Tue·Mar 10, 2020Tuesday·March 10, 2020

1. 01*

   Two-Loop Radiative Jet Function for Exclusive $B$-Meson and Higgs Decays

   Ze Long Liu (Los Alamos Nat. Lab.)🇺🇸 · Matthias Neubert (Johannes Gutenberg University Mainz)🇩🇪

   The rare radiative $B$-meson decay $B^{-}\to \gamma {\ell }^{-}\bar{\nu }$ and the radiative Higgs-boson decay $h\to \gamma \gamma$ mediated by light-quark loops both receive large logarithmic corrections in QCD, which can be resummed using factorization theorems derived in soft-collinear effective theory. In these factorization theorems the same radiative jet function appears, which is a central object in the study of factorization beyond the leading order in scale ratios. We calculate this function at two-loop order both in momentum space and in a dual space, where its renormalization-group evolution takes on a simpler form. We also derive the two-loop anomalous dimension of the jet function and present the exact solution to its evolution equation at two-loop order. Another important outcome of our analysis is the explicit form of the two-loop anomalous dimension of the $B$-meson light-cone distribution amplitude in momentum space.

   hep-phhep-thJHEP(2020)·58 citations
2. 02*

   Spectrum of singly heavy baryons from a chiral effective theory of diquarks

   Yonghee Kim🇯🇵 · Emiko Hiyama🇯🇵 · Makoto Oka🇯🇵 · Kei Suzuki🇯🇵

   The mass spectra of singly charmed and bottom baryons, ${\Lambda }_{c/b}(1/2^{\pm },3/2^{-})$ and ${\Xi }_{c/b}(1/2^{\pm },3/2^{-})$, are investigated using a nonrelativistic potential model with a heavy quark and a light diquark. The masses of the scalar and pseudoscalar diquarks are taken from a chiral effective theory. The effect of $U_A(1)$ anomaly induces an inverse hierarchy between the masses of strange and non-strange pseudoscalar diquarks, which leads to a similar inverse mass ordering in $\rho$-mode excitations of singly heavy baryons.

   hep-phhep-exPRD(2020)·29 citations
3. 03*

   Investigation of electroproduction of $\varphi$ mesons off protons

   Sang-Ho Kim🇰🇷 · Seung-il Nam🇰🇷

   We investigate $\varphi$-meson electroproduction off the proton target, i.e., ${\gamma }^{\ast }p\to \varphi p$, by employing a tree-level effective Lagrangian approach in the kinematical ranges of $Q^2$ = (0$-$4) ${\mathrm{GeV}}^2$, $W$ = (2$-$5) GeV, and $|t|\le 2{\mathrm{GeV}}^2$. In addition to the universally accepted Pomeron exchange, we consider various meson exchanges in the $t$ channel with the Regge method. Direct $\varphi$-meson radiations in the $s$- and $u$-channels are also taken into account. We find that the $Q^2$ dependence of the transverse (${\sigma }_{\mathrm{T}}$) and longitudinal (${\sigma }_{\mathrm{L}}$) cross sections are governed by Pomeron and $(a_0,f_0)$ scalar meson exchanges, respectively. Meanwhile, the contributions of $(\pi ,\eta )$ pseudoscalar- and $f_1(1285)$ axial-vector-meson exchanges are much more suppressed. The results of the interference cross sections (${\sigma }_{\mathrm{LT}},{\sigma }_{\mathrm{LT}}$) and the spin-density matrix elements indicate that $s$-channel helicity conservation holds at $Q^2$ = (1$-$4) ${\mathrm{GeV}}^2$. The result of the parity asymmetry yield $P\simeq 0.95$ at $W$ = 2.5 GeV, meaning that natural-parity exchange dominates the reaction process. Our numerical results are in fair agreement with the experimental data and thus the use of our effective Reggeized model is justified over the considered kinematical ranges of $Q^2$, $W$, and $t$.

   hep-phhep-exnucl-exPRC(2020)·9 citations
4. 04*

   Account for axial vector mesons in the $\eta \to {\pi }^{+}{\pi }^{-}\gamma$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ decays

   A. A. Osipov🇷🇺 · A. A. Pivovarov🇷🇺 · M. K. Volkov🇷🇺 · M. M. Khalifa🇷🇺

   The rates and spectra of the anomalous $\eta \to {\pi }^{+}{\pi }^{-}\gamma$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ decays are calculated. The approach is based on the effective meson Lagrangian obtained in the Nambu-Jona-Lasinio model with vector and axial-vector mesons by integrating out quark fields. The resulting action is affected by mixing between members of pseudoscalar $J^{PC}=0^{-+}$ and axial-vector $1^{++}$ nonets that violates some low-energy theorems. In this note we point out that a gauge covariant procedure to diagonalize this mixing allows for consistent description of the $\eta \to {\pi }^{+}{\pi }^{-}\gamma$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ decays.

   hep-phPRD(2020)·5 citations
5. 05*

   Spin-dependent Pomeron and Odderon in elastic proton-proton scattering

   Yoshikazu Hagiwara🇨🇳 · Yoshitaka Hatta🇺🇸 · Roman Pasechnik🇸🇪 · Jian Zhou🇨🇳

   We introduce a new model of near-forward elastic proton-(anti)proton scattering at high energy based on the modern formulation of Pomeron and Odderon in terms of Wilson lines and generalized TMDs (GTMDs). We compute the helicity-dependent elastic amplitudes ${\varphi }_{1,2,3,4,5}$ in this model and study their energy dependence from the nonlinear small-$x$ evolution equations. While both Pomeron and Odderon contribute to helicity-flip processes in general, in the forward limit $t=0$ only the double helicity-flip amplitude ${\varphi }_2$, dominated by the spin-dependent Odderon, survives. This may affect the extraction of the $\rho$ parameter as well as the total cross section in the LHC energy domain and beyond.

   hep-phhep-exEPJC(2020)·29 citations
6. 06*

   Resonant Contributions to Three-body $B\to KKK$ Decays in Perturbative QCD Approach

   Zhi-Tian Zou🇨🇳 · Ying Li🇨🇳 · Qi-Xin Li🇨🇳 · Xin Liu🇨🇳

   In this work, we study the ($S$, $P$ and $D$)-wave $K^{+}{K}^{-}$ contributions to $B\to KKK$ decays in the perturbative QCD approach at leading order. Within the two-meson wave functions describing the nonperturbative dynamics in the kaon-pair for different waves, we calculate the branching fractions and the direct $CP$ asymmetries of these decay modes in the corresponding resonance regions. Most of our numerical results are well consistent with the current measurements. We note that the narrow-width approximation is invalid in the quasi-two-body decays $B\to K{f}_0(980)\to KKK$. For other decays, under the narrow-width approximation we can extract the branching fractions of the corresponding two-body decays involving the intermediate resonant states, and the related branching fractions agree with the current experimental data well. Furthermore, we also predict the corresponding quasi-two-body decays $B\to K{\pi }^{+}{\pi }^{-}$, which are expected to be measured in the ongoing LHCb and Belle-II experiments.

   hep-phhep-exEPJC(2020)·37 citations
7. 07*

   Single spin asymmetry $A_{UL}^{\sin ({\varphi }_h-{\varphi }_R)}$ in dihadron semi-inclusive DIS

   Xuan Luo🇨🇳 · Hao Sun🇨🇳 · Yi-Ling Xie🇨🇳

   In this paper we study the single longitudinal spin asymmetry $A_{UL}^{\sin ({\varphi }_h-{\varphi }_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) via helicity-dependent dihadron fragmentation function (DiFF), which describes the correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair. Recently experimental searching for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration yielded a very small signal. Here we calculate this unknown T-odd DiFF $G_1^{\perp }$ using a spectator model to access the asymmetry and clarify why the signal is very small. The transverse momentum dependent (TMD) factorization method, in which the transverse momentum of the final state hadron pair leaves unintegrated, has been applied. We estimate the $\sin ({\varphi }_h-{\varphi }_R)$ asymmetry at the kinematics of COMPASS experiments and compare with the data. What's more, the predictions on the same asymmetry are also made at the Electron Ion Collider (EIC).

   hep-phPRD(2020)·7 citations
8. 08*

   Semi-Inclusive Jet Functions and Jet Substructure in $J_{E_T}^{(I)}$ and $J_{E_T}^{(II)}$ Algorithms

   Lei Wang🇨🇳 · Zhong-Bo Kang🇺🇸 · Hongxi Xing🇨🇳 · Ben-Wei Zhang🇨🇳

   Within the framework of Soft Collinear Effective Theory, we present calculations of semi-inclusive jet functions and fragmenting jet functions at next-to-leading order (NLO) for both quark- and gluon-initiated jets, for jet algorithms of $J_{E_T}^{(I)}$ and $J_{E_T}^{(II)}$ where one maximizes a suitable jet function. We demonstrate the consistency of the obtained results with the standard perturbative QCD calculations for $J_{E_T}^{(I)}$ algorithm, while the results for fragmenting jet functions with the $J_{E_T}^{(II)}$ algorithm are new. The renormalization group (RG) equation for both semi-inclusive jet functions and fragmenting jet functions are derived and shown to follow the time-like DGLAP evolution equations, independent of specific jet algorithms. The RG equation can be used to resum single logarithms of the jet size parameter $\beta$ for highly collimated jets in these algorithms where $\beta \gg 1$.

   hep-phnucl-thPRD(2021)·3 citations
9. 09*

   On the $\rho$ and ${\sigma }_{tot}$ measurement by the TOTEM Collaboration: in the wake of recent discoveries

   V. V. Ezhela · V. A. Petrov · N. P. Tkachenko

   We show that extraction of the quantities} $\rho (s)=\text{mbox}Re[T_N(s,0)]/\text{mbox}Im[T_N(s,0)]$ {\it and} ${\sigma }_{\text{mbox}tot}(s)$ {\it from the data on the $pp$ differential cross-section at $\sqrt{s}=13$} TeV {\it obtained by the} TOTEM {\it Collaboration gives results essentially different from those presented in publication} \cite{Ant} {\it if to use a modified formula for Coulomb-nuclear interference. The physical interpretation of these data changes accordingly.

   hep-ph11 citations
10. 10*

    Classical spectral sum rules and "half-naked" electron effects in radiation from relativistic electrons in external field

    Xavier Artru🇫🇷

    Two properties of the radiation emitted by a relativistic electron in an external field, in the classical approximation, are presented in details: 1) spectral sum rules and their relationship with the sum rules for oscillator strength in atomic physics. Filtered sum rules can be used to remove infrared or ultraviolet divergences. 2) "half-naked electron" effects like the Landau- Pomeranchuk-Migdal and Ternovskij-Shul'ga-Fomin effects. These properties are best understood when introducing the apparent transverse velocity.

    hep-phJINST(2020)·1 citation
11. 11*

    The Coming Decade of $h\to \tau \mu$ and $\tau \to \mu \gamma$ Interplay in $\tau$ Flavor Violation Search

    Wei-Shu Hou🇹🇼 · Girish Kumar🇹🇼

    We explore the interplay between $h(125)\to \tau \mu$ search at the LHC and $\tau \to \mu \gamma$ at the up and coming Belle~II experiment, in context of the general two Higgs doublet model with extra Yukawa couplings such as ${\rho }_{\tau \mu }$. The search for $h\to \tau \mu$ constrains ${\rho }_{\tau \mu }\cos \gamma$, where $\cos \gamma$ is the $h$--$H$ mixing angle of $h$ with the exotic $CP$-even scalar $H$. For $\tau \to \mu \gamma$, we define the "BSM-benchmark" by setting the extra top Yukawa coupling ${\rho }_{tt}=1(\cong {\lambda }_t)$ in two-loop diagrams, and $\cos \gamma =0$ to decouple $h$. We show that this leading effect due to $H$ and $CP$-odd scalar $A$ can be readily probed by Belle~II, even for the conservative value of ${\rho }_{\tau \mu }=0.7{\lambda }_{\tau }$. We define the subleading "$h$-benchmark" by setting ${\rho }_{tt}=0$ in two-loop diagrams, and take the conservative maximal value of $\cos \gamma =0.2$. We show that it falls beyond Belle~II reach, but can interfere with the BSM-benchmark effect, which in principle probes the phase of ${\rho }_{tt}$. We further show that the one-loop $H$, $A$ effect, proportional to ${\rho }_{\tau \mu }{\rho }_{\tau \tau }$ in amplitude, is beyond the sensitivity of Belle~II to probe, even for ${\rho }_{\tau \tau }$ as large as $3{\lambda }_{\tau }$. With the working assumption that ${\rho }_{32}^f,{\rho }_{33}^f=\mathcal{O}({\lambda }_3^f)$ for all charged fermions $f$, we find good discovery potential for both $\tau$ lepton flavor violation searches in the coming decade.

    hep-phPRD(2020)·13 citations
12. 12*

    Enhancement near the $\bar{p}\Lambda$ threshold in the ${\chi }_{c0}\to \bar{p}{K}^{+}\Lambda$ reaction

    Guan-Ying Wang🇨🇳 · Man-Yu Duan🇨🇳 · En Wang🇨🇳 · De-Min Li🇨🇳

    We have analyzed the reaction ${\chi }_{c0}\to \bar{p}{K}^{+}\Lambda$ reported by the BESIII Collaboration, taking into account the contributions from the intermediate $K(1830)$, $N(2300)$, and $\Lambda (1520)$ resonances. Our results are in good agreement with the BESIII measurements, and it is found that the anomalous enhancement near the $\bar{p}\Lambda$ threshold is mainly due to the contribution of the $K(1830)$ resonance. We also show that the interference of the high-mass $N^{\ast }$ and ${\Lambda }^{\ast }$ can not produce the anomalous enhancement near the $\bar{p}\Lambda$ threshold.

    hep-phhep-exPRD(2020)·7 citations
13. 13*

    Triggering long-lived particles in HL-LHC and the challenges in the first stage of the trigger system

    Biplob Bhattacherjee🇮🇳 · Swagata Mukherjee🇩🇪 · Rhitaja Sengupta🇮🇳 · Prabhat Solanki🇮🇳

    Triggering long-lived particles at the first stage of the trigger system is very crucial in LLP searches to ensure that we do not miss them at the very beginning. The future High Luminosity runs of the Large Hardron Collider will have increased number of pile-up events per bunch crossing. There will be major upgrades in hardware, firmware and software sides, like tracking at level-1 (L1) as well as inclusion of the MIP timing detector. The L1 trigger menu will also be modified to cope with pile-up and maintain the sensitivity to physics processes. In our study we found that the usual level-1 triggers, mostly meant for triggering prompt particles, will not be very efficient for LLP searches in the 140 PU environment of HL-LHC, thus pointing to the need to include dedicated L1 triggers in the menu for LLPs. We consider the decay of the LLP into jets and develop dedicated jet triggers using the track information and if available, the regional timing information at L1 to select LLP events. We show in our work that these triggers give promising results in identifying LLP events with moderate trigger rates.

    hep-phhep-exJHEP(2020)·28 citations
14. 14*

    Lepton Flavor Violation at muon-electron colliders

    Fabio Bossi🇮🇹 · Paolo Ciafaloni🇮🇹

    Lepton Flavor Violating (LFV) processes are clear signals of physics beyond the Standard Model. We investigate the possibility of measuring this kind of processes at present and foreseeable future muon-electron colliders, taking into account present day bounds from existing experiments. As a model of new physics we consider a Z' boson with a $U^{\prime }(1)$ gauge symmetry and generic couplings. Processes that violate lepton flavor by two units seem to be particularly promising.

    hep-phhep-exJHEP(2020)·23 citations
15. 15*

    Rejecting the Majorana nature of dark matter with electron scattering experiments

    Riccardo Catena🇸🇪 · Timon Emken🇸🇪 · Julia Ravanis🇸🇪

    Assuming that Dark Matter (DM) is made of fermions in the sub-GeV mass range with interactions dominated by electromagnetic moments of higher order, such as the electric and magnetic dipoles or the anapole moment, we show that direct detection experiments searching for atomic ionisation events in xenon targets can shed light on whether DM is a Dirac or Majorana particle. Specifically, we find that between about 45 (120) and 610 (1700) signal events are required to reject Majorana DM in favour of Dirac DM with a statistical significance corresponding to 3 (5) standard deviations. The exact number of DM signal events corresponding to a given significance depends on the relative size of the anapole, magnetic dipole and electric dipole contributions to the expected rate of DM-induced atomic ionisations under the Dirac hypothesis. Our conclusions are based on Monte Carlo simulations and the likelihood ratio test. While the use of asymptotic formulae for the latter is standard in many applications, here it requires a non-trivial extension to the case where one of the hypotheses lies on the boundary of the parameter space. Our results constitute a solid proof of concept about the possibility of using direct detection experiments to reject the Majorana DM hypothesis when the DM interactions are dominated by higher-order electromagnetic moments.

    hep-phastro-ph.COJCAP(2020)·7 citations
16. 16*

    Consequences of the MSW mechanism with Super-Kamiokande oscillation parameters and of the volume distribution of neutrino sources in the Sun

    L.M.Slad🇷🇺

    The knowledge of the parameters of the solar neutrino oscillation model, provided by the SNO and Super-Kamiokande collaborations, enables us to obtain, with the Wolfenstein equation, a simple and clear analytical and numerical picture of the transformation of the neutrino state during its travel inside the Sun. We show that the resulting picture is not implicated in the characteristics of the neutrino state at the surface of the Sun and at the surface of the Earth. This circumstance with taking into account the volume distribution of solar neutrino sources indicates an obvious contradiction between the consequences of the MSW mechanism with parameters from SNO and Super-Kamiokande and the results of three of the five observed processes with solar neutrinos. Erroneous assertions at the base of the MSW mechanism are noted.

    hep-phastro-ph.SRhep-exEPL(2021)·5 citations
17. 17*

    Nuclear shadowing in DIS at electron-ion colliders

    Michal Krelina🇨🇱 · Jan Nemchik🇨🇿

    We present a revision of predictions for nuclear shadowing in deep-inelastic scattering at small Bjorken $x_{Bj}$ corresponding to kinematic regions accessible by the future experiments at electron-ion colliders. The nuclear shadowing is treated within the color dipole formalism based on the rigorous Green function technique. This allows incorporating naturally color transparency and coherence length effects, which are not consistently and properly included in present calculations. For the lowest $|q\bar{q}⟩$ Fock component of the photon, our calculations are based on an exact numerical solution of the evolution equation for the Green function. Here the magnitude of shadowing is tested using a realistic form for the nuclear density function, as well as various phenomenological models for the dipole cross section. The corresponding variation of the transverse size of the $q\bar{q}$ photon fluctuations is important for $x_{Bj}\gtrsim 10^{-4}$, on the contrary with the most of other models, which use frequently only the eikonal approximation with the "frozen" transverse size. At $x_{Bj}\lesssim 0.01$ we calculate within the same formalism also a shadowing correction for the higher Fock component of the photon containing gluons. The corresponding magnitudes of gluon shadowing correction are compared adopting different phenomenological dipole models. Our results are tested by available data from the E665 and NMC collaborations. Finally, the magnitude of nuclear shadowing is predicted for various kinematic regions that should be scanned by the future experiments at electron-ion colliders.

    hep-phnucl-thEur.Phys.J.Plus(2020)·15 citations
18. 18*

    Minimal dark matter models with radiative neutrino masses: From Lagrangians to observables

    Simon May (Westfälische Wilhelms-Universität Münster)🇩🇪

    In this master's thesis, the minimal dark matter models with radiative neutrino masses introduced in arXiv:1308.3655 are examined both in general and, using the model T1-3-B ($\alpha =0$) as a representative, in more detail. In the process, it is both shown how such models are built and a numerical analysis tool chain is established, automating as many steps as possible from the very beginning (deriving the Lagrangian from a given field content) to the very end (calculating observables such as the dark matter relic density, the direct detection cross section and the neutrino masses and mixing matrices). As an important result in laying out the mathematical groundwork, a convention for representations of SU(2) is established which, in this form, is not found in previous works. Another major result is the development of the program minimal-lagrangians, whose capabilities are described in the thesis. It is of great use both for the construction of Lagrangians for new models as well their verification or quick surveys. minimal-lagrangians can be applied to any model within the class it is designed to handle, extending its utility far beyond a one-time result that is only obtained for a single model. Finally, the first steps in the analysis of the model T1-3-B ($\alpha =0$) are taken. It is shown that the model can reproduce both the singlet-doublet fermion dark matter model and the inert triplet model in the appropriate limits. Moreover, the neutrino mass matrix is found and it is demonstrated that the model can accommodate current constraints on the neutrino masses. Lastly, the behavior of the dark matter relic density as it depends on the parameter responsible for the generation of neutrino masses is investigated. Further in-depth study of the model T1-3-B ($\alpha =0$) was performed in a separate publication (arXiv:1812.11133).

    hep-phastro-ph.CO2 citations
19. 19*

    $DDA$, $D^{\ast }{D}^{\ast }A$ and $D^{\ast }DA$ vertices in the light-cone QCD and considering $B^0\to K_1^{+}{\pi }^{-}$ branching ratio

    S. Momeni🇮🇷 · R. Khosravi🇮🇷

    We investigate the strong coupling constants of $DDA$, $D^{\ast }{D}^{\ast }A$ and $D^{\ast }DA$ vertices in the framework of the light-cone QCD sum rules, where $A$ is an axial vector meson such as $a_1,b_1,K_{1A},K_{1B},K_1(1270)$ and $K_1(1400)$. Using the strong coupling constants of $D_{s}D{K}_1$, $D_s^{\ast }D{K}_1$ and $D_s^{\ast }{D}^{\ast }{K}_1$ vertices for $K_1(1270)$ and $K_1(1400)$ mesons, we evaluated the branching ratios of the non-leptonic decays $B^0\to K_1^{+}(1270,1400){\pi }^{-}$. Our results for the branching ratios of these decays are a good agreement with the experimental values.

    hep-ph4 citations
20. 20*

    Two-Higgs-Doublet Model with Soft CP-violation Confronting Electric Dipole Moments and Colliders

    Kingman Cheung🇹🇼 · Adil Jueid🇰🇷 · Ying-nan Mao🇹🇼 · Stefano Moretti🇬🇧

    We analyze CP-violating effects in both Electric Dipole Moment (EDM) measurements and future analyses at the Large Hadron Collider (LHC) assuming a Two-Higgs-Doublet Model (2HDM) with "soft" CP-violation. Our analysis of EDMs and current LHC constraints shows that, in the case of a 2HDM Type II and Type III, an $\mathcal{O}(0.1)$ CP-violating phase in the Yukawa interaction between $H_1$ (the $125\text{GeV}$ Higgs boson) and fermions is still allowed. For these scenarios, we study CP-violating effects in the neutron EDM and $t\bar{t}{H}_1$ production at the LHC. Our analysis shows that such an $\mathcal{O}(0.1)$ CP-violating phase can be easily confirmed or excluded by future neutron EDM tests, with LHC data providing a complementary cross-check.

    hep-phPRD(2020)·52 citations
21. 21*

    A Return To Neutrino Normalcy

    Peter B. Denton🇺🇸

    Understanding the structure of the fermion mixing matrices is an important question in particle physics. The quark mixing matrix is approximately diagonal while the lepton mixing matrix has large off-diagonal elements. Attempting to understand these structures has been the focus of an large body of literature over the last several decades. In this article we propose a new set of conditions to test the structure of mass matrices called normalcy based on how close to diagonal the mixing matrix is. The mass ordering and the octant of ${\theta }_{23}$ represent two of these conditions. We point out that the quark matrix easily satisfies all six normalcy conditions while none of them are known to be fully satisfied for leptons at high significance. All of the conditions that can be tested for leptons suggest that the matrix could satisfy the normalcy conditions and upcoming experiments such as DUNE and T2HK will most likely determine if the lepton mass matrix satisfies all of them or not.

    hep-phhep-ex16 citations
22. 22*

    Higgs Production at NNLL${}^{\prime }$+NNLO using Rapidity Dependent Jet Vetoes

    Shireen Gangal🇮🇳 · Jonathan R. Gaunt🇨🇭 · Frank J. Tackmann🇩🇪 · Eleni Vryonidou🇳🇱

    The rapidity-dependent jet veto observables ${\mathcal{T}}_{Bj}$ and ${\mathcal{T}}_{Cj}$ provide a tight jet veto at central rapidity, gradually transitioning to a loose veto at forward rapidities. They divide the phase space into exclusive jet bins in a different way to the traditional jet veto observable $p_{Tj}$, and are advantageous to use under harsh pile-up conditions. We obtain predictions for the $0$-jet gluon-fusion (ggF) Higgs cross section using both of these veto observables at NNLL${}^{\prime }+$NNLO, and compare these predictions to the prior state-of-the-art of NLL${}^{\prime }+$NLO. A significant reduction in perturbative uncertainty is observed going from NLL${}^{\prime }+$NLO to NNLL${}^{\prime }+$NNLO, with the NNLL${}^{\prime }+$NNLO predictions lying inside the uncertainty band of the NLL${}^{\prime }+$NLO predictions. We also investigate the relative sensitivities of ggF Higgs cross sections with ${\mathcal{T}}_{Bj}$, ${\mathcal{T}}_{Cj}$ and $p_{Tj}$ jet vetoes to underlying event and hadronisation effects using an NLO+parton shower calculation. We find that the cross sections with ${\mathcal{T}}_{Bj}$ and ${\mathcal{T}}_{Cj}$ vetoes have a reduced sensitivity to underlying event and hadronisation effects compared to that with a $p_{Tj}$ veto.

    hep-phJHEP(2020)·9 citations
23. 23*

    Hadronic weak decays of the charmed baryon ${\Omega }_c$

    Shiyong Hu🇨🇳 · Guanbao Meng🇨🇳 · Fanrong Xu🇨🇳

    Two-body hadronic weak decays of the charmed baryon ${\Omega }_c$, including Cabibbo-favored (CF), singly Cabibbo-suppressed (SCS) and doubly Cabibbo-suppressed (DCS) modes, are studied systematically in this work. To estimate nonfactorizable contributions, we work in the pole model for the $P$-wave amplitudes and current algebra for the $S$-wave amplitudes. Among all the channels decaying into a baryon octet and a pseudoscalar meson, ${\Omega }_c\to {\Xi }^0{\overline{K}}^0$ is the only allowed CF mode. The predicted branching fraction of order $3.8\%$ and large and positive decay asymmetry of order $0.50$ indicate that a measurement of this mode in the near future is promising. Proceeding through purely nonfactorizable contributions, the SCS mode ${\Omega }_c\to {\Lambda }^0{\overline{K}}^0$ and DCS mode ${\Omega }_c\to {\Lambda }^0\eta$ are predicted to have branching fractions as large as $0.8\%$ and $0.4\%$, respectively. The two DCS modes ${\Omega }_c\to {\Sigma }^0\eta$ and ${\Omega }_c\to {\Lambda }^0{\pi }^0$ are suggested to serve as new physics searching channels for their vanishing SM background.

    hep-phhep-exPRD(2020)·28 citations
24. 24*

    Loop Fayet-Iliopoulos terms in $T^2/Z_2$ models: instability and moduli stabilization

    Hiroyuki Abe🇯🇵 · Tatsuo Kobayashi🇯🇵 · Shohei Uemura🇯🇵 · Junji Yamamoto🇯🇵

    We study Fayet-Iliopoulos (FI) terms of six-dimensional supersymmetric Abelian gauge theory compactified on a $T^2/Z_2$ orbifold. Such orbifold compactifications can lead to localized FI-terms and instability of bulk zero modes. We study 1-loop correction to FI-terms in more general geometry than the previous works. We find induced FI-terms depend on the complex structure of the compact space. We also find the complex structure of the torus can be stabilized at a specific value corresponding to a self-consistent supersymmetric minimum of the potential by such 1-loop corrections, which is applicable to the modulus stabilization.

    ↳ hep-thhep-phPRD(2020)·43 citations
25. 25*

    N=4 SYM Quantum Spectral Curve in BFKL regime

    Mikhail Alfimov🇷🇺 · Nikolay Gromov🇬🇧 · Vladimir Kazakov🇫🇷

    We review the applications of the Quantum Spectral Curve (QSC) method to the Regge (BFKL) limit in N=4 supersymmetric Yang-Mills theory. QSC, based on quantum integrability of the AdS${}_5$/CFT${}_4$ duality, was initially developed as a tool for the study of the spectrum of anomalous dimensions of local operators in the N=4 SYM in the planar, $N_c\to \infty$ limit. We explain how to apply the QSC for the BFKL limit, which requires non-trivial analytic continuation in spin $S$ and extends the initial construction to non-local light-ray operators. We give a brief review of high precision non-perturbative numerical solutions and analytic perturbative data resulting from this approach. We also describe as a simple example of the QSC construction the leading order in the BFKL limit. We show that the QSC substantially simplifies in this limit and reduces to the Faddeev-Korchemsky Baxter equation for Q-functions. Finally, we review recent results for the Fishnet CFT, which carries a number of similarities with the Lipatov's integrable spin chain for interacting reggeized gluons.

    ↳ hep-thhep-ph20 citations
26. 26*

    Reconciling Hubble Constant Discrepancy from Holographic Dark Energy

    Wei-Ming Dai🇿🇦 · Yin-Zhe Ma🇿🇦 · Hong-Jian He🇨🇳

    Holographic dark energy (HDE) describes the vacuum energy in a cosmic IR region whose total energy saturates the limit of avoiding the collapse into a black hole. HDE predicts that the dark energy equation of the state transiting from greater than the $-1$ regime to less than $-1$, accelerating the Universe slower at the early stage and faster at the late stage. We propose the HDE as a new {\it physical} resolution to the Hubble constant discrepancy between the cosmic microwave background (CMB) and local measurements. With Planck CMB and galaxy baryon acoustic oscillation (BAO) data, we fit the HDE prediction of the Hubble constant as $H_0^{}=71.54\pm 1.78\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$, consistent with local $H_0^{}$ measurements by LMC Cepheid Standards (R19) at $1.4\sigma$ level. Combining Planck+BAO+R19, we find the HDE parameter $c=0.51\pm 0.02$ and $H_0^{}=73.12\pm 1.14\mathrm{km}{\mathrm{s}}^{-1}\mathrm{Mp}{\mathrm{c}}^{-1}$, which fits cosmological data at all redshifts. Future CMB and large-scale structure surveys will further test the holographic scenario.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·54 citations
27. 27*

    Polarization and Vorticity in the Quark Gluon Plasma

    Francesco Becattini🇮🇹 · Michael Lisa🇺🇸

    The quark-gluon plasma produced by collisions between ultra-relativistic heavy nuclei is well described in the language of hydrodynamics. Non-central collisions are characterized by very large angular momentum, which in a fluid system manifests as flow vorticity. This rotational structure can lead to a spin polarization of the hadrons that eventually emerge from the plasma, providing experimental access to flow substructure at unprecedented detail. Recently, first observations of $\Lambda$ hyperon polarization along the direction of collisional angular momentum have been reported. These measurements are in broad agreement with hydrodynamic and transport-based calculations and reveal that the QGP is the most vortical fluid ever observed. However, there remain important tensions between theory and observation which might be fundamental in nature. In the relatively mature field of heavy ion physics, the discovery of global hyperon polarization and three-dimensional simulations of the collision have opened an entirely new direction of research. We discuss the current status of this rapidly developing area and directions for future research.

    ↳ nucl-exhep-phnucl-thAnn.Rev.Nucl.Part.Sci.(2020)·292 citations
28. 28*

    Dirac-Born-Infeld realization of sound speed resonance mechanism for primordial black holes

    Chao Chen🇨🇳 · Xiao-Han Ma🇨🇳 · Yi-Fu Cai🇨🇳

    We present a concrete realization of the sound speed resonance (SSR) mechanism for primordial black hole (PBH) formation within a specific model of Dirac-Born-Infeld (DBI) inflation. We perform a perturbative approach to phenomenologically construct such a viable DBI inflation model that involves the nonoscillating stage and the oscillating stage, with a type of specific forms of the warp factor and the potential. We show that the continuous but nonsmooth conjunction of sound speed between two stages does not yield manifest effects on the phenomenology of SSR, and thus, our model gives rise to the same PBH mass spectrum as the original predictions of SSR. Additionally, we also demonstrate that the violation of adiabaticity of the Mukhanov-Sasaki equation does not affect the comoving curvature perturbation after Hubble crossing in the nonresonant region. Making use of observational data, we derive various cosmological constraints on the parameter space. Our analyses show that the predicted tensor-to-scalar ratio is typically small, while the amplitude of primordial non-Gaussianity can meet with cosmic microwave background bounds, and additionally, the consistency relation for single-field slow-roll inflation is softly violated in our case due to the small sound speed variations.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·71 citations
29. 29*

    Atomic physics studies at the Gamma Factory at CERN

    Dmitry Budker🇩🇪 · José R. Crespo López-Urrutia🇩🇪 · Andrei Derevianko🇺🇸 · Victor V. Flambaum🇦🇺 · Mieczyslaw Witold Krasny🇫🇷 · Alexey Petrenko🇷🇺 · Szymon Pustelny🇵🇱 · Andrey Surzhykov🇩🇪 · Vladimir A. Yerokhin🇷🇺 · Max Zolotorev🇺🇸

    The Gamma Factory initiative proposes to develop novel research tools at CERN by producing, accelerating and storing highly relativistic, partially stripped ion beams in the SPS and LHC storage rings. By exciting the electronic degrees of freedom of the stored ions with lasers, high-energy narrow-band photon beams will be produced by properly collimating the secondary radiation that is peaked in the direction of ions' propagation. Their intensities, up to $10^{17}$ photons per second, will be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting $\gamma$--ray energy domain reaching up to 400 MeV. This article reviews opportunities that may be afforded by utilizing the primary beams for spectroscopy of partially stripped ions circulating in the storage ring, as well as the atomic-physics opportunities afforded by the use of the secondary high-energy photon beams. The Gamma Factory will enable ground breaking experiments in spectroscopy and novel ways of testing fundamental symmetries of nature.

    ↳ physics.atom-phhep-exhep-phphysics.acc-phAnnalen Phys.(2020)·42 citations
30. 30*

    HEPLike: an open source framework for experimental likelihood evaluation

    Jihyun Bhom🇵🇱 · Marcin Chrzaszcz🇵🇱

    We present a computer framework to store and evaluate likelihoods coming from High Energy Physics experiments. Due to its flexibility it can be interfaced with existing fitting codes and allows to uniform the interpretation of the experimental results among users. The code is provided with large open database, which contains the experimental measurements. The code is of use for users who perform phenomenological studies, global fits or experimental averages.

    ↳ physics.data-anhep-phComput.Phys.Commun.(2020)·10 citations
31. 31*

    Prospects for Pre-supernova Neutrino Observation in Future Large Liquid-scintillator Detectors

    Hui-Ling Li🇨🇳 · Yu-Feng Li🇨🇳 · Liang-Jian Wen🇨🇳 · Shun Zhou🇨🇳

    Before massive stars heavier than $(8\cdots 10)$ solar masses evolve to the phase of a gravitational core collapse, they will emit a huge number of MeV-energy neutrinos that are mainly produced in the thermal processes and nuclear weak interactions. The detection of such pre-supernova (pre-SN) neutrinos could provide an important and independent early warning for the optical observations of core-collapse SNe. In this paper, we investigate the prospects of future large liquid-scintillator detectors for the observation of pre-SN neutrinos in both ${\bar{\nu }}_e^{}+p\to e^{+}+n$ and $\nu (\bar{\nu })+e^{-}\to \nu (\bar{\nu })+e^{-}$ reaction channels, where $\nu$ ($\bar{\nu }$) denotes neutrinos (antineutrinos) of all three flavors. We propose a quantitative assessment of the capability in terms of three working criteria, namely, how far the SN distance can be covered, how long the early warning before the core collapse can be sent out, and how well the direction pointing to the SN can be determined. The dependence of the final results on the different models of progenitor stars, neutrino flavor conversions and the relevant backgrounds is also discussed.

    ↳ astro-ph.HEhep-exhep-phJCAP(2020)·20 citations
32. 32*

    Effective field theory for triaxially deformed odd-mass nuclei

    Q. B. Chen🇩🇪 · N. Kaiser🇩🇪 · Ulf-G. Meißner🇩🇪 · J. Meng🇨🇳

    The effective field theory for collective rotations of triaxially deformed nuclei is generalized to odd-mass nuclei by including the angular momentum of the valence nucleon as an additional degree of freedom. The Hamiltonian is constructed up to next-to-leading order within the effective field theory formalism. The applicability of this Hamiltonian is examined by describing the wobbling bands observed in the lutetium isotopes ${}^{161,163,165,167}$Lu. It is found that by taking into account the next-to-leading order corrections, quartic in the rotor angular momentum, the wobbling energies $E_{\text{wob}}$ and spin-rotational frequency relations $\omega (I)$ are better described than with the leading order Hamiltonian.

    ↳ nucl-thhep-phnucl-ex7 citations
33. 33*

    Modular Flavor Symmetry on Magnetized Torus

    Hiroshi Ohki🇯🇵 · Shohei Uemura🇯🇵 · Risa Watanabe🇯🇵

    We study the modular invariance in magnetized torus models. Modular invariant flavor model is a recently proposed hypothesis for solving the flavor puzzle, where the flavor symmetry originates from modular invariance. In this framework coupling constants such as Yukawa couplings are also transformed under the flavor symmetry. We show that the low-energy effective theory of magnetized torus models is invariant under a specific subgroup of the modular group. Since Yukawa couplings as well as chiral zero modes transform under the modular group, the above modular subgroup (referred to as modular flavor symmetry) provides a new type of modular invariant flavor models with $D_4\times {\mathbb{Z}}_2$, $({\mathbb{Z}}_4\times {\mathbb{Z}}_2)⋊{\mathbb{Z}}_2$, and $({\mathbb{Z}}_8\times {\mathbb{Z}}_2)⋊{\mathbb{Z}}_2$. We also find that conventional discrete flavor symmetries which arise in magnetized torus model are non-commutative with the modular flavor symmetry. Combining both two symmetries we obtain a larger flavor symmetry, where the conventional flavor symmetry is a normal subgroup of the whole group.

    ↳ hep-thhep-phPRD(2020)·107 citations
34. 34*

    Consistency of hadronic vacuum polarization between lattice QCD and the R-ratio

    Christoph Lehner🇩🇪 · Aaron S. Meyer🇺🇸

    There are emerging tensions for theory results of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment both within recent lattice QCD calculations and between some lattice QCD calculations and R-ratio results. In this paper we work towards scrutinizing critical aspects of these calculations. We focus in particular on a precise calculation of Euclidean position-space windows defined by RBC/UKQCD that are ideal quantities for cross-checks within the lattice community and with R-ratio results. We perform a lattice QCD calculation using physical up, down, strange, and charm sea quark gauge ensembles generated in the staggered formalism by the MILC collaboration. We study the continuum limit using inverse lattice spacings from $a^{-1}\approx 1.6$ GeV to $3.5$ GeV, identical to recent studies by FNAL/HPQCD/MILC and Aubin et al. and similar to the recent study of BMW. Our calculation exhibits a tension for the particularly interesting window result of $a_{\mu }^{\mathrm{ud},conn.,\mathrm{isospin},\mathrm{W}}$ from $0.4$ fm to $1.0$ fm with previous results obtained with a different discretization of the vector current on the same gauge configurations. Our results may indicate a difficulty related to estimating uncertainties of the continuum extrapolation that deserves further attention. In this work we also provide results for $a_{\mu }^{\mathrm{ud},conn.,\mathrm{isospin}}$, $a_{\mu }^{\mathrm{s},conn.,\mathrm{isospin}}$, $a_{\mu }^{\mathrm{SIB},conn.}$ for the total contribution and a large set of windows. For the total contribution, we find $a_{\mu }^{\mathrm{HVP}\mathrm{LO}}=714(27)(13)10^{-10}$, $a_{\mu }^{\mathrm{ud},conn.,\mathrm{isospin}}=657(26)(12)10^{-10}$, $a_{\mu }^{\mathrm{s},conn.,\mathrm{isospin}}=52.83(22)(65)10^{-10}$, and $a_{\mu }^{\mathrm{SIB},conn.}=9.0(0.8)(1.2)10^{-10}$, where the first uncertainty is statistical and the second systematic. We also comment on finite-volume corrections for the strong-isospin-breaking corrections.

    ↳ hep-lathep-phPRD(2020)·189 citations
35. 35*

    The Hopf algebra structure of the $R^{\ast }$-operation

    Robert Beekveldt🇳🇱 · Michael Borinsky🇳🇱 · Franz Herzog🇳🇱

    We give a Hopf-algebraic formulation of the $R^{\ast }$-operation, which is a canonical way to render UV and IR divergent Euclidean Feynman diagrams finite. Our analysis uncovers a close connection to Brown's Hopf algebra of motic graphs. Using this connection we are able to provide a verbose proof of the long observed 'commutativity' of UV and IR subtractions. We also give a new duality between UV and IR counterterms, which, entirely algebraic in nature, is formulated as an inverse relation on the group of characters of the Hopf algebra of log-divergent scaleless Feynman graphs. Many explicit examples of calculations with applications to infrared rearrangement are given.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2020)·24 citations
36. 36*

    Entropy production far from equilibrium in a chiral charged plasma in the presence of external electromagnetic fields

    Casey Cartwright🇺🇸

    We report on the time evolution of a charged strongly coupled $N=4$ SYM plasma with an axial anomaly subjected to strong electromagnetic fields. The evolution of this plasma corresponds to a fully backreacted asymptotically AdS${}_5$ solution to the Einstein-Maxwell-Chern-Simons theory. We explore the evolution of the axial current and production of axial charges. As an application we show that after a sufficiently long time both the entropy and the holographic entanglement entropy of a strip-like topology ( both parallel to and transverse to the flow of axial current) grow linearly in time.

    ↳ hep-thhep-phnucl-thJHEP(2021)·16 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.