Journal articles: 'Standard Model (SM)'

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GREEN, DAN. ""REDISCOVERING" THE STANDARD MODEL AT CMS." Modern Physics Letters A 26, no. 05 (February 20, 2011): 309–17. http://dx.doi.org/10.1142/s0217732311035134.

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The Large Hadron Collider (LHC) began 7 TeV C.M. energy operation in April, 2010. The CMS experiment immediately analyzed the earliest data taken in order to "rediscover" the Standard Model (SM) of high energy physics. By the late summer, all SM particles were observed and CMS began to search for physics beyond the SM and beyond the present limits set at the Fermilab Tevatron. The first LHC run ended in Dec., 2010 with a total integrated luminosity of about 45 pb-1 delivered to the experiments.

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Knoepfel, Kyle J. "Standard Model Higgs boson searches at the Tevatron." Modern Physics Letters A 29, no. 10 (March 28, 2014): 1430009. http://dx.doi.org/10.1142/s0217732314300092.

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We give an overview of Standard Model (SM) Higgs boson studies performed at the CDF and D∅ experiments at the Tevatron proton–antiproton collider. Combining the results of many individual analyses, most of which use the full data set available, an excess with a significance of 3.0 standard deviations with respect to the SM hypothesis is observed at a Higgs boson mass of 125 GeV /c2. At that mass, the combined best-fit cross-section is consistent with the SM prediction. Constraints are also placed on the Higgs boson couplings with fermions and electroweak vector bosons and are consistent with the SM predictions within the uncertainties.

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Lunzhi Deng, Lunzhi Deng, Zhenyu Hu Lunzhi Deng, Yu Ruan Zhenyu Hu, and Tao Wang Yu Ruan. "Provably Secure Certificateless Proxy Signature Scheme in the Standard Model." 網際網路技術學刊 23, no. 2 (March 2022): 279–88. http://dx.doi.org/10.53106/160792642022032302008.

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<p>Proxy signature frees the original signer from the heavy signature work. Many certificateless proxy signature (CLPS) schemes have been proposed in the last ten years. The security proofs of most known schemes are given in the random oracle model (ROM). There are only two CLPS schemes with provably security in the standard model (SM). However, in which the size of the system parameter increase linearly with the size of the user’s identity information. That increase the storage burden of the key generation center. In this paper, a new CLPS scheme is constructed and the security proofs are showed in SM. The size of system parameters and the master key are constant in the scheme. Requiring only three pairing operations, the new scheme is more efficient and suitable for mobile computing.</p> <p> </p>

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Okada, Nobuchika, Digesh Raut, and Desmond Villalba. "Domain-Wall Standard Model in non-compact 5D and LHC phenomenology." Modern Physics Letters A 34, no. 10 (March 28, 2019): 1950080. http://dx.doi.org/10.1142/s0217732319500809.

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We propose a framework to construct “Domain-Wall Standard Model” in a non-compact 5-dimensional spacetime, where all the Standard Model (SM) fields are localized in certain domains of the 5th dimension and the SM is realized as a 4-dimensional effective theory without any compactification for the 5th dimension. In this context, we investigate the collider phenomenology of the Kaluza–Klein (KK) modes of the SM gauge bosons and the current constraints from the search for a new gauge boson resonance at the Large Hadron Collider Run-2. The couplings of the SM fermions with the KK-mode gauge bosons depend on the configuration of the SM fermions in the 5-dimensional bulk. This “geometry” of the model can be tested at the future Large Hadron Collider experiment, once a KK-mode of the SM gauge boson is discovered.

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Avrin, J. S. "ALONGSIDE THE STANDARD MODEL: UNIFICATION VIA GEOMETRY." International Journal of Modern Physics A 16, supp01c (September 2001): 916–18. http://dx.doi.org/10.1142/s0217751x01008485.

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A geometrical model (GM) featuring a visualizable reduction of the elementary particles and interactions down to common elements has been developed. As a consequence, a taxonomy of particles and various interactions emerge, all in consonance with the Standard Model (SM) of particle physics. However, the GM goes well beyond the SM, incorporating a number of fundamental phenomena and issues for which the latter has no explanation. Since the GMs largely diagramatic development cannot be displayed in this brief paper, only a summary of its conceptual basis and consequences is presented herein.

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Díaz Cruz, L. "The Higgs profile in the standard model and beyond." Revista Mexicana de Física 65, no. 5 Sept-Oct (September 2, 2019): 419. http://dx.doi.org/10.31349/revmexfis.65.419.

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We present a review of Higgs physics in the SM and beyond, including the tests of the Higgs boson properties that have been performed at LHC and have permitted to delineate its profile. After presenting the essential features of the BEH mechanism, and its implementation in the SM, we discuss how the Higgs mass limits developed over the years. These constraints in turn helped to classify the Higgs phenomenology (decays and production mechanisms), which provided the right direction to search for the Higgs particle, an enterprise that culminated with its discovery at LHC. So far, the constraints on the couplings of the Higgs particle, point towards a SM interpretation. However, the SM has open ends that suggest the need to look for extensions of the model. We discuss in general the connection of the Higgs sector with some new physics (e.g. supersymmetry, flavor and Dark matter), with special focus on a more flavored Higgs sector. Thus is realized in the most general 2HDM, and its textured version, which we study in general, and for its various limits, which contain distinctive flavor-violating signals that could be searched at current and future colliders.

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Korutlu, Beste. "Softly fine-tuned Standard Model and the scale of inflation." Modern Physics Letters A 30, no. 34 (October 20, 2015): 1550179. http://dx.doi.org/10.1142/s0217732315501795.

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The direct coupling between the Higgs field and the spacetime curvature, if finely tuned, is known to stabilize the Higgs boson mass. The fine-tuning is soft because the Standard Model (SM) parameters are subject to no fine-tuning thanks to their independence from the Higgs-curvature coupling. This soft fine-tuning leaves behind a large vacuum energy [Formula: see text] which inflates the Universe with a Hubble rate [Formula: see text], [Formula: see text] being the SM ultraviolet (UV) boundary. This means that the tensor-to-scalar ratio inferred from cosmic microwave background polarization measurements by BICEP2, Planck and others lead to the determination of [Formula: see text]. The exit from the inflationary phase, as usual, is accomplished via decays of the vacuum energy. Here, we show that, identification of [Formula: see text] with the inflaton, as a sliding UV scale upon the SM, respects the soft fine-tuning constraint and does not disrupt the stability of the SM Higgs boson.

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Vayenas, Constantinos G. "The Standard Model (SM) and the goal of force unification." Open Access Government 37, no. 1 (January 6, 2023): 228–31. http://dx.doi.org/10.56367/oag-037-10539.

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The Standard Model (SM) and the goal of force unification The unification of gravitational, Strong and Weak Forces has been a long-sought goal [1-3]. In general, force unification refers to the idea that it is possible to view all of the forces of nature as manifestations of one single, all-encompassing force. Today, within the context of the Standard Model (SM) of elementary particles, [7] scientists seek to unify Gravity with the Strong force under a Grand Unified Theory which binds quarks together and is responsible for the stability of atomic nuclei. These efforts have not been successful yet, most likely because the SM neglects neutrinos [8,9], gravity [4], special relativity [10] and quantum mechanics [11].

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Koren, Seth. "A Note on Proton Stability in the Standard Model." Universe 8, no. 6 (May 30, 2022): 308. http://dx.doi.org/10.3390/universe8060308.

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In this short note, we describe the symmetry responsible for absolute, nonperturbative proton stability in the Standard Model. The SM with Nc colors and Ng generations has an exact, anomaly-free, generation-independent, global symmetry group U(1)B−NcL×ZNgL, which contains a subgroup of baryon plus lepton number of order 2NcNg. This disallows proton decay for Ng>1. Many well-studied models beyond the SM explicitly break this global symmetry, and the alternative deserves further attention.

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Trifyllis, Lampros. "The Higgs di-photon decay in the standard model effective field theory." Facta universitatis - series: Physics, Chemistry and Technology 17, no. 1, spec.issue (2019): 89–96. http://dx.doi.org/10.2298/fupct1901089t.

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Starting from the Standard Model (SM) of elementary particle physics, we assume that new physics effects can be encoded in higher-dimensional operators added in the SM Lagrangian. The resulting theory, the SM Effective Field Theory (SMEFT), is then used for high-accuracy phenomenological studies. Through this paper, the di-photon decay of the Higgs boson is used as a sample of a concrete calculation in the SMEFT framework.

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WANG, SONG-MING. "SEARCHES FOR THE STANDARD MODEL HIGGS BOSON AT THE CDF EXPERIMENT." International Journal of Modern Physics A 24, no. 04 (February 10, 2009): 617–56. http://dx.doi.org/10.1142/s0217751x09043298.

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The understanding of the dynamics behind the breaking of the electroweak symmetry is one of the most important goals in the field of high energy physics. In the Standard Model (SM) Higgs mechanism plays a key role in the symmetry breaking, one manifestation of which is spin-0 Higgs boson. Thus the search for the Higgs boson is one of the flag-ship analyses at the Tevatron. Over the past few years the CDF experiment has made significant improvements in its sensitivity on the search for the SM Higgs boson. In this paper we summarize CDF's most recent results on the searches for the SM Higgs boson production at the Tevatron using data samples of integrated luminosities up to 3 fb-1. We also present the Tevatron's latest combined results on the SM Higgs boson search, and discuss the possibility that it could be found at the Tevatron in the near future.

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SAMUEL, MARK A. "THE TAU-LEPTON AND TESTS OF THE STANDARD MODEL." Modern Physics Letters A 08, no. 26 (August 30, 1993): 2491–96. http://dx.doi.org/10.1142/s0217732393002816.

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Using a new value for the mass of the tau-lepton we reconsider various tests of the Standard Model (SM) for the tau. The agreement with the SM is much improved. All tests agree within 1.2σ or smaller and the so-called “tau-lifetime problem” has disappeared. We also obtain bounds on the mass of the tau-neutrino. It is shown that an improved bound [Formula: see text] MeV at 95% C.L. can be obtained at the τ-charm factory in Spain or at a proposed B-factory.

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Stål, Oscar. "Prospects for Higgs boson scenarios beyond the standard model." International Journal of Modern Physics: Conference Series 31 (January 2014): 1460289. http://dx.doi.org/10.1142/s2010194514602890.

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The new particle recently discovered at the Large Hadron Collider has properties compatible with those expected for the Standard Model (SM) Higgs boson. However, this does not exclude the possibility that the discovered state is of non-standard origin, as part of an elementary Higgs sector in an extended model, or not at all a fundamental Higgs scalar. We review briefly the motivations for Higgs boson scenarios beyond the SM, discuss the phenomenology of several examples, and summarize the prospects and methods for studying interesting models with non-standard Higgs sectors using current and future data.

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Rosner, Jonathan L. "Resource Letter: SM-1: The standard model and beyond." American Journal of Physics 71, no. 4 (April 2003): 302–18. http://dx.doi.org/10.1119/1.1539087.

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ROMÃO, JORGE C., and JOÃO P. SILVA. "A RESOURCE FOR SIGNS AND FEYNMAN DIAGRAMS OF THE STANDARD MODEL." International Journal of Modern Physics A 27, no. 26 (October 18, 2012): 1230025. http://dx.doi.org/10.1142/s0217751x12300256.

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When performing a full calculation within the standard model (SM) or its extensions, it is crucial that one utilizes a consistent set of signs for the gauge couplings and gauge fields. Unfortunately, the literature is plagued with differing signs and notations. We present all SM Feynman rules, including ghosts, in a convention-independent notation, and we table the conventions in close to 40 books and reviews.

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Kitahara, Teppei. "Standard Model and New physics for ε′k/εk." EPJ Web of Conferences 179 (2018): 01007. http://dx.doi.org/10.1051/epjconf/201817901007.

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The first result of the lattice simulation and improved perturbative calculations have pointed to a discrepancy between data on ε′k/εk and the standard-model (SM) prediction. Several new physics (NP) models can explain this discrepancy, and such NP models are likely to predict deviations of ℬ(K → πvv) from the SM predictions, which can be probed precisely in the near future by NA62 and KOTO experiments. We present correlations between ε′k/εk and ℬ(K → πvv) in two types of NP scenarios: a box dominated scenario and a Z-penguin dominated one. It is shown that different correlations are predicted and the future precision measurements of K → πvv can distinguish both scenarios.

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DAS, C. R., and LARISA LAPERASHVILI. "SEESAW SCALES AND STEPS FROM THE STANDARD MODEL TOWARDS SUPERSTRING-INSPIRED FLIPPED E6." International Journal of Modern Physics A 24, no. 32 (December 30, 2009): 6011–33. http://dx.doi.org/10.1142/s0217751x09047430.

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Recently in connection with superstring theory and with an alternative nonsupersymmetric "Exceptionally Simple Theory of Everything," E8 and E6 unifications became very promising. In the present paper we have investigated a number of available paths from the Standard Model (SM) to the E6 unification, considering chains of flipped models following the extension of the SM, also a chain with a left–right symmetry. We have presented four examples including nonsupersymmetric and supersymmetric extensions of the SM and different contents of the Higgs bosons providing the breaking of the flipped SO(10) and SU(5) down to the SM. It was shown that the final unification E6× U (1) or E6 at the (Planck) GUT scale M SSG depends on the number of the Higgs boson representations considered in theory.

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BEENAKKER, WIM, and ANSGAR DENNER. "STANDARD-MODEL PREDICTIONS FOR W-PAIR PRODUCTION IN ELECTRON-POSITRON COLLISIONS." International Journal of Modern Physics A 09, no. 28 (November 10, 1994): 4837–919. http://dx.doi.org/10.1142/s0217751x94001965.

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We review the status of the theoretical predictions for W-pair production in e+e− collisions within the electroweak standard model (SM). We first consider for on-shell W bosons the lowest-order cross-section within the SM, the general effects of anomalous couplings, the radiative corrections within the SM, and approximations for them. Then we discuss the inclusion of finite-width effects in the lowest order and the existing results for radiative corrections to off-shell W-pair production, and we outline the general strategy for calculating radiative corrections within the pole scheme. We summarize the theoretical predictions for the total and partial W-boson widths including radiative corrections and discuss the quality of an improved Born approximation. Finally, we provide a general discussion on the structure-function method for calculating large-logarithmic higher-order corrections associated with collinear photon radiation.

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Morais, António P., Roman Pasechnik, and Werner Porod. "Grand Unified Origin of Gauge Interactions and Families Replication in the Standard Model." Universe 7, no. 12 (November 25, 2021): 461. http://dx.doi.org/10.3390/universe7120461.

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The tremendous phenomenological success of the Standard Model (SM) suggests that its flavor structure and gauge interactions may not be arbitrary but should have a fundamental first-principle explanation. In this work, we explore how the basic distinctive properties of the SM dynamically emerge from a unified New Physics framework tying together both flavor physics and Grand Unified Theory (GUT) concepts. This framework is suggested by a novel anomaly-free supersymmetric chiral E6×SU(2)F×U(1)F GUT containing the SM. Among the most appealing emergent properties of this theory is the Higgs-matter unification with a highly-constrained massless chiral sector featuring two universal Yukawa couplings close to the GUT scale. At the electroweak scale, the minimal SM-like effective field theory limit of this GUT represents a specific flavored three-Higgs doublet model consistent with the observed large hierarchies in the quark mass spectra and mixing already at tree level.

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Kawana, Kiyoharu. "Classical conformality in the Standard Model from Coleman’s theory." Modern Physics Letters A 31, no. 31 (September 23, 2016): 1650176. http://dx.doi.org/10.1142/s0217732316501765.

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The classical conformality (CC) is one of the possible candidates for explaining the gauge hierarchy of the Standard Model (SM). We show that it is naturally obtained from the Coleman’s theory on baby universe.

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DOS SANTOS, A. L., and D. HADJIMICHEF. "SEARCHING FOR A DARK MATTER COUPLING TO THE STANDARD MODEL WITH A STUECKELBERG EXTENSION." International Journal of Modern Physics: Conference Series 18 (January 2012): 10–12. http://dx.doi.org/10.1142/s2010194512008124.

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We investigate a double extension to the Standard Model (SM). A first extension introduces, via minimal coupling, a massive Z′ boson. This enlarged SM is coupled to a dark matter sector through the Stueckelberg mechanism by a A′ boson. However, the A′ boson does not interact directly with the SM fermions. In our study, we found that the A′ is a massless photon-like particle in dark sector. Constraints on the mass for Z′ and corrections to Z mass are obtained.

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Matute, Ernesto A. "Presymmetry in the Standard Model with adulterated Dirac neutrinos." Modern Physics Letters A 30, no. 31 (September 14, 2015): 1550160. http://dx.doi.org/10.1142/s0217732315501606.

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Recently we proposed a model for light Dirac neutrinos in which two right-handed (RH) neutrinos per generation are added to the particles of the Standard Model (SM), implemented with the symmetry of fermionic contents. The ordinary one is decoupled via the high scale type-I seesaw mechanism, while the extra pairs off with its left-handed (LH) partner. The symmetry of lepton and quark contents was merely used as a guideline to the choice of parameters because it is not a proper symmetry. Here we argue that the underlying symmetry to take for this correspondence is presymmetry, the hidden electroweak symmetry of the SM extended with RH neutrinos defined by transformations which exchange lepton and quark bare states with the same electroweak charges and no Majorana mass terms in the underlying Lagrangian. It gives a topological character to fractional charges, relates the number of families to the number of quark colors, and now guarantees the great disparity between the couplings of the two RH neutrinos. Thus, Dirac neutrinos with extremely small masses appear as natural predictions of presymmetry, satisfying the ’t Hooft’s naturalness conditions in the extended seesaw where the extra RH neutrinos serve to adulterate the mass properties in the low scale effective theory, which retains without extensions the gauge and Higgs sectors of the SM. However, the high energy threshold for the seesaw implies new physics to stabilize the quantum corrections to the Higgs boson mass in agreement with the naturalness requirement.

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Wang, Shan, Yuexing Wang, Chi Zhang, Han Shuai, and Chun-Xiang Shi. "Research on Fusing Multisatellite Soil Moisture Data Based on Bayesian Model Averaging." Advances in Meteorology 2018 (June 25, 2018): 1–7. http://dx.doi.org/10.1155/2018/9310838.

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Soil moisture (SM) is an important physical quantity that can reflect the land surface condition. There are many ways to measure SM, satellite microwave remote sensing is now considered the primary method because it can provide real-time high-resolution data. However, SM data obtained by satellite remote sensing exhibit certain deviation compared with reference data obtained from ground stations. To improve the accuracy of SM forecasts, this study proposed the use of a Bayesian model averaging (BMA) method to integrate multisatellite SM data. First, China was divided into eight regions. Then, SM data observed by satellites (FY3B, SMOS, and WINDSAT) were fused using the BMA method and a traditional averaging method. Finally, SM data were predicted using data from ground observation stations as a reference standard. Following the fusion process, three parameters (standard deviation, correlation coefficient, and root mean square deviation) were used to evaluate the fusion results, which revealed the superiority of the BMA method over the traditional averaging method.

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FUKUYAMA, TAKESHI. "SEARCHING FOR NEW PHYSICS BEYOND THE STANDARD MODEL IN ELECTRIC DIPOLE MOMENT." International Journal of Modern Physics A 27, no. 16 (June 17, 2012): 1230015. http://dx.doi.org/10.1142/s0217751x12300153.

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This is a theoretical review of exploration of new physics beyond the Standard Model (SM) in the electric dipole moment (EDM) in elementary particles, atoms and molecule. EDM is a very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarks–leptons in SM, we explore new signals beyond SM. However, these works drive us to wider frontiers where we search fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electron EDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus EDM becomes the keyword not only of New Physics but also of unprecedented fruitful collaborations among particle, atomic and molecular physics. This review intends to help such collaborations over a wide range of physicists.

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Loebbert, Florian, and Jan Plefka. "Quantum gravitational contributions to the Standard Model effective potential and vacuum stability." Modern Physics Letters A 30, no. 34 (October 20, 2015): 1550189. http://dx.doi.org/10.1142/s0217732315501898.

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We compute the quantum gravitational contributions to the Standard Model (SM) effective potential and analyze their effects on the Higgs vacuum stability in the framework of effective field theory. Einstein gravity necessarily implies the existence of higher dimension [Formula: see text] and [Formula: see text] operators with novel couplings [Formula: see text] in the Higgs sector. The beta functions of these couplings are established and the impact of the gravity induced contributions on electroweak vacuum stability is studied. We find that the true minimum of the SM effective potential now lies below the Planck scale for almost the entire parameter space [Formula: see text]. In addition quantum gravity is shown to contribute to the minimal value of the SM next-to-leading order (NLO) effective potential at the percent level. The quantum gravity induced contributions yield a metastable vacuum for a large fraction of the parameter space in the flowing couplings [Formula: see text].

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HEWETT, JOANNE L., and THOMAS G. RIZZO. "$B_s^0 \ndash - \bar B_s^0 $ MIXING IN THE FOUR GENERATION STANDARD MODEL." Modern Physics Letters A 03, no. 10 (August 1988): 975–80. http://dx.doi.org/10.1142/s0217732388001148.

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We examine the constraints imposed by recent data on [Formula: see text] mixing, ε′/ε, and |Vub|/|Vcb| on the size of [Formula: see text] mixing in the four generation standard model (SM). We show that, unlike the SM with only three generations, [Formula: see text] mixing need not be maximal in the four generation case. In particular, we show that it is quite likely that [Formula: see text] mixing is smaller than [Formula: see text] mixing.

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Ali, Ahmed. "Precision tests of the Standard Model: Rare B-meson decays." International Journal of Modern Physics A 32, no. 09 (March 23, 2017): 1741015. http://dx.doi.org/10.1142/s0217751x17410159.

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The charge given to me by the organisers of the memorial meeting for Prof. Abdus Salam’s 90th birthday is to recall my personal impressions of him and review an aspect of the standard model (SM) physics related to my work. Salam was, first and foremost, a brilliant theoretical physicist whose work is still very much en vogue, currently being tested precisely by the experiments at the Large Hadron Collider (LHC). Salam was, however, equally effective as a scientific advisor to many institutions, such as IAEA and CERN, but also to the government of Pakistan as the chief scientific strategist. He was also an untiring advocate of scientific research and higher education in developing countries, which took a concrete form in the International Centre for Theoretical Physics (ICTP) in Trieste. I discuss these aspects of his scientific life seen from my perspective in the first part. In the second part of my talk, which may appear as a disjoint piece to the first, I summarise some selected topics in rare B-decays — the current flavour physics frontier. Experiments carried out over several decades are largely in agreement with the SM, thanks also to dedicated theoretical effort in their interpretation. However, this field is undergoing an anomalous phase in a number of key measurements, in particular reported by LHCb, triggering a very lively debate and model building. These anomalies, which I review here, are too numerous to be ignored, but none is individually significant enough to announce a breakdown of the SM.

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Sun, Ke-Sheng, Jian-Bin Chen, Xiu-Yi Yang, and Hai-Bin Zhang. "One-loop correction to Z → νν in the minimal R-symmetric supersymmetric Standard Model." Modern Physics Letters A 34, no. 07n08 (March 12, 2019): 1950058. http://dx.doi.org/10.1142/s0217732319500585.

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We analyze the one-loop correction to [Formula: see text] decay in framework of Minimal R-symmetric Supersymmetric Standard Model (MRSSM) in detail with normal and inverse neutrino mass orderings, as a function of [Formula: see text], Dirac mass parameters [Formula: see text] and [Formula: see text], slepton mass [Formula: see text] that parametrize the mass matrices. The numerical results indicate that the branching ratio for [Formula: see text] decay is compatible with the experimental measurement and the SM expectation at [Formula: see text] level. For inverse neutrino mass ordering, the prediction exceeds the SM expectation at [Formula: see text] level. The prediction on [Formula: see text] increases proportionally to [Formula: see text] and inversely proportionally to [Formula: see text]. For normal neutrino mass ordering, the peak value of the prediction on [Formula: see text] exceeds the SM expectation at [Formula: see text] level.

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Abbas, Gauhar. "Right–right–left extension of the Standard Model." Modern Physics Letters A 31, no. 19 (June 21, 2016): 1650117. http://dx.doi.org/10.1142/s0217732316501170.

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A right–right–left extension of the Standard Model is proposed. In this model, SM gauge group [Formula: see text] is extended to [Formula: see text]. The gauge symmetries [Formula: see text], [Formula: see text] are the mirror counterparts of the [Formula: see text] and [Formula: see text], respectively. Parity is spontaneously broken when the scalar Higgs fields acquire vacuum expectation values (VEVs) in a certain pattern. Parity is restored at the scale of [Formula: see text]. The gauge sector has a unique pattern. The scalar sector of the model is optimum, elegant and unique.

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Mingrone, G., A. Bertuzzi, E. Capristo, A. V. Greco, M. Manco, A. Pietrobelli, S. Salinari, and S. B. Heymsfield. "Unreliable use of standard muscle hydration value in obesity." American Journal of Physiology-Endocrinology and Metabolism 280, no. 2 (February 1, 2001): E365—E371. http://dx.doi.org/10.1152/ajpendo.2001.280.2.e365.

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Intramuscular water content is assumed to be constant in humans independent of their anthropometric characteristics. To verify whether this assumption is correct, intramuscular water, proteins, glycogen, and both total and intramyocytic triglycerides were measured in 51 samples of rectus abdominis muscle obtained from 16 lean and 35 overweight and obese subjects (body mass index cutoff 24.9 kg/m2). Data (referred to as wet tissue) were analyzed by means of a composition model at the cellular level of the skeletal muscle (SM). The average SM water content was 76.3 ± 3.3% in normal-weight individuals and 65.7 ± 5.8% in obese subjects ( P < 0.0001). Total triglycerides were 5.5 ± 2.3% in controls and 19.0 ± 7.0% in obese subjects ( P < 0.0001). The intramyocytic triglyceride fraction was also increased in obese subjects. The composition model provides an explanation for the negative correlation between total triglycerides and intramuscular water, and some of the model parameters were determined from the experimental data. In conclusion, although the hydration of fat-free SM mass may be unchanged in obese subjects, the hydration of in toto muscle mass decreases as its lipid content increases.

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Vizgin, Vl P. "METAPHYSICAL ASPECTS OF THE STANDARD MODEL OF THE ELEMENTARY PARTICLES PHYSICS AND THE HISTORY OF ITS CREATION." Metafizika, no. 3 (December 15, 2020): 39–56. http://dx.doi.org/10.22363/2224-7580-2020-3-39-56.

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Metaphysical aspects of the standard model (SM) of the modern elementary particles theory are considered. This article briefly views a history of the formation of the SM (from fundamental paper of C. Yang and R. Mills (1954) to the completion of electroweak theory and quantum chromodynamics in the early 1970s). Three groups of the interrelated metaphysical aspects are discussed: local gauge symmetry’s structure of the theory, problem of the truth and reality and the role of the metaphysical factors in the construction of the theory. Scientific-realistic nature of the SM creator’s metaphysical views are emphasized. A. Einstein’s model of the theory’s construction (with “Einstein’s arc”), E. Wigner’s three layer scheme of the structure and the development of the scientific knowledge (with the symmetry principles as a main layer) and S.I. Vavilov’s “mistakability” сonception of the scientific knowledge development are proposed for the study of the metaphysical factors and their role in the formation of the SM.

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Çiftçi, A. K., and R. Çiftçi. "General structure of democratic mass matrix of lepton sector in E6 model." Canadian Journal of Physics 96, no. 7 (July 2018): 834–36. http://dx.doi.org/10.1139/cjp-2017-0783.

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An extension of the Standard Model (SM) fermion sector, which is inspired by the E6 grand unified theory model, may be a good candidate to explain a number of unanswered questions in SM. Existence of the E6 leptons may explain great mass difference of charged and neutral leptons. Also, democracy on mass matrix elements is a natural approach in SM. In this study, we have given general structure of democratic mass matrix of lepton sector in E6 model.

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Litsa, Aliki, Katherine Freese, Evangelos I. Sfakianakis, Patrick Stengel, and Luca Visinelli. "Primordial non-Gaussianity from the effects of the Standard Model Higgs during reheating after inflation." Journal of Cosmology and Astroparticle Physics 2023, no. 03 (March 1, 2023): 033. http://dx.doi.org/10.1088/1475-7516/2023/03/033.

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Abstract We propose a new way of studying the Higgs potential at extremely high energies. The Standard Model (SM) Higgs boson, as a light spectator field during inflation in the early Universe, can acquire large field values from its quantum fluctuations which vary among different causal (Hubble) patches. Such a space dependence of the Higgs after the end of inflation leads to space-dependent SM particle masses and hence variable efficiency of reheating, when the inflaton decays to Higgsed SM particles. Inhomogeneous reheating results in (observable) temperature anisotropies. Further, the resulting temperature anisotropy spectrum acquires a significant non-Gaussian component, which is constrained by Planck observations of the Cosmic Microwave Background (CMB) and potentially detectable in next-generation experiments. Constraints on this non-Gaussian signal largely exclude the possibility of the observed temperature anisotropies arising primarily from Higgs effects. Hence, in principle, observational searches for non-Gaussianity in the CMB can be used to constrain the dynamics of the Higgs boson at very high (inflationary) energies.

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DEO, B. B., and L. P. SINGH. "QUASI SUPERSYMMETRY WITHIN THE STANDARD MODEL AND HIGGS MASS." Modern Physics Letters A 14, no. 35 (November 20, 1999): 2447–52. http://dx.doi.org/10.1142/s0217732399002546.

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The 12 bosonic degrees of freedom of the standard model (SM) are exactly matched by fermionic degrees of freedom of a single colored quark, e.g. top. Indeed, we construct a charge involving top-quark, gauge and Higgs fields which satisfy usual supersymmetry algebra. The colored quark states behave like the superpartners of gauge and Higgs bosons and vice versa. When this SUSY is broken, a mass relation must be satisfied at the tree level from which the mass of the Higgs is predicted to be 300.5±11 GeV.

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AZIZ, TARIQ. "INTERNAL SELF-CONSISTENCY OF WEAK NEUTRAL CURRENT DATA AT LEP/SLC FAVORS PHYSICS BEYOND STANDARD MODEL." Modern Physics Letters A 09, no. 20 (June 28, 1994): 1857–66. http://dx.doi.org/10.1142/s0217732394001726.

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The recent measurements of Rb=Γb/Γhad together with other experimentally independent measurements of weak neutral current observables at LEP/SLC, display excellent internal self-consistency if the top dependent [Formula: see text] vertex correction is ignored. Extending this consistency further, the possibility of ignoring even the propagator/oblique corrections is not ruled out. Being a clean top mass indicator within SM, free from Higgs and strong interaction uncertainty, a comparison of Rb with the directly measured top quark mass at Tevatron clearly strengthens the above view. To preserve the weak radiative corrections of SM origin, for which evidence exists from measurements at low energies, independent of LEP/SLC, the most natural choice would be to invoke new radiative corrections of opposite sign from physics beyond SM. We stress that an improved measurement of Rb at LEP/SLC together with the direct measurement of top quark mass at Tevatron will play a clean and decisive role in this direction.

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36

Banerjee, D., M. Kumar, P. Nayek, and S. Sahoo. "Study of Bs0 → ℓ+ℓ−γ decays in a nonuniversal Z′ model." International Journal of Modern Physics A 34, no. 09 (March 30, 2019): 1950048. http://dx.doi.org/10.1142/s0217751x19500489.

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We investigate [Formula: see text] decays in a nonuniversal [Formula: see text] model derived from the extension of the Standard Model (SM). Considering the [Formula: see text]-mediated flavor-changing neutral current (FCNC) effects, we calculate the branching ratio and forward–backward asymmetry [Formula: see text] for [Formula: see text] decay processes. We compare the obtained results with predictions of the SM and discuss the sensitivity of the observables to [Formula: see text] boson coupling parameters. We find that the branching ratios are enhanced by one order from SM predictions in [Formula: see text] model scenario. We also observe that the variation of forward–backward asymmetry with the [Formula: see text] boson coupling parameters portrays discrimination between NP effects and SM results.

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37

Vizgin, Vladimir P. "Socio-Cultural Aspects of the Standard Model in Elementary Particles Physics and the History of Its Creation." Epistemology & Philosophy of Science 57, no. 3 (2020): 160–75. http://dx.doi.org/10.5840/eps202057348.

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The article соnsiders the socio-cultural aspects of the standard model (SM) in elementary particle physics and history of its creation. SM is a quantum field gauge theory of electromagnetic, weak and strong interactions, which is the basis of the modern theory of elementary particles. The process of its elaboration covers a twenty-year period: from 1954 (the concept of gauge fields by C. Yang and R. Mills) to the early 1970s., when the construction of renormalized quantum chromodynamics and electroweak theory wеre completed. The socio-cultural aspects of SM are explored on the basis of a quasi-empirical approach, by studying the texts of its creators and participants in the relevant events. We note also the important role of such an “external” factor as large-scale state projects on the creation of nuclear and thermonuclear weapons, which provided personnel and financial support for fundamental research in the field of nuclear physics and elementary particle physics (the implementation of thermonuclear projects took place just in the 1950s, and most of the theorists associated with the creation of SM were simultaneously the main developers of thermonuclear weapons, especially in the USSR). The formation of SM is considered as a competition between two research programs (paradigms) – gauge-field and phenomenological, associated with the rejection of the field concept. The split of the scientific community of physicists associated with this competition is going on during this period. It’s accompanied by a kind of “negotiations”, which in the early 1970s lead to the triumph of the gauge field program and the restoration of the unity of the scientific community. The norms and rules of the scientific ethos played the regulatory role in this process. The scientific-realistic position of the metaphysical attitudes of the majority of theorists and their negative attitude to the concepts of philosophical relativism and social construction of scientific knowledge are emphasized. Some features of the history of SM creation are also noted, such as the positive role of aesthetic judgments; “scientific-school” form of research (in the USSR), its pros and cons; a connection to historical-scientific “drama of ideas” with “dramas of people” who made a wrong choice and (or) “missed their opportunities”.

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Moussa, Mohamed. "Constraining unparticle-inspired model parameters using dwarf stars." International Journal of Modern Physics D 30, no. 05 (February 23, 2021): 2150031. http://dx.doi.org/10.1142/s0218271821500310.

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The unparticle-inspired model of gravity suggested by Georgi is based on that the standard model (SM) may contain a massive but scale invariant particles, which can be exchanged between SM massive particles, leading to a new force called ungravity. This would add a perturbed term to the Newtonian law of gravity at low energy. We use the minimum mass of hydrogen burning (MMHB) to constrain the relevant parameters of unparticle inspired model of gravity, on scales [Formula: see text] and [Formula: see text].

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Robens, Tania. "Two-Real-Singlet-Model Benchmark Planes." Symmetry 15, no. 1 (December 22, 2022): 27. http://dx.doi.org/10.3390/sym15010027.

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In this manuscript, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a Z2⊗Z2′ symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total three CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes and briefly discuss possible production at future Higgs factories, as well as regions in a more generic scan of the model. For these, I also discuss the use of the W-boson mass as a precision observable to determine allowed/excluded regions in the models’ parameter space. This work is an extension of a white paper submitted to the Snowmass process.

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KANG, KYUNGSIK, and SIN KYU KANG. "THE MINIMAL SUPERSYMMETRIC STANDARD MODEL AND PRECISION OF W-BOSON MASS AND TOP QUARK MASS." Modern Physics Letters A 13, no. 32 (October 20, 1998): 2613–20. http://dx.doi.org/10.1142/s0217732398002771.

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We argue that the present value and accuracy of MW and mt measurements tend to favor the MSSM, provided that the central values of MW and mt stay at the current values, over the SM. By speculating that a precision of order 40 MeV and 3 GeV respectively for MW and mt will be achieved at LEP2 and Tevatron, we show that the prospect for the MSSM will be further enhanced as long as the central values of MW and mt do not increase below the present values. In addition, we discuss how this scenario can constrain the Higgs boson mass and distinguish the Higgs boson of the MSSM type from that of the SM.

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Asner, David. "Studying Standard Model-Like Higgs Bosons in Two-Photon Collisions at a Linear Collider." International Journal of Modern Physics A 18, no. 16 (June 30, 2003): 2817–26. http://dx.doi.org/10.1142/s0217751x03016288.

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We examine the potential for detecting and studying a SM-like Higgs boson in two-photon collisions at a future linear collider. Our study incorporates realistic two-photon spectra based on the most probable available laser technology.

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FARGNOLI, H. G., C. GNENDIGER, S. PASSEHR, D. STÖCKINGER, and H. STÖCKINGER-KIM. "THE FULL ELECTROWEAK STANDARD MODEL PREDICTION FOR (g - 2) OF THE MUON AND IMPROVEMENTS ON THE MSSM PREDICTION." International Journal of Modern Physics: Conference Series 35 (January 2014): 1460419. http://dx.doi.org/10.1142/s2010194514604190.

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Recent progress on the (g - 2)μ prediction is presented. In the SM, the Higgs-boson mass dependent contributions have been evaluated exactly up to the two-loop level and consistently combined with leading three-loop effects. Thus, the currently most accurate value including a detailed error analysis for the SM electroweak contributions has been obtained. The SUSY two-loop corrections from fermion/sfermion-loop insertions have been computed; they are generally large and logarithmically enhanced for heavy squarks.

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Ströher, Hans, Sebastian M. Schmidt, Paolo Lenisa, and Jörg Pretz. "Precision Storage Rings for Electric Dipole Moment Searches: A Tool En Route to Physics Beyond-the-Standard-Model." Particles 6, no. 1 (March 2, 2023): 385–98. http://dx.doi.org/10.3390/particles6010020.

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Electric Dipole Moments (EDM) of particles (leptons, nucleons, and light nuclei) are currently deemed one of the best indicators for new physics, i.e., phenomena which lie outside the Standard Model (SM) of elementary particle physics—so-called physics “Beyond-the-Standard-Model” (BSM). Since EDMs of the SM are vanishingly small, a finite permanent EDM would indicate charge-parity (CP) symmetry violation in addition to the well-known sources of the SM, and could explain the baryon asymmetry of the Universe, while an oscillating EDM would hint at a possible Dark Matter (DM) field comprising axions or axion-like particles (ALPs). A new approach exploiting polarized charged particles (proton, deuteron, 3He) in precision storage rings offers the prospect to push current experimental EDM upper limits significantly further, including the possibility of an EDM discovery. In this paper, we describe the scientific background and the steps towards the realization of a precision storage ring, which will make such measurements possible.

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dos Santos, A. L., and D. Hadjimichef. "Astrophysical aspects of milli-charged dark matter in a Higgs–Stueckelberg model." Modern Physics Letters A 30, no. 18 (May 25, 2015): 1550089. http://dx.doi.org/10.1142/s0217732315500893.

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An extension of the Standard Model (SM) is studied, in which two new vector bosons are introduced, a first boson Z' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A' field, in the dark sector of the model, remains massless and originates a dark photon γ'. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. In a Compton-like process, a photon scattered by a weakly interacting massive particles (WIMP) is converted into a dark photon. This process is studied, in an astrophysical application obtaining an estimate of the impact on stellar cooling of white dwarfs and neutron stars.

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Bossi, Hannah, and Shreyashi Chakdar. "A Symmetric Two Higgs Doublet Model." Journal of Nepal Physical Society 7, no. 3 (December 31, 2021): 34–40. http://dx.doi.org/10.3126/jnphyssoc.v7i3.42189.

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In the light of ongoing experimental search efforts for the dark matter and the post-Higgs Beyond the Standard Model (BSM) null results at the Large Hadron Collider (LHC), the Electroweak sector demands to be investigated for possible new scalar states discoverable at the LHC fulfilling the role of the dark matter. In this work we present a symmetric two Higgs doublet model with a discrete interchange symmetry among the two Higgs doublets (Φ1 ↔ Φ2). Apart from the Standard Model (SM)-like scalar state (h) with mh = 125 GeV, the model has several distinguishing features including the pseudoscalar (A), the charged scalars(H±) and the neutral scalar H, not having any direct coupling to the fermions. The neutral scalar H is assumed to have mass lighter than the 125 GeV SM-like Higgs state h. Due to the presence of a residual Z2 symmetry after the spontaneous symmetry breaking (SSB), the neutral scalar H can emerge as a viable dark matter candidate. We discuss the constraints on such scalar dark matter from the current direct and indirect detection experiments. As a by-product of this construction, the SM-like scalar h ends up having an extra invisible decay mode of h → HH in this model which can also influence the dark matter parameter space. We discuss these model features in detail along with a guideline of relevant phenomenological searches at the LHC for this scenario.

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Cao, Jun, and Jie-Fen Shen. "Triple Higgs boson production at ILC in the Higgs triplet model." Modern Physics Letters A 29, no. 23 (July 24, 2014): 1450092. http://dx.doi.org/10.1142/s0217732314500928.

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Besides the Standard Model (SM)-like Higgs boson h, the Higgs Triplet Model (HTM) predicts the existence of charged and doubly charged Higgs bosons (H±and H±±). In this paper, we focus on the study of the triple Higgs production at the International Linear Collider (ILC): e-e+→hH+H-and e-e+→hH++H–. We present the production cross-sections and discuss the relevant SM backgrounds. Our numerical results show that, with reasonable parameter values, the values of the cross-sections for two processes can reach the level several fb and tens of fb, respectively. Due to large production cross-section and small SM background, the possible signals of H±and H±±might be detected via these processes in the future ILC experiments.

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Huang, Wei, Xin Li, Elizabeth A. Morris, Luminita A. Tudorica, Venkatraman E. Seshan, William D. Rooney, Ian Tagge, Ya Wang, Jingang Xu, and Charles S. Springer. "The magnetic resonance shutter speed discriminates vascular properties of malignant and benign breast tumors in vivo." Proceedings of the National Academy of Sciences 105, no. 46 (November 12, 2008): 17943–48. http://dx.doi.org/10.1073/pnas.0711226105.

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The pharmacokinetic analysis of dynamic-contrast-enhanced (DCE) MRI data yields Ktrans and kep, two parameters independently measuring the capillary wall contrast reagent transfer rate. The almost universally used standard model (SM) embeds the implicit assumption that equilibrium transcytolemmal water exchange is effectively infinitely fast. In analyses of routine DCE-MRI data from 22 patients with suspicious breast lesions initially ruled positive by institutional screening protocols, the SM Ktrans values for benign and malignant lesions exhibit considerable overlap. A form of the shutter-speed model (SSM), which allows for finite exchange kinetics, agrees with the SM Ktrans value for each of the 15 benign lesions. However, it reveals that the SM underestimates Ktrans for each of the seven malignant tumors in this population. The fact that this phenomenon is unique to malignant tumors allows their complete discrimination from the benign lesions, as validated by comparison with gold-standard pathology analyses of subsequent biopsy tissue samples. Likewise, the SM overestimates kep, particularly for the benign tumors. Thus, incorporation of the SSM into the screening protocols would have precluded all 68% of the biopsy/pathology procedures that yielded benign findings. The SM/SSM difference is well understood from molecular first principles.

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ORESTANO, DOMIZIA. "SEARCH FOR THE STANDARD MODEL HIGGS BOSON WITH THE ATLAS DETECTOR." International Journal of Modern Physics D 22, no. 07 (June 2013): 1330015. http://dx.doi.org/10.1142/s0218271813300152.

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This document presents a brief overview of some of the experimental techniques employed by the ATLAS experiment at the CERN Large Hadron Collider (LHC) in the search for the Higgs boson predicted by the standard model (SM) of particle physics. The data and the statistical analyses that allowed in July 2012, only few days before this presentation at the Marcel Grossman Meeting, to firmly establish the observation of a new particle are described. The additional studies needed to check the consistency between the newly discovered particle and the Higgs boson are also discussed.

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Dorokhov, A. E., A. E. Radzhabov, and A. S. Zhevlakov. "Past, present and future of the muon g-2." International Journal of Modern Physics: Conference Series 39 (January 2015): 1560107. http://dx.doi.org/10.1142/s2010194515601076.

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The electron and muon anomalous magnetic moments (AMM) are measured in experiments and studied in the Standard Model (SM) with the highest precision accessible in particle physics. The comparison of the measured quantity with the SM prediction for the electron AMM provides the best determination of the fine structure constant. The muon AMM is more sensitive to the appearance of New Physics effects and, at present, there appears to be a three- to four-standard deviation between the SM and experiment. The lepton AMMs are pure relativistic quantum correction effects and therefore test the foundations of relativistic quantum field theory in general, and of quantum electrodynamics (QED) and SM in particular, with highest sensitivity. Special attention is paid to the studies of the hadronic contributions to the muon AMM which constitute the main source of theoretical uncertainties of the SM.

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Gninenko, S. N., and N. V. Krasnikov. "Invisible KL decays in the SM extensions." Modern Physics Letters A 31, no. 25 (August 9, 2016): 1650142. http://dx.doi.org/10.1142/s021773231650142x.

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In the Standard Model (SM), the branching ratio for the decay [Formula: see text] is helicity suppressed and predicted to be very small [Formula: see text]. We consider two natural extensions of the SM as the two-Higgs-doublet model (2HDM) and the neutrino minimal Standard Model ([Formula: see text]MSM) with additional singlet scalar, whose main feature is that they can lead to an enhanced [Formula: see text]. In the 2HDM, the smallness of the neutrino mass is explained due to the smallness of the second Higgs doublet vacuum expectation value. Moreover, the [Formula: see text]MSM extension with additional singlet field can explain the [Formula: see text] anomaly. The considered models demonstrate that the [Formula: see text] decay is a clean probe of new physics scale well above 100 TeV, that is complementary to rare [Formula: see text] decay, and provide a strong motivation for its sensitive search in a near future low-energy experiment.

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Journal articles on the topic 'Standard Model (SM)'

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