[Clas_hadron] abstracts for DNP

[Michael Dugger]

Barry,

An extra pion that was not seen would mess up the mass X distribution 
(gamma p -> p X) and we would not see that kind of event as a
gamma p -> p eta event.

Take care,
Michael

On Fri, 28 Jun 2013, Barry Ritchie wrote:

> But we could have an undetected pion flying around, though, in the 2pi steradians CLAS doesn't cover.
>
> Barry G. Ritchie
> Vice Provost for Academic Personnel
> Arizona State University
> 300 E. University Ave, Suite 420
> Tempe, AZ 85287-7805
>  
> Phone: 480-965-7405
> Fax: 480-965-0785
>
>
> -----Original Message-----
> From: clas_hadron-bounces at jlab.org [mailto:clas_hadron-bounces at jlab.org] On Behalf Of Michael Dugger
> Sent: Friday, June 28, 2013 9:26 AM
> To: Eugene Pasyuk
> Cc: clas hadron
> Subject: Re: [Clas_hadron] abstracts for DNP
>
>
> Hi,
>
> Since we have the final state as
> p eta,
> we can't have an extra pion flying about. We can probably safely remove the "in one-step excitation processes" part.
>
> Take care,
> Michael
>
> On Fri, 28 Jun 2013, Eugene Pasyuk wrote:
>
>> Igor,
>>
>> As alternative to single step you may say that N\eta final state cannot be directly coupled to \Delta resonances.
>>
>> -Eugene
>>
>> ----- Original Message -----
>>> From: "Igor Senderovich" <senderov at jlab.org>
>>> To: "Viktor Mokeev" <mokeev at jlab.org>
>>> Cc: "clas hadron" <clas_hadron at jlab.org>
>>> Sent: Friday, June 28, 2013 5:07:33 PM
>>> Subject: Re: [Clas_hadron] abstracts for DNP
>>>
>>> Dear Viktor,
>>>
>>> What I would call a two-step process is one in which the state
>>> de-excites via two emissions - say Delta excitation decaying with
>>> pion emission to an N* which then emits an eta. This illustrates a
>>> case when detection of an eta would not offer isospin filtering. I am
>>> just being careful to avoid such a counterexample to my statement.
>>>
>>> All the best,
>>> -Igor
>>>
>>>
>>> ----- Original Message -----
>>> From: "Viktor Mokeev" <mokeev at jlab.org>
>>> To: "Igor Senderovich" <senderov at jlab.org>
>>> Cc: "clas hadron" <clas_hadron at jlab.org>
>>> Sent: Thursday, June 27, 2013 4:55:15 PM
>>> Subject: Re: [Clas_hadron] abstracts for DNP
>>>
>>>   Dear Igor,
>>>
>>>  You abstracts look good.
>>>
>>>  Could you explain what you mean by one-step excitation processes?
>>>
>>>  Best Regards,
>>>                       Victor
>>>
>>> ----- Original Message -----
>>> From: "Igor Senderovich" <senderov at jlab.org>
>>> To: "clas hadron" <clas_hadron at jlab.org>
>>> Sent: Thursday, June 27, 2013 11:30:15 AM
>>> Subject: [Clas_hadron] abstracts for DNP
>>>
>>> Dear Colleagues,
>>>
>>> I would like to submit the two abstracts that follow this e-mail for
>>> the meeting of the DNP and appreciate any feedback you can offer.
>>> Best regards,
>>> -Igor Senderovich
>>>
>>> ----------
>>> For the mini-symposium (14e. Mini-Symposium on the Excited Nucleon
>>> State Spectrum and Structure):
>>> Title: Studies of $\eta$ photo-production in the baryon resonance
>>> excitation region with CLAS
>>> Abstract:
>>> Because the pseudoscalar $\eta$ meson has zero isospin, $\eta$
>>> photo-production offers the feature of isolating N* (I=1/2) resonance
>>> states in one-step excitation processes. This ``isospin''
>>> filter property can be very useful in helping disentangle the broad
>>> and overlapping excitations that make up the nucleon resonance
>>> spectrum. For that reason, a program of measurements on $\eta$
>>> photo-production for the reaction $\gamma p \rightarrow \eta p$ has
>>> been conducted using the Hall B CEBAF Large Acceptance Spectrometer
>>> at Jefferson Lab. Results for the differential cross-section and for
>>> single- and double-polarization observables will be summarized. The
>>> general outlook for the ``complete experiment'' program for
>>> disentangling nucleon resonances decaying to the $p \eta$ channel
>>> will be discussed.
>>>
>>>
>>> A general DNP submission:
>>> Title: Double-polarization E and G observables in $\eta$
>>> photo-production on the CLAS Frozen Spin Target
>>> Abstract:
>>> $\eta$ photo-production is an important tool in baryon spectroscopy,
>>> allowing isolation of N* (I=1/2) resonances in one-step excitation
>>> processes. Furthermore, it has long been recognized that due to
>>> significant overlapping of resonances in the baryon spectrum,
>>> differential cross-sections are not enough; measuring polarization
>>> observables is vital. Extensive data have been collected at Jefferson
>>> Lab in Hall B with circularly and linearly polarized tagged photon
>>> beams incident on longitudinally polarized protons provided by the
>>> Frozen Spin Target (FROST). The presentation will cover analysis and
>>> preliminary results of double-polarization observables E and G in
>>> $\eta$ photo-production - data entirely missing from the world
>>> database.
>>> _______________________________________________
>>> Clas_hadron mailing list
>>> Clas_hadron at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/clas_hadron
>>> _______________________________________________
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>>> Clas_hadron at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/clas_hadron
>>>
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