Mon·Mar 23, 2020Monday·March 23, 2020

1. 01*

   Baryon production probability via the nuclear configurational entropy

   G. Karapetyan🇧🇷

   We study the net-baryon production at forward rapidities within the Color Glass Condensate paradigm. At high energy regime, the leading baryon production mechanism is shown to change from recombination to independent fragmentation. The nuclear configurational entropy (NCE) constructed upon forward scattering amplitudes, allows to predict the two free parameters that govern the anomalous dimension of the target gluon distribution. The global minimum of the NCE indicates a point of stability in pp/pA/AA collisions at LHC energies, corroborating and matching HERA data for hadron spectra measured in pp and dAu collisions at RHIC energies, with accuracy between 1.2\% and 1.8\%, respectively for the two free parameters.

   hep-phnucl-thEur.Phys.J.Plus(2021)·18 citations
2. 02*

   Neutrino Invisible Decay at DUNE: a multi-channel analysis

   Anish Ghoshal🇮🇹 · Alessio Giarnetti🇮🇹 · Davide Meloni🇮🇹

   The hypothesis of the decay of neutrino mass eigenstates leads to a substantial modification of the appearance and disappearance probabilities of flavor eigenstates. We investigate the impact on the standard oscillation scenario caused by the decay of the heaviest mass eigenstate ${\nu }_3$ (with a mass $m_3$ and a mean life ${\tau }_3$) to a sterile state in DUNE. We find that the lower bound of $5.1\times 10^{-11}s/eV$ at 90\% CL on the decay parameter ${\tau }_3/m_3$ can be set if the Neutral Current data are included in the analysis, thus providing the best long-baseline expected limit so far. We also show that the ${\nu }_{\tau }$ appearance channel would give only a negligible contribution to the decay parameter constraints. Our numerical results are corroborated by analytical formulae for the appearance and disappearance probabilities in vacuum (which is a useful approximation for the study of the invisible decay model) that we have developed up to the second order in the solar mass splitting and to all orders in the decay factor $t/{\tau }_3$.

   hep-phJ.Phys.G(2021)·31 citations
3. 03*

   Resummation for $2\to n$ processes in single-particle-inclusive kinematics

   Matthew Forslund🇺🇸 · Nikolaos Kidonakis🇺🇸

   We present a formalism and detailed analytical results for soft-gluon resummation for $2\to n$ processes in single-particle-inclusive (1PI) kinematics. This generalizes previous work on resummation for $2\to 2$ processes in 1PI kinematics. We also present soft anomalous dimensions at one and two loops for certain $2\to 3$ processes involving top quarks and Higgs or $Z$ bosons, and we provide some brief numerical results.

   hep-phPRD(2020)·29 citations
4. 04*

   Scalar mass dependence of angular variables in $t\bar{t}\varphi$ production

   Duarte Azevedo🇵🇹 · Rodrigo Capucha🇵🇹 · António Onofre🇵🇹 · Rui Santos🇵🇹

   In this paper we explore CP discrimination in the associated production of top-quark pairs ($t\bar{t}$) with a generic scalar boson ($\varphi$) at the LHC. We probe the CP-sensitivity of several observables for a varying scalar boson mass and CP-number, either CP-even ($\varphi =H$) or CP-odd ($\varphi =A$), using dileptonic final states of the $t\bar{t}\varphi$ system, with $\varphi \to b\bar{b}$. We show that CP-searches are virtually impossible for $\varphi$ boson masses above a few hundred GeV in this channel. A full phenomenological analysis was performed, using Standard Model background and signal events generated with MadGraph5 MC@NLO and reconstructed using a kinematic fit. The most sensitive CP-observables are used to compute Confidence Levels (CLs), as a function of luminosity, for the exclusion of different signal hypotheses with scalar and pseudoscalar boson masses that range from $m_{\varphi }$ = 40 GeV up to 200 GeV. We finalize by analysing the impact of a measurement (or limit) of the CP-violating angle in the parameter space of a complex two-Higgs doublet model known as the C2HDM.

   hep-phhep-exJHEP(2020)·15 citations
5. 05*

   D meson mass and heavy quark potential at finite temperature

   Philipp Gubler🇯🇵 · Taesoo Song🇩🇪 · Su Houng Lee🇰🇷

   Based on the observation that the heavy quark-antiquark potential value at infinity corresponds to twice the D meson mass, we constrain the asymptotic value of the heavy quark potential in a hot medium through a QCD sum rule calculation of the D meson at finite temperature. We find that to correctly reproduce the QCD sum rule results as well as a recent model calculation for the D meson mass near the critical temperature, the heavy quark potential should be composed mostly of the free energy with an addition of a small but nontrivial fraction of the internal energy. Combined with a previous study comparing potential model results for the $J/\psi$ to a QCD sum rule calculation, we conclude that the composition of the effective heavy quark potential should depend on the inter-quark distance. Namely, the potential is dominated by the free energy at short distance, while at larger separation, it has a fraction of about 20% of internal energy.

   hep-phhep-exhep-latPRD(2020)·16 citations
6. 06*

   Next-to-leading order QCD predictions for dijet photoproduction in lepton-nucleus scattering at the future EIC and at possible LHeC, HE-LHeC, and FCC facilities

   V. Guzey (St. Petersburg, INP)🇷🇺 · M. Klasen (Muenster U., ITP)🇩🇪

   We calculate cross sections for inclusive dijet photoproduction in electron-nucleus scattering in the kinematics of the future EIC and the possible LHeC, HE-LHeC, and the FCC using next-to-leading order (NLO) perturbative QCD and nCTEQ15 and EPPS16 nuclear parton density functions (nPDFs). We make predictions for distributions in the dijet average transverse momentum ${\bar{p}}_T$, the average rapidity $\bar{\eta }$, the observed nuclear momentum fraction $x_A^{\mathrm{obs}}$, and the observed photon momentum fraction $x_{\gamma }^{\mathrm{obs}}$. Comparing the kinematic reaches of the four colliders, we find that an increase of the collision energy from the EIC to the LHeC and beyond extends the coverage in all four considered variables. Notably, the LHeC and HE-LHeC will allow one to probe the dijet cross section down to $x_A^{\mathrm{obs}}\sim 10^{-4}$ (down to $x_A^{\mathrm{obs}}\sim 10^{-5}$ at the FCC). The ratio of the dijet cross sections on a nucleus and the proton, ${\sigma }_A/(A{\sigma }_p)$, depends on $x_A^{\mathrm{obs}}$ in a similar way as the ratio of gluon densities, $g_A(x_A,{\mu }^2)/[A{g}_p(x_A,{\mu }^2)]$, for which current nPDFs predict a strong suppression due to nuclear shadowing in the region $x_A^{\mathrm{obs}}<0.01$. Dijet photoproduction at future lepton-nucleus colliders can therefore be used to test this prediction and considerably reduce the current uncertainties of nPDFs.

   hep-phhep-exnucl-exPRC(2020)·12 citations
7. 07*

   A new parton model for the soft interactions at high energies: the Odderon

   E. Gotsman (Tel Aviv U.)🇮🇱 · E. Levin (Tel Aviv U./UTFSM)🇨🇱 · I. Potashnikova (UTFSM)🇨🇱

   In this paper we discuss the Odderon contribution in our model[19] that gives a fairly good description of ${\sigma }_{\mathrm{tot}}$ ${\sigma }_{\mathrm{el}}$and $B_{\mathrm{el}}$ for proton-proton scattering. We show that the shadowing corrections are large, and induce considerable dependence on energy for the Odderon contribution, which in perturbative QCD does not depend on energy. This energy dependence is in agreement with the experimental data for $\rho =\mathrm{Re}/\mathrm{Im}$, assuming that the Odderon gives a contribution of about 1 mb at W = 7 TeV. This differs greatly with our estimates for a CGC based model. We reproduce the main features of the $t$ -dependence that are measured experimentally: the slope of the elastic cross section at small $t$, the existence of the minima in $t$-dependence which is located at $|t{|}_{min}$ = 0.52 GeV 2 at W= 7 TeV; and the behaviour of the elastic cross section at $|t|>|t{|}_{min}$.The real part of the elastic amplitude turns out to be much smaller than the experimental one. Consequently, to achieve a description of the data, it is necessary to add an odderon contribution.

   hep-phPRD(2020)·10 citations
8. 08*

   Kaonic Hydrogen and Deuterium in Hamiltonian Effective Field Theory

   Zhan-Wei Liu🇨🇳 · Jia-Jun Wu🇨🇳 · Derek B. Leinweber🇦🇺 · Anthony W. Thomas🇦🇺

   The anti-kaon nucleon scattering lengths resulting from a Hamiltonian effective field theory analysis of experimental data and lattice QCD studies are presented. The same Hamiltonian is then used to compute the scattering length for the $K^{-}d$ system, taking careful account of the effects of recoil on the energy at which the $\bar{K}N$ T-matrices are evaluated. These results are then used to estimate the shift and width of the $1S$ levels of anti-kaonic hydrogen and deuterium. The $K^{-}p$ result is in excellent agreement with the SIDDHARTA measurement. In the $K^{-}d$ case the imaginary part of the scattering length and consequently the width of the $1S$ state are considerably larger than found in earlier work. This is a consequence of the effect of recoil on the energy of the $\bar{K}N$ energy, which enhances the role of the $\Lambda (1405)$ resonance.

   hep-phhep-exnucl-exnucl-thPLB(2020)·23 citations
9. 09*

   Probing vector-like top partner from same-sign dilepton events at the LHC

   Hang Zhou🇨🇳 · Ning Liu🇨🇳

   The Standard Model is a successful theory but lack of a mechanism for neutrino mass generation as well as a solution to the naturalness problem. In the models that are proposed to simultaneously solve the two problems, heavy Majorana neutrinos and top partners are usually predicted that can lead to a new decay mode of the top partner mediated by the heavy Majorana neutrinos: $T\to b{W}^{+}\to b{\ell }^{+}{\ell }^{+}q\overline{q^{\prime }}$. In this paper, we will study the observability of such a new signature via the pair production process of top partner $pp\to T\bar{T}\to 2b+{\ell }^{\pm }{\ell }^{\pm }+4j$ in a model independent way. By performing Monte-Carlo simulation, we present the $2\sigma$ exclusion limits of the top partner mass and mixing parameters at the HL-LHC.

   hep-phCommun.Theor.Phys.(2020)·4 citations
10. 10*

    Indirect detection prospects for d${}^{\ast }$(2380) dark matter

    Geoff Beck🇿🇦

    A Bose-Einstein condensate of the hexaquark particle known as d${}^{\ast }$(2380) has been recently proposed as a dark matter candidate by the authors in Bashkanov \& Watts 2020. This particle can produced in an abundant condensate state in the early universe and is argued to satisfy all the stability and weak interaction constraints of a viable dark matter candidate. This dark matter candidate is able to evade direct detection bounds and is suggested to have the best observational prospects in the form of indirect astrophysical emissions due to the decay of the d${}^{\ast }$ condensate. In this work we test the indirect observational prospects of this form of dark matter and find that its low mass $\sim 2$ GeV mean that sub-GeV gamma-rays searches have the best prospects in the Milky-Way galactic centre where we find ${\Gamma }_{d^{\ast }}<3.9\times 10^{-24}$ s${}^{-1}$, with current extra-galactic data from M31 and the Coma cluster producing constraints on the d${}^{\ast }$ decay rate two orders of magnitude weaker. In dwarf galaxies we show that the future GAMMA-400 instrument has the potential to probe down to ${\Gamma }_{d^{\ast }}\sim 10^{-25}$ s${}^{-1}$ with 4 years of exposure time.

    hep-phastro-ph.HEJCAP(2021)·5 citations
11. 11*

    Effective theory for self-interacting dark matter and massive spin-2 mediators

    Yoo-Jin Kang🇰🇷 · Hyun Min Lee🇰🇷

    We consider the effective theory for self-interacting dark matter with arbitrary spin and go beyond the previous discussion in the literature by introducing a massive spin-2 particle as the mediator for the dark matter self-scattering. We present the effective self-interactions for dark matter in the leading order expansions with the momentum transfer and the dark matter velocity. We compare between the Born cross section and the non-perturbative cross section in the leading order approximation of the effective Yukawa interaction. As a result, we find that there is a wide range of dark matter and spin-2 particle masses for a velocity-dependent self-scattering to solve small-scale problems at galaxies as well as satisfy the bounds from galaxy clusters at the same time.

    hep-phastro-ph.GAhep-thJ.Phys.G(2021)·21 citations
12. 12*

    Second Order Twist Contributions to the Balitsky-Kovchegov Equation at small-x: Deterministic and Stochastic Pictures

    Silas K Grossberndt🇺🇸

    We study the second order twist corrections to a toy model of a dipole-dipole interaction in the context of a both deterministic and stochastic effects. This work is done in the high $N_C$ limit in the Bjorken picture. We show that the correction to the second twist terms of the stochastic picture suggest additional importance of the second twist correction in the stochastic model as compared to the deterministic model.

    hep-phnucl-th1 citation
13. 13*

    Hadronic weak decays of ${\Lambda }_c$ in the quark model

    Peng-Yu Niu🇨🇳 · Jean-Marc Richard🇫🇷 · Qian Wang🇨🇳 · Qiang Zhao🇨🇳

    The hadronic weak decays of ${\Lambda }_c$ are studied in the framework of a constituent quark model. With the combined analysis of the Cabbibo-favored processes, ${\Lambda }_c\to \Lambda {\pi }^{+}$, ${\Sigma }^0{\pi }^{+}$ and ${\Sigma }^{+}{\pi }^0$, we confirm that the non-factorizable transition mechanisms play a crucial role in the understanding of their compatible branching ratios. We emphasize that the SU(3) flavor symmetry breaking effects, which is generally at the order of $1\sim 2\%$, can be amplified by the destructive interferences among the pole terms in the diagrams with internal conversion. Some contributions are sensitive to the spatial distribution of the scalar-isoscalar light-quark sector in the ${\Lambda }_c$, and its overlap with the light quarks in the final state hyperon. Namely, a compact diquark configuration is disfavored.

    hep-phhep-exPRD(2020)·30 citations
14. 14*

    Double parton correlations in mesons within AdS/QCD soft-wall models: a first comparison with lattice data

    Matteo Rinaldi🇮🇹

    Double parton distribution functions (dPDFs), entering the double parton scattering (DPS) cross section, are unknown fundamental quantities encoding new interesting properties of hadrons. Here, the pion dPDFs are investigated within different holographic QCD quark models in order to access their basic features. Results of the calculation,s obtained within the AdS/QCD soft-wall approach, have been compared with predictions of lattice QCD evaluations of the pion two-current correlation functions. The present analysis confirms that double parton correlations, affecting dPDFs, are very important and not direct accessible from generalised parton distribution functions and electromagnetic form factors. The comparison between lattice data and quark model calculations unveils the relevance of the contributions of high partonic Fock states in the pion. Nevertheless, by using a complete general procedure, results of lattice QCD have been used, for the first time, to estimate the mean value of the so called ${\sigma }_{eff}$, a relevant experimental observable for DPS processes. In addition, the results of the first calculations of the $\rho$ meson dPDFs are discussed in order to make predictions.

    hep-phEPJC(2020)·12 citations
15. 15*

    A direct dark matter detection experiment is inevitable

    Vadim A. Bednyakov🇷🇺

    This text contains the main message of my previous review \cite{Bednyakov:2015uoa} on the dark matter problem and supports resent paper \cite{Froborg:2020tdh}. True dark matter particles possess an exclusive galactic signature --- the annual modulation, which is accessible today via direct dark matter detection only. One has no another way to prove the true nature of any dark matter candidate.

    hep-ph3 citations
16. 16*

    The Higgs and Leptophobic Force at the LHC

    Pavel Fileviez Perez🇺🇸 · Elliot Golias🇺🇸 · Clara Murgui🇪🇸 · Alexis D. Plascencia🇺🇸

    The Higgs boson could provide the key to discover new physics at the Large Hadron Collider. We investigate novel decays of the Standard Model (SM) Higgs boson into leptophobic gauge bosons which can be light in agreement with all experimental constraints. We study the associated production of the SM Higgs and the leptophobic gauge boson that could be crucial to test the existence of a leptophobic force. Our results demonstrate that it is possible to have a simple gauge extension of the SM at the low scale, without assuming very small couplings and in agreement with all the experimental bounds that can be probed at the LHC.

    hep-phhep-exJHEP(2020)·9 citations
17. 17*

    Quantum causality and the arrows of time and thermodynamics

    John F. Donoghue🇺🇸 · Gabriel Menezes🇧🇷

    In the understanding of the fundamental interactions, the origin of an arrow of time is viewed as problematic. However, quantum field theory has an arrow of causality, which tells us which time direction is the past lightcone and which is the future. This direction is tied to the conventions used in the quantization procedures. The different possible causal directions have related physics - in this sense they are covariant under time-reversal. However, only one causal direction emerges for a given set of conventions. This causal arrow tells us the direction that scattering reactions proceed. The time direction of scattering in turn tells us the time direction for which entropy increases - the so-called arrow of thermodynamics. This connection is overlooked in most discussions of the arrow of time.

    ↳ quant-phgr-qchep-phhep-th+1PPNP(2020)·30 citations
18. 18*

    Semileptonic $B\to D^{(\ast )}\ell \nu$ Decay Form Factors using the Oktay-Kronfeld Action

    Tanmoy Bhattacharya🇺🇸 · Benjamin J. Choi🇰🇷 · Rajan Gupta🇺🇸 · Yong-Chull Jang🇺🇸 · Seungyeob Jwa🇰🇷 · Sunkyu Lee🇰🇷 · Weonjong Lee · Jaehoon Leem🇰🇷 · Sungwoo Park (LANL/SWME Collaboration)🇺🇸

    We report recent progress in calculating semileptonic form factors for the $\bar{B}\to D^{\ast }\ell \bar{\nu }$ and $\bar{B}\to D\ell \bar{\nu }$ decays using the Oktay-Kronfeld (OK) action for bottom and charm quarks. We use the second order in heavy quark effective power counting $\mathcal{O}({\lambda }^2)$ improved currents in this work. The HISQ action is used for the light spectator quarks. We analyzed four $2+1+1$-flavor MILC HISQ ensembles with $a\approx 0.09\mathrm{fm}$, $0.12\mathrm{fm}$ and $M_{\pi }\approx 220\mathrm{MeV}$, $310\mathrm{MeV}$: $a09m220$, $a09m310$, $a12m220$, $a12m310$. Preliminary results for $B\to D^{\ast }\ell \nu$ decays form factor $h_{A_1}(w)$ at zero recoil ($w=1$) are reported. Preliminary results for $B\to D\ell \nu$ decays form factors $h_{\pm }(w)$ over a kinematic range $1<w<1.3$ are reported as well.

    ↳ hep-lathep-phPoS(2020)·13 citations
19. 19*

    Effects of a parallel electromagnetic field in three-flavor Nambu--Jona-Lasinio model

    Gaoqing Cao🇨🇳

    In this work, we explore the ground state of QCD system and the relevant collective modes in a parallel electromagnetic (EM) field within the effective three-flavor Nambu--Jona-Lasinio model. From the features of neutral chiral condensates, three critical EM fields are identified in our study: $e{\bar{I}}_2^{c_i}(i=1,2,3)$. Moreover, competition between QCD and QED anomalies is found: the negativeness of ${\pi }_{\mathrm{d}}^{\ast }$ and ${\pi }_{\mathrm{s}}^{\ast }$ is a signal of QCD anomaly dominance for all the flavors, and the positiveness of ${\pi }_{\mathrm{s}}^{\ast }$ beyond $e{\bar{I}}_2^{c_1}$ indicates QED anomaly dominance for strange quark. For the lowest-lying neutral collective modes, the masses of $\Pi$ and $H$ modes reduce to zero around the critical EM fields and the scalar-pseudoscalar components are exchanged between $\Sigma$ and $H$ modes, as can be seen in the crossing structure.

    ↳ nucl-thhep-phPRD(2020)·12 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.