution of dark matter produced in inflaton decay: effect of inflaton mediated scatterings

   Avirup Ghosh🇮🇳 · Satyanarayan Mukhopadhyay🇮🇳

   Post-inflationary reheating is a widely discussed mechanism for non-thermal production of dark matter (DM). In this scenario the momentum distribution of the produced DM particles is usually taken to be the one obtained at reheating, red-shifted at later times due to the expansion of the Universe. However, since in such a scenario both the DM and the standard model (SM) fields couple to the inflaton, the DM particles necessarily undergo self-scatterings, as well as elastic and inelastic scattering reactions with the SM bath, all of which proceed through $s-$channel or $t-$channel inflaton exchange. We compute the momentum distribution of the DM particles including the effect of these scatterings, and find that the distributions can be significantly altered, even though DM remains non-thermal throughout the cosmological evolution. We observe that if the inflaton dominantly couples to the SM Higgs boson through a renormalizable interaction, then reheating temperatures and inflaton masses at the TeV scale lead to a large effect from the scattering processes, with the DM-inflaton coupling constrained by the DM density. The scattering effects are found to be sensitive to the duration of the reheating process -- larger the duration, more momentum modes are filled at reheating, leading to an enhanced scattering probability. We also obtain the free-streaming length of such DM using the resulting non-thermal momentum distribution, which can be used to estimate the implications of the Lyman-$\alpha$ constraints on the DM mass. It is observed that in the scenarios considered, including the scattering effects can reduce the DM average velocity at matter-radiation equality, and its free-streaming length, by upto a factor of $40$, thereby making the constraints on light DM produced in inflaton decay significantly weaker.

   hep-phastro-ph.COPRD(2022)·15 citations
2. 02*

   Identifying Hadronic Molecular States with a Neural Network

   Chang Chen🇨🇳 · Hao Chen🇨🇳 · Wen-Qi Niu🇨🇳 · Han-Qing Zheng🇨🇳

   Neural networks are trained to judge whether or not an exotic state is a hadronic molecule of a given channel according its line-shapes. This method performs well in both trainings and validation tests. As applications, it is applied to study $X(3872)$, $X(4260)$ and $Z_c(3900)$. The results show that $Z_c(3900)$ should be regarded as a ${\bar{D}}^{\ast }D$ molecular state but $X(3872)$ not. As for $X(4260)$, it can not be a molecular state of ${\chi }_{c0}\omega$. Some discussions on $X_1(2900)$ are also provided.

   hep-phEPJC(2023)·17 citations
3. 03*

   Particle dispersion in the classical vector dark matter background

   Eung Jin Chun🇰🇷 · Seokhoon Yun🇮🇹

   Interactions with a background medium modify in general the dispersion relation and canonical normalization of propagating particles. This can have an important phenomenological consequence when considering light dark matter coupling to quarks and leptons. In this paper, we address this issue in the vector dark matter background with the randomly distributed polarizations or a fixed polarization to the single direction. The observations associated with particle dispersion can give constraints on new light Abelian gauge boson models. Considering the solar neutrino transition and the electron mass measurement, stringent bounds can be put on the gauged $L_{\mu }-L_{\tau }$ model and the dark photon model. Moreover, the classical vector field turns out to induce drastic changes in the particle normalization, which rule out a significant parameter region of the generic vector dark matter model.

   hep-phPRD(2022)·4 citations
4. 04*

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

   Shashank Bhatnagar🇮🇳 · Teresa Aruja🇮🇳 · Vaishali Guleria🇮🇳

   In present work we study the production of ground and excited charmonium pairs in $e^{-}{e}^{+}\to \Psi (nS)+{\chi }_{cJ}(nP)$ for $J=0,1$ and $n=1,2$, through leading order (LO) tree-level diagrams $\sim O({\alpha }_{em}{\alpha }_s)$, which proceed through exchange of a virtual photon and an internal gluon line connecting two quark lines (in the triangle quark loop part of the diagram), in the framework of $4\times 4$ Bethe-Salpeter equation, at center of mass energy, $\sqrt{s}=10.6GeV.$ We have tried to show that the cross sections for this process calculated with use of the four leading order $\sim O({\alpha }_{em}{\alpha }_s)$ diagrams using BSE approach come close to experimental data, which might be mainly due to the consistent treatment of motion of quarks inside the hadrons in the BSE framework.

   hep-phInt.J.Theor.Phys.(2022)·2 citations
5. 05*

   The Renormalization Scale Setting Problem in QCD [Ph.D. Thesis]

   Leonardo Di Giustino🇮🇹

   A key issue in making precise predictions in perturbative QCD is the uncertainty in setting the renormalization scale. If in principle, the entire perturbative series is void of this issue, in practice the perturbative corrections are known up to a certain order of accuracy and scale invariance is only approximated leading to the so-called scheme and scale ambiguities. According to the conventional scale setting (CSS) this problem cannot be avoided and the renormalization scale is set to the typical scale of a process $Q$, and errors are estimated by varying the scale over a range of two $[Q/2;2Q]$. This method is not void of ambiguities and leads to predictions affected by large theoretical errors. Other strategies for the optimization of the truncated expansion, such as the Principle of Minimal Sensitivity (PMS) and the Fastest Apparent Convergence (FAC) criterion, have the same difficulties of CSS and lead to incorrect and unphysical results. In general a scale-setting procedure is considered reliable if it preserves important self-consistency requirements such as all the renormalization group properties. Other requirements are suggested by known tested theories, by the convergence behavior of the series or by phenomenological results and scheme independence. All theoretical requirements for a reliable scale-setting procedure can be satisfied at once, leading to accurate results by using the Principle of Maximum Conformality (PMC). This method generalizes the Brodsky-Lepage-Mackenzie (BLM) method to all orders and to all observables and in the perspective of a theory unifying all interactions, such as the grand unified theory (GUT), the PMC offers the possibility to apply the same method in all sectors of a theory, starting from first principles, eliminating the renormalon growth, the scheme and scale ambiguities, and satisfying the QED Gell-Mann-Low scheme in the $N_c\to 0$ limit.

   hep-phhep-th5 citations
6. 06*

   Next-to-leading order QCD corrections to $Z\to {\eta }_Q+Q+\bar{Q}$

   Xu-Chang Zheng🇨🇳 · Xing-Gang Wu🇨🇳 · Xi-Jie Zhan🇨🇳 · Hua Zhou🇨🇳 · Hong-Tai Li🇨🇳

   It has been found that at a high luminosity $e^{+}{e}^{-}$ collider, sizable ${\eta }_c+c\bar{c}X$ and ${\eta }_b+b\bar{b}X$ events can be produced when it works around the $Z$ peak. In this paper, we calculate the decay widths of $Z\to {\eta }_c+c+\bar{c}+X$ and $Z\to {\eta }_b+b+\bar{b}+X$ up to next-to-leading order (NLO) accuracy. We find that the NLO corrections are significant in these two processes. After including the NLO corrections, the decay widths of $Z\to {\eta }_c+c+\bar{c}+X$ and $Z\to {\eta }_b+b+\bar{b}+X$ are enhanced by about $37\%$ and $28\%$ for the case of ${\mu }_R=2m_c$ and ${\mu }_R=2m_b$, respectively. The differential decay widths $d\Gamma /d{s}_1$ and $d\Gamma /dz$ for these two decay processes are also analyzed.

   hep-phPRD(2022)·4 citations
7. 07*

   Neutron oscillation and Baryogenesis from six dimensions

   Mathew Thomas Arun🇮🇳 · Debajyoti Choudhury🇮🇳

   Considering a six-dimensional geometry orbifolded on $S^1/Z_2\times S^1/Z_2$ with quarks and leptons localised on orthogonal branes, we show that the construction admits observable $n-\bar{n}$ oscillation while naturally suppressing the proton decay rates. Consistent with other low-energy observables, the model also accommodates baryogenesis at $\mathcal{O}$(10 TeV) scale.

   hep-phhep-thPRD(2022)·6 citations
8. 08*

   UPC contribution to forward rapidity gap distribution in pPb collisions at the LHC

   V. Guzey (St. Petersburg, INP)🇷🇺 · M. Strikman (Penn State U.)🇺🇸 · M. Zhalov (St. Petersburg, INP)🇷🇺

   In this Letter, we consider strong and electromagnetic (ultraperipheral) mechanisms in proton-nucleus coherent diffraction at the CERN Large Hadron Collider. We explicitly demonstrate the dominance of the latter and explain the CMS data on the forward rapidity gap distribution in $pPb$ collisions at $\sqrt{s_{NN}}=8.16$ TeV. In particular, we provide simple estimates, which give a good, semi-quantitative description of both magnitude and shape of the $\Delta {\eta }^F$ distribution in the Pomeron-proton topology. We also make predictions for the proton-oxygen run.

   hep-phhep-exnucl-exPRC(2022)·2 citations
9. 09*

   Direct ${\rho }_L$ meson production in proton-proton and proton-antiproton collisions

   C. Aydin🇹🇷 · O. Uzun🇹🇷 · A. I. Ahmadov🇦🇿

   We have investigated the contribution of the Higher Twist (HT) Feynman diagrams to the large-$p_T$ inclusive ${\rho }_L$ meson production cross section in proton-proton and proton-antiproton collisions and we discuss the phenomenological consequences of possible HT contributions to cross sections. To extract HT subprocesses from Leading Twist (LT) background, we use various ${\rho }_L$ meson distribution amplitudes(DAs). In the numerical calculations, the dependencies of the HT contribution on the transverse momentum and the rapidity are discussed with special emphasis on DAs. Analysis of our results shows that HT contributions decrease more rapidly than LT contributions with increasing $p_T$. The preceding results demonstrate that HT contributions must be considered especially in the region of low $p_T$ and the HT contribution to the cross-section depends on the choice of the meson distribution amplitudes.

   hep-phInt.J.Mod.Phys.A(2022)·0 citations
10. 10*

    W boson mass anomaly and grand unification

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

    It is known that the recently reported shift of the W boson mass can be easily explained by an $SU(2{)}_L$ triplet Higgs boson with a zero hypercharge if it obtains a vacuum expectation value (VEV) of $O(1)$ GeV. Surprisingly, the addition of a TeV scale complex triplet Higgs boson to the standard model (SM) leads to a precise unification of the gauge couplings at around $10^{14}$ GeV. We consider that it is a consequence of $SU(5)$ grand unification and show a possible potential for the Higgs fields yielding a weak scale complex $SU(2)$ triplet scalar boson. Although it seems the proton decay constraint would doom such a low-scale unification, we show that the constraint can be avoided by introducing vector-like fermions which mix with the SM fermions through mass terms involving the VEV of GUT breaking Higgs field. Importantly, the simplest viable model only requires the addition of one pair of vector-like fermions transforming $10$ and $\overline{10}$.

    hep-phhep-exPLB(2022)·21 citations
11. 11*

    $Z_{cs}(3985)$ in next-to-leading-order chiral effective field theory -- the first truncation uncertainty analysis

    Qing-Yu Zhai🇨🇳 · Ming-Zhu Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳

    We revisit the $D_s^{-}{D}^{\ast 0}$/$D_s^{\ast -}{D}^0$ interaction and the $Z_{cs}(3985)$ state in chiral effective field theory(EFT) up to the next-to-leading order. We examine the relative importance of the leading-order contact, one-eta exchange, next-to-leading-order contact, and two-kaon-exchange contributions. We show that the leading-order and next-to-leading-order contact contributions play the most important role such that the $Z_{cs}(3985)$ state qualifies as a $D_s^{-}{D}^{\ast 0}$/$D_s^{\ast -}{D}^0$ resonance. On the other hand, the weak one-eta-exchange and weakly energy-dependent two-kaon-exchange contributions are less important in dynamically generating the $Z_{cs}(3985)$ state, indicating that chiral EFT is less predictive in the present situation. Furthermore, we apply the Bayesian method to estimate chiral truncation uncertainties and find that they are of similar magnitude as their statistical counterparts. Our study shows that if $Z_c(3900)$ exists, then SU(3)-flavor symmetry also predicts $Z_{cs}(3985)$ with a certain robustness, i.e., both can be accommodated in the chiral EFT with dominant contact contributions.

    hep-phnucl-thPRD(2022)·11 citations
12. 12*

    Fermionic decay of charged Higgs boson in low mass region in Georgi Machacek Model

    Swagata Ghosh🇮🇳

    At the Large Hadron Collider (LHC), ATLAS and CMS collaborations observed various decay modes of the light charged Higgs bosons produced by top (anti)quark decays. In this paper, we are interested in the subsequent decay of the light charged Higgs boson into a charm and a strange quark-antiquark pair and into a tau and a tau-neutrino pair, separately, in the context of the Georgi-Machacek model, which offers a large triplet vacuum expectation value (vev) preserving custodial symmetry. We show that these experimental observations constrain the triplet vev from above. We explore the model parameter space consistent with the theoretical constraints, the latest Higgs data and the experimental data for light charged Higgs decaying to $cs$ and $\tau {\nu }_{\tau }$.

    hep-phInt.J.Mod.Phys.A(2024)·14 citations
13. 13*

    Leptoquark-vectorlike quark model for the CDF $m_W$, $(g-2{)}_{\mu }$, $R_{K^{(\ast )}}$ anomalies and neutrino mass

    Talal Ahmed Chowdhury🇧🇩 · Shaikh Saad🇨🇭

    Very recently, a substantial $7\sigma$ deviation of the $W$-boson mass from the Standard Model (SM) prediction has been reported by the CDF collaboration. Furthermore, the Muon g-2 Experiment recently confirmed the longstanding tension in $(g-2{)}_{\mu }$. Besides, the updated result from the LHCb collaboration found evidence for the breaking of lepton universality in beauty-quark decays, which shows a $3.1\sigma$ discrepancy and is consistent with their previous measurements. Motivated by several of these drawbacks of the SM, in this work, we propose a model consisting of two scalar leptoquarks and a vectorlike quark to simultaneously address the $W$-boson mass shift, the $(g-2{)}_{\mu }$, and anomalies in the neutral current transitions of the $B$-meson decays. The proposed model also sheds light on the origin of neutrino mass and can be fully tested at the future colliders.

    hep-phPRD(2022)·44 citations
14. 14*

    Understanding PDF uncertainty on the $W$ boson mass measurements in CT18 global analysis

    Jun Gao🇨🇳 · DianYu Liu🇨🇳 · Keping Xie🇺🇸

    We study the dependence of the transverse mass distribution of the charged lepton and the missing energies on the parton distributions (PDFs) adapted to the $W$ boson mass measurements at the CDF and ATLAS experiments. We compare the shape variations of the distribution induced by different PDFs and find that spread of predictions from different PDF sets can be much larger than the PDF uncertainty predicted by a specific PDF set. We suggest analyzing the experimental data using up-to-date PDFs for a better understanding of the PDF uncertainties in the $W$ boson mass measurements. We further carry out a series of Lagrange multiplier scans to identify the constraints on the transverse mass distribution imposed by individual data sets in the CT18 global analysis. In the case of CDF measurement, the distribution is mostly sensitive to the $d$-quark PDFs at the intermediate $x$ region that is largely constrained by the DIS and Drell-Yan data on the deuteron target, as well as the Tevatron lepton charge asymmetry data.

    hep-phhep-exCPC(2022)·24 citations
15. 15*

    The $SU(2{)}_D$ lepton portals for muon $g-2$, $W$ boson mass and dark matter

    Seong-Sik Kim🇰🇷 · Hyun Min Lee🇰🇷 · Adriana G. Menkara🇰🇷 · Kimiko Yamashita🇰🇷

    We propose a novel model for lepton flavor and dark matter based on the $SU(2{)}_D$ gauge symmetry and vector-like leptons in its fundamental representations. We introduce a dark $SU(2{)}_D$ Higgs doublet and a Higgs bi-doublet for the mass mixing between the vector-like lepton and the lepton. As a result, the seesaw lepton masses are generated and there are sizable one-loop contributions to the muon $g-2$ via the $SU(2{)}_D$ gauge bosons and the relatively heavy vector-like lepton, as indicated in Fermilab E989. The tree-level mass mixing between the $Z$ boson and the isospin neutral gauge boson of $SU(2{)}_D$ in our model accounts for the shift in the $W$ boson mass, being consistent with Tevatron CDFII. Finally, we show that the isospin charged gauge boson of $SU(2{)}_D$ becomes a plausible candidate for dark matter with a small mass splitting tied up to the modified $W$ boson mass, and there is a viable parameter space where the favored corrections to the muon $g-2$ and the $W$ boson mass and the dark matter constraints are simultaneously fulfilled.

    hep-phPRD(2022)·18 citations
16. 16*

    Investigating the $\mathbf{{\rm Y}}(10753)\to \mathbf{{\rm Y}}(1^3{\mathbf{D}}_{\mathbf{J}})\eta$ transitions

    Yu-Shuai Li🇨🇳 · Zi-Yue Bai🇨🇳 · Xiang Liu🇨🇳

    In this work, we investigate the ${\rm Y}(10753)\to {\rm Y}(1^3{D}_J)\eta$ ($J=1,2,3$) processes, where the ${\rm Y}(10753)$ is assigned as a conventional bottomonium under the $4S$-$3D$ mixing scheme. Our result shows that the concerned processes have considerable branching ratios, {\it i.e.}, branching ratios $\mathcal{B}[{\rm Y}(10753)\to {\rm Y}(1^3{D}_1)\eta ]$ and $\mathcal{B}[{\rm Y}(10753)\to {\rm Y}(1^3{D}_2)\eta ]$ can reach up to the order of magnitude of $10^{-4}-10^{-3}$, while $\mathcal{B}[{\rm Y}(10753)\to {\rm Y}(1^3{D}_3)\eta ]$ is around $10^{-6}-10^{-5}$. With the running of Belle II, it is a good opportunity for finding out the concerned hidden-bottom hadronic decays.

    hep-phhep-exPRD(2022)·20 citations
17. 17*

    The forward-backward asymmetry in the electron positron annihilation process at twist-4

    W. Yang🇨🇳 · C. Li🇸🇬

    A quantity of particular experimental interest is the forward-backward asymmetry in the angular distribution of positively and negatively charged fermions produced in $Z^0$ decays. Measurements of this asymmetry can enable independent determinations of the neutral-current couplings of these fermions, i.e. the $Z^0$ boson couplings for left- and right-handed fermions, respectively. Due to the quark confinement, however, it is difficult to determine the electroweak interactions of quarks, especially for light quarks. In the hadron production electron positron annihilation process, the parton model with factorization theorem gives a reliable approximate description. Quantities are thus expressed in terms of fragmentation functions in the annihilation process. In this paper, we consider the vector meson production in the inclusive electron positron annihilation process and calculate the forward-backward asymmetry in the hadronic level. Calculations are carried out by applying the collinear expansion in the parton model at leading order twist-4. We note here this process provides not only a tool for analyzing the hadronic weak interactions but also an opportunity for understanding the parton model of the strong interaction. In other words, the results can be used to test the electroweak and strong interactions simultaneously.

    hep-phPRD(2022)·2 citations
18. 18*

    Mixing effects on 1S and 2S state heavy mesons in the light-front quark model

    Ahmad Jafar Arifi🇰🇷 · Ho-Meoyng Choi🇰🇷 · Chueng-Ryong ji🇺🇸 · Yongseok Oh🇰🇷

    The mass spectra and wave functions of both $1S$ and $2S$ state heavy pseudoscalar ($P$) and vector ($V$) mesons are analyzed within the light-front quark model. Important empirical constraints employed in our analysis of the mass spectra and wave functions are the experimental mass-gap relation, $\Delta M_P>\Delta M_V$, where $\Delta M_{P(V)}=M_{P(V)}^{2S}-M_{P(V)}^{1S}$ and the hierarchy of the decay constants, $f_{1S}>f_{2S}$, between $1S$ and $2S$ meson states. We maintain the orthogonality of the trial wave functions of the $1S$ and $2S$ states in our variational calculation of the Hamiltonian with the Coulomb plus confining potentials and treat the hyperfine interaction perturbatively for the heavy-heavy and heavy-light $P$ and $V$ mesons due to the nature of the heavy quark symmetry. Realizing that the empirical constraints cannot be satisfied without mixing of the $1S$ and $2S$ states, we find the lower bound of the mixing angle $\theta$ between $1S$ and $2S$ states as ${\theta }_c={\cot }^{-1}(2\sqrt{6})/2\simeq 6^{\circ }$ and obtain the optimum value of the mixing angle around $12^{\circ }$ to cover both the charm and bottom flavors of the heavy quark. The mixing effects are found to be more significant to the $2S$ state mesons than to the $1S$ state mesons. The properties of $1S$ and $2S$ state mesons including the mass spectra, decay constants, twist-2 distribution amplitudes, and electromagnetic form factors are computed. Our results are found to be in a good agreement with the available data and lattice simulations. In particular, the $2S$ state pseudoscalar $D_s$ meson is predicted to have a mass of $2600$ MeV, which is very close to the mass of the newly discovered $D_{s0}(2590{)}^{+}$ meson by the LHCb Collaboration. This supports the interpretation of the observed state as a radial excitation of the $D_s^{+}$ meson.

    hep-phnucl-thPRD(2022)·48 citations
19. 19*

    WIMP and FIMP dark matter in the inert doublet plus singlet model

    G. Belanger🇫🇷 · A. Mjallal🇫🇷 · A. Pukhov🇷🇺

    We consider multi-component dark matter in a model where one dark matter component is feebly interacting (FIMP) while the second is weakly interacting (WIMP). The model contains an inert scalar doublet and a complex scalar singlet and features a discrete $Z_4$ symmetry. We determine the parameter space that satisfies theoretical constraints, collider constraints, relic density as well as direct and indirect detection limits. We discuss the possibility to probe the model through collider and astrophysical searches. We find that it is possible that the FIMP forms the dominant DM component, in this case the astrophysical signatures of the WIMP are much suppressed. We also explore the case where the doublet can decay into pairs of singlets leaving only one DM component, the FIMP. These scenarios are constrained by BBN and are best explored at colliders since astrophysical signatures are suppressed.

    hep-phPRD(2022)·20 citations
20. 20*

    Spontaneous CP violation

    Alessandro Valenti🇮🇹

    Models of spontaneous CP violation can solve the Strong CP problem without the need of an anomalous Peccei-Quinn symmetry. In this work we review the Nelson-Barr approach, quantifying a peculiar coincidence between unrelated mass scales that these models must satisfy in order to correctly reproduce the Standard Model quark masses and CP violation. We investigate the compatibility between this requirement and the induced radiative corrections to the neutron electric dipole moment, and with bounds coming from collider, electroweak and flavor observables.

    hep-ph0 citations
21. 21*

    Probing heavy triplet leptons of the type-III seesaw mechanism at future muon colliders

    Tong Li🇨🇳 · Han Qin🇺🇸 · Chang-Yuan Yao🇨🇳 · Man Yuan🇨🇳

    We study the search potential of heavy triplet leptons in Type III Seesaw mechanism at future high-energy and high-luminosity muon colliders. The impact of up-to-date neutrino oscillation results is taken into account on neutrino parameters and the consequent decay patterns of heavy leptons in Type III Seesaw. The three heavy leptons in the Casas-Ibarra parametrization with diagonal unity matrix are distinguishable in their decay modes. We consider the pair production of charged triplet leptons $E^{+}{E}^{-}$ through both ${\mu }^{+}{\mu }^{-}$ annihilation and vector boson fusion (VBF) processes. The leading-order framework of electroweak parton distribution functions are utilized to calculate the VBF cross sections. The charged triplet leptons can be probed for masses above $\sim 1$ TeV. The $E^{+}{E}^{-}\to ZZ{\ell }^{+}{\ell }^{-}$ channel can be further utilized to fully reconstruct the three triplet leptons and distinguish neutrino mass patterns. The pair production of heavy neutrinos $N$ and the associated production $E^{\pm }N$ are only induced by VBF processes and lead to lepton-number-violating (LNV) signature. We also study the search potential of LNV processes at future high-energy muon collider with $\sqrt{s}=30$ TeV.

    hep-phPRD(2022)·12 citations
22. 22*

    Physics implication from a $Z_3$ symmetry of matter

    Phung Van Dong🇻🇳

    I show that breaking $B-L$ by one unit of this charge is suitable for neutrino mass generation through an inverse seesaw mechanism, stabilizing a dark matter candidate without supersymmetry, as well as solving the muon anomalous magnetic moment and the $W$ mass deviation via dark field contributions. The new physics is governed by the residual $Z_3$ symmetry of $B-L$ isomorphic to the center of the color group, instead of the well-studied matter parity.

    hep-phPRD(2023)·3 citations
23. 23*

    Vector leptoquark $U_3$ and CP violation at T2K, NOvA experiments

    Rudra Majhi🇮🇳 · Dinesh Kumar Singha🇮🇳 · K. N. Deepthi🇮🇳 · Rukmani Mohanta🇮🇳

    In the current epoch of neutrino physics, many experiments are aiming for precision measurements of oscillation parameters. Thus, various new physics scenarios which alter the neutrino oscillation probabilities in matter deserve careful investigation. In this context, we study the effect of a vector leptoquark which induces non-standard neutrino interactions (NSI) that modify the oscillation probabilities of neutrinos in matter. We show that such interactions provide a relatively large value of NSI parameter ${\epsilon }_{e\mu }$. Considering this NSI parameter, we successfully explain the recent discrepancy between the observed ${\delta }_{CP}$ results of T2K and NOvA.

    hep-phEPJC(2022)·9 citations
24. 24*

    In-medium polarization tensor in strong magnetic fields (I): Magneto-birefringence at finite temperature and density

    Koichi Hattori🇨🇳 · Kazunori Itakura🇯🇵

    We investigate in-medium polarization effects of the fermion and antifermion pairs at finite temperature and density in strong magnetic fields within the lowest Landau level approximation. Inspecting the integral representation of the polarization tensor by analytic and numerical methods, we provide both the real and imaginary parts of the polarization tensor obtained after delicate interplay between the vacuum and medium contributions essentially due to the Pauli-blocking effect. Especially, we provide a complete analytic form of the polarization tensor at zero temperature and finite density that exhibits an exact cancellation and associated relocation of the singular threshold behaviors for a single photon decay to a fermion and antifermion pair. As a physical application of the in-medium polarization tensor, we discuss the magneto-birefringence that is polarization-dependent dispersion relations of photons induced by the strong magnetic fields.

    hep-phastro-ph.HEnucl-thAnnals Phys.(2022)·17 citations
25. 25*

    Muon g-2 in SUSY scenarios with and without stable neutralinos

    Rafał Masełek🇵🇱

    We investigate a possibility to explain the discrepancy between the Standard Model predictions and the observed value of the anomalous magnetic moment of the muon within unorthodox SUSY scenarios in which neutralinos are unstable. We start by reviewing the muon g-2 calculations in the MSSM and confront it with the most up-to-date experimental constraints. We find out that the next generation of direct detection DM experiments combined with the current LHC results will ultimately test the parameter region that can explain the $(g-2{)}_{\mu }$ anomaly in the MSSM. Next, we study R-parity violating and gauge-mediated SUSY-breaking scenarios with unstable neutralinos. These models do not provide a viable DM candidate, which allows them to evade the DM constraints. We find that in RPV and GMSB with slepton NLSP the LHC constraints are weaker, and a large region of parameter space can explain the observed anomaly and evade experimental limits.

    hep-ph3 citations
26. 26*

    Coleman-Weinberg Abrikosov-Nielsen-Olesen strings

    Minoru Eto🇯🇵 · Yu Hamada🇯🇵 · Ryusuke Jinno🇪🇸 · Muneto Nitta🇯🇵 · Masatoshi Yamada🇩🇪

    We study properties of Abrikosov-Nielsen-Olesen (ANO) strings with the Coleman-Weinberg (CW) potential, which we call CW-ANO strings. While the scale-invariant scalar potential has a topologically trivial vacuum admitting no strings at the classical level, quantum correction allows topologically nontrivial vacua and stable string solutions. We find that the system of the CW potential exhibits significant difference from that of the conventional Abelian-Higgs model with the quadratic-quartic potential. While a single-winding string is qualitatively similar in both systems, and the static intervortex force between two strings at large distance is attractive/repulsive in the type-I/II regime for both, that between two CW-ANO strings exhibits a nontrivial structure. It develops an energy barrier between them at intermediate distance, implying that the string with winding number $n>1$ can constitute a metastable bound state even in the type-II regime. We name such a superconductor type-$\overline{1.5}$. We also discuss implications to high-energy physics and cosmology.

    hep-phcond-mat.supr-conhep-thPRD(2022)·10 citations
27. 27*

    Different degrees of complexity in multiparticle production at the LHC energies with the transition from soft to hard processes

    Hirak Koley🇮🇳 · Arindam Mondal🇮🇳 · Somnath Kar🇮🇳 · Sreejita Mukherjee🇮🇳 · Joyati Mondal🇮🇳 · Argha Deb🇮🇳 · Mitali Mondal🇮🇳

    We apply a complex network-based method of visibility graph to explore the degree of complexity and fractal nature in the multiparticle production process at the LHC energy regime. For the investigation, we have used proton-proton (pp) collision events at $\sqrt{s}$ = 7 and 13 TeV and proton-nucleus (p-A) collision events at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV, generated using a hybrid Monte-Carlo model, EPOS3 with hydrodynamical evolution. Particle production in high energy collisions becomes gradually harder with the increase of the produced particle's transverse momentum. We have presented for the first time a detailed analysis of the change of fractal behaviour as the process becomes gradually harder than the soft ones for the above mentioned colliding systems. The study reveals that the degree of complexity depends on the hardness of the particle production process. System size dependency, as well as energy dependency of fractal nature, are also exhibited by the present analysis.

    hep-ph1 citation
28. 28*

    Disentangling Quarks and Gluons with CMS Open Data

    Patrick T. Komiske🇺🇸 · Serhii Kryhin🇺🇸 · Jesse Thaler🇺🇸

    We study quark and gluon jets separately using public collider data from the CMS experiment. Our analysis is based on 2.3/fb of proton-proton collisions at 7 TeV, collected at the Large Hadron Collider in 2011. We define two non-overlapping samples via a pseudorapidity cut -- central jets with |eta| < 0.65 and forward jets with |eta| > 0.65 -- and employ jet topic modeling to extract individual distributions for the maximally separable categories. Under certain assumptions, such as sample independence and mutual irreducibility, these categories correspond to "quark" and "gluon" jets, as given by a recently proposed operational definition. We consider a number of different methods for extracting reducibility factors from the central and forward datasets, from which the fractions of quark jets in each sample can be determined. The greatest stability and robustness to statistical uncertainties is achieved by a novel method based on parametrizing the endpoints of a receiver operating characteristic (ROC) curve. To mitigate detector effects, which would otherwise induce unphysical differences between central and forward jets, we use the OmniFold method to perform central value unfolding. As a demonstration of the power of this method, we extract the intrinsic dimensionality of the quark and gluon jet samples, which exhibit Casimir scaling, as expected from the strongly-ordered limit. To our knowledge, this work is the first application of full phase space unfolding to real collider data, and one of the first applications of topic modeling to extract separate quark and gluon distributions at the LHC.

    hep-phhep-exphysics.data-anPRD(2022)·46 citations
29. 29*

    dE/dx from boosted long-lived particles

    Gian F. Giudice🇨🇭 · Matthew McCullough🇨🇭 · Daniele Teresi🇨🇭

    At colliders massive long-lived charged particles could be revealed through their anomalously large ionisation energy loss $dE/dx$. In this paper we explore a class of scenarios in which the LLPs are particularly boosted, owing to production from the decay of a heavy parent resonance. Such scenarios give rise to unique signatures as compared to traditionally considered $dE/dx$ new-physics benchmarks. We demonstrate that this class of models, unlike traditional new-physics theories, can explain the recently reported excess of events in the $dE/dx$ search by the ATLAS collaboration without conflicting with the determination of $\beta$ from ionisation and time-of-flight measurements.

    hep-phhep-exJHEP(2022)·17 citations
30. 30*

    Gauge Invariance of Non-Abelian Field Strength Correlators: the Axial Gauge Puzzle

    Bruno Scheihing-Hitschfeld🇺🇸 · Xiaojun Yao🇺🇸

    Many transport coefficients of the quark-gluon plasma and nuclear structure functions can be written as gauge invariant correlation functions of non-Abelian field strengths dressed with Wilson lines. We discuss the applicability of axial gauge $n\cdot A=0$ to calculate them. In particular, we address issues that appear when one attempts to trivialize the Wilson lines in the correlation functions by gauge-fixing. We find it is always impossible to completely remove the gauge fields $n\cdot A$ in Wilson lines that extend to infinity in the $n$-direction by means of gauge transformations. We show how the obstruction appears in an explicit example of a perturbative calculation, and we also explain it more generally from the perspective of the path integral that defines the theory. Our results explain why the two correlators that define the heavy quark and quarkonium transport coefficients, which are seemingly equal in axial gauge, are actually different physical quantities of the quark-gluon plasma and have different values. Furthermore, our findings provide insights into the difference between two inequivalent gluon parton distribution functions.

    hep-phhep-thnucl-thPRL(2023)·25 citations
31. 31*

    Next-to-leading power endpoint factorization and resummation for off-diagonal "gluon" thrust

    M. Beneke🇩🇪 · M. Garny🇩🇪 · S. Jaskiewicz🇬🇧 · J. Strohm🇩🇪 · R. Szafron🇺🇸 · L. Vernazza🇮🇹 · J. Wang🇨🇳

    The lack of convergence of the convolution integrals appearing in next-to-leading-power (NLP) factorization theorems prevents the applications of existing methods to resum power-suppressed large logarithmic corrections in collider physics. We consider thrust distribution in the two-jet region for the flavour-nonsinglet off-diagonal contribution, where a gluon-initiated jet recoils against a quark-antiquark pair, which is power-suppressed. With the help of operatorial endpoint factorization conditions, we obtain a factorization formula, where the individual terms are free from endpoint divergences in convolutions and can be expressed in terms of renormalized hard, soft and collinear functions in four dimensions. This allows us to perform the first resummation of the endpoint-divergent SCET${}_{\mathrm{I}}$ observables at the leading logarithmic accuracy using exclusively renormalization-group methods. The presented approach relies on universal properties of the soft and collinear limits and may serve as a paradigm for the systematic NLP resummation for other $1\to 2$ and $2\to 1$ collider physics processes.

    hep-phJHEP(2022)·79 citations
32. 32*

    A bridge to new physics: proposing new -- and reviving old -- explanations of $a_{\mu }$

    Guilherme Guedes🇪🇸 · Pablo Olgoso🇪🇸

    The $4.2\sigma$ tension in the combined measurement of the anomalous magnetic moment of the muon, $a_{\mu }$, and the Standard Model prediction strongly suggests the existence of beyond the Standard Model physics. Following the Standard Model Effective Field Theory approach, we study a particular topology, the \emph{bridge} diagram, which gives a chirally enhanced contribution to $a_{\mu }$. We classify all possible 2- and 3-field SM extensions that can generate this contribution and present the full $a_{\mu }$ result for them. Within our approach, we find that several 2-field fermion-scalar extensions which had been previously discarded in the literature -- when only the Yukawa-suppressed contribution was considered -- can actually be viable models to explain the observed anomaly. Furthermore, the 3-field extensions which generate the bridge diagram represent a new class of models to account for $a_{\mu }$. We explore a particular 3-field extension which, beyond explaining $a_{\mu }$, can also account for the neutral $B$-meson anomalies and the Cabibbo angle anomaly. We present the full one-loop matching for this model and a one-loop phenomenological study.

    hep-phJHEP(2022)·35 citations
33. 33*

    The last Complex WIMPs standing

    Salvatore Bottaro🇮🇹 · Dario Buttazzo🇮🇹 · Marco Costa🇮🇹 · Roberto Franceschini🇮🇹 · Paolo Panci🇮🇹 · Diego Redigolo🇮🇹 · Ludovico Vittorio🇮🇹

    We continue the study of weakly interacting massive particles (WIMP) started in [arXiv:2107.09688], focusing on a single complex electroweak $n$-plet with non-zero hypercharge added to the Standard Model. The minimal splitting between the Dark Matter and its electroweak neutral partner required to circumvent direct detection constraints allows only multiplets with hypercharge smaller or equal to 1. We compute for the first time all the calculable WIMP masses up to the largest multiplet allowed by perturbative unitarity. For the minimal allowed splitting, most of these multiplets can be fully probed at future large-exposure direct detection experiments, with the notable exception of the doublet with hypercharge 1/2. We show how a future muon collider can fully explore the parameter space of the complex doublet combining missing mass, displaced track and long-lived track searches. In the same spirit, we study how a future muon collider can probe the parameter space of complex WIMPs in regions where the direct detection cross section drops below the neutrino floor. Finally, we comment on how precision observables can provide additional constraints on complex WIMPs.

    hep-phastro-ph.COEPJC(2022)·91 citations
34. 34*

    Integer solutions to the anomaly equations for a class of chiral gauge theories

    Alessandro Podo🇺🇸 · Filippo Revello🇬🇧

    We find all the integer charge solutions to the equations for the cancellation of local gauge anomalies in a class of gauge theories which extend the Standard Model (SM) by a gauge group of the form $G\times U(1)$, where $G$ is an arbitrary semisimple compact Lie group. The SM fermions are assumed to be neutral under $G\times U(1)$ gauge interactions, while the new fermions transform in non-trivial representations of both the new and the SM gauge groups. Our analysis is valid also when the latter is embedded in an arbitrary semisimple compact Lie group. Theories with this structure have been recently studied as models of composite axions based on accidental symmetries and can provide a field theory resolution to the axion quality problem. We apply our results to cases of phenomenological interest and prove the existence of charge assignments with Peccei-Quinn symmetry protected up to dimension 18.

    ↳ hep-thhep-phmath-phmath.MPPRD(2022)·8 citations
35. 35*

    A new class of hybrid EoS with multiple critical endpoints for simulations of supernovae, neutron stars and their mergers

    Oleksii Ivanytskyi🇵🇱 · David Blaschke🇵🇱

    We introduce a family of equations of state (EoS) for hybrid neutron star (NS) matter that is obtained by a two-zone parabolic interpolation between a soft hadronic EoS at low densities and a stiff quark matter EoS with color superconductivity at high densities within a finite region of baryonic chemical potentials ${\mu }_B^h<{\mu }_B<{\mu }_B^q$. We consider two scenarios corresponding to a cross-over and a strong first-order transition between quark and hadron phases considered at finite and zero temperatures. This allows us to analyze the effects of finite entropy on the EoS and mass-radius relation of NS. We demonstrate that the formation of a color superconducting state of quark matter drives the evolution of matter in supernovae explosions under the condition of entropy conservation to higher temperatures than in the case of deconfinement to normal quark matter. Within the presented hybrid EoS scenario, regions of the QCD phase diagram may be accessible to supernovae and NS mergers that can be reached also in terrestrial experiments with relativistic heavy ion collisions.

    ↳ nucl-thastro-ph.HEhep-phEPJA(2022)·28 citations
36. 36*

    Dimensional Regularization of Topological Terms in Dilaton Gravity

    Claudio Corianò🇮🇹 · Mario Cretì🇮🇹 · Stefano Lionetti🇮🇹 · Matteo Maria Maglio🇩🇪 · Riccardo Tommasi🇮🇹

    The possibility of evading Lovelock's theorem at $d=4$, via a singular redefinition of the dimensionless coupling of the Gauss-Bonnet term, has been extensively discussed in the cosmological context. The term is added as a quadratic contribution of the curvature tensor to the Einstein-Hilbert action, originating theories of "Einstein Gauss-Bonnet" (EGB) type. These studies are interlaced with those of the conformal anomaly effective action. We review some basic results concerning the structure of these actions, their conformal constraints around flat space and their relation to EGB theories. The local and nonlocal formulations of such effective actions are illustrated. This class of theories find applications in the seemingly unrelated context of topological materials, subjected to thermal and mechanical stress.

    ↳ hep-thhep-phPoS(2022)·2 citations
37. 37*

    Phases of Quench Dynamics in the Presence of Fluctuation

    Chang Lei🇨🇳 · Shu Lin🇨🇳

    We study the effect of thermal fluctuations on a sourced quench in a system with $Z_2$ symmetry. By ignoring the fluctuation of finite momentum modes and tracing the dynamics of zero momentum mode driven by a spatially homogeneous source near the critical point, we map out a phase diagram for the quench dynamics. The phase diagram consists of three different phases. Phase I occurs for large fluctuations with the relaxation time set by fluctuation induced inverse effective mass square. Phase II occurs for small fluctuation and slow quench rate. The dynamics is characterized by a modified Kibble-Zurek scaling. Phase III corresponds to small fluctuations and rapid quench rate. The relaxation time tends to a finite value in the rapid quench limit. We also estimate the fluctuations of finite momentum modes, finding significant enhancement of the effective mass square. We speculate the qualitative features of the phase diagram may remain the same, but enhanced fluctuations can lead to shrinkage of phase II and III.

    ↳ nucl-thcond-mat.supr-conhep-phPRResearch(2023)·0 citations
38. 38*

    Spectral function for ${}^4$He using the Chebyshev expansion in coupled-cluster theory

    J. E. Sobczyk🇩🇪 · S. Bacca🇩🇪 · G. Hagen🇺🇸 · T. Papenbrock🇺🇸

    We compute spectral function for ${}^4$He by combining coupled-cluster theory with an expansion of integral transforms into Chebyshev polynomials. Our method allows to estimate the uncertainty of spectral reconstruction. The properties of the Chebyshev polynomials make the procedure numerically stable and considerably lower in memory usage than the typically employed Lanczos algorithm. We benchmark our predictions with other calculations in the literature and with electron scattering data in the quasi-elastic peak. The spectral function formalism allows one to extend ab-initio lepton-nucleus cross sections into the relativistic regime. This makes it a promising tool for modeling this process at higher energy transfers. The results we present open the door for studies of heavier nuclei, important for the neutrino oscillation programs.

    ↳ nucl-thhep-phPRC(2022)·12 citations
39. 39*

    RPS Thermodynamics of Taub-NUT AdS Black Holes in the Presence of Central Charge and the Weak Gravity Conjecture

    Jafar Sadeghi🇮🇷 · Mehdi Shokri🇮🇷 · Saeed Noori Gashti🇮🇷 · Mohammad Reza Alipour🇮🇷

    We study the thermodynamics of the Taub-NUT AdS black holes by Visser holographic method using AdS radius as a constant parameter under the restricted phase space approach. Instead of the variables $P$ and $V$, we deal with the central charge and also chemical potential as a unique couple of conjugate thermodynamic variables. We study some interesting properties of the Taub-NUT black holes e.g. supercritical phase equilibrium in the $T-S$ processes, $Q-\Phi$ and the Hawking-Page phase transition in the $\mu -C$ processes. As a consequence, the consistency of the weak gravity conjecture of multi-charge for Taub-NUT-AdS black holes at critical points is proved. We conclude that in the presence of the central charge and assuming $C=\frac{3}{8}{\ell }^2$, weak gravity conjecture could be satisfied in the Taub-NUT-AdS black holes with $\hat{n}\ll 1$.

    ↳ hep-thgr-qchep-phGen.Rel.Grav.(2022)·73 citations
40. 40*

    On preheating after inflation in general scalar-tensor theories of gravity

    Peeravit Koad (Walailak U.)🇹🇭 · Jatechan Channuie (Walailak U.)🇹🇭 · Phongpichit Channuie (Walailak U.)🇹🇭

    In this work, we investigate the preheating mechanism after inflation in general scalar-tensor theories of gravity. In the present scenario, we consider two-field scenario and then derive the potential of exponential and hyperbolic tangent forms. We study the evolution of the background system when the back reaction on the background field is neglected. We examine the particle production due to parametric resonances in both models. We find that in Minkowski space the stage of parametric resonances can be described by the Mathieu equation. Finally, we demonstrate that parametric resonances in our models are sufficiently broad possible for the exponential growth of the number of particles.

    ↳ gr-qchep-phFortsch.Phys.·2 citations
41. 41*

    Stochastic gravitational waves from long cosmic strings

    Disrael Camargo Neves da Cunha🇧🇪 · Christophe Ringeval🇧🇪 · François R. Bouchet🇫🇷

    We compute the expected strain power spectrum and energy density parameter of the stochastic gravitational wave background (SGWB) created by a network of long cosmic strings evolving during the whole cosmic history. As opposed to other studies, the contribution of cosmic string loops is discarded and our result provides a robust lower bound of the expected signal that is applicable to most string models. Our approach uses Nambu-Goto numerical simulations, running during the radiation, transition and matter eras, in which we compute the two-point unequal-time anisotropic stress correlators. These ones act as source terms in the linearised equations of motion for the tensor modes, that we solve using an exact Green's function integrator. Today, we find that the rescaled strain power spectrum $(k/{\mathcal{H}}_0{)}^2{\mathcal{P}}_h$ peaks on Hubble scales and exhibits, at large wavenumbers, high frequency oscillations around a plateau of amplitude $100(GU{)}^2$. Most of the high frequency power is generated by the long strings present in the matter era, the radiation era contribution being smaller.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2022)·17 citations
42. 42*

    Primordial Black Holes from Multifield Inflation with Nonminimal Couplings

    Sarah R. Geller🇺🇸 · Wenzer Qin🇺🇸 · Evan McDonough🇨🇦 · David I. Kaiser🇺🇸

    Primordial black holes (PBHs) provide an exciting prospect for accounting for dark matter. In this paper, we consider inflationary models that incorporate realistic features from high-energy physics -- including multiple interacting scalar fields and nonminimal couplings to the spacetime Ricci scalar -- that could produce PBHs with masses in the range required to address the present-day dark matter abundance. Such models are consistent with supersymmetric constructions, and only incorporate operators in the effective action that would be expected from generic effective field theory considerations. The models feature potentials with smooth large-field plateaus together with small-field features that can induce a brief phase of ultra-slow-roll evolution. Inflationary dynamics within this family of models yield predictions for observables in close agreement with recent measurements, such as the spectral index of primordial curvature perturbations and the ratio of power spectra for tensor to scalar perturbations. As in previous studies of PBH formation resulting from a period of ultra-slow-roll inflation, we find that at least one dimensionless parameter must be highly fine-tuned to produce PBHs in the relevant mass-range for dark matter. Nonetheless, we find that the models described here yield accurate predictions for a significant number of observable quantities using a smaller number of relevant free parameters.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2022)·88 citations
43. 43*

    Primordial Clocks within Stochastic Gravitational Wave Anisotropies

    Arushi Bodas🇺🇸 · Raman Sundrum🇺🇸

    A first-order phase transition in the early universe can give an observable stochastic gravitational background (SGWB), which will necessarily have primordial anisotropies across the sky. In multi-field inflationary scenarios, these anisotropies may have a significant isocurvature component very different from adiabatic fluctuations, providing an alternate discovery channel for high energy physics at inflationary scales. Here, we consider classically oscillating heavy fields during inflation that can imprint distinctive scale-invariance-breaking features in the power spectrum of primordial anisotropies. While such features are highly constrained in the cosmic microwave background, we show that their amplitude can be observably large in isocurvature SGWB, despite both probing a similar period of inflation. Measuring SGWB multipoles at the required level, $\ell \sim \mathcal{O}(10-100)$, will be technologically challenging. However, we expect that early detection of a strong isotropic SGWB, and the guarantee of anisotropies, would spur development of next-generation detectors with sufficient sensitivity, angular resolution, and foreground discrimination.

    ↳ astro-ph.COhep-phJCAP(2022)·13 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.