Wed·Apr 24, 2019Wednesday·April 24, 2019

1. 01*

   FIMP dark matter candidate(s) in a $B-L$ model with inverse seesaw mechanism

   Waleed Abdallah🇮🇳 · Sandhya Choubey🇮🇳 · Sarif Khan🇮🇳

   The non-thermal dark matter (DM) production via the so-called freeze-in mechanism provides a simple alternative to the standard thermal WIMP scenario. In this work, we consider a popular $U(1{)}_{B-L}$ extension of the standard model (SM) in the context of inverse seesaw mechanism which has at least one (fermionic) FIMP DM candidate. Due to the added ${\mathbb{Z}}_2$ symmetry, a SM gauge singlet fermion, with mass of order keV, is stable and can be a warm DM candidate. Also, the same ${\mathbb{Z}}_2$ symmetry helps the lightest right-handed neutrino, with mass of order GeV, to be a stable or long-lived particle by making a corresponding Yukawa coupling very small. This provides a possibility of a two component DM scenario as well. Firstly, in the absence of a GeV DM component (i.e., without tuning its corresponding Yukawa coupling to be very small), we consider only a keV DM as a single component DM, which is produced by the freeze-in mechanism via the decay of the extra $Z^{\prime }$ gauge boson associated to $U(1{)}_{B-L}$ and can consistently explain the DM relic density measurements. In contrast with most of the existing literature, we have found a reasonable DM production from the annihilation processes. After numerically studying the DM production, we show the dependence of the DM relic density as a function of its relevant free parameters. We use these results to obtain the parameter space regions that are compatible with the DM relic density bound. Secondly, we study a two component DM scenario and emphasize that the current DM relic density bound can be satisfied for a wide range of parameter space.

   hep-phastro-ph.COJHEP(2019)·16 citations
2. 02*

   Interpretation of the LHCb Pc(4312) Signal

   JPAC Collaboration: C. Fernandez-Ramirez🇲🇽 · A. Pilloni🇮🇹 · M. Albaladejo🇺🇸 · A. Jackura🇺🇸 · V. Mathieu🇺🇸 · M. Mikhasenko🇨🇭 · J.A. Silva-Castro🇲🇽 · A.P. Szczepaniak🇺🇸

   We study the nature of the new signal reported by LHCb in the J/psi p spectrum. Based on the S-matrix principles, we perform a minimum-bias analysis of the underlying reaction amplitude, focusing on the analytic properties that can be related to the microscopic origin of the Pc(4312) peak. By exploring several amplitude parametrizations, we find evidence for the attractive effect of the Sigma_c+ D0bar channel, which is not strong enough, however, to form a bound state.

   hep-phhep-exPRL(2019)·117 citations
3. 03*

   Proton-proton forward scattering at the LHC

   M. Broilo🇧🇷 · D. A. Fagundes🇧🇷 · E. G. S. Luna🇧🇷 · M. J. Menon🇧🇷

   Recently the TOTEM experiment at the LHC has released measurements at $\sqrt{s}=13$ TeV of the proton-proton total cross section, ${\sigma }_{tot}$, and the ratio of the real to imaginary parts of the forward elastic amplitude, $\rho$. Since then an intense debate on the $C$-parity asymptotic nature of the scattering amplitude was initiated. We examine the proton-proton and the antiproton-proton forward data above 10 GeV in the context of an eikonal QCD-based model, where nonperturbative effects are readily included via a QCD effective charge. We show that, despite an overall satisfactory description of the forward data is obtained by a model in which the scattering amplitude is dominated by only crossing-even elastic terms, there is evidence that the introduction of a crossing-odd term may improve the agreement with the measurements of $\rho$ at $\sqrt{s}=13$ TeV. In the Regge language the dominant even(odd)-under-crossing object is the so called Pomeron (Odderon).

   hep-phhep-exnucl-thPLB(2019)·12 citations
4. 04*

   $t{Z}^{\prime }$ production at hadron colliders

   Marco Guzzi🇺🇸 · Nikolaos Kidonakis🇺🇸

   We study the production of a single top quark in association with a heavy extra $Z^{\prime }$ at hadron colliders in new physics models with and without flavor-changing neutral-current (FCNC) couplings. We use QCD soft-gluon resummation and threshold expansions to calculate higher-order corrections for the total cross section and transverse-momentum distributions for $t{Z}^{\prime }$ production. The impact of the uncertainties due to the structure of the proton and scale dependence is also analyzed.

   hep-phEPJC(2020)·11 citations
5. 05*

   A radiatively generated source of flavor universal scalar soft masses

   Sabyasachi Chakraborty🇺🇸 · Tuhin S. Roy🇮🇳

   We report that models of electroweak supersymmetry with gaugino mass unification and sequestered scalar masses can still produce viable spectra, as long as we include a set of non-standard supersymmetry breaking terms, which are trilinear in scalars like the A-terms, but are non-holomorphic in visible sector fields unlike the A- terms. These terms impart a subtle feature to one loop renormalisation group equations of soft supersymmetry breaking terms, indirectly sourcing flavor universal contributions to all scalar masses. These new contributions can even dominate over radiative corrections form bino, and help raise right handed sleptons above bino, while leaving a tell-tale signature in the spectrum.

   hep-phPRD(2019)·9 citations
6. 06*

   Minimal Vectorlike Model in Supersymmetric Unification

   Sibo Zheng🇨🇳

   Compared to the minimal supersymmetric standard model, an extension by vectorlike fermions is able to explain the Higgs mass while retains the grand unification. We investigate the minimal vectorlike model by focusing on the vectorlike electroweak sector. We firstly derive the mass spectrum in the electroweak sector, then calculate the one-loop effects on the Higgs physics, and finally explore either vectorlike or neutralino dark matter. Collider constraints are briefly discussed.

   hep-phhep-exEPJC(2020)·23 citations
7. 07*

   Gauge-Higgs unification at $e^{+}{e}^{-}$ linear colliders

   Yutaka Hosotani🇯🇵

   In gauge-Higgs unification the 4D Higgs boson appears as a part of the fifth dimensional component of gauge potentials, namely as a fluctuation mode of the Aharonov-Bohm phase in the extra dimension. The $SO(5)\times U(1)\times SU(3)$ gauge-Higgs unification gives nearly the same phenomenology as the standard model (SM) at low energies. It predicts KK excited states of photon, $Z$ boson, and $Z_R$ boson ($Z^{\prime }$ bosons) around 7 - 8 TeV. Quarks and leptons couple to these $Z^{\prime }$ bosons with large parity violation, which leads to distinct interference effects in $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-},q\bar{q}$ processes. At 250 GeV ILC with polarized electron beams, deviation from SM can be seen at the 3 - 5 sigma level even with 250 fb${}^{-1}$ data, namely in the early stage of ILC. Signals become stronger at higher energies. Precision measurements of interference effects at electron-positron colliders at energies above 250 GeV become very important to explore physics beyond the standard model.

   hep-phhep-thPoS(2019)·5 citations
8. 08*

   Triply-heavy baryons in a constituent quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Pablo G. Ortega🇪🇸 · Jorge Segovia🇪🇸

   A constituent quark model, which has recently been successfully applied to the study of heavy quarkonium properties such as its spectrum but also a diverse array of observables related with their electromagnetic, strong and weak decays and reactions, is used herein to compute ground- and excited-state masses of $QQQ$-baryons containing either $c$- or $b$-quarks. Considering the lack of experimental information about the spectra of triply-heavy baryons, we believe that our computation could help on finding new states, since it is expected that phenomenological quark models describe triply-heavy baryons to a similar degree of accuracy as heavy quarkonia. The quark model parameters previously used to describe $c\bar{c}$ and $b\bar{b}$ properties have not been modified for this analysis. The non-relativistic three-body bound-state problem is solved by means of the Gaußian expansion method which provides enough accuracy and simplifies the subsequent evaluation of the matrix elements. Several low-lying states with quantum numbers $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$, ${\frac{5}{2}}^{\pm }$ and ${\frac{7}{2}}^{+}$ are reported. We compare our results with those predicted by many other theoretical formalisms. There is a general trend of agreement about the mass of the ground state in each sector of triply-heavy baryons; however, the situation is more puzzling for the excited states and thus appropriate comments on the most relevant features of our comparison are given.

   hep-phhep-exhep-latnucl-ex+1CPC(2020)·77 citations
9. 09*

   Consequences of $\mu$-$\tau$ reflection symmetry for $3+1$ neutrino mixing

   Kaustav Chakraborty🇮🇳 · Srubabati Goswami🇮🇳 · Biswajit Karmakar🇮🇳

   We investigate the consequences of $\mu -\tau$ reflection symmetry in presence of a light sterile neutrino for the $3+1$ neutrino mixing scheme. We discuss the implications of total $\mu -\tau$ reflection symmetry as well partial $\mu -\tau$ reflection symmetry. For the total $\mu -\tau$ reflection symmetry we find values of ${\theta }_{23}$ and $\delta$ remains confined near $\pi /4$ and $\pm \pi /2$ respectively. The current allowed region for ${\theta }_{23}$ and $\delta$ in case of inverted hierarchy lies outside the area preferred by the total $\mu -\tau$ reflection symmetry. However, interesting predictions on the neutrino mixing angles and Dirac CP violating phases are obtained considering partial $\mu -\tau$ reflection symmetry. We obtain predictive correlations between the neutrino mixing angle ${\theta }_{23}$ and Dirac CP phase $\delta$ and study the testability of these correlations at the future long baseline experiment DUNE. We find that while the imposition of $\mu -\tau$ reflection symmetry in the first column admit both normal and inverted neutrino mass hierarchy, demanding $\mu -\tau$ reflection symmetry for the second column excludes the inverted hierarchy. Interestingly, the sterile mixing angle ${\theta }_{34}$ gets tightly constrained considering the $\mu -\tau$ reflection symmetry in the fourth column. We also study consequences of $\mu -\tau$ reflection symmetry for the Majorana phases and neutrinoless double beta decay.

   hep-phhep-exPRD(2019)·11 citations
10. 10*

    Prompt $J/\psi$ production in associated with top quark pair at the LHC

    Gang Li🇨🇳 · Xue-An Pan🇨🇳 · Mao Song🇨🇳 · Yu Zhang🇨🇳

    In this work, we investigate the prompt $J/\psi$ production in associated with top quark pair to leading order in the nonrelativistic QCD factorization formalism at the LHC with $\sqrt{s}=13$ TeV. In addition to the contribution from direct $J/\psi$ production, we also include the indirect contribution from the directly produced heavier charmmonia ${\chi }_{cJ}$ and ${\psi }^{\prime }$. We present the numerical results for the total and differential cross sections and find that the $\text{sideset}{}^3{}_1^{(8)}S$ states give the dominant contributions. The prompt $t\bar{t}J/\psi$ signatures at the LHC are analyzed in the tetralepton channel $pp\to (t\to W^{+}({\ell }^{+}\nu )b)(\bar{t}\to W^{-}({\ell }^{-}\bar{\nu })\bar{b})(J/\psi \to {\mu }^{+}{\mu }^{-})$ and trilepton channel $pp\to (t\to W(q{q}^{\prime })b)(t\to W(\ell \nu )b)(J/\psi \to {\mu }^{+}{\mu }^{-})$, with the $J/\psi$ mesons decaying into muon pair, and the top quarks decaying leptonically or hadronically. We find that $t\bar{t}J/\psi$ proudction can be potentially detected at the LHC, whose measurement is useful to test the heavy quarkonium production mechanism.

    hep-phhep-exPRD(2019)·2 citations
11. 11*

    Scalar dark matter in the conformally invariant extension of the standard model

    Dong-Won Jung🇰🇷 · Jungil Lee🇰🇷 · Soo-hyeon Nam🇰🇷

    We study a classically scale-invariant model with an electroweak singlet scalar mediator together with a scalar dark matter multiplet of global $O(N)$ symmetry. Our most general conformally invariant scalar potential generates the electroweak symmetry breaking via the Coleman-Weinberg mechanism, and the new scalar singlet acquires its mass through radiative corrections of the SM particles and the scalar dark matter. Taking into account the collider bounds, we present the allowed region of new physics parameters satisfying the recent measurement of relic abundance. With the obtained parameter sets, we predict the elastic scattering cross section of the new scalar multiplet into target nuclei for a direct detection of the dark matter. We also perform a full analysis with arbitrary set of parameters for $N\ge 2$, and discuss the implication of the constraints from the on-going direct and indirect detections of dark matter.

    hep-phPLB(2019)·20 citations
12. 12*

    Matter density profile effects on neutrino oscillations at T2HK and T2HKK

    Susana Molina Sedgwick🇬🇧 · Stephen F. King🇬🇧 · Stephen J. Parke🇺🇸 · Nicholas W. Prouse🇨🇦

    This project aims to explore the effects that changes in a matter density profile could have on neutrino oscillations, and whether these could potentially be seen by the future Hyper-Kamiokande experiment (T2HK). The analysis is extended to include the possibility of having a second detector in Korea (T2HKK).

    hep-phhep-ex0 citations
13. 13*

    Analyzing doubly heavy tetra- and penta-quark states by variational method

    Ruilin Zhu🇨🇳 · Xuejie Liu🇨🇳 · Hongxia Huang🇨🇳 · Cong-Feng Qiao🇨🇳

    Motivated by the very recent observations of hidden charm pentaquarks $P_c(4312{)}^{+}$, $P_c(4440{)}^{+}$ and $P_c(4457{)}^{+}$ of the LHCb Collaboration, we systematically study the spectra of the doubly-heavy (with or without charm/bottom numbers) pentaquarks and tetraquarks in non-relativistic constituent quark model. The model independent variational method is employed to solve the Schrödinger equation, where the test functions adopted are symmetric for the light quarks. In our study, the $P_c(4312{)}^{+}$ may be assigned as the ground state with spin-parity ${\frac{1}{2}}^{-}$ or ${\frac{3}{2}}^{-}$, while the $P_c(4440{)}^{+}$ and $P_c(4457{)}^{+}$ may be assigned as the excited states with ${\frac{1}{2}}^{-}$, which might all belong to the sextet with $s_{c\bar{c}}=1$ and $s_{\ell }=\frac{3}{2}$. It is notable that our working framework is quite similar to that of Hydrogen molecule, but with different potential structure. We also classify these pentaquarks and tetraquarks in light of the heavy quark symmetry and their decay properties are analyzed. Several promising channels for the observation of doubly-heavy pentaquarks and doubly-heavy tetraquarks in experiment are proposed.

    hep-phhep-exPLB(2019)·100 citations
14. 14*

    Soft-gluon effective coupling and cusp anomalous dimension

    Stefano Catani🇮🇹 · Daniel de Florian🇦🇷 · Massimiliano Grazzini🇨🇭

    We consider the extension of the CMW soft-gluon effective coupling in the context of soft-gluon resummation for QCD hard-scattering observables beyond the next-to-leading logarithmic accuracy. We present two proposals of a soft-gluon effective coupling that extend the CMW coupling to all perturbative orders in the \ms\ coupling $\text{as}$. Although both effective couplings are well-defined in the physical four-dimensional space time, we examine their behaviour in $d=4-2\text{ep}$ space time dimensions. We uncover an all-order perturbative relation with the cusp anomalous dimension: the (four dimensional) cusp anomalous dimension is equal to the $d$-dimensional soft-gluon effective coupling at the conformal point $\text{ep}=\beta (\text{as})$, where the $d$-dimensional QCD $\beta$-function, $\beta (\text{as})-\text{ep}$, vanishes. We present the explicit expressions of the two soft-gluon couplings up to $\mathcal{O}({\text{as}}^2)$ in $d$ dimensions. In the four-dimensional case we compute the two soft couplings up to $\mathcal{O}({\text{as}}^3)$. For one of the two couplings, we confirm the $\mathcal{O}({\text{as}}^3)$ result previously presented by other authors. For the other coupling, we obtain the explicit relation with the cusp anomalous dimension up to $\mathcal{O}({\text{as}}^4)$. We comment on Casimir scaling at $\mathcal{O}({\text{as}}^4)$.

    hep-phhep-thEPJC(2019)·44 citations
15. 15*

    Testing unitarity of the $3\times 3$ neutrino mixing matrix in an atomic system

    Guo-yuan Huang🇨🇳 · Noboru Sasao🇯🇵 · Zhi-zhong Xing🇨🇳 · Motohiko Yoshimura🇯🇵

    Unitarity of the $3\times 3$ lepton flavor mixing matrix $V$ is unavoidably violated in a seesaw mechanism if its new heavy degrees of freedom are slightly mixed with the active neutrino flavors. We propose to use the atomic transition process $|\mathrm{e}⟩\to |\mathrm{g}⟩+\gamma +{\nu }_i^{}+{\overline{\nu }}_j^{}$ (for $i,j=1,2,3$), where $|\mathrm{e}⟩$ and $|\mathrm{g}⟩$ stand respectively for the excited and ground levels of an atomic system, to probe or constrain the unitarity-violating effects of $V$. We find that the photon spectrum of this transition will be distorted by the effects of $V{V}^{†}\ne 1$ and $V^{†}V\ne 1$ as compared with the $V{V}^{†}=V^{†}V=1$ case. We locate certain frequencies in the photon spectrum to minimize the degeneracy of effects of the unitarity violation and uncertainties of the flavor mixing parameters themselves. The requirements of a nominal experimental setup to test the unitarity of $V$ are briefly discussed.

    hep-phphysics.atom-phInt.J.Mod.Phys.A(2020)·7 citations
16. 16*

    Companion poles: from the $a_0(980)$ to the $X(3872)$

    Francesco Giacosa🇵🇱

    When an unstable ordinary quark-antiquark state couples strongly to other low-mass mesons (such as pions, kaons, $D$-mesons, etc.), the quantum fluctuations generated by the decay products dress the bare `seed' $\bar{q}q$ state and modify its spectral functions. The state is associated to a pole on the complex plane. When the coupling to the decay products is sufficiently large, a remarkable and interesting phenomenon takes place: dynamically generated companion states (or poles) might emerge. Some resonances listed in the PDG , such as the $a_0(980),$ the $K_0^{\ast }(700),$ and the $X(3872),$ can be well understood by this mechanism, that we briefly review in these proceedings. On the other hand, we show that the $Y(4008)$ and $Y(4260)$ are not independent resonances (or poles), but manifestations of $\psi (4040)$ and $\psi (4160),$ respectively.

    hep-phActa Phys.Polon.Supp.(2020)·3 citations
17. 17*

    B-meson charged current anomalies: the post-Moriond status

    Debjyoti Bardhan🇮🇱 · Diptimoy Ghosh🇮🇳

    In this note, we discuss the impact of the recent Belle result on the various theoretical explanations of the $R_D$ and $R_{D^{\ast }}$ anomalies. The pure tensor explanation, which was strongly disfavoured by the measurements of $F_L^{D^{\ast }}$ and high-$p_T$ $pp\to \tau \nu$ searches before Moriond, is now completely allowed because of reduction of the experimental world-average. Moreover, the pure right-chiral vector solution (involving right-chiral neutrinos) has now moved into the $2\sigma$ allowed range of the LHC $pp\to \tau \nu$ searches. We also critically re-examine the bound on $\mathcal{B}(B_c^{-}\to {\tau }^{-}{\bar{\nu }}_{\tau })$ from LEP data and show that the bound is considerably weaker than the number $10\%$ often used in the recent literature.

    hep-phhep-exPRD(2019)·55 citations
18. 18*

    Phenomenology of GeV-scale scalar portal

    Iryna Boiarska🇩🇰 · Kyrylo Bondarenko🇳🇱 · Alexey Boyarsky🇳🇱 · Volodymyr Gorkavenko🇺🇦 · Maksym Ovchynnikov🇳🇱 · Anastasia Sokolenko🇳🇴

    We review and revise the phenomenology of the scalar portal -- a new scalar particle with the mass in GeV range that mixes with the Higgs boson. In particular, we consider production channels $B\to S{K}_1(1270)$ and $B\to S{K}_0^{\ast }(700)$ and show that their contribution is significant. We extend the previous analysis by comparing the production of scalars from decays of mesons, of the Higgs bosons and direct production via proton bremsstrahlung, deep inelastic scattering and coherent scattering on nuclei. Relative efficiency of the production channels depends on the energy of the beam and we consider the energies of DUNE, SHiP and LHC-based experiments. We present our results in the form directly suitable for calculations of experimental sensitivities.

    hep-phhep-exJHEP(2019)·106 citations
19. 19*

    Breaking Mirror Twin Hypercharge

    Brian Batell🇺🇸 · Christopher B. Verhaaren🇺🇸

    The Twin Higgs scenario stabilizes the Higgs mass through an approximate global symmetry and has remained natural in the face of increasingly stringent LHC bounds on colored top partners. Two basic structural questions in this framework concern the nature of the twin hypercharge gauge symmetry and the origin of the ${\mathbb{Z}}_2$ symmetry breaking needed to achieve the correct vacuum alignment. Both questions are addressed in a simple extension of the Mirror Twin Higgs model with an exact ${\mathbb{Z}}_2$ symmetry and a scalar field that spontaneously breaks both twin hypercharge and ${\mathbb{Z}}_2$. Due to the ${\mathbb{Z}}_2$ symmetry and an approximate $U(2)$ symmetry in the potential, a new hypercharge scalar appears in the visible sector and, like the Higgs, is a pseudo-Nambu-Goldstone boson with a weak-scale mass. Couplings between the hypercharge scalar and matter provide a new dynamical source of twin sector fermion masses. Depending on the nature and size of these couplings, a variety of experimental signatures may arise, including quark and lepton flavor violation, neutrino masses and mixings as well as direct collider probes of the hypercharged scalar. These signals are correlated with the twin matter spectrum, which can differ dramatically from the visible one, including dynamical realizations of fraternal-like scenarios.

    hep-phJHEP(2019)·32 citations
20. 20*

    Naturalness in D-brane Inspired Models

    Ron De Benedetti🇺🇸 · Tianjun Li🇨🇳 · James A. Maxin🇺🇸 · Dimitri V. Nanopoulos🇺🇸

    We examine the naturalness of the D-brane inspired model constructed in flipped $SU(5)$ supplemented with vector-like particles at the TeV scale, dubbed flippons. We find the model can produce a mainly Higgsino-like lightest supersymmetric particle (LSP) and small light stops, as favored by naturalness. In fact, a large trilinear scalar $A_t$ term at the electroweak (EW) scale creates a large mass splitting between the top squarks, driving the light stop to near degeneracy with an LSP that is almost all Higgsino, with $\Delta M({\tilde{t}}_1,{\tilde{\chi }}_1^0)<5$ GeV, evading the LHC constraint on ${\tilde{t}}_1\to c{\tilde{\chi }}_1^0$ thus far. Given the smallness of the light stop, generating a 125 GeV light Higgs boson mass is aided by one-loop contributions from the Yukawa couplings between the flippons and Higgs fields. The resulting parameter space satisfying naturalness is rather constrained, thus we assess its viability by means of comparison to the LHC constraint on soft charm jets and direction detection limits on spin-independent cross-sections. Finally, we compute the level of electroweak fine-tuning and uncover a region with ${\Delta }_{EW}<30$, $i.e.$, fine-tuning better than 3%, regarded as low electroweak fine-tuning. Given the small light stop, the electroweak fine-tuning from only the top squarks is of $\mathcal{O}$(1), indicating no fine-tuning from neither the light stop ${\tilde{t}}_1$ nor the heavy stop ${\tilde{t}}_2$.

    hep-phhep-thJHEP(2019)·2 citations
21. 21*

    Benchmark Suggestions for Resonant Double Higgs Production at the LHC for Extended Higgs Sectors

    Sebastian Baum🇸🇪 · Nausheen R. Shah🇺🇸

    In this note we present benchmark scenarios for resonant double Higgs production at the $13$TeV LHC in the 2HDM+S model and the $Z_3$ Next-to-Minimal Supersymmetric Standard Model (NMSSM), which may be accessible with 300 fb${}^{-1}$ of data. The NMSSM Higgs sector can be mapped onto the 2HDM+S. We show benchmark points and relevant parameter planes in the 2HDM+S for three sets of signatures: ($A\to h_{125}a,H\to h_{125}h)$, ($A\to ah,H\to hh,H\to aa)$, and ($H\to h_{125}{h}_{125}$). The first two signatures are optimized in what we call $Z$-Phobic scenarios where $H/A$ decays into final states with $Z$ bosons are suppressed. The last signature, $h_{125}$ pair production, is directly proportional to the misalignment of $h_{125}$ with the interaction state sharing the couplings of a SM Higgs boson, and hence is presented in the Max Misalignment scenario. We also present two NMSSM benchmark points for the ($A\to h_{125}a,H\to h_{125}h)$ signatures. The benchmark scenarios presented here are based on Refs. [1,2].

    hep-phhep-ex15 citations
22. 22*

    Mass reconstruction of MSSM Higgs boson

    T.V. Obikhod🇺🇦 · I.A. Petrenko🇺🇦

    The problems of Standard Model as well as questions related to Higgs boson properties led to the need for modeling of ttH associated production and Higgs boson decay to top quark pair within the MSSM model. With the help of computer programs MadGraph, Pythia and Delphes and using the latest kinematic cuts taken from experimental data obtained at the LHC we predicted the masses of MSSM Higgs bosons, A and H.

    hep-phUkr.J.Phys.(2019)·0 citations
23. 23*

    Scalar-metric-affine theories: Can we get ghost-free theories from symmetry?

    Katsuki Aoki🇯🇵 · Keigo Shimada🇯🇵

    We reveal the existence of a certain hidden symmetry in general ghost-free scalar-tensor theories which can only be seen when generalizing the geometry of the spacetime from Riemannian. For this purpose, we study scalar-tensor theories in the metric-affine (Palatini) formalism of gravity, which we call scalar-metric-affine theories for short, where the metric and the connection are independent. We show that the projective symmetry, a local symmetry under a shift of the connection, can provide a ghost-free structure of scalar-metric-affine theories. The ghostly sector of the second-order derivative of the scalar is absorbed into the projective gauge mode when the unitary gauge can be imposed. Incidentally, the connection does not have the kinetic term in these theories and then it is just an auxiliary field. We can thus (at least in principle) integrate the connection out and obtain a form of scalar-tensor theories in the Riemannian geometry. The projective symmetry then hides in the ghost-free scalar-tensor theories. As an explicit example, we show the relationship between the quadratic order scalar-metric-affine theory and the quadratic U-degenerate theory. The explicit correspondence between the metric-affine (Palatini) formalism and the metric one could be also useful for analyzing phenomenology such as inflation.

    ↳ hep-thgr-qchep-phPRD(2019)·70 citations
24. 24*

    Magnetic catalysis and inverse catalysis for heavy pions

    Gergely Endrodi🇩🇪 · Matteo Giordano🇭🇺 · Sandor D. Katz🇭🇺 · Tamas G. Kovacs🇭🇺 · Ferenc Pittler🇩🇪

    We investigate the QCD phase diagram for nonzero background magnetic fields using first-principles lattice simulations. At the physical point (in terms of quark masses), the thermodynamics of this system is controlled by two opposing effects: magnetic catalysis (enhancement of the quark condensate) at low temperature and inverse magnetic catalysis (reduction of the condensate) in the transition region. While the former is known to be robust and independent of the details of the interactions, inverse catalysis arises as a result of a delicate competition, effective only for light quarks. By performing simulations at different quark masses, we determine the pion mass above which inverse catalysis does not take place in the transition region anymore. Even for pions heavier than this limiting value - where the quark condensate undergoes magnetic catalysis - our results are consistent with the notion that the transition temperature is reduced by the magnetic field. These findings will be useful to guide low-energy models and effective theories of QCD.

    ↳ hep-lathep-phnucl-thJHEP(2019)·80 citations
25. 25*

    Primordial black hole tower: Dark matter, earth-mass, and LIGO black holes

    Yuichiro Tada🇯🇵 · Shuichiro Yokoyama🇯🇵

    We investigate a possibility of primordial black hole (PBH) formation with a hierarchical mass spectrum in multiple phases of inflation. As an example, we find that one can simultaneously realize a mass spectrum which has recently attracted a lot of attention: stellar-mass PBHs ($\sim \mathcal{O}(10)M_{\odot }$) as a possible source of binary black holes detected by LIGO/Virgo collaboration, asteroid-mass ($\sim \mathcal{O}(10^{-12})M_{\odot }$) as a main component of dark matter, and earth-mass ($\sim \mathcal{O}(10^{-5})M_{\odot }$) as a source of ultrashort-timescale events in Optical Gravitational Lensing Experiment microlensing data. The recent refined de Sitter swampland conjecture may support such a multi-phase inflationary scenario with hierarchical mass PBHs as a transition signal of each inflationary phase.

    ↳ astro-ph.COhep-phPRD(2019)·95 citations
26. 26*

    Primordial non-Gaussianity in heavy-ion collisions

    Rajeev S. Bhalerao🇮🇳 · Giuliano Giacalone🇫🇷 · Jean-Yves Ollitrault🇫🇷

    We show that experimental data on cumulants of anisotropic flow in heavy-ion collisions probe the non-Gaussian statistics of the energy density field created right after the collision. We carry out a perturbative expansion of the initial anisotropies of the system in terms of its density fluctuations. We argue that the correlation between the magnitudes of elliptic flow and triangular flow, dubbed $sc(3,2)$, is generically of the same sign and order of magnitude as the kurtosis of triangular flow in a hydrodynamic picture. The experimental observation that these quantities are negative implies that the distribution of energy around a given point has positive skew.

    ↳ nucl-thhep-phnucl-exPRC(2019)·14 citations
27. 27*

    Disentangle contributions to small-system collectivity via scans of light nucleus-nucleus collisions

    Shengli Huang🇺🇸 · Zhenyu Chen🇺🇸 · Jiangyong Jia🇺🇸 · Wei Li🇺🇸

    The observation of multi-particle azimuthal correlations in high-energy small-system collisions has led to intense debate on its origin and the possible coexistence from two competing theoretical scenarios: one based on initial-state intrinsic momentum anisotropy (ISM), and the other based on final-state collective response to the collision geometry (FSM). To complement the previous scan of asymmetric collision systems ($p$+Au, $d$+Au and He+Au), we propose a scan of small symmetric collision systems at RHIC, such as C+C, O+O, Al+Al and Ar+Ar $\sqrt{s_{\mathrm{NN}}}=0.2$ TeV, to provide further insights in disentangling contributions from these two scenarios. These symmetric small systems have the advantage of providing a better controlled initial geometry dominated by the average shape of the overlap region, as opposed to fluctuation-driven geometries in asymmetric systems. A transport model is employed to investigate the expected geometry response in the FSM scenario. Different trends of elliptic flow with increasing charge particle multiplicity are observed between symmetric and asymmetric systems, while triangular flow appears to show a similar behavior. Furthermore, a comparison of O+O collisions at $\sqrt{s_{\mathrm{NN}}}=0.2$ TeV and at $\sqrt{s_{\mathrm{NN}}}=2.76-7$ TeV, as proposed at the LHC, provides a unique opportunity to disentangle the collision geometry effects at nucleon level from those arising from subnucleon fluctuations.

    ↳ nucl-exhep-phnucl-thPRC(2020)·46 citations
28. 28*

    Minimally-Entangled State Preparation of Localized Wavefunctions on Quantum Computers

    Natalie Klco🇺🇸 · Martin J. Savage🇺🇸

    Initializing a single site of a lattice scalar field theory into an arbitrary state with support throughout the quantum register requires $\mathcal{O}(2^{n_Q})$ entangling gates on a quantum computer with $n_Q$ qubits per site. It is conceivable that, instead, initializing to functions that are good approximations to states may have utility in reducing the number of required entangling gates. In the case of a single site of a non-interacting scalar field theory, initializing to a symmetric exponential wavefunction requires $n_Q-1$ entangling gates, compared with the $2^{n_Q-1}+n_Q-3+{\delta }_{n_Q,1}$ required for a symmetric Gaussian wavefunction. In this work, we explore the initialization of 1-site ($n_Q=4$), 2-site ($n_Q=3$) and 3-site ($n_Q=3$) non-interacting scalar field theories with symmetric exponential wavefunctions using IBM's quantum simulators and quantum devices (Poughkeepsie and Tokyo). With the digitizations attainable with $n_Q=3,4$, these tensor-product wavefunctions are found to have large overlap with a Gaussian wavefunction, and provide a suitable low-noise initialization for improvement and \emph{Somma Inflation}. In performing these simulations, we have employed a workflow that interleaves calibrations to mitigate systematic errors in production. The calibrations allow tolerance cuts on gate performance including the fidelity of the symmetrizing Hadamard gate, both in vacuum ($|0{⟩}^{\otimes n_Q}$) and in medium ($n_Q-1$ qubits initialized to an exponential function). The results obtained in this work are relevant to systems beyond scalar field theories, such as the deuteron radial wavefunction, 2- and 3-dimensional cartesian-space wavefunctions, and non-relativistic multi-nucleon systems built on a localized eigenbasis.

    ↳ quant-phhep-lathep-phnucl-thPRA(2020)·92 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.