The first results on next-to-leading order QCD corrections to production of direct photon pairs in hadronic collisions in the large extra dimension models- ADD and RS are presented. Various kinematical distributions are obtained to order alpha_s in QCD by taking into account all the parton level subprocesses. Our Monte Carlo based code incorporates all the experimental cuts suitable for physics studies at the LHC. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorisation scale uncertainity when order alpha_s effects are included.
A review of the current experimental results on searches for Higgs bosons in models beyond the Standard Model is presented. Searches from ATLAS, CMS and LHCb use datasets from Run 1 of the LHC, including 7 and 8 TeV proton-proton collisions. Searches from CDF and D0 use the full or partial 1.96 TeV proton-anti-proton collision datasets from the Tevatron.
In this review, we first discuss the perspectives concerning a better determination of the proton structure in terms of quarks and gluons at LHC after describing the results coming from HERA and Tevatron. In a second part of the review, we describe the diffractive phenomena at HERA and Tevatron and the consequences for LHC.
We consider effective Higgs boson couplings, including both the CP-even and CP-odd couplings, that affect Higgs boson pair production in this study. Through the partial wave analysis, we find that the process $gg\to hh$ is dominated by the $s$-wave component even at a 100~TeV $pp$-collider. Making use of the $s$-wave kinematics, we propose a cut efficiency function to mimic the collider simulation and obtain the potential of measuring Higgs effective couplings at the 14~TeV LHC with an integrated luminosity of $3000~{\rm fb}^{-1}$ and at a 100 TeV $pp$-collider. Analytical expressions of the $…
We study high energy $\small{\rm{pp}}$ and $\small{\rm{\bar {p}p}}$ elastic scattering in the TeV region based on an effective field theory model of the proton. We phenomenologically investigate the main processes underlying elastic scattering and quantitatively describe the measured elastic d$\smallσ$/dt at energies 7.0 TeV (LHC $\small{\rm{pp}}$), 1.96 TeV (Tevatron $\small{\rm{\bar {p}p}}$), and 0.630 TeV (SPS $\small{\rm{\bar {p}p}}$). Finally, we give our prediction for $\small{\rm{pp}}$ elastic d$\smallσ$/dt at 14 TeV that will be measured by the TOTEM Collaboration.
We study the prospects for long-lived charged particle (LLCP) searches at current and future LHC runs and at a 100 TeV pp collider, using Drell-Yan slepton pair production as an example. Because momentum measurements become more challenging for very energetic particles, we carefully treat the expected momentum resolution. At the same time, a novel feature of 100 TeV collisions is the significant energy loss of energetic muons in detectors. We use this to help discriminate between muons and LLCPs. We find that the 14 TeV LHC with an integrated luminosity of 3 ab$^{-1}$ can probe LLCP slepton ma…
Motivated by the null results of LHC searches, which together with the Higgs mass, severely constrain minimal supersymmetric extensions of the standard model, we adopt a model-independent approach to study charged slepton flavor. We examine a number of simplified models, with different subsets of sleptons, electroweak gauginos, and Higgsinos, and derive the allowed slepton flavor dependence in the region probed by current LHC searches, and in the region relevant for the 14 TeV LHC. We then study the impact of the allowed flavor dependence on lepton plus missing energy searches. In some cases, …
Intense and collimated neutrino beams are produced by charm and beauty particle decays from proton-proton collisions at the LHC. A neutrino experiment would be run parasitically without interrupting the LHC physics program during the collider run. We estimate the neutrino fluxes from proton-proton collisions at $\sqrt{s}=14$ TeV of the LHC with the designed luminosity, $10^{34} \lumi$. By mounting about 200 tons of fiducial volume of a neutrino detector at 300 $\m$ away from the interaction point, about 150,000 of charged current neutrino events per year can be observable.
I present the latest calculations of total and differential cross sections for top-antitop pair production and single top quark production via all main partonic channels. Higher-order corrections from the resummation of soft gluons are added through NNLL accuracy. Detailed numerical results are presented for approximate NNLO cross sections and top quark transverse momentum distributions at the Tevatron and LHC colliders.
We discuss production of charm and bottom quarks at forward rapidity in pp collisions at the LHC, updating the QCD predictions for the run at \sqrt{S}=13 TeV. We show that, while the absolute rates suffer from large theoretical systematics, dominated by scale uncertainties, the increase relative to the rates precisely measured at 7 TeV can be predicted with an accuracy of a few percent, sufficient to highlight the sensitivity to the gluon distribution function.
We argue that already the first year run at the LHC with 3.5 TeV proton beams will provide a quick and effective way to test the dynamics of the color dipole-gluon interactions and the small x behavior of the gluon density in proton from study of the vector meson photoproduction in ultraperipheral proton-proton collisions.
We investigate the prospects of supersymmetry searches at the LHC with 7 TeV energy. A new set of selection cuts is proposed based on event shapes to control backgrounds. Our preliminary studies show that it is possible to minimize backgrounds to a significantly low level and conservative estimate suggests that the mass reach can be extended to $\sim$ 1.1 TeV for luminosity 1/fb with a reasonable signal-to-background ratio.
The $p_{\perp}$-distributions for the dimuon production at the LHC are calculated in the Randall-Sundrum scenario with a small curvature $κ$. The $pp$ collisions at 7 TeV and 14 TeV are considered. The widths of massive graviton excitations are taken into account. It is found that the LHC discovery limit on 5-dimensional gravity scale $M_5$ is equal to 5.5 TeV for $\sqrt{s} = 7$ TeV and integrated luminositiy 5 fb$^{-1}$. For $\sqrt{s} = 14$ TeV and integrated luminosities 30 fb$^{-1}$ and 100 fb$^{-1}$, the search limits in the dimuon events are 12.0 TeV and 14.6 TeV, respectively. Contrary t…
We report on the first measurements of the LHCb experiment, as obtained from $pp$ collisions at $\sqrt{s} = 0.9$ TeV and 7 TeV recorded using a minimum bias trigger. In particular measurements of the absolute $K^0_S$ production cross section at $\sqrt{s} = 0.9$ TeV and of the $\barΛ/Λ$ ratio both at $\sqrt{s} = 0.9$ TeV and 7 TeV are discussed and preliminary results are presented.
The CDF PYTHIA 6.2 Tune DW predictions for the behavior of the LHC underlying event (UE) data at 900 GeV and 7 TeV are examined in detail. The behavior of the UE at the LHC is roughly what we expected. The LHC PYTHIA 6.4 Tune Z1 does an excellent job describing the UE data at 900 GeV and 7 TeV. Both Tune DW and Tune Z1 describe fairly well the Drell-Yan UE data at 1.96 TeV and 7 TeV. No model describes all the features of "min-bias" (MB) collisions at 900 GeV and 7 TeV.
We propose TeV-scale Dirac fermions producing Majorana masses of the known neutrinos via tree-level seesaw, different from standard type I and III seesaw. The employed weak five-plet with nonzero hypercharge leads to new seesaw formula m_ν~ v^6/M^5 and to empirical masses m_ν~ 10^{-1} eV for M ~ TeV new states. For a limited range of the parameter space, where M < a few 100 GeV, the proposed mechanism is testable at the LHC via characteristic decays of Dirac type heavy leptons, produced by a Drell-Yan fusion.
Higgs bosons can be searched for in the channels $p\bar p/pp\to t\bar tH+X$ at the Tevatron and the LHC. We have calculated the QCD corrections to these processes in the Standard Model at next-to-leading order. The higher-order corrections reduce the renormalization and factorization scale dependence considerably and stabilize the theoretical predictions for the cross sections. At the central scale $μ=(2m_t+M_H)/2$ the properly defined $K$ factors are slightly below unity for the Tevatron ($K \sim 0.8$) and slightly above unity for the LHC ($K \sim 1.2$).
We study contributions of a scalar diquark particle in a color representation of anti-triplet and sextet to the top quark pair production at the Tevatron and the Large hadron collider (LHC). The model can give Forward-Backward (FB) asymmetry at the Tevatron while can avoid the same sign top quark production at the LHC by assuming the top-number conserving diquark couplings. We study compatibility between the large positive FB asymmetry observed at the Tevatron and non-observation of the charge asymmetry at the LHC, by including contributions from the single and pair production of diquarks. We …
The measurement of a charge asymmetry in t tbar production at LHC constitutes more than an independent confirmation of the forward-backward asymmetry found at Tevatron. Indeed, both measurements together can be used to identify the source of the asymmetry. This is demonstrated for the case of new Z', W' vector bosons and colour-sextet and triplet scalars, exchanged in t, u channels respectively, and a very heavy axigluon in the s channel.
We present a renormalizable theory that includes a $W'$ boson of mass in the 1.8-2 TeV range, which may explain the excess events reported by the ATLAS Collaboration in a $WZ$ final state, and by the CMS Collaboration in $e^+\!e^- jj$, $Wh^0$ and $jj$ final states. The $W'$ boson couples to right-handed quarks and leptons, including Dirac neutrinos with TeV-scale masses. This theory predicts a $Z'$ boson of mass in the 3.4-4.5 TeV range. The cross section times branching fractions for the narrow $Z'$ dijet and dilepton peaks at the 13 TeV LHC are 10 fb and 0.6 fb, respectively, for $M_{Z'}= 3.…
We study the precision with which the t-channel single top quark production cross section is expected to be measured in future LHC runs at 14 TeV. The single top final state has a lepton and neutrino from the top quark decay plus two jets, one of which is required to be b-tagged. This measurement is done in the context of the Snowmass 2013 study for the low-luminosity 14 TeV and the high-luminosity 14 TeV LHC as well as for high-luminosity 33 TeV LHC.
If all the supersymmetry particles (sparticles) except a light Higgs boson are too heavy to be directly produced at the Large Hadron Collider (LHC) and Tevatron, a possible way to reveal evidence for supersymmetry is through their virtual effects in other processes. We examine such supersymmetric QCD effects in bottom pair production associated with a light Higgs boson at the LHC and Tevatron. We find that if the relevant sparticles (gluinos and squarks) are well above the TeV scale, too heavy to be directly produced, they can still have sizable virtual effects in this process. For large $\tan…
The uncertainties in estimating the hadronic production of the $B_c$ meson are studied under the framework of the complete $α_s^4$ approach of the perturbative QCD and the gluon-gluon fusion mechanism. Quantitative comparisons on the production at TEVATRON and LHC are made. Considering the detectors at TEVATRON and LHC, we have also estimated the production with proper kinematic cuts. Based on the results, we conclude that the experimental studies of the $B_c$ meson at the two colliders will be complimentary and stimulative. We find that as c.m. energy is increasing from RUN-I to RUN-II at TEV…
We study the phenomenology of same sign top pair production at the LHC in a model-independent way. The complete set of dimension six operators involving two top (or anti-top) quarks is introduced and the connection with all possible t- or s-channel particle exchanges is established. Only in the former case, same and opposite sign top pair production can be related. We find that while current Tevatron data disfavor t-channel models, other production mechanisms are viable and can be tested at the LHC.
The measurement of Higgs self-coupling is one of the most crucial physics goals at the future colliders. At the LHC, the di-Higgs production is a main way to measure the Higgs trilinear coupling. As a complementary to the di-Higgs production, $t \bar{t} hh$ process may open a new avenue to measure di-Higgs physics at the LHC and a future 100 TeV $pp$ collider or a high energy $e^+e^-$ collider since the extra $t\bar t$ in the final states may efficiently suppress the backgrounds. However, such a kind of process is also controlled by the top-Higgs coupling. In this work, we investigate the impa…
We present a systematic comparison of jet predictions at the LHC and the Tevatron, with accuracy up to next-to-next-to-leading order (NNLO). The exact computation at NNLO is completed for the gluons-only channel, so we compare the exact predictions for this channel with an approximate prediction based on threshold resummation, in order to determine the regions where this approximation is reliable at NNLO. The kinematic regions used in this study are identical to the experimental setup used by recently published jet data from the ATLAS and CMS experiments at the LHC, and CDF and D0 experiments …
The recent Tevatron measurement of the forward-backward asymmetry of the top quark shows an intriguing discrepancy with Standard Model expectations, particularly at large $\ttbar$ invariant masses. Measurements of this quantity are subtle at the LHC, due to its $pp$ initial state, however, one can define a forward-central-charge asymmetry which captures the physics. We study the capability of the LHC to measure this asymmetry and find that within the SM a measurement at the $5σ$ level is possible with roughly 60 fb$^{-1}$ at $\sqrt{s} = 14$ TeV. If nature realizes a model which enhances the as…
In this work, we derive lower mass bounds on the Z' gauge boson based on the dilepton data from LHC with 13 TeV of center-of-mass energy, and forecast the sensitivity of the High-Luminosity-LHC with $L=3000 fb^{-1}$, the High-Energy LHC with $\sqrt{s}=27$ TeV, and also at the Future Circular Collider with $\sqrt{s}=100$ TeV. We take into account the presence of exotic and invisible decays of the Z' gauge boson to find a more conservative and robust limit, different from previous studies. We investigate the impact of these new decays channels for several benchmark models in the scope of two dif…
The discovery of the Higgs boson at $\sim 125$ GeV indicates that the scale of weak scale supersymmetry is higher than what was perceived in the pre-Higgs boson discovery era and lies in the several TeV region. This makes the discovery of supersymmetry more challenging and argues for hadron colliders beyond LHC at $\sqrt s=14$ TeV. The Future Circular Collider (FCC) study at CERN is considering a 100 TeV collider to be installed in a 100 km tunnel in the Lake Geneva basin. Another 100 km collider being considered in China is the Super proton-proton Collider (SppC). A third possibility recently…
We exploit all LHC available Run 2 data at center-of-mass energies of 8 and 13 TeV for searches for physics beyond the Standard Model. We scrutinize the allowed parameter space of Little Higgs models with the concrete symmetry of T-parity by providing comprehensive analyses of all relevant production channels of heavy vectors, top partners, heavy quarks and heavy leptons and all phenomenologically relevant decay channels. Constraints on the model will be derived from the signatures of jets and missing energy or leptons and missing energy. Besides the symmetric case, we also study the case of T…
A sizeable charge asymmetry in top quark pair production has been observed at the Tevatron. The experimental results seem to exceed systematically the Standard Model theory predictions by a significant amount and have triggered a large number of suggestions for 'new physics'. The effect is also visible at the LHC, and preliminary results have already been presented by the ATLAS and CMS collaborations. In this talk, we review the present status of the theoretical predictions, and their comparison with the experimental measurements.
We calculate the total cross section for single charged slepton production in association with a top quark at hadron colliders in the baryon triality (B$_3$) supersymmetric model. We compute event rates for the Tevatron and LHC. We study the signatures for different supersymmetric scenarios including neutralino and stau LSPs. We perform a detailed analysis with basic cuts for the B$_3$ operator $\lam^\prime_{231}$ using Monte Carlo simulations to show that the signal can be distinguished from the background at the LHC. In particular we employ the resulting lepton charge asymmetry.
Predictions from the GR@PPA event generator concerning the transverse-momentum ($p_{T}$) spectrum of $Z$ bosons are compared with recent measurements at LHC and Tevatron. The simulation results are in reasonable agreement with the measurements, although marginal discrepancies are observed in high-$p_{T}$ regions. The principal agreements imply that the leading-order simulation with a primitive parton shower based on the leading-logarithmic approximation still provides a reasonable description of the transverse motion of the hard-interaction system in hadron collisions, without the need to intr…
The LHC is well on track toward the discovery or exclusion of a light Standard Model (SM)-like Higgs boson. Such a Higgs has a very small SM width and can easily have large branching fractions to physics beyond the SM, making Higgs decays an excellent opportunity to observe new physics. Decays into collider-invisible particles are particularly interesting as they are theoretically well motivated and relatively clean experimentally. In this work we estimate the potential of the 7 and 8 TeV LHC to observe an invisible Higgs branching fraction. We analyze three channels that can be used to direct…
In this work we study the collider phenomenology of a compressed supersymmetric model with gluino and the lightest neutralino. All other sparticles are assumed to be heavy. We consider gluino pair production at the 14 TeV LHC and present the mass reach of gluino as a function of mass splitting between gluino and the the lightest neutralino. We find that the gluino mass below 1 TeV can be excluded at 95% CL with integrated luminosity of 100 fb$^{-1}$ for extreme degenerate case where mass separation between gluino and the lightest neutralino is about 20 GeV. On the other hand, the lower bound o…
We present strategies to search for heavy neutral Higgs bosons decaying to top quark pairs, as often occurs at low $\tan β$ in type II two Higgs doublet models such as the Higgs sector of the MSSM. The resonant production channel is unsatisfactory due to interference with the SM background. We instead propose to utilize same-sign dilepton signatures arising from the production of heavy Higgs bosons in association with one or two top quarks and subsequent decay to a top pair. We find that for heavier neutral Higgs bosons the production in association with one top quark provides greater sensitiv…
Multiplicity dependencies of midrapidity transverse momentum distributions of identified charged particles in inelastic proton-proton collisions at center-of-mass energy of 7 TeV at the Large Hadron Collider (LHC), measured by ALICE Collaboration, have been analyzed. The full abstract with important results on the established effective temperature versus energy density dependence, estimated critical energy densities for probable deconfinement phase transition in proton-proton collisions at center-of-mass energy of 7 and 13 TeV and other results is given in the manuscript file.
We present the inclusive Higgs boson cross-section at the LHC with collision energy of 8 TeV. Our predictions are obtained using our publicly available program iHixs which incorporates NNLO QCD corrections and electroweak corrections. We review the convergence of the QCD perturbative expansion at this new energy and examine the impact of finite Higgs width effects. We also study the impact of different parton distribution functions on the cross-section. We present tables with the cross-section values and estimates for their uncertainty due to uncalculated higher orders in the perturbative expa…
We have revisited the prospects of Supersymmetry(SUSY) searches at the LHC with 7 TeV energy along with the prediction of the discovery potential at 8 TeV energy assuming an integrated luminosity 5 $fb ^{-1}$ and 20 $\invfb$ with mSUGRA/CMSSM as a model framework. We discuss further optimization of our selection strategy which is based on the hadronic event shape variables. Evaluating the standard model backgrounds and signal rates in detail we predict the discovery reach in the $m_0 - m_{1/2}$ plane for 7 TeV with 5$\invfb$ luminosity. We also present the discovery reach for 8 TeV energy with…
We describe recent developments of the public computer code HiggsBounds. In particular, these include the incorporation of LHC Higgs search results from Run 2 at a center-of-mass energy of 13 TeV, and an updated and extended framework for the theoretical input that accounts for improved Higgs cross section and branching ratio predictions and new search channels. We furthermore discuss an improved method used in HiggsBounds to approximately reconstruct the exclusion likelihood for LHC searches for non-standard Higgs bosons decaying to $ττ$ final states. We describe in detail the new and updated…
Since the precise study of Higgs gauge couplings is important to test the Standard Model (SM), we calculate the complete next-to-leading order QCD(NLO QCD) correction to the $pp \to HZW^{\pm}$ production in the SM at 14 TeV LHC. Our results show that the NLO QCD correction can enhance the leading-order cross section of $pp \to HZW^{\pm}$ by 45%, when $ m_H $ = 125.3 GeV. We also study the dependence of the LO and NLO corrected cross sections on the renormalization and factorization scale $μ$. Besides, due to the unbalance of parton distribution functions, we investigate the charge asymmetry of…
Predictions for angular distributions of top quark decay products that are sensitive to t tbar spin correlations are presented at next-to-leading order in alpha_s for the Tevatron and the LHC.
We use the POMWIG Monte Carlo generator to predict the cross-sections for double diffractive higgs and di-photon production at the Tevatron and LHC. We find that the higgs production cross-section is too small to be observable at Tevatron energies, and even at the LHC observation would be difficult. Double diffractive di-photon production, however, should be observable within one year of Tevatron Run II.
We discuss the different models of central diffractive production of the Higgs boson at the Tevatron and the LHC. We also describe how the models can be tested using diffractive production data being taken at the Tevatron. We finally discuss the advantages of using diffractive events to reconstruct the mass of the Higgs boson especially at the LHC.
The Large Hadron Collider (LHC) recently started operating at 8 TeV. In this note, we update our earlier LHC forward hadronic scattering predictions \cite{physicsreports,update7, blackdisk}, giving new predictions, including errors, for the $pp$ total and inelastic cross sections, the $ρ$-value, the nuclear slope parameter $B$, $dσ_{\rm el}/dt$, and the large gap survival probability at 8 TeV.
The LHC has successfully run for a long period at half energy, 7 TeV. In this note, we update earlier full-energy Large Hadron Collider (LHC) forward hadronic scattering predictions \cite{physicsreports}, giving new predictions, including errors, for the $pp$ total and inelastic cross sections, the $ρ$-value, the nuclear slope parameter $B$, $dσ_{\rm el}/dt$, and the large gap survival probability at the current 7 TeV energy.
Motivated by the idea of alpha-vacua in Schwarzschild spacetime, we studied the deformed spectrum of Hawking radiation. Such a deformation would leave signatures on the small black hole evaporation in LHC because their vacuum deviates from the Unruh state.
We show that the search for supersymmetry at LHC will be very problematic for the particular case of nonuniversal relations among gaugino masses. Namely, if gluino, first chargino and LSP masses are closed to each other it would be very difficult to discover supersymmetry even if sparticle masses are lighter than 1 TeV.
We perform a BFKL-NLL analysis of forward jet production at HERA which leads to a good description of data over the full kinematical domain. We also predict the azimuthal angle dependence of Mueller-Navelet jet production at the Tevatron and the LHC using the BFKL NLL formalism.
We discuss expectations for the total and inelastic cross-sections at LHC CM energies $\sqrt{s}\ =\ 7\ TeV$ {and $ 14\ TeV$} obtained in an eikonal minijet model augmented by soft gluon $k_t$-resummation, which we describe in some detail. We present a band of predictions which encompass recent LHC data and suggest that the inelastic cross-section described by two channel eikonal models include only uncorrelated processes. We show that this interpretation of the model is supported by the LHC data.
Analysis of the charged multiplicity in proton-proton inelastic interactions at the LHC energies in the setting of Dual Parton Model is presented. Data from the CMS experiment and the data simulated at different energies in various pseudo-rapidity windows using the event generator PYTHIA8are analysed and compared with the calculations from the model. Each inelastic scattering is assumed to follow the Poisson distribution. The theoretical Koba-Nielsen-Olesen (KNO) scaling of the multiplicity distributions is studied and compared with previously published experimental results at $\sqrt{s}$ = 0.9…
Improved possibilities to find the Higgs boson in diffractive events, having less hadronic activity, depend on whether the cross section is large enough. Based on the soft color interaction models that successfully describe diffractive hard scattering at HERA and the Tevatron, we find that only a few diffractive Higgs events may be produced at the Tevatron, but we predict a substantial rate at the LHC.
In this work we explore the 7 TeV LHC implication on light top squark (stop) and investigate discovery limits at both 8 and 14 TeV LHC using same-sign dilepton signature. We consider a simplified spectrum with gluino pair production followed by heavy gluino decay into on-shell stop and top quark in pair. The light stop is then assumed to uniquely decay into c\tildeχ_1^0, bW^+\tildeχ_1^0 or t\tildeχ_1^0. The same-sign dilepton search at 7 TeV LHC places a lower bound of about 800 GeV on the gluino mass in this scenario. We find that the 8 TeV LHC with 30 fb^{-1} luminosity can reach 960 (900) G…
Models with essential non-perturbative QCD dynamics and describing Tevatron data on high-$p_\perp$ charmonium are extrapolated to give predictions of prompt J/psi production at the LHC. Differences of up to an order of magnitude occurs. An important point is here the treatment of higher order perturbative QCD effects.
In view of the annnouncement that in 2012 the LHC will run at 8 TeV, we study the possibility of detecting signals of alternative mechanisms of ElectroWeak Symmetry Breaking, described phenomenologically by unitarized models, at energies lower than 14 TeV. A complete calculation with six fermions in the final state is performed using the PHANTOM event generator. Our results indicate that at 8 TeV some of the scenarios with TeV scale resonances are likely to be identified while models with no resonances or with very heavy ones will be inaccessible, unless the available luminosity will be much h…
Discussions are underway for a high-energy proton-proton collider. Two preliminary ideas are the $\sqrt{s}=33$ TeV HE-LHC and the $\sqrt{s}=100$ TeV VLHC. With Bayesian statistics, we calculate the probabilities that the LHC, HE-LHC and VLHC discover SUSY in the future, assuming that nature is described by the CMSSM and given the experimental data from the LHC, LUX and Planck. We find that the LHC with $300$/fb at $\sqrt{s}=14$ TeV has a $15$-$75%$ probability of discovering SUSY. Should that run fail to discover SUSY, the probability of discovering SUSY with $3000$/fb is merely $1$-$10%$. Wer…
We describe new QCD fits to diffractive cross sections measured at HERA and we use the parton densities derived from these fits to predict the shape of the dijet mass fraction in double Pomeron exchange at the Tevatron. We discuss the existence of exclusive events in this dijet channel and some prospects are given for the LHC.
We show that the charge asymmetry in t tbar production at the LHC, A_C, and the forward-backward asymmetry at the Tevatron, A_FB, are in general not tightly correlated. They can even have opposite signs, if the underlying new physics (NP) model is general enough. We demonstrate this using two examples of NP: a light axigluon, and a vector that is a color octet and electroweak triplet. The small value of A_C measured at the LHC is thus shown not to exclude a NP interpretation of the anomalously large A_FB at the Tevatron. We identify two observables where significant NP effects are still expect…
In the prospect of diffractive Higgs production at the LHC collider, we give an extensive study of Higgs boson, dijet, diphoton and dilepton production at hadronic colliders via diffraction at both hadron vertices. Our model, based on non factorizable Pomeron exchange, describes well the observed dijet rate observed at Tevatron Run I. Taking the absolute normalization from data, our predictions are given for diffractive processes at Tevatron and LHC. Stringent tests of our model and of its parameters using data being taken now at Tevatron Run II are suggested. These measurements will also allo…
The main production channels of the Higgs boson at hadron colliders are briefly reviewed and recent developments in the calculation of QCD effects are discussed.
An alternative calculation of the lowest order electroweak radiative corrections to the single W-boson production in hadron-hadron collision in the framework of the quark parton model without any absorption of the collinear quark singularity into the parton distributions is carried out. Numerical analysis under Tevatron and LHC kinematic conditions is performed.
