No Arabic abstract
The low energy effective potential for the model with a light scalar and a heavy scalar is derived. We perform the path integration for both heavy and light scalars and derive the low energy effective potential in terms of only the light scalar. The effective potential is independent of the renormalization scale approximately. By setting the renormalization scale equal to the mass of the heavy scalar, one finds the corrections with the logarithm of the ratio of the two scalar masses. The large logarithm is summed with the renormalization group (RG) and the RG improved effective potential is derived. The improved effective potential includes the one-loop correction of the heavy scalar and the leading logarithmic corrections due to the light scalar. We discuss the implication of the corrections to the parameters of the mass squared dimension as well as the cosmological constants.
To understand the phase transition phenomena, information theoretical approaches can pick up some important properties of the phenomena based on the probability distribution. In this paper, we show information theoretical aspects of the 3-dimensional 3-state Potts model with the external field which is corresponding to the QCD effective model with heavy quarks. The transfer mutual information which represents the information flow of two spin variables is numerically estimated based on the Markov-chain Monte-Carlo method. The transfer mutual information has the peak near the confinement-deconfinement transition, and it may be used to detect the precursors of the transition. Since the transfer mutual information still have the peak even if the Polyakov-loop changes continuously and smoothly, we may pick up some aspects of the confinement-deconfinement nature from the information flow properties. Particularly, the transfer mutual information shows the significantly different behavior below and above the Roberge-Weiss endpoint existed in the pure imaginary chemical potential region, which may indicate the system change by the confinement-deconfinement transition.
The scaling behavior of semileptonic form-factors in Heavy to Light transitions is studied in the Heavy Quark Effective Theory. In the case of $Hrightarrow pi e u$ it is shown that the same scaling violations affecting the heavy meson decay constant will be present in the semileptonic form-factors.
I develop an Effective Field Theory (EFT) framework to compute jet substructure observables for heavy ion collision experiments. As an illustration, I consider dijet events that accompany the formation of a weakly coupled Quark Gluon Plasma(QGP) medium in a heavy ion collision and look at an observable insensitive to jet selection bias: the simultaneous measurement of jet mass along with the transverse momentum imbalance between the jets that are groomed to remove soft radiation. Treating the jet as an open quantum system, I write down a factorization formula within the SCET(Soft Collinear Effective Theory) framework in the forward scattering regime. The physics of the medium is encoded in a universal soft field correlator while the jet-medium interaction is captured by a medium induced jet function. The factorization formula leads to a Lindblad type equation for the evolution of the reduced density matrix of the jet in the Markovian approximation. The solution for this equation allows a resummation of large logarithms that arise due to the final state measurements imposed while simultaneously summing over multiple incoherent interactions of the jet with the medium.
We perform a comprehensive analysis of the Minimal Supersymmetric Standard Model (MSSM) in the scenario where the scalar partners of the fermions and the Higgs particles (except for the Standard-Model-like one) are assumed to be very heavy and are removed from the low-energy spectrum. We first summarize our determination of the mass spectrum, in which we include the one-loop radiative corrections and resum to all orders the leading logarithms of the large scalar masses, and describe the implementation of these features in the FORTRAN code SuSpect which calculates the masses and couplings of the MSSM particles. We then study in detail the phenomenology of the model in scenarios where the gaugino mass parameters are non-universal at the GUT scale, which leads to very interesting features that are not present in the widely studied case of universal gaugino mass parameters. We discuss the constraints from collider searches and high-precision measurements, the cosmological constraints on the relic abundance of the neutralino candidate for the Dark Matter in the Universe - where new and interesting channels for neutralino annihilation appear - and the gluino lifetime. We then analyze, in the case of non-universal gaugino masses, the decays of the Higgs boson (in particular decays into and contributions of SUSY particles), of charginos and neutralinos (in particular decays into Higgs bosons and photons) and of gluinos, and highlight the differences from the case of universal gaugino masses.
We have explored the prospect of probing a neutral scalar ($H$) produced in association with one $b$-quark and decaying either invisibly or into a pair of $b$-quarks at the LHC with centre of mass energy $sqrt s = 14$ TeV. In this regard, we adopt an effective theory approach to parameterize a $Hbbar bg$ vertex arising from a dimension six operator that encompasses the effect of some new physics setting in at a high scale. We concentrate solely on the five-flavor scheme to ascertain the sensitivity of the 14 TeV LHC in probing such an effective coupling as a function of the scalar mass at the highest possible projected luminosity, $3000~{rm fb}^{-1}$. Through our multivariate analysis using machine learning algorithm we show that staying within the perturbative limit of the Wilson coefficient of the effective interaction, evidence with statistical significance of $3sigma$ can be obtained in two different signal regions for $m_Hlesssim 2$ TeV and the scale of new physics $Lambda = 3$ TeV.