Transverse energy 45GeV?

[sunshaker]

Can someone please simply explain this transverse energy of 45GeV?

I am not sure what this transverse energy of 45 GeV is, I have been looking for any news of a particle/decay path of 45GeV for my "pet model",

Is this a possible particle or decay path or something else?

 

http://inspirehep.net/record/1352917?ln=en

 

 

The phase space consisting of a photon with a transverse energy of at least 45 GeV and significant missing transverse energy was further examined in a model independent way by varying the selection requirements on the missing transverse energy and the transverse mass of the system

 

[Mordred]

One way to look at at is particle decays that miss the detectors. Or rather the detectors cannot pick up. Here is how this paper describes it.

 

"Neutral weakly interacting particles, such as neutrinos, escape from typical collider detectors

without producing any direct response in the detector elements. The presence of such particles

must be inferred from the imbalance of total momentum. The vector momentum imbalance in

the plane perpendicular to the beam direction is particularly useful in pp and pp colliders, and ¯

is known as missing transverse momentum, "

 

http://arxiv.org/abs/1106.5048

[sunshaker]

Does this then mean this missing 45 gev could be a unknown particle?

[Mordred]

Not necessarily, think of the 45 GeV as more of a jet channel. This particular jet has cropped up in the search for the 125 GeV Higgs boson in some papers. However I've also seen the 45 GeV transverse energy In papers involving neutralinos , dileptons and higglets.

 

In and of itself I would consider it as detection channel or calibration method to detect other particles rather than a detection of a 45 GeV particle which it isn't. Remember the measured energy of a particle depends on the observer.

 

A key note is that transverse energy is essentially measurements of the transverse wave. Recall that the electromagnetic force Carrier is the photon.

 

http://en.m.wikipedia.org/wiki/Transverse_wave

More accurately the 45 GeV is a signal in a transverse angle, how it is measured at other angles will have different energy signatures. The combination of the various channels or jets is used to isolate the properties of the particle in question. This particular channel and 45 FeB signal is often mentioned in searches for the 125 GeV Higgs, neurtralinos, dileptons and higglets in various papers. Without reading the full paper you referenced I cannot tell which one he suggests.

 

 

Here I found this in a thesis paper

 

http://lss.fnal.gov/archive/thesis/2000/fermilab-thesis-2015-02.shtml

 

It describes the process in extreme detail. Here is the opening paragraph.

 

"Neutral weakly interacting particles, such as neutrinos, escape from typical collider detectors

without producing any direct response in the detector elements. The presence of such particles

must be inferred from the imbalance of total momentum. The vector momentum imbalance in

the plane perpendicular to the beam direction is particularly useful in pp and pp colliders, and ¯

is known as missing transverse momentum, here denoted ~E/T. Its magnitude is called missing

transverse energy, and is denoted E/T.

Missing transverse energy is one of the most important observables for discriminating leptonic

decays of W bosons and top quarks from background events which do not contain neutrinos,

such as multijet and DrellYan events. It is also an important variable in searches for new

weakly interacting, long-lived particles. Many beyond-the-standard-model scenarios, includ-

ing supersymmetry, predict events with large E/T. The reconstruction of ~E/T is very sensitive to

particle momentum mismeasurements, particle misidentification, detector malfunctions, parti-

cles impinging on poorly instrumented regions of the detector, cosmic-ray particles, and beam-

halo particles, which may result in artificial E/T."

Edited May 29, 2015 by Mordred

[sunshaker]

Thanks Mordred very helpful,

I'm halfway through this thesis http://lss.fnal.gov/archive/thesis/2000/fermilab-thesis-2015-02.shtmlit is a very good read, and explains much I did not realize. in terms even I can understand (mostly).

[Mordred]

Your welcome.