MoEDAL – a new light on the high-energy frontier

In 2010, the MoEDAL (MOnopole and Exotics Detector at the LHC) experiment at the Large Hadron Collider (LHC) was unanimously approved by European Centre for Nuclear Research’s Research Board to start data taking in 2015. MoEDAL is a pioneering experiment designed to search for highly ionising manifestations of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles. Its groundbreaking physics programme defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; does magnetic charge exist; what is the nature of dark matter; and, how did the Big Bang develop. MoEDAL’s purpose is to meet such far-reaching challenges at the frontier of the field. The innovative MoEDAL detector employs unconventional methodologies tuned to the prospect of discovery physics. The largely passive MoEDAL detector, deployed at Point 8 on the LHC ring, has a dual nature. First, it acts like a giant camera, comprised of nuclear track detectors – analysed offline by ultra fast scanning microscopes – sensitive only to new physics. Second, it is uniquely able to trap the particle messengers of physics beyond the Standard Model for further study. MoEDAL’s radiation environment is monitored by a state-of-the-art real-time TimePix pixel detector array. A new MoEDAL sub-detector designed to extend MoEDAL reach to mini-charged, minimally ionising particles is under study.     

Transverse momentum distribution of the Z produced at the Large Hadron Collider and related phenomena

From the recent theoretical result on the production of the Higgs boson at the Large Hadron Collider, it follows that other particles will also be produced with small transverse momentum, of the order of 1 GeV/c$1\text{GeV}/c$. The leptonic decay mode of the Z is especially suited for a first observation of this phenomenon. Other related effects, such as paired jets, are also discussed.     

Rapidity distributions of net protons from AGS to LHC energy regions

Taking the conservation of baryon number into account in a non-uniform flow model, the rapidity distribution of the net protons at the LHC is predicted. The energy dependence of the rapidity distribution, baryon stopping and collective flow from BNL/AGS to CERN/LHC are systematically investigated.     

Production of the neutral top-pion πt^0 in association with a high-pw jet at the LHC＊

In the framework of the topcolor-assisted technicolor （TC2） model, we study the production of the neutral top-pion πt^0 in association with a high-pw jet at the LHC, which proceeds via the partonic processes gg→πt^0g, gq →πt^0q, qq→πt^0g, gb（b）→πt^0b（b）, and bb→πt^0g. We find that it is very challenging to detect the neutral top-pion πt^0 via the process pp → πt^0 ＋jet ＋ X＋ tt＋jet ＋X, while the possible signatures of πt^0 might be detected via the process pp→πt^0 ＋jet ＋ X→（tc＋tc）＋jet＋X at the LHC.     

Production of the neutral top-pion πt0 in association with a high-pw jet al the LHC

In the framework of the topcolor-assisted technicolor (TC2) model, we study the production of the neutral top-pion πt0 in association with a high-pT jet al the LHC, which proceeds via the partonic processes gg→πt0g, gq→πt0q, qq→πt0g, gb(b)→πt0b(b), and bb→πt0g. We find that it is very challenging to detect the neutral top-pion πt0 via the process pp→πt0 +jet-t-X→tt +jet + X, while the possible signatures of πt0 might be detected via the process pp→πt0 +jet+X→(tc+tc)+jet+X at the LHC.     

Single top production associated with a neutral scalar at LHC in topcolor-assisted technicolor

The topcolor-assisted technicolor(TC2)model predicts a number of neutral SCalars like the top-pion (π0t)and the top-Higgs(h0t).These scalar8 have flavor-changing neutral-current(FCNC)top quark couphngs,among which the top-charm transition couplings may be sizable.Such FCNC couplings induce single top productions associated with a neutral scalar at the CERN Large Hadron Collider(LHC)through the parton processes cg→tπ0t and cg→th0t.In this paper we examine these productions and find their production rates can exceed the 3σ sensitivity of the LHC in a large part of parameter space.Since in the Standard Model and the minimal supersymmetric model such rare productions have unobservably small production rates at the LHC.these rare processes will serve as a good probe for the TC2 model.     

Direct photon and photon-jet measurement capability of the ATLAS experiment at the LHC

Direct photon and photon-jet correlations are perfect tools for tomographic studies of the dense medium produced in heavy ion collisions at LHC energies. Due to their weak interactions with the medium, direct photons serve as standard candles for hard-scattering processes, providing a clean calibration of the momentum of the associated jets. The ATLAS detector has powerful opportunities to carry out these measurements. The combination of fine granularity, longitudinal segmentation and large acceptance is unique for the LHC detectors. We show how it will provide optimal capability to distinguish direct photon clusters from neutral meson clusters based on their shower profile over a wide acceptance in η−?$\eta -?$ up to 200 GeV in pT$p_T$. We show that combined with a photon isolation cut ATLAS would be able to measure a relatively background-free direct photon yield from 50–200 GeV along with the corresponding gamma-jet correlations in one nominal LHC Pb+Pb year. These high pT$p_T$ photons provide clean and statistically significant measurements of gamma-jet correlations and the fragmentation function for photon-tagged jets.