Tue·Aug 23, 2016Tuesday·August 23, 2016

1. 01*

   Diphoton Signal of light pseudoscalar in NMSSM at the LHC

   Monoranjan Guchait🇮🇳 · Jacky Kumar🇮🇳

   We explore the detection possibility of light pseudoscalar Higgs boson in the next-to-minimal supersymmetric Standard Model(NMSSM) at the LHC with the center of mass energy, $\sqrt{S}=13$ TeV. We focus on the parameter space which provides one of the Higgs boson as the SM-like with a mass of 125 GeV and some of the non-SM-like Higgs bosons can be light having suppressed couplings with fermions and gauge bosons due to their singlet nature. It is observed that for certain region of model parameter space, the singlet like light pseudoscalar can decay to di-photon($\gamma \gamma$) channel with a substantial branching ratio. In this study, we consider this di-photon signal of light pseudoscalar Higgs boson producing it through the chargino-neutralino production and the subsequent decay of neutralino. We consider signal consisting of two photons plus missing energy along with a lepton from the chargino decay. Performing a detailed simulation of the signal and backgrounds including detector effects, we present results for a few benchmark points corresponding to the pseudoscalar Higgs boson mass in the range 60 -100 GeV. Our studies indicate that some of the benchmark points in the parameter space can be probed with a reasonable significance for 100 fb${}^{-1}$ integrated luminosity. We also conclude that exploiting this channel it is possible to distinguish the NMSSM from the other supersymmetric models.

   hep-phhep-exPRD(2017)·27 citations
2. 02*

   A Tale of Two Twin Higgses: Addressing Little Hierarchy in Natural 2HDM Framework

   Jiang-Hao Yu🇺🇸

   In original twin Higgs model, vacuum misalignment between electroweak and new physics scales is realized by adding explicit ${\mathbb{Z}}_2$ breaking term. Introducing additional twin Higgs could accommodate spontaneous ${\mathbb{Z}}_2$ breaking, which explains the origin of this misalignment. We introduce a class of two twin Higgs doublet models with most general scalar potential, and discuss general conditions which trigger electroweak and ${\mathbb{Z}}_2$ symmetry breaking. Various scenarios on realising the vacuum misalignment are systematically discussed in a natural two Higgs double model framework: explicit ${\mathbb{Z}}_2$ breaking, radiative ${\mathbb{Z}}_2$ breaking, tadpole-induced ${\mathbb{Z}}_2$ breaking, and quartic-induced ${\mathbb{Z}}_2$ breaking. We investigate the Higgs mass spectra and the Higgs phenomenology in these scenarios.

   hep-phJHEP(2016)·30 citations
3. 03*

   The LPM effect in sequential bremsstrahlung: 4-gluon vertices

   Peter Arnold🇺🇸 · Han-Chih Chang🇺🇸 · Shahin Iqbal🇵🇰

   The splitting processes of bremsstrahlung and pair production in a medium are coherent over large distances in the very high energy limit, which leads to a suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect. In this paper, we continue study of the case when the coherence lengths of two consecutive splitting processes overlap (which is important for understanding corrections to standard treatments of the LPM effect in QCD), avoiding soft-gluon approximations. In particular, this paper completes the calculation of the rate for real double gluon bremsstrahlung from an initial gluon with various simplifying assumptions (thick media; $\hat{q}$ approximation; and large $N_c$) by now including processes involving 4-gluon vertices.

   hep-phnucl-thJHEP(2016)·29 citations
4. 04*

   First Search for Lorentz and CPT Violation in Double Beta Decay with EXO-200

   L.J. Kaufman (for the EXO-200 Collaboration)🇺🇸

   This proceedings contribution reports the first experimental search for Lorentz- and CPT-violating signals specifically studying the effect of the Standard-Model Extension (SME) oscillation-free momentum-independent neutrino coupling operator in the double beta decay process. The search has been performed using an exposure of 100 kg yr of ${}^{136}$Xe with the EXO-200 detector. No significant evidence of the spectral modification due to isotropic Lorentz violation was found. A two-sided limit of $-2.65\times 10^{-5}$ GeV $<$ ${\mathring{a}}_{\mathrm{of}}^{(3)}$ $<7.60\times 10^{-6}$ GeV (90% C.L.) is placed on the relevant coefficient within the SME.

   hep-ph0 citations
5. 05*

   The energy loss effect of incoming gluon from $J/\psi$ production in p-A collisions

   Li-Hua Song🇨🇳 · Lin-Wan Yan🇨🇳 · Chun-Gui Duan🇨🇳

   The energy loss effect of incoming gluon from $J/\psi$ production in p-A (or d-A) collisions is investigated by means of the E866, RHIC and LHC experimental data. The gluon mean energy loss per unit path length $dE/dL=2.18\pm 0.14$ GeV/fm is extracted by fitting the E866 experimental data for $J/\psi$ production cross section ratios $R_{W(Fe)/Be}(x_F)$. The obtained result indicates that the incoming gluons lose more energy than the incident quarks. By comparing the theoretical results with E866, RHIC, and LHC experimental data, it is found that the nuclear suppression due to the incident gluon (quark) energy loss reduces (increases) with the increase of the kinematic variable $x_F$ (or $y$). The energy loss effect of incoming gluon plays an important role on the suppression of $J/\psi$ production in a wide energy range from $\sqrt{s}=38.7$ GeV to $\sqrt{s}=5.0$ TeV, and the influence of incident quark energy loss can be ignored for high energy(such as at RHIC and LHC energy).

   hep-phCPC(2017)·3 citations
6. 06*

   $c\bar{b}$ spectrum and decay properties with coupled channel effects

   Antony Prakash Monteiro🇮🇳 · Manjunath Bhat🇮🇳 · K. B. Vijaya Kumar🇮🇳

   The mass spectrum of $c\bar{b}$ states has been obtained using the phenomenological relativistic quark model (RQM) with coupled channel effects. The Hamiltonian used in the investigation has confinement potential and confined one gluon exchange potential (COGEP). In the frame work of RQM a study of M1 and E1 radiative decays of $c\bar{b}$ states has been made. The weak decay widths in the spectator quark approximation have been estimated. An overall agreement is obtained with the experimental masses and decay widths.

   hep-phPRD(2017)·39 citations
7. 07*

   Addenda to General Spin Precession and Betatron Oscillation in Storage Ring

   Takeshi Fukuyama🇯🇵

   We give the geralized expression of spin precession of extended bunch particles having both anomalous magnetic and electric dipole moments in storage ring in higher order than the previous work and in the presence of $\mathbf{E}$ field as well as $\mathbf{B}$ field. These addenda are essential since some experiments consider the focusing field in the second order of the beam extent and in the presence of both $\mathbf{B}$ and $\mathbf{E}$ fields . It is shown that some focusing fields with constant magnitude of the velocity considered in many literatures lead to the violation of self consistency.

   hep-phhep-exMod.Phys.Lett.A(2017)·3 citations
8. 08*

   Radiative Symmetry Breaking in the Supersymmetric Minimal B-L Extended Standard Model

   Zachary Burell🇺🇸

   The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others). There is no reason to expect the validity of the ad hoc SM to remain intact at energy scales above a few TeV, thus a more fundamental theory will almost certainly be required. Motivated by these considerations, we investigate a Supersymmetric version of a natural extension of the SM, the $U(1{)}_{B-L}$ model, that is obtained by gauging the accidental B-L symmetry that exists in the ordinary SM. The Supersymmetric $U(1{)}_{B-L}$ extended SM can resolve the neutrino mass problem, the dark matter problem, the hierarchy problem, and provides a mechanism for establishing the observed baryon asymmetry of the Universe. When we include quantum corrections to the Higgs potential of the model, we find that Radiative $B-L$ symmetry breaking occurs through the interplay between large Majorana Yukawa couplings and SUSY breaking masses, and the SM neutrino masses arise through the Type-I seesaw mechanism. We deduce from the form RGEs that $B-L$ will be broken near the TeV scale when the Majorana Yukawa couplings are of order 0.5, leading to TeV scale right-handed neutrinos, which could be accessible at the LHC. We discuss the different vacua of the theory and the viability of a right-handed neutrino dark matter candidate in the R-parity conserving and violating sectors. A new ${\mathbb{Z}}_2$ parity is postulated in the R-parity violating sector in which case the lightest right handed neutrino becomes a viable Dark Matter candidate in addition to the gravitino.

   hep-ph0 citations
9. 09*

   The possibility to observe the non-standard interaction by the Hyperkamiokande atmospheric neutrino experiment

   Shinya Fukasawa🇯🇵 · Osamu Yasuda🇯🇵

   It was suggested that a tension between the mass-squared differences obtained from the solar neutrino and KamLAND experiments can be solved by introducing the non-standard flavor-dependent interaction in neutrino propagation. In this paper we discuss the possibility to test such a hypothesis by atmospheric neutrino observations at the future Hyper-Kamiokande experiment. Assuming that the mass hierarchy is known, we find that the best-fit value from the solar neutrino and KamLAND data can be tested at more than 8 $\sigma$, while the one from the global analysis can be examined at 5.0 $\sigma$ (1.4 $\sigma$) for the normal (inverted) mass hierarchy.

   hep-phNPB(2017)·23 citations
10. 10*

    Two-loop QCD Correction to Massive Spin-2 Resonance $\to q\bar{q}g$

    Taushif Ahmed🇮🇳 · Goutam Das🇮🇳 · Prakash Mathews🇮🇳 · Narayan Rana🇮🇳 · V. Ravindran🇮🇳

    Two-loop QCD correction to massive spin-2 Graviton decaying to $q+\bar{q}+g$ is presented considering a generic universal spin-2 coupling to the SM through the conserved energy-momentum tensor. Such a massive spin-2 particle can arise in extra-dimensional models. The ultraviolet and infrared structure of the QCD amplitudes are studied. In dimensional regularisation, the infrared pole structure is in agreement with Catani's proposal, confirming the universal factorization property of QCD amplitudes, even with the spin-2 tensorial coupling. This computation now completes the full two-loop QCD corrections for the production of a spin-2 in association with a jet.

    hep-phhep-exEPJC(2016)·6 citations
11. 11*

    Flavor violating leptonic decays of the Higgs boson

    Seham Fathy🇪🇬 · Tarek Ibrahim🇪🇬 · Ahmad Itani🇱🇧 · Pran Nath🇺🇸

    Recent data from the ATLAS and CMS detectors at the Large Hadron Collider at CERN give a hint of possible violation of flavor in the leptonic decays of the Higgs boson. In this work we analyze the flavor violating leptonic decays $H_1^0\to l_i{\bar{l}}_j$ ($i\ne j$) within the framework of an MSSM extension with a vectorlike leptonic generation. Specifically we focus on the decay mode $H_1^0\to \mu \tau$. The analysis is done including tree and loop contributions involving exchange of $W,Z$, charge and neutral higgs and leptons and mirror leptons, charginos and neutralinos and sleptons and mirror sleptons. It is found that a substantial branching ratio of $H_1^0\to \mu \tau$, i.e., of as much a $\mathcal{O}(1)\%$, can be achieved in this model, the size hinted by the ATLAS and CMS data. The flavor violating decays $H_1^0\to e\mu ,e\tau$ are also analyzed and found to be consistent with the current experimental limits. An analysis of the dependence of flavor violating decays on CP phases is given. The analysis is extended to include flavor decays of the heavier Higgs bosons. A confirmation of the flavor violation in Higgs boson decays with more data that is expected from LHC at $\sqrt{s}=13$ TeV will be evidence of new physics beyond the standard model.

    hep-phhep-exPRD(2016)·7 citations
12. 12*

    Quark self-energy in an ellipsoidally anisotropic quark-gluon plasma

    Babak S. Kasmaei🇺🇸 · Mohammad Nopoush🇺🇸 · Michael Strickland🇺🇸

    We calculate the quark self-energy in a quark-gluon plasma that possesses an ellipsoidal momentum-space anisotropy in the local rest frame. By introducing additional transverse momentum anisotropy parameters into the parton distribution functions, we generalize previous results which were obtained for the case of a spheroidal anisotropy. Our results demonstrate that the presence of anisotropies in the transverse directions affects the real and imaginary parts of quark self-energy and, consequently, the self-energy depends on both the polar and azimuthal angles in the local rest frame of the matter. Our results for the quark self-energy set the stage for the calculation of the effects of ellipsoidal momentum-space anisotropy on quark-gluon plasma photon spectra and collective flow.

    hep-phnucl-thPRD(2016)·15 citations
13. 13*

    Meson-baryon effective chiral Lagrangians at order $p^4$

    Shao-Zhou Jiang🇨🇳 · Qing-Sen Chen🇨🇳 · Yan-Rui Liu🇨🇳

    We construct the three-flavor Lorentz-invariant meson-baryon chiral Lagrangians at the order $p^4$, with which a full one-loop investigation may be performed. One obtains 540 independent terms. The processes with the minimal number of mesons and photons that this order Lagrangians may contribute to are also presented.

    hep-phPRD(2017)·20 citations
14. 14*

    Z(3) metastable states in Polyakov Quark Meson model

    Ranjita K. Mohapatra🇮🇳 · Hiranmaya Mishra🇮🇳

    We study the existence of Z(3) metastable states in the presence of the dynamical quarks within the ambit of Polyakov quark meson (PQM) model. Within the parameters of the model, it is seen that for temperatures $T_m$ greater than the chiral transition temperature $T_c$, Z(3) metastable states exist ( $T_m\sim 310$ MeV at zero chemical potential). At finite chemical potential $T_m$ is larger than the same at vanishing chemical potential. We also observe a shift of ($\sim 5^{\circ }$) in the phase of the metastable vacua at zero chemical potential. The energy density difference between true and Z(3) metastable vacua is very large in this model. This indicates a strong explicit symmetry breaking effect due to quarks in PQM model. We compare this explicit symmetry breaking in PQM model with small explicit symmetry breaking as a linear term in Polyakov loop added to the Polyakov loop potential. We also study about the possibility of domain growth in a quenched transition to QGP in relativistic heavy ion collisions.

    hep-phhep-exnucl-thPRD(2017)·7 citations
15. 15*

    Improving the measurement of the CKM phase ${\varphi }_2=\alpha$ in $B\to \pi \pi$ and $B\to \rho \rho$ decays

    Michael Gronau🇮🇱 · Jonathan L. Rosner🇺🇸

    CP-violating asymmetries in $B\to \pi \pi$ and $B\to \rho \rho$ decays can help specify the weak phase ${\varphi }_2=\alpha$ of the Cabibbo-Kobayashi-% Maskawa (CKM) matrix. We discuss the impact of improved measurements of these processes such as will be available in the near future, finding special value in better measurement of the time-dependent CP violation parameter $S_{00}$ in $B^0\to {\pi }^0{\pi }^0$ and $B^0\to {\rho }^0{\rho }^0$. Reducing the errors on $B\to \rho \rho$ measurements by a factor of two can potentially lead to an error in ${\varphi }_2=\alpha$ just above $2^{\circ }$, at which level isospin-breaking corrections must be considered.

    hep-phhep-exPLB(2016)·9 citations
16. 16*

    NLO QCD Corrections for $J/\psi +c+\bar{c}$ Production in Photon-Photon Collision

    Zi-Qiang Chen🇨🇳 · Long-Bin Chen🇨🇳 · Cong-Feng Qiao🇨🇳

    The $\gamma +\gamma \to J/\psi +c+\bar{c}$ inclusive process is an extremely important subprocess in $J/\psi$ production via photon-photon scattering, like at LEP\uppercase\expandafter{\romannumeral2} or various types future electron-positron colliders. In this work we perform the next-to-leading(NLO) QCD corrections to this process in the framework of non-relativistic QCD(NRQCD) factorization formalism, the first NLO calculation for two projectiles to 3-body quarkonium inclusive production process. By setting the center-of-mass energy at LEP\uppercase\expandafter{\romannumeral2}, the $\sqrt{s}=197$ GeV, we conduct analyses of the $p_t^2$ distribution and total cross section of this process at the NLO accuracy. It turns out that the total cross section is moderately enhanced by the NLO correction with a $K$ factor of about 1.46, and hence the discrepancy between DELPHI data and color-singlet(CS) calculation is reduced while the color-octet(CO) contributions are still inevitable at this order. At the future Circular Electron-Positron Collider(CEPC), the NLO corrections are found to be more significant, with a $K$ factor of about 1.76.

    hep-phPRD(2017)·15 citations
17. 17*

    Domain walls and gravitational waves in the Standard Model

    Tomasz Krajewski🇵🇱 · Zygmunt Lalak🇵🇱 · Marek Lewicki🇵🇱 · Paweł Olszewski🇵🇱

    We study domain walls which can be created in the Standard Model under the assumption that it is valid up to very high energy scales. We focus on domain walls interpolating between the physical electroweak vacuum and the global minimum appearing at very high field strengths. The creation of the network which ends up in the electroweak vacuum percolating through the Universe is not as difficult to obtain as one may expect, although it requires certain tuning of initial conditions. Our numerical simulations confirm that such domain walls would swiftly decay and thus cannot dominate the Universe. We discuss the possibility of detection of gravitational waves produced in this scenario. We have found that for the standard cosmology the energy density of these gravitational waves is too small to be observed in present and planned detectors.

    ↳ astro-ph.COhep-phhep-thJCAP(2016)·30 citations
18. 18*

    Vladimir Naumovich Gribov: Pieces of biography

    Ya.I. Azimov🇷🇺

    The talk presents the main lines of biography of the prominent physicist and bright personality. Also given is a necessarily brief description of Gribov's scientific work.

    ↳ physics.hist-phhep-phhep-thInt.J.Mod.Phys.A(2016)·0 citations
19. 19*

    Constraints on exotic spin-dependent interactions between electrons from helium fine-structure spectroscopy

    Filip Ficek🇵🇱 · Derek F. Jackson Kimball🇺🇸 · Mikhail Kozlov🇷🇺 · Nathan Leefer🇩🇪 · Szymon Pustelny🇵🇱 · Dmitry Budker🇩🇪

    Agreement between theoretical calculations of atomic structure and spectroscopic measurements is used to constrain possible contribution of exotic spin-dependent interactions between electrons to the energy differences between states in helium-4. In particular, constraints on dipole-dipole interactions associated with the exchange of pseudoscalar bosons (such as axions or axion-like particles, ALPs) with masses $10^{-2}\mathrm{eV}\lesssim m\lesssim 10^4\mathrm{eV}$ are improved by a factor of $\sim 100$. The first atomic-scale constraints on several exotic velocity-dependent dipole-dipole interactions are established as well.

    ↳ physics.atom-phhep-phPRA(2017)·78 citations
20. 20*

    Glauber theory and the quantum coherence of curvature inhomogeneities

    Massimo Giovannini🇨🇭

    The curvature inhomogeneities are systematically scrutinized in the framework of the Glauber approach. The amplified quantum fluctuations of the scalar and tensor modes of the geometry are shown to be first-order coherent while the interference of the corresponding intensities is larger than in the case of Bose-Einstein correlations. After showing that the degree of second-order coherence does not suffice to characterize unambiguously the curvature inhomogeneities, we argue that direct analyses of the degrees of third and fourth-order coherence are necessary to discriminate between different correlated states and to infer more reliably the statistical properties of the large-scale fluctuations. We speculate that the moments of the multiplicity distributions of the relic phonons might be observationally accessible thanks to new generations of instruments able to count the single photons of the Cosmic Microwave Background in the THz region.

    ↳ hep-thastro-ph.COgr-qchep-ph+1Class.Quant.Grav.(2017)·20 citations
21. 21*

    Detecting ultralight axion dark matter wind with laser interferometers

    Arata Aoki🇯🇵 · Jiro Soda🇯🇵

    The ultralight axion with mass around $10^{-22}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v\sim 300\text{km}/\text{s}=10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter with a wide mass range by using laser interferometer detectors. We calculate the detector signal induced by the oscillating pressure of the ultralight axion field, which would be detected by future laser interferometer experiments. We also argue that the detector signal can be enhanced due to the resonance in modified gravity theory explaining the dark energy.

    ↳ astro-ph.COhep-phInt.J.Mod.Phys.D(2016)·61 citations
22. 22*

    The fluctuations of quadrangular flow

    Giuliano Giacalone🇫🇷 · Li Yan🇫🇷 · Jacquelyn Noronha-Hostler🇺🇸 · Jean-Yves Ollitrault🇫🇷

    The ATLAS Collaboration has measured for the first time the fourth cumulant of quadrangular flow, $v_4\{4{\}}^4$. Unlike the fourth cumulants of elliptic and triangular flows, it presents a change of sign above 30\% centrality. We show that this change of sign is predicted by event-by-event hydrodynamics. We argue that it results from the combined effects of a nonlinear hydrodynamic response, which couples quadrangular flow to elliptic flow, and elliptic flow fluctuations.

    ↳ nucl-thhep-phnucl-exJ.Phys.Conf.Ser.(2017)·15 citations
23. 23*

    Modular symmetry in magnetized/intersecting D-brane models

    Tatsuo Kobayashi🇯🇵 · Satoshi Nagamoto🇯🇵 · Shohei Uemura🇯🇵

    We study the modular symmetry in four-dimensional low-energy effective field theory, which is derived from type IIB magnetized D-brane models and type IIA intersecting D-brane models. We analyze modular symmetric behaviors of perturbative terms and non-perturbative terms induced by D-brane instanton effects. Anomalies are also investigated and such an analysis on anomalies suggests corrections in effective field theory.

    ↳ hep-thhep-phPTEP(2017)·45 citations
24. 24*

    Dissipative Axial Inflation

    Alessio Notari🇪🇸 · Konrad Tywoniuk🇨🇭

    We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\frac{\varphi }{f_{\gamma }}F\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density ${\rho }_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_{\gamma }$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_{\gamma }$ is smaller than the field excursion ${\varphi }_0$ by about a factor of at least $\mathcal{O}(20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of perturbations, scalars and tensors. Such oscillations have a period of 4-5 efolds and an amplitude which is typically less than a few percent and decreases linearly with $f_{\gamma }$. We also stress that the comoving curvature perturbation on uniform density should be sensitive to slow-roll parameters related to ${\rho }_R$ rather than ${\dot{\varphi }}^2/2$, although we postpone a calculation of the power spectrum and of non-gaussianity to future work and we simply define and compute suitable slow roll parameters. Finally we stress that this scenario may be realized in the axion case, if the coupling $1/f_{\gamma }$ to U(1) (photons) is much larger than the coupling $1/f_G$ to non-abelian gauge fields (gluons), since the latter sets the range of the potential and therefore the maximal allowed ${\varphi }_0\sim f_G$.

    ↳ hep-thastro-ph.COhep-phJCAP(2016)·79 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.